Search

Prediction models for estimating feed intake (FI) or metabolizable energy intake (MEI) of pigs are available in the literature. During the recent two decades, several reports have addressed the influence of heat stress on FI. The objectives of the present work were to validate the accuracy of prediction equations for estimating FI or MEI of pigs in the literature using data from heat stress experiments and to develop novel equations for estimating FI and MEI of pigs under thermoneutral or heat stress environment. A total of 123 data from 25 research papers measuring the effects of heat stress on FI of pigs published between 2001 and 2021 were used for the validation of previous equations and the development of novel equations. In the 25 papers, the thermoneutral temperature (T) ranged from 17 to 24℃ and the heat stress T ranged from 21 to 35℃. The body weight (BW) of pigs ranged from 19 to 119 kg. In the first validation study, the equation for estimating FI was evaluated: FI, g/day = -1,264 + 73.6×BW - 0.26×BW² + 117×T - 2.40×T² - 0.95×T×BW. The slope representing a linear bias did not differ from 0 but the intercept representing a mean bias was greater than 0 (109 ± 36; P < 0.01), meaning that the predicted mean underestimated the FI. In the second validation study, the equation for estimating MEI using equations for lower critical temperature (LCT) and fraction of MEI: LCT, ℃ = 17.9 - 0.0375×BW and fraction of MEI = 1 - 0.012914 × [T - (LCT + 3)] - 0.001179 × [T - (LCT + 3)]2. The slope representing a linear bias did not differ from 0 but the intercept representing a mean bias was greater than 0 (731 ± 68; P < 0.001), meaning that the predicted mean underestimated the MEI. A novel equation for estimating MEI under thermoneutral or heat stress environment was developed: MEI, kcal/day = 2,603 + 137×BW - 0.189×BW² - 38.4×T - 0.556×T² - 1.165×T×BW (P < 0.001; R² = 0.83). An equation for estimating fraction of MEI under thermoneutral or heat stress environment was also developed: fraction of MEI = 1 - 0.00677 × [T - (LCT + 3)] - 0.000668 × [T - (LCT + 3)]² (P < 0.001; R² = 0.98). In conclusion, previously published equations underestimate FI and MEI and novel equations for estimating MEI under thermoneutral or heat stress environment have been developed in the present work. However, the novel equations have not been validated under cold stress. [ABSTRACT FROM AUTHOR]

Precision feeding (PF) with the daily mixing of 2 diets with different lysine content (high (H) or low (L)) was previously reported for growing pigs to reduce protein intake and N excretion compared with a conventional feeding (CF) based on a single diet (C). Using a simulation approach based on farm data, the objective of the present paper was to describe and evaluate a decision support system for the PF of gestating sows allowing the daily distribution of a tailored ration to each sow. Two datasets, 1 of 2,511 gestations (farm A) and 1 of 2,528 gestations (farm B), reporting sows' characteristics at insemination and objectives at farrowing were used as inputs for a Python model. This model, mainly based on InraPorc, calculates the nutrient requirements of each sow over gestation and simulates the impact of PF in comparison to CF. Simulated diets L, H, and C contained 3.0, 6.5, and 4.8 g/kg of standardized ileal digestible lysine (SID Lys) and 2.0, 3.3, and 2.5 g/kg of standardized total tract digestible phosphorus (STTD-P), respectively. The influence of farm, parity, gestation week, and their interactions, on calculated SID Lys and STTD-P requirements was analyzed applying a mixed model. The calculated SID Lys and STTD-P requirements increased markedly in the last third of gestation (P < 0.01) and were higher for primiparous than for multiparous sows, unless after week 14 for STTD-P requirement. The calculated SID AA and mineral requirements were lower for farm B than farm A (respectively, 2.94 vs. 3.08 g/kg for SID Lys and 1.30 vs. 1.35 g/kg for STTD-P, P < 0.01). On average, feed L represented 86% and 92% of the feed projected to be delivered by the PF strategy in farms A and B, respectively. Compared to CF, average calculated dietary SID Lys content was lowered by 27% and 32% with PF, for farms A and B, respectively, while average calculated dietary phosphorus content was lowered by 13% and 16%. The simulated proportions of sows in excess and deficient in SID Lys were reduced with PF. Compared to CF, the PF strategy allowed for a 3.6% reduction in simulated feed cost per sow during gestation, and reduced nitrogen and phosphorus intake (by 11.0% and 13.8%, respectively) and excretion (by 16.7% and 15.4%, respectively). To conclude, these simulations indicate that PF of gestating sow appears to be relevant to meet the amino acid requirement while reducing feed cost, and supplies and excretion of nitrogen and phosphorus., (© The Author(s) 2020. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Genetic improvement of animals plays an important role in improving the economic and environmental sustainability of livestock production systems. This paper proposes a method to incorporate mitigation of environmental impacts and risk preferences of producers into a breeding objective via economic values (EV s). The paper assesses the effects of using these alternative EVs of breeding goal traits on discounted economic response to selection and on environmental impacts at commercial farm level. The application focuses on a Brazilian pig production system. Separate dam- and sire-line breeding programs that supply parents in a 3-tier production system for producing crossbreds (fattening pigs) at commercial level were assumed. Using EVs that are derived from utility functions by incorporating risk aversion increases the cumulative discounted economic response to selection in sire-line selection (6%) while reducing response in dam-line selection (12%) compared with the use of traditional EVs. The use of EVs that include environmental costs increases the cumulative discounted social response to selection in both dam-line (5%) and sire-line (10%) selections. Emission of greenhouse gases, and excretion of nitrogen and phosphorus can be reduced more with genetic improvements of production traits than reproduction traits for the typical Brazilian farrow-to-finish pig farm. Reductions in environmental impacts do not, however, depend on the use of the different EVs (i.e. with and without taking into account environmental costs and risk). Both environmental costs and risk preferences of producers need to be considered in sire-line selection, and only environmental costs in dam-line selection to improve, at the same time, the economic and environmental sustainability of the Brazilian pig production system. [ABSTRACT FROM AUTHOR]

Methionine is an essential dietary amino acid that can be supplied in different chemical forms: DL-methionine, L-methionine, and OH-methionine. It has been hypothesized that L-methionine might be used with greater efficacy for average daily gain (ADG) in weaning pigs due to their decreased enzymatic capacity to convert the other methionine forms. This study aimed to compare DL-methionine, L-methionine, and OH-methionine efficiency of utilization for ADG in weaned pigs through meta-analysis. The systematic review resulted in 2,167 papers screened for the title and abstract, with 24 papers meeting the inclusion criteria. The ADG was regressed as a function of the standardized ileal digestible (SID) methionine intake (Meti). The study was used as a random intercept, and regressions were weighted by the square root of the number of observations. Non-linear models were used to determine the Meti requirements. The average Meti requirement for pigs of 5 to 25 kg body weight (BW) was 2.09 g/d. The slopes of linear mixed-effects regression models were compared for the different methionine sources. Average initial BW was 7.99 (DL-methionine), 8.82 (L-methionine), and 7.06 kg (OH-methionine). Meti was 1.5 g/d for all sources whereas SID cysteine intake was 1.90, 2.23, and 1.93 g/d, for DL-methionine, L-methionine, and OH-methionine, respectively. Increase in Meti below the estimated requirement linearly increased ADG (ADG = 107 + 138 × Meti; P < 0.01). No difference between the slopes of methionine sources was observed, rejecting the hypothesis that L-methionine is used with greater efficiency in weaned pigs. Pigs receiving DL-methionine, L-methionine, and OH-methionine presented an estimated ADG of 319, 317, and 311 (SE = 19, 25 and, 26, respectively) g/d, respectively. In conclusion, methionine efficiency of utilization for ADG in post-weaned pigs is not affected by methionine sources. [ABSTRACT FROM AUTHOR]

Threonine (Thr) is generally the second limiting amino acid (AA) in growing pig diets, and it has a vital role in supporting intestinal functions and the immune system. Additionally, providing pigs with the correct AA requirements decreases nitrogen excretion and improves growth performance. This study aimed to determine standardized ileal digestibility (SID) Thr requirements for individual post-weaned pigs. Additionally, the Thr supplementation effect on average daily gain (ADG) of weaning and growing [7.3 - 51.5 kg of body weight (BW)] pigs under a sanitary challenge was evaluated. Eleven papers published from 1993 to 2015 composed the dataset used to determine the SID Thr requirement in the nursery phase, and five studies conducted from 2014 to 2020 composed the enteric sanitary challenge dataset. The SID Thr was obtained from publications when available or estimated based on the ingredient composition using EvaPig software. The average individual pig SID Thr requirements were estimated by bootstrapping 1,000 repetitions of a linear-plateau mixed model where all parameters were considered random as a function of the trial code. A general positive-definite matrix was used to represent the between-factors covariance using the nlme package of the R software. The effect of supplementing SID Thr above the requirement to attenuate ADG losses during a challenge was evaluated by an effect size analysis using a mixed model of the R Metafor package. Due to the low number of studies assessing pigs' response to enteric challenges, a P < 0.25 was considered significant. In the post-weaning (14 kg average BW), the estimated ADG was 457 g/d (411 to 493 g/d) as a function of SID Thr individual requirement, which was 4.71 g/d for the average pig, with the least demanding pig requiring 4.4 g/d and the most demanding one requiring 5.1 g/d. For challenged pigs, the across-study heterogeneity was moderate (Higgs index = 36%). Increasing Thr intake by 18% above the estimated requirement attenuated (P = 0.15) ADG losses by 0.7 standard deviations (60 g) compared with pigs fed diets meeting Thr requirements. For pigs in individual precision feeding, the SID Thr requirement is estimated to be 1.03 g per 100 g of ADG for post-weaned pigs. The increase of SID Thr intake by 18% attenuated the ADG losses by 19% compared with non-supplemented pigs with enteric challenges. [ABSTRACT FROM AUTHOR]

Ionophores are a separate class of nonmedically important antibiotics used in animal production to increase growth rate. Narasin (Skycis; Elanco Animal Health, Greenfield, IN) is an ionophore labeled for increased rate of body weight gain and improved feed efficiency in growing-finishing swine. The mode of action of this ionophore is to increase energy availability by altering volatile fatty acid production in the hindgut in favor of propionate, which is the most efficient product of fermentation. Therefore, a metaregression analysis was conducted to evaluate the effects of narasin inclusion in growing-finishing pig diets to predict average daily gain and feed efficiency. A database was developed that contained 21 papers from 2012 to 2021 representing 308 observations including both individual period data as well as overall trial data. For statistical analysis two models were created. The individual period model considered only data with single continuous narasin feeding periods while the overall trial model considered complete data sets representing periods with and without narasin feeding. Regression model equations were developed with the GLIMMIX procedure of SAS (Version 9.4, SAS institute, Cary, NC). Predictor variables were assessed with a stepwise manual forward selection for model inclusion. Predictor variables were required to provide an improvement of at least 2 Bayesian information criterion units to be included in the final model. For individual period data for G:F, the model selected included concentration of narasin in the feed, ADG and ADFI of the control group not provided narasin, and average BW of the control group categorized into greater than 105 kg or less than 105 kg (Table 1). There were 2 competing models to predict improvement in overall G:F. For model 1, significant predictors included concentration of narasin in feed and ADG of the control group. Model 2 for overall G:F included concentration of narasin in feed, ADG and ADFI of the control group. For the individual period model that predicted ADG, the predictors were concentration of narasin in the feed, ADFI, G:F of the control group and BW category for feeding period. The best fitting ADG model using the overall trial data included concentration of narasin in feed, ADFI and G:F of the control group, and feeding duration categorized as longer than 65 days or shorter than 65 days. Together, these models can be used to predict the response to narasin supplementation in finishing pigs. Based on the results, the overall response to narasin inclusion rate for ADG and G:F is quadratic in nature. Additionally, as ADG and G:F increase, the response to narasin supplementation decreases. In summary, using average values from the database for predictor variables, this meta-analysis demonstrates narasin would be expected to improve overall G:F from 0.74 to 1.13% and ADG from 1 to 3%. [ABSTRACT FROM AUTHOR]

Several papers report greater bioavailability of dietary trace mineral fed as organic in pigs compared with inorganic sources. However, only a few studies have tried to assess the variability of the trace mineral bioavailability among different organic sources. Growing barrows (n = 54; initial BW = 28.9 ± 1.3 kg) were used to determine the effects of trace mineral source on growth performance, bones mineralization and mineral status over the entire fattening period (d0-d73). Pigs were blocked by BW and randomly assigned to supplementation of trace minerals as inorganic (ITM) or one of 2 organic sources (OTM): glycine complex (GLY) or amino acids complex (AA). During the two feeding phases (growing: d0-d35; finishing: d35-d73), the experimental diets were supplemented with 5, 35 and 5 mg/kg of Cu, Zn and Mn, respectively. Pigs were fed restricted all through the experimental period. Feed intake was therefore comparable all through the experimental period for all pigs. Growth performance did not differ among the three experimental groups during the growing phase. However, Feed:Gain ratio measured during the finishing period tended to be affected by the dietary treatments (P=0.10). When grouping the GLY and AA pigs, the Feed:Gain ratio measured from d35 to d73 for the OTM pigs was significantly lower compared with ITM pigs (-0.07, P = 0.03). There was no significant effect of the dietary treatment on plasma trace mineral concentrations and alkaline phosphatase activity measured at day 34. At the end of the growing phase, plasma ceruloplasmin activity tended to be greater for the GLY and AA groups in comparison with the ITM pigs (+6.9%, P = 0.06). The zinc deposition in the proximal phalanx was significantly increased when the trace minerals were offered as organic compared with the group ITM (+10.9%, P = 0.06). Zinc content in the liver was greater for the pigs fed the OTM sources compared with the others (+6.0%, P = 0.10). The quantity of copper deposited in the liver did not differ significantly among the 3 trace mineral sources. This study indicates that the total replacement of inorganic Zn, Cu and Mn by organic sources brings benefits in terms of feed efficiency in fattening pigs. A better bioavailability as suggested by greater deposition levels in bone and liver as well as the increased J. Anim. Sci Vol. 101, Suppl. S2 103 circulating ceruloplasmin activity could explain the improvement of performance during the finishing period. Regardless of the variable considered, no significant differences were noticed between the two organic trace mineral sources. [ABSTRACT FROM AUTHOR]

A meta-analysis was conducted to evaluate the effects of branched-chain amino acids (BCAA), their interactions, and interactions with large neutral amino acids (LNAA) to develop prediction equations for growth performance of pigs. Data from 25 papers, published from 1995 to 2018, for a total of 44 trials and 210 observations were recorded in a database. Diets were reformulated using the NRC (2012) loading values to estimate nutrient concentrations. The response variables were average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F). The predictor variables tested included average body weight (BW), crude protein, neutral detergent fiber, Ile:Lys, Leu:Lys, Val:Lys, BCAA:Lys, Ile:Leu, Val:Leu, Ile:Val, (Ile+Val):Leu, Trp:Lys, Leu:Trp, Ile:Trp, Val:Trp, BCAA:Trp, Met:Lys, Leu:Met, Ile:Met, Val:Met, BCAA:Met, His:Lys, Leu:His, Ile:His, Val:His, BCAA:His, Thr:Lys, Leu:Thr, Ile:Thr, Val:Thr, BCAA:Thr, (Phe+Tyr):Lys, Leu:(Phe+Tyr), Ile:(Phe+Tyr), Val:(Phe+Tyr), BCAA:(Phe+Tyr), LNAA:Lys, Leu:LNAA, Ile:LNAA, Val:LNAA, and BCAA:LNAA. Amino acids were expressed on standardized ileal digestible basis. The MIXED procedure of SAS (SAS Institute Inc., Cary, NC) was used to develop the equations. The inverse of squared SEM was used to account for heterogeneous errors using the WEIGHT statement. Models were selected with a step-wise manual forward selection. In order to be included in the final model, predictor variables had to be statistically significant (P < 0.05) and provide an improvement of at least 2 points in Bayesian information criterion. The optimum equations were: ADG, g = - 985.94 + (15.2499 × average BW (kg)) - (0.08885 × average BW × average BW) + (1.063 × Leu:Lys) + (20.2659 × Ile:Lys) - (0.1479 × Ile:Lys × Ile:Lys) + (9.2243 × (Ile+Val):Leu) - (0.03321 × (Ile+Val):Leu × (Ile+Val):Leu) - (0.4413 × Ile:Trp); G:F, g/kg = 648.3 - (6.2974 × average BW (kg)) + (0.02051 × average BW × average BW) + (0.5396 × Ile:Lys) + (1.7284 × Val:Lys) - (0.00795 × Val:Lys × Val:Lys) - (1.7594 × Met:Lys); and ADFI, kg = predicted ADG/predicted G:F. Overall, the prediction equations suggest that increasing Leu:Lys negatively impacts ADG due to a reduction in G:F and ADFI caused by insufficient levels of other BCAA and LNAA relative to Leu. According to the model, the addition of Val, Ile, and Trp, alone or in combination, has the potential to counteract the negative effects of high dietary Leu concentrations on growth performance., (© The Author(s) 2019. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The weight of a pig and the rate of its growth are key elements in pig production. In particular, predicting future growth is extremely useful, since it can help in determining feed costs, pen space requirements, and the age at which a pig reaches a desired slaughter weight. However, making these predictions is challenging, due to the natural variation in how individual pigs grow, and the different causes of this variation. In this paper, we used machine learning, namely random forest (RF) regression, for predicting the age at which the slaughter weight of 120 kg is reached. Additionally, we used the variable importance score from RF to quantify the importance of different types of input data for that prediction. Data of 32,979 purebred Large White pigs were provided by Topigs Norsvin, consisting of phenotypic data, estimated breeding values (EBVs), along with pedigree and pedigree-genetic relationships. Moreover, we presented a 2-step data reduction procedure, based on random projections (RPs) and principal component analysis (PCA), to extract features from the pedigree and genetic similarity matrices for use as inputs in the prediction models. Our results showed that relevant phenotypic features were the most effective in predicting the output (age at 120 kg), explaining approximately 62% of its variance (i.e., R2 = 0.62). Estimated breeding value, pedigree, or pedigree-genetic features interchangeably explain 2% of additional variance when added to the phenotypic features, while explaining, respectively, 38%, 39%, and 34% of the variance when used separately.

Pig and poultry production relies on crossbreeding of purebred populations to produce production animals. In those breeding schemes, selection takes place within the purebred population to improve crossbred performance (CB performance). The genetic correlation between purebred performance (PB performance) and CB performance () is, however, lower than unity for many traits. When is low, the use of CB performance in selection is required to achieve sizable genetic progress. The objectives of this paper were to describe the different components and importance of , and to review existing literature that report estimates in pigs. The has 3 components: 1) genotype by genotype interactions, 2) genotype by environment interactions, and 3) differences in trait measurements. We theoretically showed that direct selection for CB performance reduces the response to selection in purebreds for.

The intramuscular fat (IMF) and oleic acid (OL) content have been favorably related to pork quality and human health. This influences the purchasing behavior of consumers and, therefore, also shifts the attention of breeding companies toward whether these traits are included into the breeding goal of the lines producing for high-valued markets. Because IMF and OL are unfavorably associated with lean content, a key economic trait, the real challenge for the industry is not simply to increase IMF and OL, but rather to come up with the right trade-off between them and lean content. In this paper we review the efforts performed to genetically improve IMF and OL, with particular reference to the research we conducted in a Duroc line aimed at producing high quality fresh and dry-cured pork products. Based on this research, we conclude that there are selection strategies that lead to response scenarios where IMF, OL, and lean content can be simultaneously improved. Such scenarios involve regular recording of IMF and OL, so that developing a cost-efficient phenotyping system for these traits is paramount. With the economic benefits of genomic selection needing further assessment in pigs, selection on a combination of pedigree-connected phenotypes and genotypes from a panel of selected genetic markers is presented as a suitable alternative. Evidence is provided supporting that at least a polymorphism in the leptin receptor and another in the stearoyl-CoA desaturase genes should be in that panel. Selection for IMF and OL results in an opportunity cost on lean growth. The extent to which it is affordable relies on the consumers' willingness to pay for premium products and on the cost to benefit ratio of alternative management strategies, such as specific dietary manipulations. How the genotype can influence the effect of the diet on IMF and OL remains a topic for further research.

This paper deals with the use of the Choquet integral to identify breeding objectives and construct an aggregate genotype. The Choquet integral can be interpreted as an extension of the aggregate genotype based on profit equations, substituting the vector of economic weights by a monotone function, called capacity, which allows the aggregation of traits based, for instance, on the preferences of decision makers. It allows the aggregation of traits with or without economic value, taking into account not only the importance of the breeding value of each trait but also the interaction among them. Two examples have been worked out for pig and dairy cattle breeding scenarios to illustrate its application. It is shown that the expression of stakeholders' or decision makers' preferences, as a single ranking of animals or groups of animals, could be sufficient to extract information to derive breeding objectives. It is also shown that coalitions among traits can be identified to evaluate whether a linear additive function, equivalent of the Hazel aggregate genotype where economic values are replaced by Shapley values, could be adequate to define the net merit of breeding animals.

The selection of animals for improved performance affects the profitability of pig fattening and has environmental consequences. The goal of this paper was to examine how changes in genetic and market parameters impact the biophysical (feeding patterns, timing of slaughter, nitrogen excretion) and economic (return per pig space unit) results describing pig fattening in a Finnish farm. The analysis can be viewed as focusing on terminal line breeding goals. An integrated model using recursive stochastic dynamic programming and a biological pig growth model was used to estimate biophysical results and economic values. Combining these models allowed us to provide more accurate estimates for the value of genetic improvement and, thus, provide better feedback to animal breeding programs than the traditional approach, which is based on fixed management patterns. Besides the benchmark scenario, the results were simulated for 5 other scenarios. In each scenario, genotype was improved regarding daily growth potential, carcass lean meat content, or the parameters of the Gompertz growth curve (maturing rate [], adult weight of protein [α], and adult weight of lipid mass []). The change in each parameter was equal to approximately 1 SD genetic improvement (ceteris paribus). Increasing , , daily growth potential, or carcass lean meat content increased the return on pig space unit by €12.60, €7.60, €4.10, or €2.90 per year, respectively, whereas an increase in decreased the return by €3.10. The genetic improvement in and resulted in the highest decrease in nitrogen excretion calculated in total or per kilogram of carcass gain but only under the optimal feeding pattern. Simulated changes in the Gompertz growth function parameters imply greater changes in ADG and lean meat content than changes in scenarios focusing on improving ADG and lean meat content directly. The economic value of genetic improvements as well as the quantity of nitrogen excreted during the fattening period largely depends on feeding. Improved genotypes can require changes in pig management pattern. Estimating the influence of the genotype on the nitrogen excretion without considering changes in the management pattern can result in flawed conclusions. To improve overall economic performance and to decrease the environmental footprint of fattening pig production, the pig producer can adjust the herd management pattern according to the pigs' genetics.

Data from existing literature were used to generate equations to predict finishing pig back, belly, and jowl fat iodine values (IV) and an experiment was conducted to evaluate these equations. The final database included 24, 21, and 29 papers for back, belly, and jowl fat IV, respectively. For experiments that changed dietary fatty acid composition, initial (INT) diets were defined as those fed before the change in diet composition and final (FIN) diets were those fed after. The predictor variables tested were divided into 5 groups: 1) diet fat composition (dietary percent C16:1, C18:1, C18:2, C18:3, EFA, unsaturated fatty acids, and IV product) for both INT and FIN diets, 2) day feeding the INT and FIN diets, 3) ME or NE of the INT and FIN diet, 4) live performance criteria (initial BW, final BW, ADG, ADFI, and G:F), and 5) carcass criteria (HCW and backfat thickness). The PROC MIXED procedure of SAS (SAS Inst., Inc., Cary, NC) was used to develop regression equations. Evaluation of models with significant terms was then conducted based on the Bayesian information criterion. The optimum equations to predict back, belly, and jowl fat IV were backfat IV = 84.83 + (6.87 × INT EFA) - (3.90 × FIN EFA) - (0.12 × INT days) - (1.30 × FIN days) - (0.11 × INT EFA × FIN days) + (0.048 × FIN EFA × INT days) + (0.12 × FIN EFA × FIN days) - (0.0060 × FIN NE) + (0.0005 × FIN NE × FIN days) - (0.26 × backfat depth); belly fat IV = 106.16 + (6.21 × INT EFA) - (1.50 × FIN days) - (0.11 × INT EFA × FIN days) - (0.012 × INT NE) + (0.00069 × INT NE × FIN days) - (0.18 × HCW) - (0.25 × backfat depth); and jowl fat IV = 85.50 + (1.08 × INT EFA) + (0.87 × FIN EFA) - (0.014 × INT days) - (0.050 × FIN days) + (0.038 × INT EFA × INT days) + (0.054 × FIN EFA × FIN days) - (0.0066 × INT NE) + (0.071 × INT BW) - (2.19 × ADFI) - (0.29 × backfat depth). Dietary treatments from the evaluation experiment consisted of a corn-soybean meal control diet with no added fat or a 3 × 3 factorial arrangement with main effects of fat source (4% tallow, 4% soybean oil, or a blend of 2% tallow and 2% soybean oil) and feeding duration (d 0 to 42, 42 to 84, or 0 to 84). The back, belly, and jowl fat IV equations tended to overestimate IV when observed IV were less than approximately 65 g/100 g and underestimate belly fat IV when actual IV are greater than approximately 74 g/100 g or when the fat blend was fed from d 0 to 84 or 42 to 84. Overall, with the exceptions noted, the regression equations were an accurate tool for predicting carcass fat quality based on dietary and pig performance factors.

A better understanding of the fate of dietary P use by growing pigs will allow an optimization of P use and enhance sustainable practices. The optimization of P utilization is complicated by the multiple criteria, such as growth performance, bone mineralization, and manure P used for assessment of needs. Mathematical modeling is a useful tool to describe relevant biological mechanisms and predict relationships that describe the whole system behavior. Modeling allows development of robust multicriteria approaches to optimize P utilization, feeding cost, and manure application cost. This paper describes and evaluates a model developed to simulate the fate of dietary P, that is, to simulate its digestive and metabolic utilization through digestion, soft tissue, and ash modules. The digestion module takes into account the varied sources of dietary minerals including responses to microbial and plant phytase and Ca and P interactions and predicts absorption and fecal excretion. The soft tissue module simulates the growth of the protein and is based on InraPorc model principles. The ash module simulates the partitioning of absorbed Ca and P into the bone, protein, and lipid compartments as well as urinary excretion. Model behavior showed that the model was able to accurately represent the impact of Lys deficiency on P retention, of Ca and P imbalances, and of Ca and P depletion and repletion sequences. The model's prediction capabilities in simulating whole-body protein, Ca, P, and ash based on published data showed high accuracy, with a slope and intercept that did not differ from 1 and 0, respectively, and an error due to disturbance (ED; variance not accounted for by regression of observed on predicted values). The model's prediction capabilities in simulating balance trial data showed good accuracy for apparent total tract digestibility (ATTD) of P (observed = -0.77 + 1.06 predicted) and P retention coefficient (observed = -4.5 + 1.15 predicted) with an ED of 89% for both criteria. The model's prediction capabilities in simulating Ca ATTD and Ca retention coefficient are lower (ED of 88 and 28%, respectively). This model simulates body ash independently of body protein and accounts for the impact of past and current dietary Ca and P supply. That ability is essential for the real-time adaptation of mineral supplies to suit individual production objectives, which would contribute to the overall success of pig production.

The porcine model has been utilized by researchers to study human developmental aspects, surgical procedures, disease impacts, and nutritional interventions for over 60 yr. However, when it comes to investigating how nutrients regulate human gastrointestinal tract (GIT) function and health, and nutritional research evolves from dietary composition to potential nutraceutical applications, the question needs to be asked: is the pig an appropriate translational animal model? Morphologically and functionally, the porcine GIT has more similarity to the human GIT than commonly used models such as rats. Food intake related to BW is much lower in humans than in pigs, which explains the higher and faster growth and earlier maturation in the latter species. In addition, the digestion and metabolism of carbohydrates, prebiotics, lipids, and amino acids produce similar metabolites and subsequent effects on GIT development and health in pigs and humans, making the pig a more comparable model to study human GIT issues than other nonprimate species. However, there are key divergences. Pigs have a functional cecum, larger colon, and the endogenous microbiota of the GIT, while similar at the phylum level is vastly different at the genera level. One notable microbial species that is low to nonexistent in the porcine GIT are the Bifidobacterium, which is a major probiotic species in humans. Several porcine models have been developed to overcome these issues, but they are new and have yet to be fully tested. This paper will provide a comparative analysis between the human and porcine GIT in regards to structure, function, and health and how various nutritional factors influence these characteristics and future developments of the porcine model. [ABSTRACT FROM AUTHOR]

This paper provides a review on the effects of functional ingredients and processing of ingredients and diets on the functions of the gastrointestinal tract (GIT) and health of the GIT in pigs. There is increasing attention for these topics since the ban of in-feed growth promoting antibiotics in many parts of the world and due to the pressure on the use of antibiotics in animal production. A prime function of the GIT is to digest and absorb nutrients. In addition, it has a complex barrier function of which the intestinal microbiota and the residing local immune system are important components. The health of the GIT is related to the capacity of the GIT to exert these functions. Ingredient and nutrient composition of the diet affect the various functions of the GIT and, therefore, also influence GIT health. Feed and feed ingredient processing can affect the extent and site of enzymatic nutrient digestion within the small intestine but can also induce changes in the extent of fermentation of dietary constituents by intestinal microbiota and induce changes in microbiota composition in various segments of the GIT. Further understanding of the mechanisms involved in the complex interactions among the diet, intestinal microbiota, and intestinal tissue can assist in supporting functions of the GIT and health of the GIT via targeted modifications of the diet. [ABSTRACT FROM AUTHOR]

Optimal lean tissue production can be severely compromised by health challenges in nurseryfinisher pig production systems. Common pig immune challenges in the U.S. can come from pathogens such as Porcine Reproductive and Respiratory Syndrome virus, Lawsonia intracellularis, Mycoplasma spp, Coccidia, pathogenic E. coli and Porcine Epidemic Diarrhea virus. The subsequent disease that can manifests in response to these pathogens can lead to mitochondrial damage, impaired capacity to generate sufficient ATP for homeostasis, limited energy availability (exacerbated by disease hypophagia) and compromised cell survival and organ function. Collectively, skeletal muscle hypertrophy is reduced in a trade off to support the energetic and protein synthesis needs of immune system response. In growing pigs, we have reported that sub-clinical and clinical enteric and respiratory disease can significantly impact intestinal function, feed intake, lean tissue accretion and feed efficiency. This has a major economic impact for pork producers, pig welfare and wellbeing. While significant advances in molecular and quantitative genetics, clinical diagnostics and virology have been made to enhance poor performance and heath, we are still unsure on how to best feed and manage poor-health pigs. By understanding the longitudinal impact pathogens on digestibility, metabolism, protein accretion and feed efficiency, insights into nutritional requirements and management strategies can be developed to improve poor-health pig production. This paper will discuss the molecular and physiological impact of sub-clinical and clinical disease on nutrient and energy intake and utilization to support lean tissue accretion in growing pigs. [ABSTRACT FROM AUTHOR]

The swine industry has been constantly evolving to select animals with improved performance traits and to minimize variation in body weight (BW) in order to meet packer specifications. Therefore, understanding variation presents an opportunity for producers to find strategies that could help reduce, manage, or deal with variation of pigs in a barn. A systematic review and meta-analysis was conducted by collecting data from multiple studies and available data sets in order to develop prediction equations for coefficient of variation (CV) and standard deviation (SD) as a function of BW. Information regarding BW variation from 16 papers was recorded to provide approximately 204 data points. Together, these data included 117,268 individually weighed pigs with a sample size that ranged from 104 to 4,108 pigs. A random-effects model with study used as a random effect was developed. Observations were weighted using sample size as an estimate for precision on the analysis, where larger data sets accounted for increased accuracy in the model. Regression equations were developed using the nlme package of R to determine the relationship between BW and its variation. Polynomial regression analysis was conducted separately for each variation measurement. When CV was reported in the data set, SD was calculated and vice versa. The resulting prediction equations were: CV (%) = 20.04 - 0.135 × (BW) + 0.00043 × (BW)², R²=0.79; SD = 0.41 + 0.150 × (BW) - 0.00041 × (BW)², R² = 0.95. These equations suggest that there is evidence for a decreasing quadratic relationship between mean CV of a population and BW of pigs whereby the rate of decrease is smaller as mean pig BW increases from birth to market. Conversely, the rate of increase of SD of a population of pigs is smaller as mean pig BW increases from birth to market. [ABSTRACT FROM AUTHOR]

Scientific evidence remains equivocal with regard to what is die best way to house gestating sows. However, 9 U.S. states have joined the precedent of the European Union and instituted legislation to phase out the use of gestational stalls. Concurrently, sixty or more large national companies in the retail and food service industry have pledged to eliminate gestation stalls from their supply chain over a 5 to 10 yr time horizon. Several packers have also committed to moving some or all of their company owned sows out of stalls and in some instances have also signaled a similar intention for those that supply them with fat hogs. Furthermore, in Canada, a new code of practice was released in July of 2014 that also places restrictions on the use of gestation stalls. Thus, if a producer plans to build new sow facilities and/or plans to stay in the business long enough to recapitalize their existing sow facilities, they will likely need to confront the decision about whether to continue to work with gestation stalls or explore what is the best option for pen gestation. While many producers are expressing concern, anxiety, and even anger today given the possibility of having to transition from gestation stalls to pen gestation, the goal of this paper is to address some of the possible upside potential available from selected pen gestation options. In particular, electronic sow feeding (ESF) provides the opportunity to capture many advantages previously unrealized in the feeding and management of gestating sows. Individual sows are uniquely and electronically identified with a radio-frequency-identification (RFID) tag. Sows enter the feed station one at a time, their tag is read and they are fed their specified allotment for the day. ESF is the only alternative to gestation stalls that provides true individual animal nutrition. However, this paper will make the argument that ESF is actually a better way to feed an individual sow than a gestation stall. In particular, ESF provides unique opportunities for managing the gestating sow through improved approaches to feed utilization, meeting her nutritional needs, estrus control, individual animal care, and autogenous immunization. Specific examples of each of these opportunities will be discussed in detail. [ABSTRACT FROM AUTHOR]

African swine fever (ASF) virus (ASFV) is responsible for one of the most severe swine diseases worldwide, with a morbidity rate of up to 100%; no vaccines or antiviral medicines are available against the virus. Exosomal miRNAs from individual cells can regulate the immune response to infectious diseases. In this study, pigs were infected with an ASFV Pig/HN/07 strain that was classified as acute form, and exosomal miRNA expression in the serum of infected pigs was analyzed using small RNA sequencing (small RNA-seq). Twenty-seven differentially expressed (DE) miRNAs were identified in the ASFV-infected pigs compared to that in the uninfected controls. Of these, 10 were upregulated and 17 were downregulated in the infected pigs. All DE miRNAs were analyzed using gene ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and the DE miRNAs were found to be highly involved in T-cell receptor signaling, cGMP-PKG signaling, Toll-like receptor, MAPK signaling, and mTOR signaling pathways. Furthermore, the Cytoscape network analysis identified the network of interactions between DE miRNAs and target genes. Finally, the transcription levels of four miRNA genes (ssc-miR-24-3p, ssc-miR-130b-3p, ssc-let-7a, and ssc-let-7c) were examined using quantitative real-time PCR (qRT-PCR) and were found to be consistent with the small RNA-seq data. These DE miRNAs were associated with cellular genes involved in the pathways related to immune response, virus–host interactions, and several viral genes. Overall, our findings provide an important reference and improve our understanding of ASF pathogenesis and the immune or protective responses during an acute infection in the host. [ABSTRACT FROM AUTHOR]

This study investigated the effects of a low-protein diet with or without an increase in dietary protein and feed-grade amino acids (AAs) on the growth performance, body composition, metabolism, and serum acute-phase proteins of finishing pigs reared in thermoneutrality or cyclic heat stress conditions. A total of 90 gilts (67.7 ± 6.2 kg) were distributed in a 2 × 3 factorial arrangement (two ambient temperatures and three diets). Ambient temperatures (AT) were thermoneutral (TN , 22 °C for 24 h) and cyclic heat stress (CHS , 12 h to 35 °C and 12 h to 22 °C). The evaluated diets (D) were high crude protein (HP); low CP-free AA-supplemented diets (LPAAs); low CP-free AA-supplemented diets and digestible Lys level (+20%), and Lys:AA ratios above recommendations (LPAA+). The experimental period lasted 48 d (two experimental phases: days 0–27 and days 28–48, respectively). CHS pigs had higher skin temperature (P < 0.05) than TN pigs. Pigs in CHS had higher rectal temperature (P < 0.05) than TN pigs until day 38 but similar (P > 0.10) to TN pigs from 38 to 45 d. For the entire experiment, CHS pigs had lower (P < 0.05) final BW, average daily gain and daily feed intake, net energy intake, body lipid, bone mineral, lipid deposition, energy retention, Lys and CP intake, and nitrogen excretion than TN pigs. The level of CP intake impacted nitrogen excretion, nitrogen retention efficiency, and urea as pigs fed HP had the highest values, and pigs fed LPAA had the lowest values (P < 0.05). On day 27, CHS pigs had lower (P < 0.05) free triiodothyronine than TN pigs. LPAA+ pigs had lower (P < 0.05) insulin than LPAA. On day 48, CHS pigs had lower (P < 0.05) thyroxine, albumin, and lactate than TN pigs. On day 27, pigs fed LPAA+ had higher (P < 0.05) lactate than pigs fed HP or LPAA. Both AT and D were enough to stimulate the immune system as CHS pigs had lower (P < 0.05) transferrin and 23-kDa protein levels than TN pigs, and HP pigs had higher haptoglobin than LPAA on day 27. These results confirm the deleterious effects of high AT on performance, body composition, metabolism, and immune system stimulation in finishing pigs. These data also show that a diet with low levels of CP can be provided to pigs in CHS without affecting performance and body composition while reducing nitrogen excretion. However, the use of a diet with an AA level above the requirements obtained by increasing intact protein and free AA did not attenuate the impact of CHS on performance and body composition of pigs. [ABSTRACT FROM AUTHOR]

Twenty-four gilts (PIC 337 × 1050, PIC Genus, Hendersonville, TN) with an initial body weight (BW) of 33.09 ± 1.33 kg were used to investigate the effects of benzoic acid (BA) and a Bacillus-based direct-fed microbial (DFM) on the nutrient metabolism and manure gas emissions of growing pigs. Pigs were blocked by BW, placed into metabolism stalls, and randomly assigned to one of four dietary treatments: basal control (PC), low nitrogen (NC), PC plus 0.3% BA (PC+BA; VevoVitall, DSM Nutritional Products), and PC plus 0.3% BA and 0.025% DFM (PC+BA+DFM; PureGro, DSM Nutritional Products). Pigs were fed a common diet from day 0 to 14, and the experimental diets were fed in two phases (day 14 to 28 and day 28 to 53). The experiment consisted of four collection periods, with each period subdivided into two subperiods to collect samples for gas emissions and nutrient balance. Firstly, manure samples were collected for 72 h. Twice daily, urine and feces were weighed, and urine pH was measured. After each period, manure was subsampled and taken to the lab to measure gas emissions. Secondly, urine and feces were quantitatively collected for 96 h to allow for measurement of nutrient digestibility (ATTD) and retention. Data were analyzed as repeated measures in SAS 9.4 (SAS Inst., Cary, NC) with fixed effects of treatment, collection period, and block. Pig was the experimental unit, and results were considered significant at P ≤ 0.05 and a tendency at 0.05 < P ≤ 0.10. Pigs fed PC+BA had the greatest ADG compared to pigs fed NC (P = 0.016), with intermediate ADG for pigs fed PC or PC+BA+DFM (P ≥ 0.148). The ATTD of dry matter, gross energy, P, and N did not differ between treatments (P ≥ 0.093). However, the ATTD of Ca was reduced in pigs fed PC+BA+DFM compared to pigs fed PC+BA (P = 0.012). Pigs fed PC+BA or NC excreted less urinary N compared to PC and PC+BA+DFM (P ≤ 0.034), which contributed to greater nitrogen retention in PC+BA compared to PC (P = 0.016). Furthermore, decreased manure pH from pigs fed PC+BA or NC resulted in lower ammonia (NH3 ) emissions compared to pigs fed PC+BA+DFM or PC. There was no effect of dietary treatment on manure hydrogen sulfide, methane, or carbon dioxide emissions. In conclusion, supplementing 0.3% BA improved N retention and reduced manure pH and NH3 emissions, similar to feeding pigs low N, but improved the ADG of pigs when compared to feeding a low N diet. [ABSTRACT FROM AUTHOR]

Very low-protein (VLP) diets are beneficial for reducing the nitrogen excretion from swine production, but these diets depress the performance of pigs while supplemented with first four limiting amino acids (FFL; i.e. Lys, Met, Thr and Trp). The objective of this study was to investigate the effect of supplementation of Val and Ile above NRC (2012) levels on performance, thermal radiation and blood metabolites of pigs fed with VLP diets. Three-week-old weaned barrows (n = 40) were assigned to: positive control (PC): normal protein diet; negative control (NC): VLP diet containing FFL at NRC levels; HV: NC with Val above NRC; HI: NC with Ile above NRC; HVI: NC with both Val and Ile above NRC. After 5 weeks of data collection, blood samples were collected. Univariate GLM with Tukey post-hoc test was used to analyze the data (SPSS). Pigs fed with NC had a decreased average daily gain (ADG) and average daily feed intake (ADFI) compared with PC (P< 0.05). HVI pigs had less ADG than PC, but greater ADG than NC (P< 0.05). ADFI of pigs fed with HVI was similar to PC and it was greater than NC (P< 0.05). HVI pigs had a higher thermal radiation than NC (P< 0.05). While HVI pigs had greater blood glucose than PC and NC at baseline (P< 0.05), no differences among these groups were observed on postprandial blood glucose concentration. HVI pigs had less blood triglycerides than PC. All groups increased the blood cholesterol compared with PC (P< 0.05). There were no differences in blood urea nitrogen (BUN) for NC vs. PC; however, pigs fed with HVI reduced the BUN compared with NC (P< 0.05). In conclusion, supplementation of Val and Ile greater than NRC into VLP diets partially restored the performance and fully recovered the ADFI, reduced the blood triglycerides and BUN, and improved the glucose tolerance. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to investigate the effects of dietary crude protein (CP) contents and crystalline amino acids (CAA) supplementation patterns on growth performance, intestinal histomorphology, and immune response in weaned pigs under clean (CSC) or unclean sanitary conditions (USC). A total of 144 weaned pigs (6.35 ± 0.63 kg body weight) were assigned to 6 treatments in a 3 × 2 factorial arrangement based on CP content and sanitary conditions using a randomized complete block design, giving 8 replicates per treatment with 3 pigs per pen. Pigs were fed one of three diets for 21 d: one high CP (HCP ; 22%) and two low CP (LCP ; 19%) diets supplemented with 9 indispensable AA or only 6 AA (Lys, Met, Thr, Trp, Val, and Ile) as CAA. The CSC room was washed weekly, whereas the USC room had sow manure spread in the pens and was not washed throughout the experiment. Body weight and feed disappearance were recorded weekly. Blood was sampled from 1 pig per pen weekly, and the same pig was euthanized for jejunal tissues sampling on day 21. Pigs raised under USC had reduced (P < 0.05) average daily gain (ADG) and gain to feed ratio (G:F) in week 2, but contrary results that greater (P < 0.05) ADG and G:F were found in pigs under USC in week 3. Overall, there was an interaction where G:F did not differ between HCP and LCP under CSC, however, LCP decreased (P < 0.05) G:F compared to HCP under USC. Pigs fed the HCP diet had higher (P < 0.05) fecal scores than those fed the LCP diets throughout the experiment. Pigs fed the LCP had higher (P < 0.05) villus height to crypt depth ratio than those fed the HCP. An interaction was observed where goblet cell density in the jejunum was higher (P < 0.05) in pigs fed LCP than HCP under CSC, but no difference was found between HCP and LCP under USC. Different CAA supplementation patterns did not influence both growth performance and histomorphology. Pigs raised under USC had greater (P < 0.05) plasma interleukin (IL)-10 and IL-6 concentrations and reduced (P < 0.05) plasma tumor necrosis factor-alpha concentration. Also, the LCP diets resulted in a greater (P < 0.05) plasma IL-10 concentration. In conclusion, overall growth performance did not differ between HCP and LCP under CSC, but LCP diets reduced G:F under USC. Feeding LCP diets to weaned pigs improved gut morphology under USC and ameliorated systemic inflammation induced by USC, whereas CAA supplementation patterns did not affect growth performance and gut morphology. [ABSTRACT FROM AUTHOR]

Feeding growing-finishing pigs supplemental fat is a common practice in the swine industry and can result in improved feed efficiency and reduced feed intake; however, dietary lipids also play a key role in determining pork quality. Objectives of the study were to evaluate the effects of feeding graded levels of high oleic soybean oil (HOSO) on loin and belly quality. A total of 288 pig raised in two separate blocks (144 pigs each) were assigned to one of four diets containing either 25% dried distiller's grains with solubles (DDGS), 2% high oleic soybean oil (HOSO 2 ), 4% high oleic soybean oil (HOSO 4 ), or 6% high oleic soybean oil (HOSO6). Following the conclusion of the feeding trial, 144 pigs were slaughtered at the University of Illinois Meat Science Laboratory. Following fabrication, loins were collected for the evaluation of fresh quality measurements and color stability. Belly quality and fatty acid composition were evaluated using skin-on natural fall bellies. There were no differences (P ≥ 0.11) in pH, visual color, lightness (L *), drip loss, or WBSF among dietary treatments. However, visual marbling was increased (P ≤ 0.01) in loin chops from pigs fed HOSO4 and HOSO6 treatments compared with chops from pigs fed the DDGS dietary treatment. Additionally, loin chops were more red (a *) (P ≤ 0.01) from pigs fed HOSO diets when compared with pigs fed DDGS. Extractable lipid was decreased (P ≤ 0.01) in fresh loin chops from pigs fed DDGS and HOSO2 diets compared with pigs fed HOSO6. There were no differences (P ≥ 0.75) in trained sensory tenderness, juiciness, or flavor for loin chops from pigs fed different dietary treatments. Pork fatty acid composition was altered by dietary HOSO inclusion, with pigs fed DDGS having (P ≤ 0.01) the greatest concentration of C16:0 and was decreased with increasing levels of HOSO inclusion. Inversely, the percentage of C18:1 n -9 was least (P ≤ 0.01) in pigs fed DDGS and increased with increasing levels of HOSO inclusion. Pigs fed DDGS produced wider (P ≤ 0.03) and thinner (P ≤ 0.04) bellies with reduced flop distance compared with pigs fed HOSO diets. Overall, HOSO diets did not negatively affect fresh loin quality or sensory traits of loin chops. Furthermore, feeding HOSO to swine resulted in bellies containing greater percentages of oleic acid and reduced percentages of palmitic and linoleic acid. [ABSTRACT FROM AUTHOR]

The microbial composition resemblance among individuals in a group can be summarized in a square covariance matrix and fitted in linear models. We investigated eight approaches to create the matrix that quantified the resemblance between animals based on the gut microbiota composition. We aimed to compare the performance of different methods in estimating trait microbiability and predicting growth and body composition traits in three pig breeds. This study included 651 purebred boars from either breed: Duroc (n = 205), Landrace (n = 226), and Large White (n = 220). Growth and body composition traits, including body weight (BW), ultrasound backfat thickness (BF), ultrasound loin depth (LD), and ultrasound intramuscular fat (IMF) content, were measured on live animals at the market weight (156 ± 2.5 d of age). Rectal swabs were taken from each animal at 158 ± 4 d of age and subjected to 16S rRNA gene sequencing. Eight methods were used to create the microbial similarity matrices, including 4 kernel functions (Linear Kernel, LK ; Polynomial Kernel, PK ; Gaussian Kernel, GK ; Arc-cosine Kernel with one hidden layer, AK1), 2 dissimilarity methods (Bray-Curtis, BC ; Jaccard, JA), and 2 ordination methods (Metric Multidimensional Scaling, MDS ; Detrended Correspondence analysis, DCA). Based on the matrix used, microbiability estimates ranged from 0.07 to 0.21 and 0.12 to 0.53 for Duroc, 0.03 to 0.21 and 0.05 to 0.44 for Landrace, and 0.02 to 0.24 and 0.05 to 0.52 for Large White pigs averaged over traits in the model with sire, pen, and microbiome, and model with the only microbiome, respectively. The GK, JA, BC, and AK1 obtained greater microbiability estimates than the remaining methods across traits and breeds. Predictions were made within each breed group using four-fold cross-validation based on the relatedness of sires in each breed group. The prediction accuracy ranged from 0.03 to 0.18 for BW, 0.08 to 0.31 for BF, 0.21 to 0.48 for LD, and 0.04 to 0.16 for IMF when averaged across breeds. The BC, MDS, LK, and JA achieved better accuracy than other methods in most predictions. Overall, the PK and DCA exhibited the worst performance compared to other microbiability estimation and prediction methods. The current study shows how alternative approaches summarized the resemblance of gut microbiota composition among animals and contributed this information to variance component estimation and phenotypic prediction in swine. [ABSTRACT FROM AUTHOR]

The beneficial effect of elevated concentrations of copper (Cu) on growth performance of pigs has been already demonstrated; however, their mechanism of action is not fully discovered. The objective of the present experiment was to investigate the effects of including Cu from copper sulfate (CuSO4) or monovalent copper oxide (Cu2O) in the diet of growing pigs on oxidative stress, inflammation, gene abundance, and microbial modulation. We used 120 pigs with initial body weight (BW) of 11.5 ± 0.98 kg in 2 blocks of 60 pigs, 3 dietary treatments, 5 pigs per pen, and 4 replicate pens per treatment within each block for a total of 8 pens per treatment. Dietary treatments included the negative control (NC) diet containing 20 mg Cu/kg and 2 diets in which 250 mg Cu/kg from CuSO4 or Cu2O was added to the NC. On day 28, serum samples were collected from one pig per pen and this pig was then euthanized to obtain liver samples for the analysis of oxidative stress markers (Cu/Zn superoxide dismutase, glutathione peroxidase, and malondialdehyde, MDA). Serum samples were analyzed for cytokines. Jejunum tissue and colon content were collected and used for transcriptomic analyses and microbial characterization, respectively. Results indicated that there were greater (P < 0.05) MDA levels in the liver of pigs fed the diet with 250 mg/kg CuSO4 than in pigs fed the other diets. The serum concentration of tumor necrosis factor-alpha was greater (P < 0.05) in pigs fed diets containing CuSO4 compared with pigs fed the NC diet or the diet with 250 mg Cu/kg from Cu2O. Pigs fed diets containing CuSO4 or Cu2O had a greater (P < 0.05) abundance of genes related to the intestinal barrier function and nutrient transport, but a lower (P < 0.05) abundance of pro-inflammatory genes compared with pigs fed the NC diet. Supplementing diets with CuSO4 or Cu2O also increased (P < 0.05) the abundance of Lachnospiraceae and Peptostreptococcaceae families and reduced (P < 0.05) the abundance of the Rikenellaceae family, Campylobacter, and Streptococcus genera in the colon of pigs. In conclusion, adding 250 mg/kg of Cu from CuSO4 or Cu2O regulates genes abundance in charge of the immune system and growth, and promotes changes in the intestinal microbiota; however, Cu2O induces less systemic oxidation and inflammation compared with CuSO4. [ABSTRACT FROM AUTHOR]

Substantial economic losses in animal agriculture result from animals experiencing heat stress (HS). Pigs are especially susceptible to HS, resulting in reductions in growth, altered body composition, and compromised substrate metabolism. In this study, an artificial high-intensity sweetener and capsaicin (CAPS-SUC; Pancosma, Switzerland) were supplemented in combination to mitigate the adverse effects of HS on pig performance. Forty cross-bred barrows (16.2 ± 6 kg) were assigned to one of five treatments: thermal neutral controls (TN) (22 ± 1.2 °C; 38%–73% relative humidity) with ad libitum feed, HS conditions with ad libitum feed with (HS+) or without (HS−) supplementation, and pair-fed to HS with (PF+) or without supplementation (PF−). Pigs in heat-stressed treatments were exposed to a cyclical environmental temperature of 12 h at 35 ± 1.2 °C with 27%–45% relative humidity and 12 h at 30 ± 1.1 °C with 24%–35% relative humidity for 21 d. Supplementation (0.1 g/kg feed) began 7 d before and persisted through the duration of environmental or dietary treatments (HS/PF), which lasted for 21 d. Rectal temperatures and respiration rates (RR; breaths/minute) were recorded thrice daily, and feed intake (FI) was recorded daily. Before the start and at the termination of environmental treatments (HS/PF), a muscle biopsy of the longissimus dorsi was taken for metabolic analyses. Blood samples were collected weekly, and animals were weighed every 3 d during treatment. Core temperature (TN 39.2 ± 0.02 °C, HS− 39.6 ± 0.02 °C, and HS+ 39.6 ± 0.02 °C, P < 0.001) and RR (P < 0.001) were increased in both HS− and HS+ groups, but no difference was detected between HS− and HS+. PF− pigs exhibited reduced core temperature (39.1 ± 0.02 °C, P < 0.001), which was restored in PF+ pigs (39.3 ± 0.02 °C) to match TN. Weight gain and feed efficiency were reduced in PF− pigs (P < 0.05) but not in the PF+ or the HS− or HS+ groups. Metabolic flexibility was decreased in the HS− group (−48.4%, P < 0.05) but maintained in the HS+ group. CAPS-SUC did not influence core temperature or weight gain in HS pigs but did restore core temperature, weight gain, and feed efficiency in supplemented PF pigs. In addition, supplementation restored metabolic flexibility during HS and improved weight gain and feed efficiency during PF, highlighting CAPS-SUC's therapeutic metabolic effects. [ABSTRACT FROM AUTHOR]

Considering welfare through the "neonatal and nursery pig perspective" is an exciting approach and one that resonates with consumers. Overlaying this with the Five Domains Model, as we suggest in this review, points to practical on-farm improvements that provide each pig the opportunity to experience positive mental states. The Five Domains Model is broken into physical and functional states, which include Domain 1: Nutrition, Domain 2: Physical Environment, Domain 3: Health, and Domain 4: Behavioral Interaction, and Domain 5: Mental State. The Five Domains Model can build on the breadth and depth of swine welfare science to highlight opportunities to improve welfare on-farm. In Domain 1, management of increasingly large litters is considered, with examples of sow vs. artificial rearing, colostrum quality and quantity, and creep feed management strategies. Efforts can result in positive mental states such as feeling full and content and the ability to experience the pleasure of drinking and food tastes and smells. Domain 2 considers space complexity and access to key resources, along with thermal and physical amenities, to promote feelings of physical comfort. Domain 3 considers pig health in three broads, yet inter-linking categories 1) congenital and hereditary health, 2) environmental pathogen load, and 3) colostrum quality and quantity, and its effect on the microbiome. Improvements can result in a pig that displays vitality and feels healthy. Domain 4 provides the pig opportunities to express its rich behavioral repertoire, specifically positive social interactions, play, and exploration. These efforts can result in pigs feeling calm, safe, comfortable, having companionship, engaged, interested, and rewarded. In conclusion, using the Five Domains Model can highlight numerous opportunities to improve current and future housing and management through the "neonatal and nursery pig perspective" with a focus on inducing positive mental states that can result in improved quality of life and welfare state. [ABSTRACT FROM AUTHOR]

Precision livestock farming has become an important research focus with the rising demand of meat production in the swine industry. Currently, the farming practice is widely conducted by the technology of computer vision (CV), which automates monitoring pig activity solely based on video recordings. Automation is fulfilled by deriving imagery features that can guide CV systems to recognize animals' body contours, positions, and behavioral categories. Nevertheless, the performance of the CV systems is sensitive to the quality of imagery features. When the CV system is deployed in a variable environment, its performance may decrease as the features are not generalized enough under different illumination conditions. Moreover, most CV systems are established by supervised learning, in which intensive effort in labeling ground truths for the training process is required. Hence, a semi-supervised pipeline, VTag, is developed in this study. The pipeline focuses on long-term tracking of pig activity without requesting any pre-labeled video but a few human supervisions to build a CV system. The pipeline can be rapidly deployed as only one top-view RGB camera is needed for the tracking task. Additionally, the pipeline was released as a software tool with a friendly graphical interface available to general users. Among the presented datasets, the average tracking error was 17.99 cm. Besides, with the prediction results, the pig moving distance per unit time can be estimated for activity studies. Finally, as the motion is monitored, a heat map showing spatial hot spots visited by the pigs can be useful guidance for farming management. The presented pipeline saves massive laborious work in preparing training dataset. The rapid deployment of the tracking system paves the way for pig behavior monitoring. [ABSTRACT FROM AUTHOR]

The goals of this study were to determine the impact of maternal PRRSV infection on offspring muscle and immune development and the potential of dietary soy isoflavones to mitigate those effects. Thirteen first-parity gilts ("gilts") were randomly allotted into one of three treatments: not infected and fed a diet devoid of isoflavones (CON), infected with porcine reproductive and respiratory syndrome virus (PRRSV) and fed the control diet (POS) or that supplemented with 1,500 mg/kg soy-derived isoflavones (ISF). Gilts were inoculated with PRRSV intranasally on gestational day (GD) 70. After farrowing (GD 114 ± 2), 1–2 offspring ("pigs") closest to the average litter weight were selected either at birth (3 ± 2 d of age) or weaning (21 ± 2 d of age) to determine body, muscle, and organ weights as well as muscle cell number and size. Four weaned pigs of average body weight within each litter were selected for postnatal immune challenge. At PND 52, pigs were injected with 5 µg/kg BW lipopolysaccharide (LPS) intraperitoneally. Serum was collected at 0, 4, and 8 h following LPS administration to analyze tumor necrosis factor alpha (TNF-α). At PND 59, pigs were administered a novel vaccine to elicit an adaptive immune response. At PND 59, 66, and 73, peripheral blood mononuclear cells were isolated and T-cell populations determined by flow cytometry. Both POS and ISF pigs exhibited persistent PRRSV infections throughout the study (PND 1-73). At PND 3, whole body, muscle, and organ weights were not different (P > 0.22) between groups, with the exception of relative liver weight, which was increased (P < 0.05) in POS compared with CON pigs. At PND 21, ISF pigs had reduced (P ≤ 0.05) whole body and muscle weights, but greater (P < 0.05) kidney weight compared with CON, and greater (P < 0.05) relative liver weight compared with CON and POS. Muscle fiber number and size were not different (P > 0.39) between groups at birth or weaning. After LPS administration, TNF-α was greatest in ISF pigs (P < 0.05) at both 0 and 8 h post-challenge. At the peak time-point of 4 h post-challenge, ISF pigs had the greatest concentration of TNF-α and CON pigs had the lowest, with POS pigs being intermediate (P = 0.01). After vaccination, ISF offspring had shifts in T-cell populations indicating an impaired immune response. These data indicate that maternal PRRSV infection may impact offspring organ growth and immune function, particularly when the dam is supplemented with isoflavones. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the energy utilization responses of growing pigs and broiler chickens to poultry meal that was autoclaved at 134 °C for 0 to 180 min. Poultry meal from the same batch was autoclaved at 134 °C for 7 autoclaving times of 0, 30, 60, 90, 120, 150, or 180 min to generate 7 samples. Eight experimental diets consisting of a basal diet based on corn and soybean meal, and seven test diets in which 15% of energy-contributing ingredients in the basal diet were replaced with each of the seven poultry meal samples were used. In experiment 1, there were 64 barrows (initial body weight = 19.4 ± 1.0 kg) allotted to 8 experimental diets in a randomized complete block design with body weight as a blocking factor. Each pig received an experimental diet during 5 d of adaptation followed by 5 d of quantitative total, but separate, collection of urine and feces. In experiment 2, a total of 512 male broiler chickens at day 17 post-hatching (initial body weight = 660 ± 80 g) in 8 replicate cages were allotted to 8 experimental diets in a randomized complete block design with body weight as a blocking factor. Excreta were collected from days 20 to 22 post-hatching, and birds were euthanized by CO2 asphyxiation for ileal digesta collection. Data from experiments 1 and 2 were pooled together for statistical analysis as a 2 × 7 factorial treatment arrangement with the effect of species (pigs or broiler chickens) and autoclaving time of poultry meal (7 autoclaving times between 0 and 180 min). An interaction between species and their linear effect of autoclaving time was observed (P < 0.05) in metabolizable energy (ME) of poultry meal. Specifically, linear decrease in ME values in poultry meal with increasing autoclaving time was greater (P < 0.05) in growing pigs (4,792 to 3,897 kcal/kg dry matter) compared with broiler chickens (3,591 to 3,306 kcal/kg dry matter). The ME value of unautoclaved poultry meal was greater (P < 0.01) for pigs than broiler chickens at 4,792 vs. 3,591 kcal/kg dry matter. Although decrease in ME values with autoclaving time of poultry meal was greater in growing pigs than in broiler chickens, the ME in autoclaved poultry meal fed to pigs was greater than ME in non-autoclaved poultry meal fed to broiler chickens. Furthermore, the ratio of cysteine to crude protein concentration is a potential indicator for estimating the ratio of ME to gross energy in poultry meal for growing pigs (r 2 = 0.81) and broiler chickens (r 2 = 0.84). [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the functional roles of an endo-β-1,4-xylanase on the intestinal health and growth performance of nursery pigs. A total of 60 pigs (21 d old, 6.9 ± 0.8 kg body weight [ BW ]) were allotted based on a randomized complete block design with sex and initial BW as blocks. Dietary treatments had nutrients meeting the requirements with increasing levels of endo-β-1,4-xylanase (0, 220, 440, 880, 1,760 xylanase unit [ XU ] per kg feed) and fed to pigs in three phases (phases 1, 2, and 3 for 10, 14, and 14 d, respectively). Titanium dioxide (0.4%) was added to the phase 3 diets as an indigestible marker. On day 38, all pigs were euthanized to collect ileal digesta to measure apparent ileal digestibility (AID), jejunal digesta to measure viscosity, and jejunal mucosa to evaluate intestinal health. Data were analyzed using the MIXED procedure for polynomial contrasts and the NLMIXED procedure for broken line analysis of SAS. Increasing xylanase in the nursery diets reduced (linear, P < 0.05) the digesta viscosity in the jejunum. Increasing xylanase tended to reduce the relative abundance of Cupriavidus (P = 0.073) and Megasphaera (P = 0.063); tended to increase the relative abundance of Succinivibrio (P = 0.076) and Pseudomonas (P = 0.060); and had a quadratic effect (P < 0.05) on the relative abundance of Acinetobacter (maximum: 2.01% at 867 XU per kg feed). Xylanase from 0 to 1,087 XU per kg feed reduced (P < 0.05) jejunal malondialdehyde. Xylanase from 0 to 1,475 XU per kg feed increased (P < 0.05) the AID of neutral detergent fiber. Increasing xylanase increased (P < 0.05) the AID of ether extract and tended to increase (P = 0.058) the AID of crude protein. Increasing xylanase did not affect growth performance on overall period, whereas xylanase from 0 to 736 XU per kg feed increased (P < 0.05) average daily gain (ADG) during days 31 to 38. In conclusion, xylanase supplementation showed benefits on intestinal health by reducing digesta viscosity, the relative abundance of potentially harmful bacteria, and the oxidative stress in the jejunal mucosa, collectively enhancing intestinal morphology and the AID of nutrients. Xylanase supplementation at a range of 750 to 1,500 XU per kg feed provided benefits associated with reduced oxidative stress, increased nutrient digestibility, resulting in potential improvement on growth performance of nursery pigs by increasing the average daily feed intake and moderately improving the ADG throughout the last week of feeding. [ABSTRACT FROM AUTHOR]

Three experiments were conducted to determine the metabolizable energy (ME) and nitrogen-corrected ME (MEn) contents of hydrolyzed feather meal (HFM) and flash-dried poultry protein (FDPP) for broiler chickens and to determine their digestible energy (DE) and ME for pigs. The energy-yielding ingredients in a reference diet (RD) were replaced at 0, 75, or 150 g/kg by HFM in experiment (Exp.) 1; at 0, 75, or 150 g/kg by FDPP in Exp. 2; and at 0, 150 g/kg HFM, or 150 g/kg FDPP in Exp. 3. Birds were fed a standard broiler starter diet from hatch to days 18 and 17 for respective Exp. 1 and 2, following which 144 birds (8 replicate cages of 6 birds per cage) were assigned to the three experimental diets in a randomized complete block design with body weight as the blocking factor. Experimental diets were fed for 5 d, and excreta were collected during the last 3 d. Twenty-four 20-kg barrows, individually housed in metabolic crates equipped with a feeder and drinker, were used in Exp. 3. The barrows were assigned to the three experimental diets in a randomized complete block design with body weight as a blocking factor. Following a 5-d adaptation period, feces and urine were collected for 5 d in a total collection method. Data were used to determine the regression-derived ME and MEn of HFM and FDPP for broiler chickens in Exp. 1 and 2, respectively. The DE and ME of HFM and FDPP for pigs in Exp. 3 were determined using the difference procedure. In Exp. 1, the inclusion of HFM linearly increased (P < 0.05) ME from 3,231 to 3,368 kcal/kg DM for 0 to 150 g/kg replacement of RD. The total tract retention of DM and metabolizability of energy linearly increased (P < 0.05) as replacement of RD with FDPP increased from 0 to 150 g/kg in Exp. 2. Inclusion of FDPP linearly increased (P < 0.01) ME from 3,425 to 3,591 kcal/kg DM. In Exp. 3, the diets containing 150 g/kg HFM or FDPP induced greater (P < 0.05) fecal DM and energy losses than the RD; however, the digestibility of energy across the three experimental diets was not different. The respective regression-derived ME and MEn of hydrolyzed feather meal for broiler chickens in the current study were 4,250 and 3,745 kcal/kg DM with corresponding values of 4,710 and 4,081 kcal/kg DM for flash-dried poultry protein. In pigs, 4,783 and 4,405 kcal/kg DM were the respective DE and ME of hydrolyzed feather meal, and 4,553 and 4,320 kcal/kg DM were the corresponding estimates for flash-dried poultry protein. [ABSTRACT FROM AUTHOR]

Feeding growing-finishing pigs supplemental fat is a common practice in the swine industry and can result in improved feed efficiency and reduced feed intake; however, dietary lipids also play a key role in determining pork composition. The objectives of the current study were to evaluate the effects of feeding graded levels of high oleic soybean oil (HOSO) on growth performance and carcass characteristics. A total of 288 pigs raised in two separate blocks (144 pigs each) were assigned to one of four diets containing either 25% dried distiller's grains with solubles (DDGS), 2% high oleic soybean oil (HOSO2), 4% high oleic soybean oil (HOSO4), or 6% high oleic soybean oil (HOSO6). Pigs were housed 4 per pen and fed for 98 d using a 3-phase feeding system. Pigs were individually weighed and feed intake was recorded throughout the trial to calculate average daily feed intake (ADFI) and gain to feed ratio (G:F). A total of 144 pigs were transported to the University of Illinois Meat Science Laboratory and fabricated into primal and subprimal cuts to calculate carcass cutting yields. Differences in growth performance were observed, with pigs fed the DDGS treatment exhibiting greater (P ≤ 0.01) overall ADFI consuming 0.21, 0.18, and 0.28 kg/d more than HOSO2, HOSO4, and HOSO6 diets, respectively. Pigs fed the HOSO6 diet had greater (P ≤ 0.03) overall G:F than pigs fed DDGS and HOSO2 diets but did not differ (P = 0.12) from pigs fed HOSO4. Furthermore, differences in carcass traits were observed. Hot carcass weight was increased (P ≤ 0.03) in pigs fed the HOSO6 diet compared with pigs fed the DDGS and HOSO2 diets, while pigs fed HOSO4 did not differ (P > 0.05) from either extreme. Additionally, pigs fed HOSO4 and HOSO6 produced fatter (P ≤ 0.01) carcasses with reduced (P ≤ 0.01) standardized fat-free lean. Minimal differences were observed in primal weights expressed as a percentage of chilled side including bone-in Boston butt, trimmed loin, and trimmed ham with primal weights decreasing with increasing inclusion of dietary HOSO. Overall, pigs fed HOSO2 had reduced ADFI with similar backfat thickness and standardized fat-free lean compared with pigs fed the DDGS treatment. However, pigs fed HOSO 4% and 6% not only had improvements in ADFI and G:F but also had increased backfat thickness, which resulted in reductions in standardized fat-free lean and primal weights expressed as a percentage of chilled side weight. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the chemical composition, DE, ME, and NE contents, and the apparent and standardized ileal digestibility (AID and SID) of AA in Cyperus esculentus co-products fed to growing pigs. The five C. esculentus co-products included expeller-pressed C. esculentus cake (EPCC), cold-pressed C. esculentus cake (CPCC), solvent-extracted C. esculentus meal (SECM), C. esculentus distillers's dried grains with solubles (CE DDGS), and C. esculentus meal (CEM). In Exp. 1, a total of 36 crossbred growing pigs (Duroc × Landrace × Yorkshire; BW: 50.12 ± 2.91 kg) were fed one of six diets in a completely randomized design. The diets included a corn-soybean meal basal diet and five experimental diets containing 24.31% C. esculentus co-products. In Exp. 2, 12 same breed of growing pigs (BW: 47.12 ± 3.2 kg), surgically fitted with a T-cannula in the distal ileum, were allotted to one of four experimental diets in a 2-period Youden Square design. The diets included one N-free diet and three experimental diets containing 50% C. esculentus co-products (including EPCC, SECM, and CE DDGS). Results indicated that the SECM and CE DDGS had the greatest contents of starch and CP, respectively. The contents of CF, NDF, and ADF were the greatest in CEM and the lowest in SECM. On a DM basis, the DE, ME, predicted NE, and apparent total tract digestibility (ATTD) of GE values of the 5 C. esculentus co-products ranged from 1,203 to 3,897 kcal/kg, 1,127 to 3,621 kcal/kg, 536 to 2,871 kcal/kg, and 28% to 79%, respectively. The EPCC and CPCC had the greatest DE, ME, and predicted NE values, and CPCC, EPCC, and SECM had the greatest ATTD of GE, whereas CEM had the lowest DE, ME, NE, and ATTD of GE (P < 0.001). The NDF and ADF were negatively correlated with DE, ME, and NE (P < 0.05). The AID and SID of CP varied from 53.57 % to 57.86% and from 69.99% to 87.85%, respectively. The EPCC and SECM had greater SID of CP, Ile, Met, Val, Asp, Cys, and Tyr compared to those of CE DDGS (P < 0.05). These results indicated that the chemical composition, DE, ME, and NE as well as the most AA digestibility of C. esculentus co-products obtained from different processing techniques varied greatly. Based on the energy contents and AA digestibility, the EPCC is a better feedstuff for growing pigs compared with the other 4 C. esculentus co-products. [ABSTRACT FROM AUTHOR]

The objective of this project was to determine the impact of feeding growing pigs with high wheat millrun diets supplemented with a multi-carbohydrase enzyme (amylase, cellulase, glucanase, xylanase, and invertase activities) on nutrient digestibility, growth performance, and greenhouse gas (GHG) output (carbon dioxide, CO2; nitrous oxide, N2O; methane, CH4). Three experiments were conducted utilizing six treatments arranged as a 3 × 2 factorial (0%, 15%, or 30% wheat millrun; with or without enzyme) for the digestibility experiment or as a 2 × 2 factorial (0% or 30% wheat millrun; with or without enzyme) for the performance and GHG experiments. The digestibility, performance, and GHG experiments utilized 48 individually housed pigs, 180 pigs housed 5 per pen, or 96 pigs housed 6 per chamber, respectively. Increasing wheat millrun up to 30% in the diet of growing pigs resulted in decreased energy, nitrogen (N) and phosphorus (P) apparent total tract digestibility and net energy content (P < 0.01). Overall, average daily gain (ADG) and gain to feed ratio were reduced in pigs fed wheat millrun (P < 0.05). Enzyme supplementation had minimal effects on the digestibility or performance parameters measured. Feeding diets with 30% millrun did not affect GHG output (CH4: 4.7 and 4.9; N2O: 0.45 and 0.42; CO2: 1,610 and 1,711 mg/s without or with millrun inclusion, respectively; P > 0.78). Enzyme supplementation had no effect on GHG emissions (CH4: 4.5 and 5.1; N2O: 0.46 and 0.42; CO2: 1,808 and 1,513 mg/s without or with enzymes, respectively; P > 0.51). Overall, the carbohydrase enzyme had minimal effects on parameters measured, regardless of wheat millrun inclusion (P > 0.10). Although energy, N and P digestibility, and ADG were reduced, the inclusion of up to 30% wheat millrun in the diet has no effect on GHG emissions from growing pigs (P > 0.10). [ABSTRACT FROM AUTHOR]

Case studies can be a useful teaching tool but are not commonly utilized in undergraduate courses. Notably, others have demonstrated that case-based reasoning enhances information retention in a veterinary physiology course. Thus, case studies may be an undervalued teaching tool for undergraduate physiology courses. Accordingly, our objective was to evaluate whether swine-based case studies enhanced learning in an undergraduate reproductive physiology class. In addition, interest in pigs and swine industry careers will also be assessed to determine if case-based reasoning can serve as a recruitment tool. At the beginning of the semester, all students (n = 80) completed a pre-test to assess baseline knowledge of swine reproductive physiology and a pre-survey (n = 72; Likert-like scale; 1 = strongly agree and 5 = strongly disagree) evaluating their species interests. Then, students were given the option to complete 4 case studies for extra credit throughout the semester (n = 40- 42). Case studies were industry-based scenarios that encompassed 4 different aspects of swine reproduction (puberty, boar management, breeding and parturition/ lactation); students were asked to individually solve the issues using their notes and supplementary papers. Student demographics: 71.2% were female, 79.2% were juniors and 46.5% originated from a farming/ranching background. About 8% of the population indicated that their family actively raised pigs while 79.1% of students did not have a pig background. Students reported that their primary species of interest was as follows: cattle (42.5%), horses (23.3%), companion animals (17.8%), exotics (11.0%), pigs (2.7%), poultry (1.4%) and wildlife (1.4%). However, 35% of students stated that swine are among the species relevant to them. In contrast, 40.5% of participants indicated that they were not interested in swine. Logically, students did not yet feel knowledgeable about swine reproductive physiology (mean survey response = 3.2), despite having learned about pigs in previous classes (2.0). In addition, students did not feel able to advise producers on reproductive issues (4.1) and were uninterested in pursuing a career in the swine industry (3.7). Pre-test data revealed the following: 53.8% of students answered boar management questions correctly, followed by puberty (44.1%), breeding (43.1%) and parturition/lactation (42.5%). At the end of the semester, all students will take a post-survey and post-test to re-evaluate their swine interest and assess concept mastery, respectively. Ultimately, these data could validate case-based reasoning as a teaching tool in undergraduate physiology courses as well as expose new avenues to recruit young scholars to swine-based careers. [ABSTRACT FROM AUTHOR]

Limits on the use and efficacy of various antibiotics coupled with negative consumer perception of the practice have together spurred substantial research into compounds that could reduce the use antibiotics to control bacterial diseases in pigs. Bacteriophages are often among such potential compounds, and various groups have examined the efficacy of bacteriophages or bacteriophage products in limiting transmission or colonization of targeted bacteria. The study presented here provides a systematic review of such studies followed by a meta-analysis of aggregated data produced by each study. The data set was limited to inputs (n = 19; 576 total observations) from studies where: 1) live pigs were inoculated with a known quantity of challenge bacteria; 2) challenged animals were treated with a known quantity of phages; 3) concentrations of the challenge bacteria were measured in different tissues/fluids following phage treatment; and 4) SD (or SE to allow calculation of SD) was reported. Concentrations of challenge bacteria were significantly lower in phage-treated pigs versus challenged but untreated pigs (P < 0.0001; effect size = −1.06 1log10 colony-forming units [ CFU ]/g). The effect size of phage treatment was significantly greater (P < 0.05) in samples collected 48 to 96 h following phage treatment versus those collected ≤ 24 h following phage treatment. Likewise, effect size of phage treatment was significantly greater in piglets versus market-weight pigs. Across observations, phage treatment effect sizes were greatest (P < 0.01) in fecal samples versus ileal or cecal samples. Taken together, these data indicate that phage treatment can significantly reduce the concentrations of targeted bacteria in pigs; scenarios exist, however, where phage treatment could predictably be more or less effective. [ABSTRACT FROM AUTHOR]

Factors associated with the severity with which different challenge models (CM s) compromise growth performance in pigs were investigated using hierarchical clustering on principal components (HCPC) analysis. One hundred seventy-eight studies reporting growth performance variables (average daily gain [ ADG ], average daily feed intake [ ADFI ], gain:feed [ GF ], and final body weight [ FBW ]) of a Control (Ct) vs. a Challenged (Ch) group of pigs using different CMs (enteric [ ENT ], environmental [ ENV ], lipopolysaccharide [ LPS ], respiratory [ RES ], or sanitary condition [ SAN ] challenges) were included. Studies were grouped by similarity in performance in three clusters (C1 , C2 , and C3) by HCPC. The effects of CM, cluster, and sex (males [ M ], females [ F ], mixed [ Mi ]) were investigated. Linear (LRP) and quadratic (QRP) response plateau models were fitted to assess the interrelationships between the change in ADG (∆ADG) and ADFI (∆ADFI) and the duration of challenge. All variables increased from C1 through C3, except for GF, which decreased (P < 0.05). LPS was more detrimental to ADG than ENV, RES, and SAN models (P < 0.05). Furthermore, LPS also lowered GF more than all the other CMs (P < 0.05). The ∆ADG independent of ∆ADFI was significant in LPS and SAN (P < 0.05), showed a trend toward the significance in ENT and RES (P < 0.10), and was not significant in ENV (P > 0.10), while the ∆ADG dependent on ∆ADFI was significant in ENT, ENV, and LPS only (P < 0.05). The critical value of ∆ADFI influencing the ∆ADG was significant in pigs belonging to C1 (P < 0.05) but not C2 or C3 (P > 0.10). The ∆ADG independent of duration post-Ch (irreparable portion of growth) was significant in C1 and C2 pigs, whereas the ∆ADFI independent of duration post-Ch (irreparable portion of feed intake) was significant in C1 pigs only (P < 0.05). Moreover, the time for recovery of ADG and ADFI after Ch was significant in pigs belonging to C1 and C2 (P < 0.05). Control F showed reduced ADG compared with Ct-M, and Ch-F showed reduced ADFI compared with Ch-M (P < 0.05). Moreover, the irreparable portion of ΔADG was 4.8 higher in F (−187.7; P < 0.05) compared with M (−39.1; P < 0.05). There are significant differences in growth performance response to CM based on cluster and sex. Furthermore, bacterial lipopolysaccharide appears to be an appropriate noninfectious model for immune stimulation and growth impairment in pigs. [ABSTRACT FROM AUTHOR]

An enriched environment is widely used to improve domestic animals' welfare and promote their natural behaviors. Music can reduce abnormal behavior in humans, nonhuman primates, and rodents. However, little is known about the effects of music on pigs. This study aims to explore the effects of repeated music stimulation on the behavior, physiology, and immunity of growing pigs. A total of 72 hybrid piglets (Large White × Duroc × Minpig) were randomly divided into three groups, including music (Mozart K.448, 60 to 70 dB), noise (recorded mechanical noise, 80 to 85 dB), and control (natural background sound, <40 dB), and 6 h sound stimulation was given per day (1000 to 1600 hours) from 40 to 100 d of age. The behavioral activities of the pigs were observed during the music stimulation, and their serum cortisol, salivary cortisol, and serum immune indices were also measured. Compared with the control group, the music group and noise group increased activity but decreased lying of pigs (P < 0.05). A significant increase in tail-wagging, playing, and exploring behaviors of pigs was found in the music group (P < 0.05), and the noise significantly increased the aggressive behavior of the pigs (P < 0.05). Tail-wagging, playing, exploring, manipulating, and aggressive behaviors decreased over time. Short-term (8 d) music stimulus had a lower cortisol level than that of the noise and control groups (P < 0.05), whereas long-term (60 d) music stimulus increased immunoglobulin G (IgG), interleukin-2 (IL-2), and interferon-gamma (IFN-γ) levels (P < 0.05) and decreased interleukin-4 (IL-4) level (P < 0.05). Long-term noise stimulus significantly reduced the level of IgG (P < 0.05) but did not affect the level of IL-2, IL-4, and IFN-γ levels (P > 0.05). In conclusion, short-term music stimulus (8 d) reduced the stress response, whereas long-term music stimulus (60 d) enhanced the immune responses. In addition, the noise increased the aggressive behavior, and long-term noise reduced the immunity of the growing pigs. [ABSTRACT FROM AUTHOR]

Automatic feeding systems in pig production allow for the recording of individual feeding behavior traits, which might be influenced by the social interactions among individuals. This study fitted mixed models to estimate the direct and social effects on visit duration at the feeder of group-housed pigs. The dataset included 74,413 records of each visit duration time (min) event at the automatic feeder from 135 pigs housed in 14 pens. The sequence of visits at the feeder was employed as a proxy for the social interaction between individuals. To estimate animal effects, the direct effect was apportioned to the animal feeding (feeding pig), and the social effect was apportioned to the animal that entered the feeder immediately after the feeding pig left the feeding station (follower). The data were divided into two subsets: "non-immediate replacement" time (NIRT , N = 6,256), where the follower pig occupied the feeder at least 600 s after the feeding pig left the feeder, and "immediate replacement" time (IRT , N   = 58,255), where the elapsed time between replacements was less than or equal to 60 s. The marginal posterior distribution of the parameters was obtained by Bayesian method. Using the IRT subset, the posterior mean of the proportion of variance explained by the direct effect (Prp σ ^ d 2 ⁠) was 18% for all models. The proportion of variance explained by the follower social effect (Prp σ ^ f 2 ⁠) was 2%, and the residual variance (⁠ σ ^ e 2 ⁠) decreased, suggesting an improved model fit by including the follower effect. Fitting the models with the NIRT subset, the estimate of Prp σ ^ d 2 was 20% but the Prp σ ^ f 2 was almost zero and σ ^ e 2 was identical for all models. For the IRT subset, the predicted best linear unbiased predictor (BLUP) of direct (Direct BLUP) and social (Follower BLUP) random effects on visit duration at the feeder of an animal was calculated. Feeder visit duration time was not correlated with traits, such as weight gain or average feed intake (P > 0.05), whereas for the daily feeder occupation time, the estimated correlation was positive with the Direct BLUP (⁠ r ^   = 0.51, P < 0.05) and negative with the Follower BLUP (⁠ r ^ = −0.26, P < 0.05). The results suggest that the visit duration of an animal at the single-space feeder was influenced by both direct and social effects when the replacement time between visits was less than 1 min. Finally, animals that spent a longer time per day at the feeder seemed to do so by shortening the meal length of the preceding individual at the feeder. [ABSTRACT FROM AUTHOR]

Several feed additives have shown benefits throughout the literature in improving growth performance and carcass characteristics when fed to finishing pigs. The mechanisms of action of these feed additives may be by improving health status, energy metabolism, and/or nutrient digestibility. However, the results have been variable and have not been well summarized. In addition, few of the feed additives have a review of all the available literature, and to our knowledge, no review summarizes each feed additive in one centralized effort. Therefore, this review summarizes the available research on feed additives fed in swine diets for the grow-finish phase (Table 1). The feed additive categories chosen for this review were acidifiers, betaine, Cr, conjugated linoleic acid (CLA), Cu, direct-fed microbials (DFM), carbohydrases, proteases, phytases, multi-enzymes, essential oils (EO), L-carnitine, yeasts, and Zn. Research articles were collected from online research databases. Inclusion and exclusion criteria were utilized to select qualified research articles. The percentage difference for each response variable between the treatment and control group was calculated to determine the magnitude of effect. Results indicated that positive outcomes for each feed additive can be found; however, the magnitude of improvement varied, and many experiments did not observe statistically significant improvements in response criteria. For G:F, acidifiers (n = 65 total comparisons, 3.1% improvement across all comparisons), betaine (n = 35, 2.7%), CLA (n = 57, 3.5%), multi-enzymes (n = 29, 3.3%), DFM (n = 66, 3.3%), L-carnitine (n = 24, 2.5%), and yeasts (n = 33, 2.7%) showed relatively large and positive effects (> 2%) across a reasonable number of comparisons (n > 20) with > 14% of them being statistically (P≤ 0.10) positive. For ADG, DFM (n = 71, 3.3%), Cu (n = 155, 2.5%), L-carnitine (n = 24, 2.1%), and multi-enzymes (n = 29, 3.1%) showed relatively large and positive effects (>2%) across a reasonable number of comparisons (n >20) with > 21% of them being statistically (P ≤ 0.10) positive. Moreover, except for betaine, Cr, CLA, and L-carnitine, most feed additives showed little, inconsistent, or non-significant effects on carcass characteristics. The improvements in carcass characteristics were probably due to the improved energy metabolism. Publication bias and the location of studies need to be considered when evaluating the data, as many studies that show no effect might not be published. Furthermore, even though the economics was not discussed in this review, the decision to include feed additives in the pig diets should consider the return on investment based on the price and the magnitude of benefit. In conclusion, this literature review provides descriptive analysis and databases for commonly used feed additives in the hope of better understanding the effect of feed additives on improving the efficiency of swine production. [ABSTRACT FROM AUTHOR]

Previous research indicated that phytase may release less phosphorus (P) from phytate when it is evaluated using diets with P levels above requirement as compared with diets below requirement. The objectives of this experiment were to further test the hypothesis that the P release values determined for phytase are higher when pigs are fed diets that are deficient (DE) in P compared with when they are fed diets that are adequate (AD) in P, and that phytase will increase the digestibility of dry matter (DM), gross energy (GE), nitrogen (N), and calcium (Ca) independent of dietary P status. Twenty-four barrows (body weight: 23.2 ± 1.8 kg) were randomly assigned to one of eight dietary treatments and housed in individual pens for 21 d and then moved to metabolism crates for 9 d, with the collection of urine and feces occurring on the final 5 d. A basal corn–soybean meal diet (P-AD) was formulated at 0.36% standardized total tract digestible (STTD) P and total calcium:STTD P (Ca:STTD P) of 2:1. A P-DE diet was also formulated to maintain a constant Ca:STTD P of 2:1 in both basal diets. Phytase was added to AD and DE diets at 350, 600, 1,000 phytase units (FYT)/kg. Pig was the experimental unit; diet (P-AD or P-DE), phytase level, and replicate were fixed effects. Orthogonal polynomial contrasts were used to test linear and quadratic effects of phytase within P-AD and P-DE diets. Phytase improved apparent total tract digestibility (ATTD) and STTD of P in both P-AD (linear P < 0.001) and P-DE diets (quadratic P < 0.001). Estimates for STTD P release were 0.07%, 0.09%, and 0.09% for 350, 600, and 1,000 phytase units (FYT)/kg in P-DE diets, and 0.02%, 0.03%, and 0.05% in P-AD diets, respectively. In P-DE diets, phytase improved absorption and retention of P and increased urinary excretion of P (quadratic P < 0.001). In P-AD diets, phytase improved absorption of P (linear P = 0.066), tended to improve retention (linear P = 0.066), and increased urinary excretion of P (quadratic P = 0.021). Phytase improved ATTD of Ca in P-DE diets (quadratic P = 0.002) but not in P-AD diets (P > 0.1). In conclusion, the release of P by phytase is lower in diets that are AD in P than those which are DE. Phytase increased the availability of Ca only in the diets DE in P. Finally, phytase increased the ATTD of DM and tended to increase the ATTD of energy, independent of dietary P status. [ABSTRACT FROM AUTHOR]

An experiment was conducted to test the hypothesis that the requirement for Ca expressed as a ratio between standardized total tract digestible (STTD) Ca and STTD P obtained in short-term experiments may be applied to pigs fed diets without or with microbial phytase from 11 to 130 kg. In a 5-phase program, 160 pigs (body weight: 11.2 ± 1.8 kg) were randomly allotted to 32 pens and 4 corn–soybean meal-based diets in a 2 × 2 factorial design with 2 diet formulation principles (total Ca or STTD Ca), and 2 phytase inclusion levels (0 or 500 units/kg of feed) assuming phytase released 0.11% STTD P and 0.16% total Ca. The STTD Ca:STTD P ratios were 1.40:1, 1.35:1, 1.25:1, 1.18:1, and 1.10:1 for phases 1 to 5, and STTD P was at the requirement. Weights of pigs and feed left in feeders were recorded at the end of each phase. At the conclusion of phase 1 (day 24), 1 pig per pen was euthanized and a blood sample and the right femur were collected. At the end of phases 2 to 5, a blood sample was collected from the same pig in each pen. At the conclusion of the experiment (day 126), the right femur of 1 pig per pen was collected and carcass characteristics from this pig were measured. No interactions were observed between diet formulation principle and phytase inclusion for growth performance in any phase and no differences among treatments were observed for overall growth performance. Plasma Ca and P and bone ash at the end of phase 1 were also not influenced by dietary treatments. However, on day 126, pigs fed nonphytase diets formulated based on total Ca had greater bone ash than pigs fed STTD Ca-based diets, but if phytase was used, no differences were observed between the 2 formulation principles (interaction P < 0.05). At the end of phases 2 and 3, pigs fed diets without phytase had greater (P < 0.05) plasma P than pigs fed diets with phytase, but no differences were observed at the end of phases 4 and 5. A negative quadratic effect (P < 0.05) of phase (2 to 5) on the concentration of plasma Ca was observed, whereas plasma P increased (quadratic; P < 0.05) from phases 2 to 5. However, there was no interaction or effect of diet formulation principle or phytase inclusion on any carcass characteristics measured. In conclusion, STTD Ca to STTD P ratios can be used in diet formulation for growing-finishing pigs without affecting growth performance or carcass characteristics and phytase inclusion ameliorates bone resorption caused by low dietary Ca and P. [ABSTRACT FROM AUTHOR]

This study aimed to determine whether pig responses to heat stress (HS) were directly due to heat exposure (regardless of feeding level and pattern) or were indirectly due to the reduction of feed intake (FI) and to determine if increasing feeding frequency (splitting heat increments) can improve pig response to HS. A total of 48 pigs (66.1 ± 1.7 kg) were allocated to four groups in three replicates. After 7 d in thermoneutral (TN) conditions (22 °C; period 1 [ P1 ; day −7 to −1]), pigs were placed in either TN or HS (32 °C) conditions for 20 d (period 2 [ P2 ; day 0 to 19]). The diet was provided either ad libitum (AL ; 2 distributions/d) or pair-fed (PF8 ; 8 distributions/d) using HS–AL pigs as the reference group. Thus, the four experimental groups were TN–AL, HS–AL, TN–PF8, and HS–PF8. The daily ration of PF8 pigs was distributed at every 90-min intervals from 0900 to 1930 hours. Data were analyzed using the PROC MIXED procedure with replicate (n = 3), experimental group (n = 4), and their interactions as fixed effects, and the REPEATED statement was used for repeated measures data. Pigs had a similar average daily feed intake (ADFI) during P1 (P > 0.05). In P2, HS–AL and PF8 pigs had lower ADFI (−19%), average daily gain (−25%), and final body weight (−6.1 kg) than TN–AL pigs (P < 0.01). TN–AL pigs had thicker backfat than TN–PF8 pigs (P < 0.05), while the HS pigs had intermediate results. HS pigs had a higher perirenal fat percentage based on the contrast analysis between PF8 pigs (P < 0.05). Thermoregulatory responses of pigs increased with HS exposure but did not differ between HS or between TN groups (P > 0.05). For TN pigs, variation in muscle temperature (T muscle ) depended on feeding and physical activity, while for HS pigs, Tmuscle gradually increased throughout the day. The Tmuscle of PF8 pigs increased with each additional meal but plateaued earlier for HS–PF8 than TN–PF8 pigs; an increase in Tmuscle per meal was also lower in HS–PF8 than TN–PF8 (P < 0.05). Exposure to HS decreased plasma T3 and T4 (P < 0.05) and increased plasma creatinine (P < 0.05). Between the PF8 groups, HS pigs also had a transient increase in plasma insulin on day 8 (P < 0.05). The effect of HS on FI decreased the growth rate of pigs but there are heat-induced effects, such as altered physiological responses, which might explain the direct HS effects seen in other literature especially in terms of increased adiposity. The increased feed provision frequency in the present study did not improve the HS response of pigs. [ABSTRACT FROM AUTHOR]