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The study aimed to assess the effects of vitamin E (VE) supplementation and fat source on fatty acid (FA) composition, VE concentrations, and antioxidant capacity in plasma and tissues of pigs fed to a heavy slaughter weight (150 kg). A total of 64 pigs (32 barrows, 32 gilts; 28.41 ± 0.83 kg) were blocked by sex and weight, and randomly assigned to one of eight dietary treatments (n = 8 per treatment) in a 4 × 2 factorial arrangement. Fat sources included corn starch (CS), 5% tallow (TW), 5% distiller's corn oil (DCO), and 5% coconut oil (CN); VE supplementation levels were 11 and 200 ppm. Five-phase diets were formulated to meet requirement estimates of NRC (2012) and fed to pigs for each period of 25 kg from 25 to 150 kg. Increasing VE supplementation level increased C16:1 (P 0.05) content but decreased C20:0 (P 0.05) content in backfat and belly fat, while in liver, it increased C17:0 (P 0.05) but decreased C18:0 (P 0.05). Compared to the pigs fed the CS diet, the pigs fed the CN diet had greater (P 0.05) content of total saturated FA, the pigs fed the DCO diet had greater (P 0.05) content of total polyunsaturated FA content and iodine value, and the pigs fed the TW diet had greater (P 0.05) content of total monounsaturated FA in backfat, belly fat, and liver. Plasma VE concentrations increased linearly (P 0.05) with increasing length of feeding but faster (P 0.05) in the pigs fed the CN and TW diets compared with the CS and DCO diets within the 200 ppm VE level; the pigs fed the DCO diet had the highest plasma VE concentrations (P 0.05) from Phase 2 to Phase 5 within the 11 ppm VE level. The VE concentrations in liver and loin muscle (P 0.05) increased with increasing dietary VE level from 11 to 200 ppm, but it was not affected by dietary fat source. There was no effect of VE supplementation and fat source on antioxidant capacity in plasma and liver except that pigs fed the DCO diet had greater liver SOD activity (P 0.05) than the pigs fed the CN diet. In conclusion, dietary VE supplementation did not affect FA profile in backfat, belly fat, and liver consistently, while dietary FA composition with different fat sources affected much of the FA profile in backfat, belly fat, and liver. The higher level of VE supplementation increased liver and muscle VE concentrations and dietary fat sources affected plasma VE concentrations differently (P 0.05), wherein the TW and CN diets increased the VE absorption greater than the DCO diet.The study evaluated vitamin E (VE) supplementation and fat source on fatty acid (FA) composition and VE concentrations in pigs. Three fat sources with distinctive fatty acid profiles were used; VE levels were 11 (the requirement estimate) and 200 (a high level to assure any responses could be seen) ppm. Increasing VE affected very few FA in tissues. Compared with the control pigs, pigs fed the coconut oil diet had greater content of saturated FA, pigs fed the distiller’s corn oil diet had greater content of polyunsaturated FA content, and pigs fed the tallow diet had greater content of monounsaturated FA in tissues. Plasma VE increased with increasing length of feeding but faster in pigs fed the coconut oil and tallow diets compared with the control and distiller’s corn oil diets when the 200 ppm VE level was fed; pigs fed the distiller’s corn oil diet had the highest plasma VE concentrations when the 11 ppm VE level was fed. In conclusion, dietary VE did not affect FA profile in backfat, belly fat, and liver consistently, while different dietary fat sources affected much of the FA profile in tissues. The higher level of VE, as expected, increased liver and muscle VE concentrations.

The study aimed to assess the effect of vitamin E (VE) supplementation and fat source on growth performance, lean growth, organ size, carcass characteristics, and pork quality of pigs at a heavy slaughter weight of 150 kg. A total of 64 pigs (32 barrows and 32 gilts; 28.41 ± 0.83 kg) were blocked by sex and body weight, and randomly assigned to one of eight dietary treatments (n = 8 per treatment) in a 4 × 2 factorial arrangement with main effects of fat source (corn starch [CS; no fat added], 5% tallow [TW], 5% distiller's corn oil [DCO], and 5% coconut oil [CN]) and VE supplementation level (11 and 200 ppm). Five-phase diets were formulated to meet requirement estimates of NRC and fed to pigs with each period of 25 kg from 25 to 150 kg. Increasing dietary VE supplementation from 11 to 200 ppm tended to increase average daily gain (ADG) in phase 5 (P = 0.08), and gain to feed ratio (G/F) in phase 4 (P = 0.06) and phase 5 (P = 0.06) resulting in increased G/F in the overall period (P = 0.10). Compared with the pigs fed the CS diet in the overall period, the pigs fed DCO diets had greater ADG (P0.05), the pigs fed the TW and CN diets had lower average daily feed intake (P0.05), and the pigs fed the fat-added diets had greater G/F (P0.05). Belly firmness was greatest in the pigs fed the CN diet and lowest in those fed the DCO diet (P0.05). Increasing dietary VE level from 11 to 200 ppm increased absolute and relative liver weight, absolute ham yield (P0.05), and tended to increase the relative yield of picnic shoulder (P = 0.07) and ham (P = 0.06) and the pigs fed the corn oil diet tended to have greater belly yield (P = 0.08) than the other fat treatments. Increasing dietary VE level increased 45-min pH and ΔpH at slaughter but decreased a* value, chroma (P0.10), and belly depth (P0.05). However, no effects of VE supplementation and fat source were observed on the other carcass traits and meat quality measurements. In conclusion, increasing dietary VE level from 11 to 200 ppm slightly increased growth rate and feed efficiency in the late finishing periods, and the addition of fat increased feed efficiency and backfat thickness, decreased lean content, and altered belly firmness. While there were some effects of VE supplementation and fat source observed on organ weight, primal cuts, carcass traits, and meat quality, there was no strong evidence that VE supplementation and fat source materially affected these measurements except for belly firmness.The study aimed to assess the effect of vitamin E (VE) supplementation and fat source on growth performance, carcass characteristics, and pork quality of pigs slaughtered at 150 kg. Fat sources included corn starch (no fat added), or 5% tallow, distiller’s corn oil (DCO), or coconut oil (CN); VE supplementation levels were 11 and 200 ppm. Increasing dietary VE from 11 to 200 ppm tended to increase the efficiency of conversion of feed to body weight gain for the overall study period. The pigs fed the DCO diet had greater backfat depth at slaughter. Belly (from which bacon is made) firmness was greatest in the pigs fed the CN diet and lowest in those fed the DCO diet. In conclusion, increasing dietary VE levels from 11 to 200 ppm slightly increased growth rate and feed efficiency, and the addition of fat increased feed efficiency and backfat thickness, decreased lean muscle content, and altered belly firmness. While there were some effects of VE supplementation and fat source, there was no strong evidence that VE supplementation and fat source materially affected these measurements except for belly firmness.

A cooperative study involving 189 litters from 114 sows [initial breeding body weight (BW), 200.8 ± 37.1 kg] was conducted at two experiment stations to investigate the effects of OmniGen AF (OG; Phibro Animal Health Corporation) supplementation in sow diets on reproductive performance and milk composition. Diets were: 1) corn-soybean meal-based control diet that met NRC (2012) requirement estimates or 2) control plus 0.75% OG. A common diet formulation was used by both stations. Sow allotment was balanced for breed, parity, and BW. Sows were allotted to diets at least 21 days prebreeding and were fed the diets continuously at 1.82 kg daily in gestation and ad libitum in lactation. Sow BWs were measured at breeding, prefarrowing, postfarrowing and weaning. Litter size responses were recorded within 24 h postpartum and individual pig weights were measured at birth and weaning. Milk samples were collected twice during lactation on d 5–7 and d 14–17. Supplementation with OG resulted in less (P < 0.05) BW change of sows during lactation (-12.1 vs. -8.2 kg). Total born (12.9 vs. 13.0), live born (11.7 vs. 12.0), and weaned (10.3 vs. 10.5) were similar for control and OG sows, respectively. Sows fed OG-based diets had greater (P < 0.05) litter weight for total born (18.3 vs. 19.3 kg) and weaned (63.2 vs. 67.0 kg), and lactation litter gain (47.8 vs. 50.7 kg). Lactation feed intake for control and OG sows (5.32 vs 5.52 kg, respectively) did not differ. Supplementing sow diets with OG increased (P = 0.057) lactose content (5.78 vs. 5.84%) and reduced (P = 0.047) protein content (4.77 vs. 4.68%) in milk. The results of this study demonstrated that supplemental OG at 0.75% in sow diets reduced weight loss during lactation and improved litter weights with marginal effects on milk composition of sows.

The effect of developmental age (d) on expression of genes responsible for hepatic glycogen (GLY) synthesis and degradation, glucose flux, and GLY content, was determined in crossbred pigs euthanized (n = 6) at birth (d 0, pre-suckle), 1, 3, 7, 14, and 21 d. Liver GLY content and relative abundance of mRNA (RT-PCR) was determined. The relative content of liver mRNA was determined in 2 experiments, d 0, 1, 3, 7 (Experiment 1) and d 0, 1, 7, 14, 21 (Experiment 2). Within each experiment, data were analyzed using the GLM procedure of SAS. Fisher’s protected LSD procedure was used to separate treatment means. Day 0 (76.0) GLY content (mg/g) decreased (P < 0.01) 82% from d 0 to d 1, increased (P < 0.05) from d 1 (13.8) through d 14 (28.4), and did not differ (P = 0.07) between d 1 and 21. In Experiment 1, mRNA content of GLY synthesis proteins GYG1 and GYS1 was greatest (P < 0.01) at d 3 and 7; and 1 and 3; respectively, whereas mRNA content of GLY degrading proteins PGM1, PGM2, and PGM5 was greatest (P ≤ 0.01) at d 1; d 0; and d 1 and 7; respectively. In Experiment 2, mRNA content of GLY synthesis proteins GBE1 and GYS1 was greatest (P < 0.01) at d 0 and 21; and d 1 and 21; respectively, whereas mRNA content of GLY degrading proteins AGL, PGM2, PGM2L, and PGM5 was greatest (P < 0.01) at d 21; d 0; d 7, 14, and 21; and d 14 and 21; respectively. Glucose transporter SGLT1 mRNA content was greatest (P < 0.01) at d 14 and 21. These findings indicate that the pattern of mRNA content of key hepatic GLY degradation and synthesis proteins was consistent with GLY content of suckling pigs.

Two experiments were conducted to investigate effects of feeding graded levels of PBM on performance of weanling pigs and to evaluate feed preference for PBM-based diets relative to spray-dried plasma protein (SDPP)-based diets. A third experiment evaluated PBM in grower diets on performance. In Exp. 1, 120 pigs [body weight (BW) 7.1 ± 0.6 kg] were randomly allotted to 1 of 5 treatments (0, 1, 2, 3, or 5% PBM) and housed 4 pigs/pen for a 28-d growth trial. In Exp. 2, 60 pigs (BW 6.7 ± 1.4 kg) were randomly allotted to 1 of 3 comparisons including: Comparison 1) 0% PBM vs. 2% PBM, Comparison 2) 0% PBM vs. 2% SDPP, and Comparison 3) 2% PBM vs. 2% SDPP and housed 4 pigs/pen for a 28-d preference trial; pigs were provided ad libitum access to feeders; feeder location was switched 3 times/wk. In Exp. 3, 120 pigs (BW 25.9 ± 2.1 kg) were randomly allotted to 1 of 4 treatments (0, 1.25, 2.5 or 5% PBM) and housed 5 pigs/pen for a 41-d growth trial. Increasing PBM from 0 to 5% in Exp. 1 resulted in no differences in ADG (398, 417, 424, 432, and 428 g) or G:F (0.675, 0.686, 0.733, 0.711, and 0.717). Feed preference results (Exp. 2) demonstrated that pigs consumed a higher percentage (76 vs. 24%, P < 0.01) of their total feed intake from the 2% PBM-based diet compared to the 2% SDPP-based diet (Comparison 3). In Exp. 3, increasing PBM for grower pigs resulted in no differences in ADG (1007, 1025, 1002, and 1025 g) or G:F (0.484, 0.472, 0.484, and 0.478). Thus, feeding PBM up to 5% of the diet had no effect on overall performance of nursery or grower pigs, indicating it is an acceptable option as a feed ingredient.

A cooperative study evaluated effects of supplemental dietary OmniGen AF (OG; Phibro Animal Health Corporation) on reproductive characteristics of gilts. Crossbred gilts (n = 56; initial body weight = 152.3 ± 9.7 kg) were assigned to treatments in a 2 x 2 factorial design [diet (OG or control) and PG600 (Merck Animal Health, El Dora, KS) injection (Yes or No)]. Dietary treatments were: 1) corn-SBM basal diet (control) that met NRC (2012) requirement estimates, or 2) control plus 0.75% OG and were fed 35 to 40 d prior to breeding. A common diet formulation was used by both stations. Gilts were estrous-synchronized by 14-d feeding of Matrix (Merck Animal Health). PG600 injections occurred 24 hours after Matrix withdrawal. Gilts were weighed at breeding and preslaughter (at d 39 to 48 postbreeding) and were euthanized to evaluate reproductive characteristics. There were no OG x PG600 interactions on any response measures (P > 0.15). Mean responses did not differ (P > 0.20) when gilts were fed control or OG diets, respectively, for total uterus weight (6,065 vs. 5,883 g), uterine horn length (129.2 vs. 123.9 cm), ovary weight (9.66 vs. 9.94 g), total corpora lutea (CL) number (25.0 vs. 25.3), individual CL weight (0.41 vs. 0.43 g), total follicular fluid weight (3.17 vs. 3.03 g), individual placenta weight (86.3 vs. 86.4 g), total fetuses (14.2 vs. 13.0), and fetus crown-rump length (7.97 vs. 7.66 cm). Supplementation with OG reduced (P = 0.04) individual placenta fluid volume of gilts (150.6 vs. 115.4 mL). PG600 injection increased (P < 0.001) ovary weight (9.03 vs. 10.57 g), total CL (18.09 vs 32.27) and reduced CL weight (0.46 vs. 0.38 g). The results demonstrated classic PG600 responses on reproductive characteristics but no effects of 0.75% OG supplementation nor an interaction between the two factors.

Visceral organs (VO) are essential for their role in the metabolism and distribution of consumed nutrients as well as other life functions in animals. Two experiments were conducted to assess the natural longitudinal changes that the VO undergo from birth through 150 kg body weight (BW). In Experiment 1, a total of 96 crossbred pigs were euthanized at birth (pre-suckle), d 1, 2, 3, 5, 7, 14, 21 (weaning), 22, 23, 24, 26, 28, 42, 49, and 63 of age. In Experiment 2, a total of 48 crossbred pigs were euthanized at 30, 50, 75, 100, 125, and 150 kg of BW. The absolute weight of VO, and the volume and length of the gastrointestinal tract (GIT) were measured. In both experiments, the absolute weight of VO, GIT length, and their volume increased (linear, quadratic, and/or cubic, P < 0.05) as BW and age increased. In Experiment 1, the relative weight of VO (liver, kidney, heart, and lung) decreased after initially increasing within the first week of life (linear, quadratic, and/or cubic, P < 0.05), whereas the relative weight of all VO decreased as BW increased in Experiment 2 (linear and/or quadratic, P < 0.05). The relative length of small intestine decreased and that of large intestine increased as age increased in Experiment 1 (linear and quadratic, P < 0.05), whereas the relative length of the small and large intestine in Experiment 2 were relatively constant at 80% and 20% of the total length of the intestine, respectively. As age and BW increased, the relative volume of the large intestine to the total volume of the GIT increased (linear and/or quadratic, P < 0.05), while the relative volume of the small intestine decreased (linear and/or quadratic, P < 0.05). In conclusion, results showed that both absolute and relative measurements (weight, volume, and length) of VO were dependent on the BW (age) of the pig.

Dietary omega-3 polyunsaturated fatty acids (n-3 PUFA) are precursors for lipid metabolites that reduce inflammation. Two experiments were conducted to test the hypothesis that enriching the sow diet in n-3 PUFA during late gestation and throughout lactation reduces stress and inflammation and promotes growth in weaned pigs. A protected fish oil product (PFO; Gromega) was used to enrich the diet in n-3 PUFA. In the initial experiment, time-bred gilts were fed a gestation and lactation diet supplemented with 0% (control; n = 5), 0.25% (n = 4), 0.5% (n = 4), or 1% (n = 5) PFO from 101 ± 2 d of gestation to day 16 of lactation. Adding 1% PFO to the diet increased the n-3:n-6 PUFA ratio in colostrum and milk compared with controls (P = 0.05). A subsequent experiment was performed to determine whether supplementing the sow diet with 1% PFO improved growth and reduced circulating markers of acute inflammation and stress in the offspring. Plasma was harvested from piglets (16 per treatment group) on day 0 (d of weaning) and days 1 and 3 postweaning. Pigs from the 1% PFO treatment group weighed more (P = 0.03) on day 3 postweaning and had a greater (P ˂ 0.05) n-3:n-6 PUFA ratio in plasma on each day sampled compared with 0% PFO controls. There was an overall treatment effect on plasma total cortisol (P = 0.03) and haptoglobin (P = 0.04), with lesser concentrations in pigs on the 1% PFO diet. Plasma corticosteroid-binding globulin (CBG) concentrations were not different between treatment groups but were less (P ˂ 0.001) on days 1 and 3 when compared with day 0. The resultant free cortisol index [FCI (cortisol/CBG)] was less (P = 0.02) on days 1 and 3 for pigs from the 1% treatment group compared with the controls. An ex vivo lipopolysaccharide (LPS) challenge of whole blood collected on days 0 and 1 was used to determine whether 1% PFO attenuated release of inflammatory cytokines (IL-1β, IL-6, and TNF-α). Blood from pigs within the 1% PFO treatment group tended (P = 0.098) to have a lesser mean concentration of TNF-α in response to LPS compared with blood from controls. These results suggest that providing a PFO supplement as 1% of the diet to sows beginning in late gestation and during lactation can increase the n-3:n-6 PUFA ratio in their offspring, which may improve growth and reduce the acute physiological stress response in the pigs postweaning.

A 36-d experiment evaluated effects of supplemental OptiPhos Plus phytase (Huvepharma, Peachtree City, GA) on growth, bone mineralization, Ca and P digestibility of nursery-grower pigs. Individually housed crossbred pigs (n = 42; initial body weight [BW], 16.1 ± 0.4 kg) were randomly allotted to 7 dietary treatments based on BW and sex. A positive control (PC) diet was formulated to contain 0.601% Ca and 0.296% standardized total tract digestible (STTD) P, which were marginally lower than NRC (2012) requirement estimates for 25–50 kg pigs. A negative control (NC) diet (0.431% Ca and 0.164% STTD P) was developed by the removal of dicalcium phosphate from the PC diet and replacement with limestone and sand. Diets were: 1) PC, 2) NC, and 3–7) NC + 250, 500, 750, 1,000 and 1,500 FTU phytase/kg diet. On d 36, all pigs were euthanized for femur and metacarpal measures. Compared with NC, pigs fed the PC diet provided greater (P < 0.05) response for ADG (966 vs. 730 g/d), ADFI (1,660 vs. 1,329 g/d); bone measures (37.1 vs. 17.4 g ash/femur and 71.9 vs. 29.3 kg for metacarpal strength), and apparent total tract digestibility (ATTD) of Ca (69.5 vs. 63.5%) and P (62.5 vs. 49.3%). As supplemental phytase increased from 0 to 1,500 FTU/kg of diet, linear and quadratic increases (P < 0.002) occurred in overall ADG and ADFI, femur mineral content, metacarpal breaking strength, and ATTD of Ca and P. Responses statistically similar to PC were achieved at 250 or 500 FTU/kg and peak responses occurred at 750 to 1,500 FTU/kg that were numerically greater than PC for all but metacarpal strength. In conclusion, supplemental OptiPhos Plus improved growth, bone mineralization, Ca and P digestibility of pigs fed Ca and P-deficient diets, demonstrating enhanced Ca and P utilization of corn-soybean meal-based diets by nursery-grower pigs.

The objective of the experiment was to critically monitor the blood profile and growth performance of piglets during the lactation period after receiving various amounts of injectable iron at birth. A total of 70, newborn pigs (initial BW 1.51 ± 0.26 kg) from 7 litters were assigned to 1 of 5 iron dosage treatments on d 0. Injectable iron dosage treatments were 0, 50, 100, 200, and 300 mg iron from iron dextran. BW and blood samples were collected on d 0, 1, 2, 3, 4, 6, 8, 11, 14, 17, and 22 (weaning) and blood was analyzed for a complete blood count (CBC). Blood was only sampled from 50 of the 70 pigs as the pigs not sampled were used for tissue collection at weaning and postweaning. Data were analyzed as repeated measures using the individual pig as the experimental unit. As early as d 1 after the injection, hemoglobin concentration (Hb) improved (linear: P < 0.05). The Hb response was both linear (P < 0.001) and quadratic (P ≤ 0.01) from d 3 through weaning at d 22. For the 50 and 100 mg iron treatments, Hb peaked at d 6, whereas Hb for the 200 and 300 mg iron treatments peaked on d 17. Other CBC measures followed a similar pattern of improvement from d 2-3 through weaning as the iron dosage increased. Average daily gain was greater (linear: P = 0.04 and quadratic: P = 0.05) from d 0 to 22 which, in turn, led to a linear improvement (P ≤ 0.05) in weaning BW. Increasing iron injection dosage at birth leads to an improved blood profile and greater ADG during the nursing period (d 0-22). The dosage provided also affects the timing and magnitude of the peak Hb response.

Effects of folic acid and protein levels on growth and serum chemistry in pigs fed aflatoxin were determined in two experiments. Increasing aflatoxin (250 to 800 ppb) decreased (P &lt, 0.05) weight gain and feed intake for both of the 35-day trials. In Experiment 1, increasing aflatoxin (0, 250, 500 ppb), increased linearly (P &lt, 0.05) aspartate aminotransferase (AST), alkaline phosphatase (ALKP) and ɣ-glutamyl transferase (GGT). Folic acid (0, 2.0, 5.0, 12.5 ppm) increased linearly (P &lt, 0.05) serum K, Ca, P, Mg, and AST with the largest effect observed at 12.5 ppm. Folic acid decreased (P &lt, 0.05) blood urea nitrogen (BUN): creatinine and Na:K. In Experiment 2, aflatoxin (800 ppb) increased (P &lt, 0.05) glucose and GGT, and decreased (P &lt, 0.05) Na:K and albumin:globulin. Increasing protein from 15 to 18% elevated BUN: creatinine (P &lt, 0.05), albumin: globulin (P &lt, 0.05), albumin (P &lt, 0.05) and ALKP (P &lt, 0.05). Folic acid (2 ppm) elevated (P &lt, 0.05) BUN, and interacted with both aflatoxin (P &lt, 0.10) and protein (P &lt, 0.05) on BUN. Adding folic acid to aflatoxin contaminated diets improved some measures of clinical chemistry in Experiment 1 but not traditional growth performance measures. The higher protein level reduced the effects of aflatoxicosis on growth.

Experiments were conducted to determine the relative bioavailability (RBV) of the calcium salt of the hydroxy analog of dl-methionine (MHA-Ca, 84%) to dl-methionine (dl-Met, 99%) as Met sources fed to pigs. In experiment 1, 42 crossbred barrows (initial BW of 15.0 ± 0.7 kg) were allotted to 7 treatments in an N-balance study. The basal diet (BD) was formulated to contain 15.4% CP and 0.22% Met (70% of requirement). Diets included (1) BD, (2) BD + 0.025% dl-Met, (3) BD + 0.050% dl-Met, (4) BD + 0.075% dl-Met, (5) BD + 0.038% MHA-Ca, (6) BD + 0.077% MHA-Ca, and (7) BD + 0.115% MHA-Ca. An increase in dietary inclusion rates of both Met sources linearly increased (P < 0.01) N retained (g/d) and N retention (% of intake). Using linear slope-ratio regression, the RBV value of MHA-Ca to dl-Met for N retained (g/d) was 63.0% on a product-to-product basis (75.0% on an equimolar basis). In experiment 2, 40 crossbred barrows (initial BW of 15.5 ± 1.5 kg) were allotted to 5 treatments in another N-balance study. The BD was formulated to contain 17.0% CP and 0.22% Met (70% of requirement). Diets included (1) BD, (2) BD + 0.030% dl-Met, (3) BD + 0.060% dl-Met, (4) BD + 0.046% MHA-Ca, and (5) BD + 0.092% MHA-Ca. Increasing levels of dl-Met or MHA-Ca increased N retained (g/d) and N retention (% of intake) linearly (P < 0.001) and quadratically (P < 0.05). Using linear slope-ratio regression, a product-to-product RBV value of MHA-Ca to dl-Met was 68.4% (81.4% on an equimolar basis) for N retained (g/d). In experiment 3, 276 pigs (12 barrow and 11 gilt replicates; initial BW of 7.09 ± 1.1 kg) were used in 3 diet preference studies. Pigs were randomly allotted to 1 of 3 treatment comparisons of feed choice: (1) BD (0.23% Met) or BD + 0.07% dl-Met; (2) BD or BD + 0.0825% MHA-Ca, and (3) BD + 0.07% dl-Met or BD + 0.0825% MHA-Ca. Pigs consumed a higher percentage (55 vs. 45%; P = 0.008) of their total feed intake from the diet supplemented with 0.07% dl-Met in Comparison 1, but a lower percentage (45 vs. 55%; P = 0.003) of their total feed intake from the diet supplemented with 0.0825% MHA-Ca in Comparison 2. There was no diet preference for dl-Met or MHA-Ca in Comparison 3. The observed Met source preference differences occurred in the barrow replicates but not in the gilt replicates. These results demonstrated the mean RBV of MHA-Ca to dl-Met of 65.7% on a product-to-product (wt/wt) basis or 78.2% on an equimolar basis and that a preference for Met sources was observed in barrows but not in gilts.

Advancements in genetics have led to an increase in growth rates of nursing piglets. Previous studies have suggested that the common 100–200 mg Fe injection shortly after birth is not sufficient to prevent anemia for all pigs throughout the suckling and nursery phases, more so for heavy (fast-growing) piglets. Therefore, the objective of this study was to evaluate the growth performance and hematological effects of supplementing an additional iron injection 4 days before weaning. A total of 136 crossbred pigs from 20 litters with an initial BW of 5.48 ± 1.08 kg were assigned to either the control or an added-injection treatment. All pigs had received a 150 mg Fe intramuscular (IM) injection 1 d after birth. The added-injection group received an additional 150 mg Fe IM injection 4 days before weaning. Pigs were weaned at 18–24 days. All pigs received a common nursery diet, formulated to meet or exceed the NRC (2012) requirement estimates. Body weight and feed disappearance were recorded weekly. Blood and tissue samples were collected at pre-wean (-4), weaning (0), 14, and 28 days in the nursery. All data were subjected to ANOVA by the GLM procedure of SAS. Hemoglobin concentration was greater at weaning (12.1 vs. 10.3 g/dL, P < 0.0001) and 14 d (11.9 vs. 11.5 g/dL, P = 0.016) for the added-injection treatment. Added-injection pigs had a greater overall ADG (526 vs. 498 g, P = 0.033) for the experiment. Added-injection pigs also had a greater liver Fe concentration at weaning (36.6 vs. 11.7 mg/kg of liver, P = 0.009). In conclusion, an additional 150 mg Fe injection administered 4 d before weaning increased blood and liver iron status at weaning as well as improved ADG in the nursery.

Objective An experiment was conducted to evaluate dietary supplemental trace mineral source and deletion on mineral content in tissues. Methods Weanling crossbred pigs (n = 144; 72 barrows and 72 gilts; body weight [BW] = 7.4±1.05 kg) were used. A basal diet was prepared, and trace mineral premix containing either inorganic (ITM) or organic (OTM) trace minerals (Cu, Fe, Mn, and Zn) was added to the basal diet. Pigs were blocked by sex and BW and randomly allotted to 24 pens for a total of 6 pigs per pen, and fed a diet containing either ITM or OTM supplemented at the 1998 NRC requirement estimates for each of 5 BW phases (Phase I to V) from 7 to 120 kg. The trace mineral supplementation was deleted for 6, 4, 2, and 0 wk of Phase V; regarding nutrient adequacy during this phase, the indigenous dietary Fe and Mn was sufficient, Cu was marginal and Zn was deficient. Results At the end of Phase IV, Mn content (mg/kg on the dry matter basis) was greater (p

Two 21-d experiments were conducted to determine the optimum standardized ileal digestible (SID) Trp:Lys ratio for growing pigs; 1 experiment fed diets supplemented with or without an antibiotic. The primary response variables in both experiments were ADG, ADFI, G:F, and plasma urea N (PUN) concentrations with the optimum SID Trp:Lys ratio detected using broken-line analysis. Experiment 1 evaluated the optimum SID Trp:Lys ratio in growing pigs fed diets supplemented with an antibiotic. This experiment used 120 crossbred pigs that were blocked by sex and initial BW (24.13 ± 2.72 kg) and allotted to 6 SID Trp:Lys ratios in 4 replicates. Dietary treatments were formulated by the addition of crystalline Trp to create 6 SID Trp:Lys ratios (13.08%, 14.06%, 15.04%, 17.00%, 18.95%, and 20.91%) with a constant SID Lys level of 0.655%. As SID Trp:Lys ratios increased, ADG, ADFI, and G:F increased, and PUN concentrations decreased linearly ( 0.49) and no interactions between antibiotics and Trp:Lys ratios ( > 0.29). When the data for all pigs were pooled for the various Trp:Lys ratios, the optimum SID Trp:Lys ratios for ADG and PUN based on linear broken-line analysis were 14.58% ( < 0.001) and 14.54% ( < 0.001), respectively, resulting in an optimum SID Trp:Lys ratio of 14.56% as the mean of the determined optima for ADG and PUN responses. These results demonstrate that the optimum SID Trp:Lys ratio for 30- to 50-kg growing pigs is not impacted by the dietary inclusion of an antibiotic as long as the diets are formulated on an SID AA basis.

Digestive Physiology of Pigs (DPP) was organized in 1979 to promote exchange of information among scientists working in swine digestive physiology and nutrition. The objective of this presentation is to provide an overview of the past, present, and future of the most important global scientific event in the fields of pig gut physiology and nutrition. To date, fourteen symposia have been conducted including the 12th International Symposium, which was held in Keystone, Colorado (DPP-2012). In order to facilitate the activities of DPP-2012, DPP-North America was established as a non-profit entity with a mission to collaborate internationally to “establish triennial venues that present the most current research and discovery information relative to digestive physiology of pigs.” Regarding DPP-2012, 403 attendees from 28 countries were in attendance, and 250 abstracts were accepted for presentation. The attendees represented academia, industry, and major swine production entities. Today, in addition to digestive physiology and nutrition, the global DPP community has evolved to include topics such as immunology, microbiology, and the use of pigs as a model for human health. As part of the global DPP community, DPP-North America continues to work with the global DPP community to establish global networks, to learn about the latest scientific discoveries, to promote academia-industry partnerships, to involve and train the next generation of scientists, and to contribute to sustainable pork systems. Since its establishment, DPP-North America has sponsored digestive physiology lectures at the annual ASAS Midwest meetings and has provided travel scholarships for North American graduate students to attend and present research at international DPP meetings.

A cooperative study utilizing 514 weanling pigs from 7 experiment stations was conducted to determine the effects of an additional iron injection administered to piglets before weaning on growth performance and hematological measures. All pigs received an initial iron injection at the time of processing postfarrowing. At each station, pigs were assigned to either the control or an added-injection treatment by pairing two same-sex pigs with a BW difference ≤ 0.453 kg within a litter. One pig within each pair received the additional iron injection (same dose received at processing) 3 to 5 days preweaning. Once weaned, both the control and added-injection group received common station-specific nursery diets. Body weight was recorded weekly by all stations. Blood samples were also collected at second injection, weaning, 14 and 28 days postweaning by 3 of the 7 stations. All data were subjected to ANOVA with the model containing the terms treatment, station, and treatment by station interaction. Average daily gain (Table 1) was greater for the added-injection group during d 0 to 14 (212.5 vs. 202.6 g, P = 0.03) which resulted in an increase in d 14 BW (P = 0.05). Although there was no treatment effect for overall ADG (d -4 to d 28), the tendency for a treatment by station interaction (P = 0.09) illustrated both responsive and nonresponsive stations, indicating that iron status was not the most limiting factor for growth at all stations. Hemoglobin concentration was greater (P < 0.0001) for the added-injection group at weaning and d 14 postweaning. In conclusion, an additional iron injection administered before weaning may lead to early success in the nursery resulting in a heavier BW in subsequent periods; however, the beneficial effects of an additional iron injection are likely dependent on herd status and characteristics.

A 49-d experiment evaluated the effects of supplemental boron (B) on growth, and serum insulin and glucose concentration of pigs. Crossbred pigs [n = 48; initial body weight (BW) 19.18 ± 0.29 kg] were randomly allotted to 1 of 4 diets based on BW and sex. Diets were corn-SBM-based, formulated to meet NRC (2012) nutrient requirement estimates, and were supplemented with 0, 25, 50, or 100 mg B/kg diet as sodium tetraborate decahydrate. On d 20 and 41, blood samples were collected. Fasting samples were collected following an overnight fast; then a postprandial sample was taken approximately 50 minutes after the pigs had 10 minutes of ad libitum access to feed. Samples were processed and serum analyzed for insulin and glucose concentration. Increasing B levels resulted in a linear decrease for overall ADG (0.87, 0.86, 0.85, and 0.82 kg, P = 0.02). On d 20, supplemental B resulted in a quadratic response on fasting serum glucose concentration (5.25, 4.80, 4.65, and 5.01, P = 0.03) and a linear decrease in postprandial serum insulin concentration (29.1, 25.5, 18.2, and 18.1 µU/mL, P = 0.02). Furthermore, there was a tendency for a linear decrease in fasting insulin:glucose ratio (0.85, 0.84, 0.42, and 0.59, P = 0.08), which became more noticeable during the postprandial state (3.96, 3.63, 2.63, and 2.73, P = 0.02). Again on d 41, there was a quadratic response on fasting serum glucose concentration (4.32, 4.07, 3.91, and 4.68, P = 0.01) with supplemental B. Results suggest that supplemental boron may impact serum insulin and glucose concentrations by reducing the amount of insulin needed to maintain glucose concentrations. However, higher levels of supplemental boron did result in suppressed growth performance. Thus, additional research is warranted to determine the optimum level of supplemental B.

An accurate understanding of the AA composition of the products of conception is needed to accurately model dietary AA needs of pregnant swine. To determine AA composition in fetal pigs, the placenta, and the uterus at various stages of gestation, samples from a total of 65 gilts slaughtered at assigned days of gestation (d 43, 58, 73, 91, 101, and 108) were used. The AA concentrations (g/kg each wet tissue) in the fetus, placenta, or uterus increased as gestation progressed, with major increases occurring from d 73 to 108 of gestation ( < 0.05). For fetus, AA content on a DM basis (%) and AA contribution to total fetal AA (g/100 g total AA of fetal tissue) generally decreased as gestation progressed ( < 0.05) except for Arg and Ala, which increased from d 73 of gestation, and for Gly and Pro, which increased progressively ( < 0.05) from d 43. Placental AA content on a DM basis increased up to d 91 or 101 of gestation ( < 0.05) and then slightly decreased on d 108 of gestation except for His, Cys, and Met + Cys. Amino acid contribution to total placental AA decreased for all AA as gestation progressed ( < 0.05), except for Arg, Ala, Gly, and Pro, which increased from d 58 of gestation. Essential AA content in the uterus on a DM basis had no major changes during gestation, whereas nonessential AA content decreased ( < 0.05) as gestation progressed, except for Asp. For AA contribution to total uterine AA, some essential AA (Ile, Leu, Lys, Met, Trp, and Val; < 0.06) and Asp ( < 0.01) contributions increased with increasing gestational ages, whereas Arg ( = 0.08), Cys, Gly, and Pro ( < 0.05) contributions decreased as gestation progressed. Differences in AA contribution to total AA within each tissue varied among the fetus, placenta, and uterus by type of AA. These results demonstrate that AA compositions of fetal pigs, placenta, and uterus are changed differentially as gestation progresses; in particular, Arg, Ala, Gly, and Pro compositions in fetus and placenta increased progressively. These compositional data for each reproductive tissue and fetus will help to model AA requirements in gestation.

Three experiments involving a total of 405 crossbred pigs were performed to evaluate the effects of increasing vitamin supplementation on growth performance and carcass characteristics. A common vitamin premix (VP) that provided adequate amounts of vitamins (4 fat-soluble and 7 B vitamins), was added at varied levels in Exp. 1 and 2. Experiment 1 used 125 weanling pigs with initial body weight (BW) of 7.5 ± 0.2 kg. Dietary treatments were basal diet with 0.00%, 0.05%, 0.10%, 0.25%, and 0.50% added VP. The experimental diets were fed for 28 d in a single phase. The results demonstrated that average daily gain (ADG) and average daily feed intake (ADFI) linearly increased (P

Phytate has been shown to be an antinutrient, and the feeding of high levels of phytase can break down phytate to improve nutrient utilization and pig performance. Dietary xylanase targets arabinoxylan breakdown, thereby improving energy utilization in pigs. However, the effects of simultaneous supplementation have not been clearly determined. Crossbred pigs ( = 45; mean initial weight, 26.4 ± 0.2 kg) were allotted to 1 of 9 treatments to evaluate the effects of both xylanase (endo-1,4-β xylanase [EC 3.2.1.8]) and phytase (6-phytase [EC 3.1.3.26]) supplementation as follows: 1) positive control (PC), a corn-soybean meal-based diet with 15% corn distillers dried grains with solubles, 15% wheat middlings, and 13% corn germ meal; 2) negative control (NC), ME was reduced by 103 kcal/kg from the PC diet by replacement of fat with corn starch; 3) NC + phytase (500 phytase units (FTU)/kg diet); 4) NC + phytase (1,000 FTU/kg diet); 5) NC + phytase (2,000 FTU/kg diet); 6) NC + xylanase (24,000 xylanase units [BXU]/kg diet); 7) NC + phytase (500 FTU/kg diet) + xylanase (24,000 BXU/kg diet); 8) NC + phytase (1,000 FTU/kg diet) + xylanase (24,000 BXU/kg diet); and 9) NC + phytase (2,000 FTU/kg diet) + xylanase (24,000 BXU/kg diet). All diets were formulated to meet nutrient requirements before phytase and xylanase addition to the diets. There were no significant interactions between xylanase and phytase supplementation on growth performance, carcass characteristics, and apparent total tract digestibility (ATTD). The ADG ( < 0.01, quadratic) and G:F ( < 0.05, linear) for the overall period increased as phytase level increased. The ATTD of P increased as phytase supplementation level increased ( < 0.05, linear and quadratic). The ATTD of DM, NDF, ether extract ( < 0.05), and hemicellulose ( = 0.05) increased quadratically as phytase level increased. Estimated carcass lean percentage and lean gain increased ( < 0.05, linear) as phytase level increased. Xylanase supplementation had no effect on growth performance, ATTD, and carcass characteristics. The results demonstrated an improved nutrient digestibility, performance, and carcass response to phytase supplementation beyond P provision because all diets exceeded current P requirement estimates based on standardized total tract digestible P.

Background Indigestible markers are commonly utilized in digestion studies, but the complete disappearance or maximum appearance of a marker in feces can be affected by diet composition, feed intake, or an animal’s BW. The objectives of this study were to determine the impact of previous (Phase 1, P1) and current- (Phase 2, P2) diet composition on marker disappearance (Cr) and appearance (Ti) in pigs fed 3 diets differing in NDF content. Results When pigs were maintained on the 25.1, 72.5, and 125.0 g/kg NDF diets, it took 5.1, 4.1, and 2.5 d, respectively, for Cr levels to decrease below the limit of quantitation; or 4.6, 3.7, or 2.8 d, respectively, for Ti to be maximized. These effects were not, however, independent of the previous diet as indicated by the interaction between P1 and P2 diets on fecal marker concentrations (P

Three experiments were conducted to evaluate the effect of coated sodium butyrate (CSB) supplementation to peripartal and lactating sows and nursery pigs on lactation performance and nursery growth performance. In Exp. 1, a total of 43 gestating sows (d 81–92 of gestation) were allotted to 0 (n=15), 500 (n=16), or 1000 (n=12) ppm of CSB supplementation based on breed, parity and body weight (BW), and then fed treatment diets until weaning. In Exp. 2 and 3, a total of 144 weanling pigs (72 pigs for Exp. 2 and 3, respectively) from 0 or 1000 ppm CSB sow treatments in Exp. 1 were allotted within the sow treatment to 0, 500, or 1000 ppm of CSB supplementation in nursery diets based on breed and BW in a split plot design for a 35-d growth study. All pigs in Exp. 2 were injected with ovalbumin at weaning and d 14 postweaning as an immune challenge. In Exp. 1, there were no differences in sow BW, litter size, litter weight, lactation feed intake or milk composition among treatments. However, colostral IgG (P=0.06) and IgA (P=0.09) concentrations tended to increase quadratically as CSB supplementation levels increased. In Exp. 2, pigs from the 1000 ppm CSB sow treatment had greater BW at d 35 (P

The objective was to determine effects of nursery group-size-floor space allowance on growth, physiology, and hematology of replacement gilts. A 3 × 3 factorial arrangement of treatments was used wherein gilts classified as large, medium, or small ( = 2537; BW = 5.6 ± 0.6 kg) from 13 groups of weaned pigs were placed in pens of 14, 11, or 8 pigs resulting in floor space allowances of 0.15, 0.19, or 0.27 m/pig, respectively. Pigs were weighed on d 0 (weaning) and d 46 (exit from nursery). The ADG was affected by group-size-floor space allowance × pig size ( = 0.04). Large- and medium-size gilts allowed the most floor space had greater ( 0.05) of group size-floor space allowance. Mortality in the nursery was not affected ( > 0.05) by treatment, size, or treatment × size and overall was approximately 2.1%. Complete blood counts and blood chemistry analyses were performed on samples collected at d 6 and 43 from a subsample of gilts ( = 18/group-size-floor space allowance) within a single group. The concentration ( < 0.01) and percentage ( = 0.03) of reticulocytes was the least and red blood cell distribution width the greatest ( < 0.01) in gilts allowed 0.15 m floor space (effects of treatment). Blood calcium was affected by treatment ( = 0.02) and concentrations for gilts allowed the greatest and intermediate amounts of floor space were greater ( < 0.05) than for gilts allowed the least floor space. Serum concentrations of cortisol were not affected by treatment × day ( = 0.27). Cortisol concentrations increased from d 6 to d 43 in all groups and were affected by day ( < 0.01) but not treatment ( = 0.53). Greater space allowance achieved by placing fewer pigs per pen in the nursery affected blood parameters and resulted in large- and medium-size replacement gilts displaying increased ADG. Further study will determine if these effects influence lifetime reproductive capacity and sow longevity.

Piglet weaning weight is a critical factor that influences post-weaning growth and performance. Weaning weight is a function of birth weight and the amount and nutrient density of the milk consumed during lactation. Milk production is influenced by sow mammary gland development and diet consumption but may also be a biological function of teat location along the udder line. The objective of this study was then to determine the effects of piglet nursing location along the udder on overall piglet gain and weaning weight. A total of 1,078 individual piglets were observed during the nursing period at three time points during lactation. The teat pairs along the udder line were labeled from anterior to posterior (1-7, respectively) to define nursing location. At the end of the lactation period, the observed piglet nursing location was evaluated for both actual weaning weight and overall piglet weight gain during lactation. Data were evaluated by analysis of variance with the statistical model utilizing litter size as a covariate. As expected, when litter size was utilized as a covariate, there was a significant effect on piglet weaning weight (P < 0.0001), and there was both a linear and quadratic effect of location (L, P < 0.0001; Q, P = 0.0009) on both weaning weight and lactation piglet gain. Heavier piglets were weaned from more anterior teats (teat pairs 1-4), with the numerically heaviest piglets weaned from teat pair 4 (6.12 kg), with the lowest weight piglets being weaned from teat pair 7 (5.17 kg). Piglet weight gain during lactation was impacted by litter size (P < 0.0001), but nursing location did not affect lactation weight gain (P = 0.57). Due to the differences in piglet weights at weaning, it can be concluded that piglet nursing location influences overall piglet weaning weight.

The objective of this experiment was to evaluate the blood profile, growth performance, and tissue mineral concentration during the nursery period in weanling pigs that received various dosages of iron at birth. A total of 70 crossbred pigs (weaning BW 6.36 ± 0.92) from 5 different injectable iron dosage treatments administered at birth (0, 50, 100, 200, and 300 mg iron from iron dextran) were used. Pigs were weighed at d 22 (weaning), 23, 24, 25, 29, 38, 44, and 52. Blood was collected from 10 pigs per treatment at the same times as above except for d 44 and analyzed for a complete blood count (CBC). A total of 3 pigs per treatment were euthanized on d 22, 38, and 52 to determine tissue mineral concentration. All pigs were fed a common nursery diet supplemented with 100 mg/kg Fe from ferrous sulfate. All data were subjected to ANOVA with the pig as the experimental unit. As injectable iron dosage at birth increased, hemoglobin concentration (Hb) increased at weaning (linear and quadratic: P < 0.05), to d 29 and then quadratically through (P < 0.05) d 38. Along with the other CBC measurements, Hb was similar between treatments at d 52. There was a quadratic response (P < 0.05) for ADG from d 22 to 52. Although by d 52, final BW peaked (quadratic: P < 0.05) for pigs receiving 100 mg iron. Iron concentration of the liver and spleen were greater (linear: P < 0.05) at weaning as iron injection dosage increased but was greater only in the liver at d 38 (P < 0.05) and the spleen at d 52 (P < 0.05). Results indicate that an iron injection administered shortly after birth is vital for proper growth and hematological functions during the nursery period.

Research with many nutrients for growing swine has historically focused on the effects of supplementation levels on feed intake, growth, and feed conversion ratio. Following the establishment of nutrient requirement estimates for the maximization of, principally, growth rate, there certainly have been studies that have evaluated altered nutrient supplementation effects on a variety of metabolic responses related to health. However, often the value of increased nutrients for health improvement in a typical production setting is not fully realized because of the difference in the conditions that exist between a typical production setting and a university research setting coupled with a use of only a subset of animals in a university setting and the fact that the subset of animals that are used may not include the most health-susceptible portion of the population. Thus, research in many university settings will not capture the true effect of health challenges or of added supplementation on mortality and morbidity. Further, when decisions about nutrient supplementation levels are made on the farm, the decisions must consider the cost of the nutrient relative to the potential improvement in performance; this exercise determines the return on investment (ROI). Consequently, in situations where the effects of a nutrient on health are inadequately quantified or infrequently observed, the ROI for increased nutrient supplementation is underestimated. Examples from vitamin supplementation demonstrate the difference between the ROI when it is calculated only from growth performance compared to a calculation that includes both growth performance and mortality. The examples argue for a more robust ROI calculator that includes mortality. Additionally, the lack of knowledge of nutrient supplementation effects on the entire pig population, with specific knowledge of the most health-susceptible segment, argues for scaling up of promising results observed in a university setting to a commercial setting.

We previously reported that reduced floor space allowance caused by increasing the number of gilts per pen decreased growth and affected blood chemistry and immunology. The current objective was to determine effects of nursery group-size-floor space allowance on future litter sizes and retention in the breeding herd through three parities in sows. A 3 × 3 factorial arrangement of treatments was employed with 2,537 gilts classified as large (6.92 ± 0.06 kg), medium (5.60 ± 0.06 kg), or small (4.42 ± 0.06 kg), and placed in nursery pens of 14, 11, or 8 pigs to allow 0.15, 0.19, or 0.27 m2 floor space/pig, respectively. After the nursery and grow-finish periods, 1,453 gilts selected for breeding were relocated to one of 11 sow farms. Total litter size and pigs born alive increased (P < 0.01) with increasing parity and total litter size was 12.94, 13.28, and 13.99 (SE = 0.13) and pigs born alive was 12.21, 12.64, and 13.23 (SE = 0.11) for Parities 1, 2, and 3, respectively. There was a tendency (P = 0.08) for a quadratic relationship of group-size-floor space allowance and total litter size (13.39, 13.54, and 13.27 [SE = 0.13] for gilts allowed 0.15, 0.19, or 0.27 m2 floor space/pig, respectively). A linear effect of size of pig at weaning (P = 0.03) on pigs born dead was detected and was 0.64, 0.75, and 0.75, for small, medium, and large size pigs, respectively. There was no effect of group-size-floor space allowance on the percentages of gilts completing zero (P = 0.36), one (P = 0.35), two (P = 0.32), or three (P = 0.50) parities. In contrast, the percentage of small gilts that failed to complete one parity was greater (P < 0.05) and the percentage completing one parity (P < 0.05) was less than for either large or medium gilts. Abortion rate was greater (P < 0.01) in gilts classified as small (2.51%) or medium (1.36%) at weaning compared with those classified as large (0.20%). Size at weaning did not affect the proportion of gilts completing two (P = 0.88) or three (P = 0.72) parities. Group-size-floor space allowance during the nursery phase of production did not have remarkable effects on future litter sizes or retention in sows. Likewise, size of pig at weaning did not affect litter size and pigs born alive. Compared with larger pigs, however, more pigs classified as small at weaning and entering the breeding herd did not complete a parity and displayed a greater abortion rate.

The study objective was to assess the contribution of fat source and vitamin E (VE) supplementation on growth performance, antioxidant status, and fatty acid profile in the liver of pigs at heavy slaughter weight (148.09 ±1.64 kg). A total of 72 individually-fed pigs (36 barrows, 36 gilts; 28.55 ±1.16 kg) were randomly assigned to 12 dietary treatments in a 2 × 6 factorial arrangement. Fat treatments were tallow and corn-oil. The VE treatments included four levels of α-tocopheryl-acetate (ATA; 11, 40, 100, and 200 ppm) and two levels of mixed tocopherols (primarily γ-tocopherol; 40 and 100 ppm). Liver samples were collected at slaughter. Data analysis were performed by ANOVA using GLM in SAS. No effect of dietary fat sources, isoforms of VE, and levels of γ-tocopherol were detected on growth performance or liver antioxidant status (GSH, GSSG, SOD, and MDA). Increasing dietary ATA linearly increased overall ADG (0.98, 1.02, 1.02, and 1.08 kg/day; P = 0.02) from 28 to 150 kg; overall ADG of pigs fed γ-tocopherol-diets was 1.07 and 1.04 kg/day, respectively. An interaction between fat sources and ATA was observed on cumulative ADG during Phase1-3 (28-100 kg; P = 0.04) and Phase1-4 (28-125 kg; P = 0.03) wherein pigs fed corn-oil-diet, but not tallow-diet, had increased ADG with increased dietary ATA. Increasing dietary ATA quadratically increased SOD activity (P < 0.05; highest at 100 ppm), and quadratically decreased MDA content (P < 0.05; lowest at 40 ppm) in the liver. Liver fatty acid profile was affected by fat source (P < 0.05) but not VE treatment, pigs fed corn-oil-diets had less SFA (34.23 vs. 35.45%; P = 0.02) and MUFA (11.98 vs. 18.38%; P < 0.0001), but more PUFA (49.14 vs. 40.78%; P < 0.0001) than pigs fed tallow-diets in the liver. Beneficial effects of dietary VE supplementation were observed on growth performance and antioxidant status of pigs under conditions of this study.

We previously reported that crowding in the nursery decreased growth rate and affected blood chemistry and hematology measures in gilts. In the current experiment, weanling gilts were allowed decreased floor space in the nursery to determine effects of crowding on their future litter sizes and retention as sows. Of 2,537 gilts classified at weaning as large (6.92 kg), medium (4.42 kg), or small (5.60 kg) and reared in nursery pens of 14, 11, or 8 pigs (to allow 0.15, 0.19, or 0.27 m2 floor space/pig, respectively), 1,453 gilts were selected for breeding and distributed among 11 sow farms. As expected, total litter size (12.94, 13.28, and 13.99; SE = 0.13) and born alive (12.21, 12.64, and 13.23; SE = 0.11) increased (P < 0.01) from parity one to three. A tendency (P = 0.08) existed for a quadratic relationship between space and total litter size [13.39, 13.54, and 13.27 (SE = 0.13) for gilts allowed 0.15, 0.19, or 0.27 m2 floor space/pig, respectively]. A linear effect of pig size (P = 0.03) on stillborns was detected (0.64, 0.75, and 0.75, for small, medium, and large, respectively). There was no effect of space on the percentages of gilts completing zero (P = 0.36), one (P = 0.35), two (P = 0.32) or three (P = 0.50) parities. However, the percentage of small gilts completing zero parities was greater (P < 0.01), and the percentage completing one parity was less (P < 0.01) than for large or medium gilts. Abortion rate was greater (P < 0.01) in gilts classified as small (2.51%) or medium (1.36%) compared with large (0.20%). Floor space allowed in the nursery did not remarkably affect litter sizes or retention through three parities in sows. Compared with larger pigs, however, more small pigs entering the breeding herd did not complete a parity and displayed a greater abortion rate.

Crossbred pigs (24 barrows and 24 gilts; BW 35.59±0.24 kg) were blocked by body weight, sex, and allotted in a randomized complete block design to 3 dietary treatments: 1) Control [CON], 2) CON+0.25%, and 3) CON+0.50% inclusion of a dacitic tuff breccia (DTB) to evaluate effects on growth performance. Diets were formulated to meet or exceed NRC (2012) requirement estimates and fed for 2 phases (d0-14=PHS_1 and d14-28=PHS_2). Diets were limit fed based on metabolic body weight (3.5 x maintenance ME needs [3.5 × 106 Kcal ME/kg BW0.75]). Pigs were weighed weekly and feed allowance adjusted accordingly. In PHS_1, a tendency for a sex difference, gilt vs. barrow, respectively, for ADG (4.92%; 0.913 vs. 0.870 kg; P=0.10) and G:F (4.14%; 0.528 vs. 0.507; P=0.06) existed. The responses to treatments 1–3, respectively, for ADG (0.877, 0.900, and 0.896 kg; linear P=0.54) and G:F (0.510, 0.522, 0.521; linear P=0.46) were numerically greater. In PHS_2, sex differences, gilt vs. barrow, respectively, for ADG (5.67%; 0.946 vs. 0.895 kg; P=0.05) and G:F (7.98%; 0.460 vs. 0.426; P< 0.01) existed. The numerical responses to treatments 1–3, respectively, for ADG (0.912, 0.944 and 0.905 kg; P=0.41) and G:F (0.439, 0.446, 0.444; linear P=0.70) continued. A tendency for a quadratic response in ADFI (P=0.06) existed because feed allowance increased with increasing weekly BW for treatments 2 and 3. Overall, sex differences, gilt vs. barrow, respectively, for ADG (5.30%; 0.929 vs. 0.882 kg; P< 0.05) and G:F (6.23%; 0.491 vs. 0.462; P< 0.01) occurred. Numerical responses to treatments 1–3, respectively, for ADG (0.895, 0.921 and 0.900 kg, P=0.32) and G:F (0.471, 0.480, 0.479; linear P=0.50) occurred. Additionally, the response to DTB appeared to be higher in barrows.

A cooperative study comprising growth performance, bone mineralization, and nutrient balance experiments was conducted at 11 stations to determine the standardized total-tract digestible (STTD) P requirement of 20-kg pigs using broken-line regression analysis. Monocalcium phosphate and limestone were added to a corn-soybean meal-based diet at the expense of cornstarch to establish 6 concentrations of STTD P from 1.54 to 5.15 g/kg in increments of 0.62 g/kg at a constant Ca:total P of 1.52:1.0. Diets were fed to 936 pigs (average initial BW of 19 kg) in 240 pens for 20 replicate pens of barrows and 20 replicate pens of gilts per diet. As STTD P increased from 1.54 to 5.15 g/kg of the diet for d 0 to 14, 14 to 28, and 0 to 28, the ADG, ADFI, and G:F increased ( < 0.01). Barrows gained and ate more ( < 0.05) than gilts during d 14 to 28 and 0 to 28. There was no interaction between sex and STTD P concentration for any of the growth performance response criteria. There were both linear and quadratic increases ( < 0.05) in mineral density and content of ash, Ca, and P in the femur expressed as a percentage of dry, fat-free metacarpal as dietary STTD P increased. Furthermore, the maximum load of the femur and mineral density and content and maximum load as well as the Ca and P expressed as a percentage of metacarpal ash linearly increased ( < 0.01) with increasing dietary concentrations of STTD P. There were both linear and quadratic increases ( < 0.01) in apparent digestibility and retention of P with increasing concentrations of STTD P in the diets. Digestibility and retention of Ca linearly ( < 0.01) increased with increasing dietary concentrations of STTD P. Breakpoints determined from nonlinear broken-line regression analyses revealed estimates of 4.20 ± 0.102, 3.20 ± 0.036, or 3.87 ± 0.090 g/kg for ADG during d 0 to 14, 14 to 28, or 0 to 28, respectively. Corresponding estimates using G:F as the response criterion were 4.34 ± 0.146, 3.38 ± 0.139, or 4.08 ± 0.195 g/kg. When mineralization of the femur was used as criteria of response, estimates of STTD P requirement were 4.28, 4.28, or 4.34, g/kg for mineral density, mineral content, or maximum load, respectively. Using mineralization of the metacarpal as criteria of response, estimates of STTD P requirement ranged from 3.5 to 5.0 g/kg depending on the metacarpal response criteria. The study provided empirical estimates of STTD P requirements of 20- to 40-kg pigs.

A total of 185 crossbred pigs (Yorkshire x Landrace; 20.7 ± 2.5 d of age and 6.7 ± 1.1 kg BW) from 3 weaning groups were used to evaluate dietary n-6:n-3 fatty acid (FA) ratios on nursery and growing pigs. Within each weaning group, pigs were blocked by BW and randomly assigned to 1 of 5 dietary treatments in a randomized complete block design with balanced sex and 4 or 5 pigs/pen within each block. The dietary treatments were: 1) low n-6:n-3 FA ratio (LO): 5.0% menhaden oil (MO) and 0.0% corn oil (CO); 2) low-medium n-6:n-3 FA ratio (LO-MED): 3.5% MO and 1.5% CO; 3) medium n-6:n-3 FA ratio (MED): 1.5% MO and 3.5% CO; 4) high-medium n-6:n-3 FA ratio (HI-MED): 0.2% MO and 4.8% CO; and 5) high n-6:n-3 FA ratio (HI): 0.0% MO and 5.0% CO. The diets were fed in 2 phases as d 0 to 28 (nursery phase) and d 29 to 70 (grower phase). In vivo cell-mediated immune response was assessed on d 14 and 28 for Group 1 and 2 by measuring the inflammatory response to an intradermal injection of 100 µL of phosphate buffered saline (PBS) or phytohemagglutinin (PHA, 0.5 mg/mL of PBS). One pig was euthanized from each pen in Group 1 and 2 at the end of the nursery and grower phase to assess intestinal morphology. During the nursery or grower phase, average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio were not affected by increasing dietary n-6:n-3 FA ratios (P > 0.16). However, pigs fed the LO diet had lower (P 0.10). Jejunum crypt depth increase in a quadratic manner at the end of the nursery phase (P 0.10). In summary, increasing dietary n-6:n-3 FA ratios altered plasma n-3 FA concentration and n-6:n-3 FA ratio and might influence the intestinal morphology, but did not generally affect growth performance or the skin inflammatory response of pigs in the nursery or grower phases.

Two 21-d experiments were conducted to determine the optimum standardized ileal digestible (SID) Trp:Lys ratio for growing pigs; 1 experiment fed diets supplemented with or without an antibiotic. The primary response variables in both experiments were ADG, ADFI, G:F, and plasma urea N (PUN) concentrations with the optimum SID Trp:Lys ratio detected using broken-line analysis. Experiment 1 evaluated the optimum SID Trp:Lys ratio in growing pigs fed diets supplemented with an antibiotic. This experiment used 120 crossbred pigs that were blocked by sex and initial BW (24.13 ± 2.72 kg) and allotted to 6 SID Trp:Lys ratios in 4 replicates. Dietary treatments were formulated by the addition of crystalline Trp to create 6 SID Trp:Lys ratios (13.08%, 14.06%, 15.04%, 17.00%, 18.95%, and 20.91%) with a constant SID Lys level of 0.655%. As SID Trp:Lys ratios increased, ADG, ADFI, and G:F increased, and PUN concentrations decreased linearly (P < 0.05) and quadratically (P < 0.05). Linear broken-line analysis yielded optimum SID Trp:Lys ratios of 17.93% (P < 0.001) and 16.17% (P = 0.009) for ADG and PUN, respectively, resulting in a mean optimum SID Trp:Lys ratio of 17.05%. Experiment 2 evaluated the optimum SID Trp:Lys ratio in growing pigs fed diets supplemented with or without an antibiotic. It used a total of 324 crossbred pigs (initial BW: 30.81 ± 3.56 kg) that were allotted to 6 SID Trp:Lys ratios in 6 replicates. Dietary treatments were formulated by the addition of crystalline Trp to create 6 SID Trp:Lys ratios (12.52%, 14.86%, 17.20%, 19.54%, 21.88%, and 24.22%) with a constant SID Lys level of 0.67%. As SID Trp:Lys ratios increased, ADG, ADFI, and G:F increased, and PUN concentrations decreased linearly (P < 0.001) and quadratically (P < 0.001) regardless of antibiotic inclusion. There were no differences by the antibiotic treatment in ADG, ADFI, G:F, or PUN concentrations (P > 0.49) and no interactions between antibiotics and Trp:Lys ratios (P > 0.29). When the data for all pigs were pooled for the various Trp:Lys ratios, the optimum SID Trp:Lys ratios for ADG and PUN based on linear broken-line analysis were 14.58% (P < 0.001) and 14.54% (P < 0.001), respectively, resulting in an optimum SID Trp:Lys ratio of 14.56% as the mean of the determined optima for ADG and PUN responses. These results demonstrate that the optimum SID Trp:Lys ratio for 30- to 50-kg growing pigs is not impacted by the dietary inclusion of an antibiotic as long as the diets are formulated on an SID AA basis.