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Wooden breast (WB) myopathy was investigated in broilers fed varying energy and protein at early ages. Correlation analyses were conducted between echogenicity of ultrasound images (US) of breast muscle from live birds and WB after slaughter. A total of 1,000 Cobb 500 one-day-old male chicks were fed on five dietary programs with eight replicates of 25 birds each, in a completely randomized design. Control feeds (commercially used ME and ideally balanced amino acids) or low-density feeds (low EP, with reductions of 50 kcal/kg ME and 0.20% dig. Lys compared to the control) were formulated. Feeds were provided in different periods: 1 to 7 d, 8 to 14 d, 15 to 21 d or 22 to 28 d. All broilers were fed a common basal diet thereafter until 49 d. Images using US were obtained once a week from all individuals and WB scored from one slaughtered bird per replication (0, normal; 1, mild hardening in the upper breast muscle; 2; moderate hardening in the upper and/or lower breast muscle; 3, severe hardening; 4, severe hardening with hemorrhagic lesions and yellow fluid). Blood was collected for enzyme investigation from the weekly slaughtered bird. Broilers had lower BWG and higher FCR when fed low EP feeds, regardless of the period fed when compared to the control (P < 0.001). Growth compensation, however, occurred afterwards such that all birds presented similar performance at the end. At 14, 21, and 28 d, broilers previously fed low EP feeds had lower WB scores (P < 0.001) compared to birds fed the control; however, both groups presented increased WB scores after 28 d. Wooden breast was positively correlated with breast echogenicity at 21 d (r = 0.31), 28 d (r = 0.43), 35 d (r = 0.21) and 42 d (r = 0.39). In conclusion, dietary energy and protein affected the development of WB scores in broilers and breast US images can be used as an early predictor of WB., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

We aimed to evaluate the effect of different grazing management strategies on carcass characteristics traits, meat quality and CH 4 intensity and yield of lambs grazing Italian ryegrass pastures in Southern Brazil. A grazing trial was performed (2014 and 2015) in a randomized complete block design with two grazing management targets and four replicates. Treatments were traditional rotational stocking (RT), with pre- and post-grazing sward heights of 25 and 5 cm, respectively, and 'Rotatinuous' stocking (RN), with pre- and post-grazing sward heights of 18 and 11 cm, respectively. Castrated crossbred Texel and Polwarth lambs were used. Results indicated that diet cost per kg of dry matter (p = 0.001) and per hectare (p < 0.001) were lower for RN than for RT treatment. Final live weight (p = 0.022) and hot and cold carcass weight (p = 0.006) were greater for the RN treatment. All commercial cuts were greater for RN than for RT treatment. The RN treatment presented greater (p < 0.001) production of carcass, edible food and crude protein. Feed efficiency and feed cost conversion were better for RN than for RT treatment. CH 4 intensity per kg of carcass, edible food and crude protein gain were 2.6, 2.7 and 2.1 times lower (p < 0.001) for RN. Moreover, CH 4 yield was lower (p = 0.014) for RN than for RT treatment, with an average of 7.6 and 8.3% of the gross energy intake, respectively. We conclude that the 'Rotatinuous' stocking results in a greater carcass production, carcass quality and lower diet cost, and CH 4 intensity and yield of grazing lambs. Adopting this grazing management strategy could enhance both lamb production and mitigation of CH 4 intensity and yield in grazing ecosystems, which could be considered a good example of climate-smart livestock production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The effectiveness of rice protein coatings enriched with essential oils on maintaining interior quality of fresh eggs was evaluated during storage at 20°C for 6 wk. Egg quality was assessed by weight loss, Haugh unit (HU), albumen pH, and yolk index (YI) in uncoated eggs (control treatment) and eggs coated with rice protein concentrate at 8% enriched or not with different essential oils (1%): tea tree (Melaleuca alternifolia), copaíba (Copaifera langsdorffii), or thymo (Thymus vulgaris). The HU and YI were higher in coated eggs (P < 0.001). Data were submitted to variance analysis, and the statistical models included the effects of treatments (coating types), storage periods (weeks), and interaction (treatments by storage periods). Weight loss increased (P < 0.001) during long-term storage. Uncoated eggs showed the highest weight loss (5.43%), whereas coatings of rice protein alone (4.23%) or enriched with tea tree (4.10%), copaíba (3.90%), and thymo (4.08%) solutions were effective in preventing weight lost (P < 0.001). The coating use preserved the internal quality of the eggs for up to 3 wk longer than uncoated eggs in terms of HU, YI, and pH. Uncoated eggs had the worst (P < 0.001) HU (58.46), albumen pH (9.48), and YI (0.33) after 6 wk of storage. In conclusion, the use of coatings based on rice protein concentrate enriched with different essential oils influences the internal quality of eggs during storage and may be an effective alternative for increasing the shelf life of commercial eggs., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

Although eggs are an excellent protein source, they are a perishable product. Many methods exist to extend shelf life of food and one of them is the use of protein coatings that may be combined with antimicrobial substances, as propolis. The effectiveness of rice protein coatings plus propolis on maintaining interior quality and eggshell breaking strength of fresh eggs was evaluated during storage at 20°C for 6 wk. Egg quality was assessed by weight loss, Haugh unit (HU), albumen pH, yolk index (YI), shell strength, and scanning electron microscopy in uncoated eggs (control treatment) and eggs coated with rice protein concentrate and propolis at 5 or 10%. The HU and YI were higher in coated eggs (P < 0.001). Weight loss increased (P < 0.001) during long-term storage. Uncoated eggs showed the highest weight loss (5.39%), whereas rice protein (4.27%) and rice protein plus propolis at 5% (4.11%) and 10% (4.40%) solutions were effective in preventing weight lost (P < 0.001). Uncoated eggs had the worst (P < 0.001) HU (58.47), albumen pH (9.48), and YI (0.33) after 6 wk of storage. The eggs coated with rice protein and rice protein plus propolis presented results with similar intern quality between them during all the storage period. Scanning electron microscopy demonstrated a lower surface porosity in coated eggshell, indicating that the use of the coating may provide a protective barrier against the transfer of gases and moisture. In conclusion rice protein and propolis treatments helped to maintain egg quality for a longer time compared to uncoated eggs. These could be a viable alternative for maintaining the internal quality of fresh eggs during long-term storage at room temperature., (© 2019 Poultry Science Association Inc.)

The effectiveness of rice protein coatings or mineral oil on maintaining interior quality and eggshell breaking strength of fresh eggs was evaluated during storage at 20°C for 8 wk. Egg quality was assessed by weight loss, Haugh unit (HU), albumen pH, yolk index (YI), shell strength, and scanning electron microscopy in uncoated eggs (control treatment) and eggs coated with mineral oil or rice protein concentrate at 5, 10, or 15%. The HU and YI were higher in coated eggs (P < 0.001). Weight loss increased (P < 0.001) during long-term storage. Uncoated eggs showed the highest weight loss (8.28%), whereas mineral oil (0.87%) and rice protein at 5% (5.60%), 10% (5.45%), 15% (5.54%) solutions were effective in preventing weight lost (P < 0.001). The use of the coatings preserved the internal quality of the eggs for up to 4 wk longer than uncoated eggs (HU, YI, and pH). Uncoated eggs had the worst (P < 0.001) HU (54.45), albumen pH (9.18), and YI (0.28) after 8 wk of storage. Among the coated eggs, the mineral oil had the best values of HU (70.54), pH (8.48), and YI (0.35) after storage. The eggs coated with 5, 10, and 15% of rice protein presented results with similar intern quality between them and intermediary quality in relation to the others treatments during all the storage period. Scanning electron microscopy demonstrated a lower surface porosity in coated eggshell, indicating that the use of the coating may provide a protective barrier against the transfer of gases and moisture. In conclusion, the use of coatings based on rice protein concentrate or mineral oil influences the internal quality of eggs during storage and may be an effective alternative for increasing the shelf-life of commercial eggs., (© 2018 Poultry Science Association Inc.)

One hundred and twenty Cobb 500 hens, 20 wk of age, were randomly allocated into individual cages with the objective of estimating their Zn requirements. The study was composed of 3 phases: adaptation to cages (basal diet), depletion (deficient diet containing 18.7 ± 0.47 ppm Zn) for 7 wk, and experimental phases. Hens were fed diets with graded increments of Zn sulfate heptahydrate (ZnSO4·7H2O), totaling 18.7 ± 0.47, 50.3 ± 10.6, 77.3.0 ± 11.0, 110.2 ± 12.8, 140 ± 12.2, and 170.6 ± 13.2 ppm analyzed Zn in feeds for 12 wk (experimental phase). Requirements of Zn were done using quadratic polynomial (QP), broken line quadratic (BLQ), and exponential asymptotic (EA) models. In general, the non-linear statistical models were the ones that best fit the results in this study. Requirements obtained for hen day egg production and settable egg production were 83.3, 78.6 ppm and 61.4, 65.4 ppm for period of 33 to 36 wk, and 63.3, 53.1 and 60.4, 46.1 ppm for period of 37 to 40 wk, and 62.8, 52.8, and 67.7, 62.1 ppm for period of 41 to 44 wk, respectively, using BLQ and EA models. Total eggs and total settable eggs produced per hen had Zn requirements estimated as 75.7, 64.7 ppm, and 56.5, 41.5 ppm, respectively, for BLQ and EA models, whereas for alkaline phosphatase and eggshell percentage were 161.8, 124.9 ppm and 126.1, 122.4 ppm, using QP and BLQ models. Maximum responses for Zn in yolk for periods of 37 to 40 and 41 to 44 wk were 71.0, 78.1 and 64.5, 59.6 ppm, respectively, using BLQ and EA models. Breaking strength had Zn requirements estimated at 68.0 and 96.7 ppm, whereas eggshell palisade layer and eggshell thickness were maximized with 67.9, 67.9 ppm, and 67.7, 64.4 ppm, respectively, for BLQ and EA models. The average of all Zn requirement estimates obtained by EA and BLQ models in the present study was 72.28 ppm or 11.1 mg/hen/d., (© 2018 Poultry Science Association Inc.)

One-hundred-twenty Cobb 500 hens, 20 wk of age, were randomly allocated into individual cages with the objective of estimating Cu requirements. After being fed a Cu deficient diet for 4 wk, hens were fed diets with graded increments of supplemental Cu (0.0; 3.5; 7.0; 10.5; 14; and 17.5 ppm) from Cu sulfate (CuSO4 5H2O), totaling 2.67; 5.82; 9.38; 12.92; 16.83; and 20.19 ppm analyzed Cu in feeds for 20 weeks. Estimations of Cu requirements were done using exponential asymptotic (EA), broken line quadratic (BLQ), and quadratic polynomial (QP) models. Obtained Cu requirements for hen d egg production and total settable eggs per hen were 6.2, 7.3, and 12.9 ppm and 8.1, 9.0, and 13.4 ppm, respectively, using EA, BLQ, and QP models. The QP model was the only one having a fit for total eggs per hen with 13.1 ppm Cu as a requirement. Hemoglobin, hematocrit, and serum Cu from hens had requirements estimated as 13.9, 11.3, and 18.5, ppm; 14.6, 13.0, and 19.0 ppm; and 16.2, 14.6, and 14.2 ppm, respectively, for EA, BLQ, and QP models. Hatching chick hemoglobin was not affected by dietary Cu, whereas requirements estimated for hatching chick hematocrit and body weight and length were 10.2, 12.3, and 13.3 ppm using EA, BLQ, and QP models; and 6.8 and 7.1 ppm, and 12.9 and 13.9 ppm Cu using EA and BLQ models, respectively. Maximum responses for egg weight, yolk Cu content, and eggshell membrane thickness were 14.9, 12.7, and 15.1 ppm; 15.0, 16.3, and 15.7 ppm; and 7.3, 7.8, and 14.0 ppm Cu, respectively, for EA, BLQ, and QP models. Yolk and albumen percentage were adjusted only with the QP model and had requirements estimated at 11.0 ppm and 11.3 ppm, respectively, whereas eggshell mammillary layer was maximized with 10.6, 10.1, and 14.4 ppm Cu using EA, BLQ, and QP models, respectively. The average of all Cu requirement estimates obtained in the present study was 12.5 ppm Cu.

A study was conducted to evaluate growth performance, carcass and breast yields, and the occurrence and severity of white striping (WS) and wooden breast (WB) myopathies of broilers fed diets supplemented with increasing dietary levels of an organic source of selenium (Zn-L-SeMet). Broilers were fed 6 treatments with 12 replications of 26 birds in a 4-phase feeding program from 1 to 42 days. Corn-soy-based diets were supplemented with 0, 0.2, 0.4, 0.6, 0.8, and 1.0 ppm of Zn-L-SeMet. At 42 d, 6 birds were randomly selected from each pen (n = 72) and processed for carcass and breast yields. Breast fillets were scored for WS and WB at 42 days. Increasing Zn-L-SeMet led to quadratic responses (P < 0.05) for FCR from 1 to 7 d, BWG from 22 to 35 d, and for both responses from 8 to 21 d and 36 to 42 d, as well as in the overall period of 42 days. Carcass and breast yields presented a quadratic improvement (P < 0.01) with increasing Zn-L-SeMet supplementation and Se requirements were estimated at 0.85 and 0.86 ppm, respectively. In the overall period, estimates of Se requirements were 0.64 ppm for BWG and 0.67 ppm for FCR. White striping and WB scores presented quadratic increases (P < 0.01), and maximum scores were observed at 0.68 and 0.67 ppm, respectively. Broilers fed diets formulated without Se supplementation had a higher percentage of normal fillets compared to other Se supplementation levels (quadratic, P < 0.05). In conclusion, increasing Se supplementation to reach maximum growth performance led to higher degrees of severity of WS and WB. Selenium requirements determined in the present study were significantly higher than the present commercial recommendations.

As the first limiting amino acid in corn-soy broiler diets, methionine (Met) is supplemented using commercial synthetic sources as demanded to obtain economic feed formulations. The Met analogue DL-2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) is largely utilized with that objective. This study intended to obtain responses of broilers fed with increasing levels of HMTBA, from 28 to 42 d, such that economic returns can be calculated. A total of 2,106 Cobb × Cobb 500 one-day-old male broilers was randomly placed in 81 floor pens (2.7 m2 each). Birds were fed conventional starter (zero to 14 d) and grower (14 to 28 d) diets. Starting at 28 d of age, pens of 26 birds were randomly allocated into 9 feed treatments with 9 replications having increasing supplementations with HMTBA (0.00, 0.07, 0.14, 0.21, 0.28, 0.35, 0.42, 0.49 and 0.56%). These were prepared by mixing different proportions of corn-soy dilution and summit diets, which had the same formulated concentration of nutrients and energy [19.7% CP, 0.90% Ca, 0.45% Av. P, 0.95% digestible Lys, and 3,150 kcal/kg AMEn], with the exception of HMTBA [0.56% in the summit but not supplemented in the corn-soy dilution diet (0.52% digestible TSAA)]]. Growth performance was evaluated until 42 d when carcass yield and commercial cuts were evaluated using 6 birds randomly taken from each pen. Body weight gain (BWG), feed conversion ratio (FCR), proportion of breast fillets, and abdominal fat were adjusted using linear broken-line, exponential asymptotic and quadratic polynomial regression models (P < 0.05). Estimations of maximum responses for supplemented HMTBA by the linear broken-line model were 0.17% for BWG, 0.14% for FCR, and 0.29% for breast fillets. Using exponential and quadratic regressions, optimized HMTBA supplementations were obtained at 0.34 and 0.35% for BWG, 0.20 and 0.33% for FCR, and 0.31 and 0.36% for breast fillets, respectively. Supplemental levels of HMTBA that optimize growth performance and breast meat in male broilers from 28 to 42 d, using different regression models, varied from 0.14 to 0.36%.

A study was conducted to determine the AMEn contents of fat by-products from the soybean oil industry for broiler chickens. A total of 390 slow-feathering Cobb × Cobb 500 male broilers were randomly distributed into 13 treatments having 6 replicates of 5 birds each. Birds were fed a common starter diet from placement to 21 d. Experimental corn-soy diets were composed of four fat sources, added at 3 increasing levels each, and were fed from 21 to 28 d. Fat sources utilized were acidulated soybean soapstock (ASS), glycerol (GLY), lecithin (LEC), and a mixture (MIX) containing 85% ASS, 10% GLY and 5% LEC. A 4 × 3 + 1 factorial arrangement was used with 4 by-products (ASS, GLY, LEC, or MIX), 3 inclusion levels and 1 basal diet. Each of the four fat by-product sources was included in the diets as follow: 2% of by-products (98% basal + 2% by-product), 4% (96% basal + 4% by-product), or 6% (94% basal + 6% by-product). Birds were submitted to 94, 96, 98, and 100% of ad libitum feed intake; therefore, the differences in AMEn consumption were only due to the added by-product. Total excreta were collected twice daily for 72 h to determine apparent metabolizable energy contents starting at 25 d. The AMEn intake was regressed against feed intake and the slope was used to estimate AMEn values for each fat source. Linear regression equations (P < 0.05) estimated for each by-product were as follow: 7,153X - 451.9 for ASS; 3,916X - 68.2 for GLY; 7,051X - 448.3 for LEC, and 8,515X - 622.3 for MIX. Values of AMEn were 7,153, 3,916, 7,051, and 8,515 kcal/kg DM for ASS, GLY, LEC, and MIX, respectively. The present study generated AMEn for fat by-products data that can be used in poultry feed formulation. It also provides indications that, by adding the 3 by-products in the proportions present in the MIX, considerable economic advantage can be attained., (© 2017 Poultry Science Association Inc.)

Dorsal cranial myopathy (DCM), which affects the anterior latissimus dorsi (ALD) muscles of commercial broilers, is of unknown etiology, and it represents up to 6% of the partial condemnations in Brazilian slaughterhouses. This study was performed to achieve histomorphometric characterizations of the ALD muscles from male Cobb 500 broilers slaughtered at either 35 d or 42 d and to evaluate the effects of DCM on the enzymatic markers aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK), and lactate dehydrogenase (LDH) and on uric acid and creatinine metabolites. Blood samples (1.5 to 3 mL) and ALD muscle fragments were collected from each carcass, all of which were processed in a commercial inline processing system. For each age, twelve macroscopically normal animals and twelve animals found to exhibit DCM were randomly selected for histomorphometric evaluation and analysis of serologic profiles. Microscopic evaluations demonstrated that the muscle fibers of those with DCM exhibited a strong presence of multifocal regenerative myodegeneration as well as a substitution of muscle tissue with connective tissue (P < 0.001) through fibrosis, thus characterizing the chronicity and hardness of the affected muscle. It is suggested that DCM is a localized muscle lesion because the detected serum levels of CK (P < 0.001), AST (P < 0.001), ALT (P = 0.01), and LDH (P < 0.001) enzymes were strongly associated with the group affected by DCM. Additional studies are needed to gain an understanding of this myopathy because it is an emerging problem in the poultry industry. In addition, it is related to DCM lesions in fast-growing broilers with the greatest slaughter weights., (© 2017 Poultry Science Association Inc.)

A study was conducted to investigate Fe requirements of broiler breeders. One-hundred-fifty-six Cobb 500 broiler breeder hens were individually placed in electrostatically painted cages at 22 weeks. The study was composed of an adaptation phase, in which hens were fed corn-soy-wheat bran diets until 35 wks. An Fe deficient mash diet (24.6 ppm Fe) was provided from 35 to 46 wk in order to induce a partial body Fe depletion. A production phase followed from 47 to 70 wk when hens were fed 6 diets with increasing Fe sulfate supplementation, which, upon analyses had 24.6, 48.6, 74.3, 99.6, 125.6, and 148.2 ppm Fe. Thirty hatching eggs from each treatment were randomly collected in the last wk of each production period and incubated. Hemoglobin and hematocrit were analyzed from 6 hens as well as all hatched chicks per treatment. Analyses of production and hatching data were conducted using quadratic polynomial (QP), broken-line (BL), and exponential asymptotic (EA) models. Effects of dietary Fe were observed for total eggs and total hatching eggs, egg yolk Fe content, and hen and chick hematocrit and hemoglobin (P < 0.05). These responses to added Fe were optimized when dietary Fe were 96.8, 97.1, 130.6, 122.6, 120.0, and 125.0 ppm (QP) and 76.4, 89.3, 135.0, 128.4, 133.8, and 95.0 ppm (BL) for total hatching eggs, egg yolk Fe content, and hen and chick hematocrit and hemoglobin, respectively. Optimization with the EA model was obtained for total hatching eggs, egg yolk Fe, and hen and chick hemoglobin at 97.9, 111.0, 77.9, and 96.3 ppm Fe for total hatching eggs, egg yolk Fe, and hen and chick hemoglobin, respectively. Adequate Fe levels are needed to maintain egg production as well as hatching chicks' indexes. Fe concentration in the yolk and diet are positively influenced. The average of all Fe requirement estimates obtained in the present study was 106 ppm total Fe, whereas averaged values for BL, QP, and EA models were 107, 113, and 97 ppm Fe, respectively., (© 2017 Poultry Science Association Inc.)

Two experiments were conducted to evaluate the prevalence and severity of white striping (WS) and wooden breast (WB) in breast fillets from broilers fed diets with increasing digestible Lysine (dLys) from 12 to 28 d (Exp. 1) and from 28 to 42 d (Exp. 2). Trials were sequentially conducted using one-d-old male, slow-feathering Cobb 500 × Cobb broilers, both with 6 treatments and 8 replicates. Increasing dLys levels were equally spaced from 0.77 to 1.17% in Exp. 1 and from 0.68 to 1.07% in Exp. 2. The lowest dLys diet was not supplemented with L-Lysine (L-Lys) in either one of the studies and all other essential amino acid (AA) met or exceeded current commercial recommendations such that their dietary concentrations did not limit broiler growth. Four birds per pen were randomly selected from each replication and processed at 35 and 42 d in Exp. 1 and Exp. 2, respectively. Deboned breast fillets (Pectoralis major) were submitted to a 3 subject panel evaluation to detect the presence of WS and WB, as well as to provide scores of WS (0-normal, 1-moderate, 2-severe) and WB (0-normal, 1-moderate light, 2-moderate, 3-severe). Increasing the level of dLys had a positive effect on BW, carcass, and breast weight, as well as breast yield. White striping and WB prevalences were 32.3 and 85.9% in Exp. 1 and 87.1 and 89.2% in Exp. 2. Birds fed diets not supplemented with L-Lys had the lowest average WS and WB scores (0.22 and 0.78 in Exp. 1 and 0.61 and 0.68 in Exp. 2). White striping and WB presented linear responses to performance variables in Exp. 1, whereas quadratic responses were observed for all variables in Exp. 2. In conclusion, increasing the level of dLys improved growth performance and carcass traits as well as induced the occurrence and severity of WS and WB lesions., (© 2016 Poultry Science Association Inc.)

A study was conducted to evaluate the effects of dietary α-amylase and β-xylanase supplementation of corn-soy diets, formulated with or without supplemental phytase, on growth performance, energy utilization, and starch digestibility in broiler chickens. A total of 336 slow-feathering, Cobb × Cobb 500 male broilers were randomly distributed to 6 treatments having 8 replicates of 7 birds each. Birds were fed a common starter diet to d 14 post-hatch (3,050 kcal/kg AMEn, 21.7% CP, 1.05% Ca, and 0.53% nPP). The experimental diets were provided afterwards until d 25. A 2 × 3 factorial arrangement of 2 control diets (basal = corn-soy diet without added phytase or PHY = corn-soy diet formulated with 1,000 phytase units/kg) and 3 carbohydrase supplementations (0, 80 kilo-Novo α-amylase units/kg, or 80 kilo-Novo α-amylase units/kg + 100 fungal β-xylanase units/kg) was used from d 14 to 25. Excreta were collected from 21 to 24 d and all birds were euthanized at 25 d for jejunum and ileum content collection. Samples of feed, excreta, and jejunal and ileal digesta were analyzed for determination of total tract retention and ileal apparent digestibility. No interactions between diet and carbohydrase were observed. Broilers fed diets formulated with phytase or supplemented with amylase + xylanase had higher BW gain (BWG) and lower FCR (P < 0.05) when compared with birds fed diets without carbohydrases. Relative to the basal diet, AMEn was increased (P < 0.01) by 70 kcal/kg and 99 kcal/kg when birds were fed the diet supplemented with amylase and amylase + xylanase, respectively. Starch digestibility in the jejunum and ileum was increased (P < 0.05) by 3.5% and 2.4%, respectively, when birds were fed the diet supplemented with amylase + xylanase. Results from this experiment show that corn-soy diets having phytase and supplemented with amylase and xylanase led to increased growth performance, AMEn, and starch digestibility in broilers. Furthermore, the efficacy of exogenous amylase and xylanase was independent of the presence of microbial phytase., (© 2015 Poultry Science Association Inc.)

The objective of this study was to evaluate the immunoglobulin G (IgG) absorption by Santa Ines lambs under two colostrum management systems usually used by producers. Twenty-seven Santa Ines newborn lambs received two meals of 250 ml of bovine colostrum from Holstein cows (BC group) or ovine colostrum from Santa Ines ewes (OC group) at 0 and 6 h of life. Pools of BC and OC were analyzed by radial immunodiffusion to quantify IgG. Results are expressed as least-square means and standard errors of mean (means ± s.e.m.). The concentration of IgG in bovine and ovine pools averaged 115.7 ± 20.5 and 48.1 ± 5.0 mg/ml, respectively, levels of concentration found in similar regular colostrum managements. The efficiency of IgG absorption was evaluated under two aspects, maximum apparent efficiency of absorption and total apparent efficiency of absorption (AEAmax and AEAtotal, respectively). The AEAmax was calculated taking into account the mass of IgG ingested just in the first meal of colostrum at birth and the serum IgG concentration at 6 h while the AEAtotal took into account the serum IgG concentration at 24 h of life that reflects the first colostrum offered at birth and the second meal at 6 h. The IgG and apparent efficiency of absorption results were transformed into the square root and log base 10, respectively, and were presented as geometric least-square means. In BC, lower (P < 0.05) AEAmax and AEAtotal were verified (14.2% and 15.6%, respectively), in relation to OC (23.6% and 24.4%, respectively). Serum IgG concentrations at 24 h were significantly higher (P < 0.05) in BC (31.4 mg/ml, respectively) compared with OC (22.2 mg/ml, respectively). The results in this study confirm that there is a limitation to the process of IgG absorption by the enterocytes of newborn lambs, which determined a nonlinear behavior of passive immunity acquisition. Similar values of AEAmax and AEAtotal for the two sources of colostrum reveal that the process of IgG absorption from the first and second meals during the first 6 h of life did not change and indicates that the ingestion of a second feeding of quality colostrum can enhance the acquisition of immune protection of newborn lambs.