Chicken liver morphology as affected by feed withdrawal time and dietary aflatoxins.

1. An investigation was conducted on the effects of aflatoxin (AFL)-contaminated diets and feed withdrawal periods from 0 to 12 h in broiler chickens at 28 d of age. Both factors can potentially affect liver colour and can cause failure at veterinary inspection in the slaughterhouse.2. A total of 240, one-d-old female Cobb 500 broiler chickens were fed a common corn-soy pre-starters (d 1-7) and then either a non-contaminated control (CON) or feed with 1 ppm AFL (AFL) from d 8 to 28. The inoculum of AFL had 792 ppb of aflatoxin B1, 35 ppb of aflatoxin B2 and 219 ppb of aflatoxin G1. On d 28, all broilers were weighed and euthanised for necropsy following three different feed withdrawal time periods (0, 6 or 12 h), in a 2 × 3 factorial arrangement.3. Body weight gain, liver weight and liver fat content decreased as feed withdrawal lengthened, whereas FCR and gallbladder weight increased (P ≤ 0.05). AFL-fed birds had reduced body weight and proportion of liver fat and increased FCR, liver and gallbladder weights (P ≤ 0.05).4. Livers from fed broilers (0 h withdrawal) showed more lightness (L*) and yellowness (b*) than livers of broilers from 6 or 12 h withdrawal (P ≤ 0.05). The L* and redness (a*) values of livers from broilers fed diets COB were lower than those from AFL fed broilers (P ≤ 0.05).5. Prolonging pre-slaughter feed withdrawal decreased liver L*, whereas feeding AFL increased liver b*. These findings can be used to support veterinary assessment in slaughterhouses as shackled birds move on line through the inspection site. Since chicken liver is a valuable organ and an indicator of animal health, attention must be paid to these differences to ensure consumer safety.

Optimizing cost, growth performance, and nutrient absorption with a bio-emulsifier based on lysophospholipids for broiler chickens.

Two experiments (Exp.) were conducted to evaluate effects of a lysophospholipid-based bio-emulsifier (LPL) on growth performance, nutrient digestibility and energy utilization of broilers as well as the return on investment (ROI). In Exp. 1, 392 chicks were housed in battery cages in a completely randomized design with 8 treatments and 7 replicates of 7 birds each from d 0 to 21 posthatch. In Exp. 2, 1,400 chicks were allocated in floor pens and fed the same 8 treatments, with 7 replicates and 25 birds each from d 0 to 43 posthatch. Treatments consisted of 6 degummed soybean oil-based diets: positive control (PC1); PC1 formulated with 500 g/ton LPL (PC1+LPL on top); PC1 formulated with 60 kcal LPL matrix (PC1+LPL60); PC1 formulated with 100 kcal LPL matrix (PC1+LPL100); and two negative controls NC-60 and NC-100 with reductions of 60 and 100 kcal/kg ME, respectively. Two other diets were formulated with acid soybean oil: positive control (PC2) and PC2 formulated with 60 kcal LPL matrix (PC2+LPL60). In Exp. 1, performance was evaluated from d 0 to 21, ME and ileal digestibility of DM, CP and energy were determined on d 21. In Exp. 2, growth performance was evaluated from d 0 to 42, and on d 43 carcass and abdominal fat yields were calculated. There were no effects of soybean oil sources in any parameter. Inclusion of LPL increased (P < 0.05) BW gain and ileal digestibility of DM, fat and CP. Broilers fed the PC1+LPL on top diet had increased (P < 0.05) performance, ileal digestibility and energy utilization as well as decreased abdominal fat compared to NC-60 or NC-100. The use of LPL on top had a ROI of 8:1 vs. PC1, considering the gains in revenue of the slaughtered broilers in relation to the investment with LPL in feed. In conclusion, a lysophospholipid-based bio-emulsifier increased performance, digestibility and return on investment of broilers fed standard or reformulated diets.

An in vivo evaluation of the effects of feed restriction regimens on wooden breast using ultrasound images as a predictive tool.

1. Gradual feed restriction was applied to broilers in order to reduce growth rate and, as a consequence, gradually impacts wooden breast myopathy occurrence. Ultrasound (US) images of breast muscle in live birds were correlated with breast fillets presenting wooden breast characteristics (WB). 2. A total of 1800 Cobb × Cobb 500 slow-feathering male chicks were fed one of the six feed restriction treatments with 12 replicates of 25 birds each, in a completely randomised design. Birds were fed ad libitum or were pair-fed to 50%, 60%, 70%, 80% or 90% of normal ad libitum intakes from 8 to 49 d to provide a gradual reduction in growth rate. Ultrasound images were obtained weekly from all birds and, in parallel, one bird per pen was weekly slaughtered and the major breast muscle was weighed and WB graded as 0 (normal), 1 (mild hardening in the upper), 2 (moderate hardening in the upper and/or lower), 3 (severe hardening) and 4 (severe hardening with haemorrhagic lesions and yellow fluid). Blood was taken for analysis of enzymes related to muscle cell breakdown. 3. Feed restriction applied at 50%, 60%, 70%, 80% and 90% of the ad libitum feed intake (FI) resulted in decreased body weight gain (BWG; P ≤ 0.05). 4. From 21 to 49 d, the increasing feed restriction led to linear increases (P ≤ 0.05) in WB scores, fibre density as well as breast depth and breast echogenicity. Creatine kinase, lactate dehydrogenase and aspartate aminotransferase concentration decreased linearly when broilers were feed restricted (P ≤ 0.05). 5. Wooden breast was positively correlated with echogenicity at 21 d (r = 0.510), 28 (r = 0.531), 35 (r = 0.470), 42 (r = 0.430) and 49 d (r = 0.548) (P ≤ 0.001). The use of breast echogenicity can be an additional tool to early detect alterations related to wooden breast.

Utilization of corn-based diets supplemented with an exogenous α-amylase for broilers.

A study was conducted to evaluate the effects of a supplemental α-amylase on energy and nutrient utilization of broiler chickens fed diets with variable amounts of corn. A total of 480 slow feathering Cobb × Cobb 500 male broilers were randomly distributed into 10 treatments with 8 replicates of 6 birds each. Birds were fed a common starter to 14 D post-hatch. The experimental diets were provided subsequently until 25 D, which were a conventional corn-soy basal diet (CS) and a corn-soy diet displaced with 40% of corn (CN). These were fed as-is or supplemented with 40, 80, 120, or 160 kilo-Novo α-amylase units (KNU)/kg. Dietary treatments were distributed factorially as a 2 × 5 arrangement (diet type vs. amylase). Samples of feed, excreta, and ileal digesta were analyzed for determination of ileal digestible energy (IDE), ME, total tract retention, and digestibility of dry matter, protein, and fat. No interactions between diet type and amylase were observed. The CN diet had lower (P < 0.05) energy utilization and nutrient digestibility when compared to the CS diet. AMEn and IDE increased (P < 0.05) by 110 and 207 kcal/kg, respectively, when CS and CN diets were supplemented with 80 KNU/kg. The amylase added to the CS diet led to quadratic increases (P < 0.05) on growth performance, IDE, AME, and AMEn, as well as in dry matter, protein, and fat digestibility. Energy utilization and crude protein digestibility were linearly increased (P < 0.05) when amylase was added to the CN diet or the extrapolated 100% of corn. In conclusion, energy utilization, digestibility of crude protein, fat, and dry matter increased with amylase supplementation in corn-soy-based diets. When amylase was tested in a complete diet having 53.6% corn, 100 and 105 KNU/kg maximized AMEn and IDE, respectively; however, the maximum energy response in the CN diet or 100% of corn was not achieved until 160 KNU/kg, suggesting an association between amylase dose optimization and dietary starch concentration.

Productive performance, bone characteristics, and intestinal morphology of laying hens fed diets formulated with L-glutamic acid.

This study was conducted to evaluate the effects of L-glutamic acid (Glu) on the productive performance, eggshell quality, bone characteristics, and morphologic parameters of laying hens. Two hundred and forty 53-wk-old Hy-Line W36 laying hens were randomly allocated into 5 treatments, 6 replicates, and 8 birds each. The experimental period was 16 wk. The treatments consisted of a Basal diet (Glu calculated at 2.68%) and 4 L-glutamic acid inclusion levels: 2.88, 3.08, 3.28, and 3.48%. Glu inclusion levels in the hens diet had an increasing linear effect (P < 0.05) on eggshell Ca concentration and bone (tibiotarsus) strength index, and a decreasing linear effect (P < 0.05) on the Seedor index. Serum biochemistry results for total and ionic Ca, inorganic P, and alkaline phosphatase were affected by blood collection time (04:00 Pm, 03:00 Am, and 12:00 Pm) but not by the treatments. Jejunum morphometric variables were not influenced by the treatments except for crypt depth, which demonstrated a quadratic effect (P < 0.05). However, proliferating cell nuclear antigen qualitative immunohistochemical analysis of the jejunum showed more positive nuclei in the villus with the addition of Glu. Both with the basal diet and the lowest Glu inclusion treatment, positive nuclei were observed in the crypts and at the base of the villus, while in the treatments with higher Glu levels, positive cells were common all along the villus mucosa, including its extremity. In conclusion, diets formulated with increased levels of Glu had beneficial effects on eggshell Ca concentration, tibiotarsus structure, and proliferative activity of the jejunum of 69-wk-old laying hens. Therefore, dietary L-glutamic acid can be considered an alternative additive to improve bone characteristics in the productive phase of laying hens.

Influence of european quail breeders age on egg quality, incubation, fertility and progeny performance

The influence of age (85, 140, and 270 days) of European quails breeders on the egg quality and hatching, fertility and progeny performance was evaluated. The experimental design was completely randomized in a 3x3 factorial arrangement (females' age x males' age), with ten replicates and six birds per experimental unit (four females and two males). Egg production and quality were determined during 3 periods of 14 days and incubation parameters were evaluated in eggs obtained in five consecutive days. The live performance of the progenies was analyzed until 35 days. There was no effect of male age or any interaction between the age of males and females for the evaluated variable. The female's age influenced egg production, egg weight and chick weight, with better results obtained for 140-d-old breeders. The age of females reduced the hatchability, increased the late mortality in incubated eggs, and had no effect on fertility, total embryo mortality or eggshell structure, when analyzed by electron microscopy. The number of sperm trapped in the outer perivitelline layer (sptz/mm²) was determined in 10 fertile eggs per experimental unit. Young females fertilized by young males (80 days) had reduced sptz/mm². Progeny live performance was not affected by breeder's age. Breeders with 270 days retain fertility; however, their egg production, weight and hatchability of fertilized eggs is reduced. In conclusion, European quail breeders with 140 days of age have better egg quality, hatching and breeding results.(AU)

Efficacy and Metabolizable Energy Equivalence of an -Amylase--Glucanase Complex for Broilers

A trial was conducted to evaluate the effects of adding an exogenous -amylase--glucanase complex produced from Bacillus amyloliquefaciens on the growth performance, carcass yield, and relative AME bioequivalence in broilers fed corn-soy diets from 1 to 40 d of age. One thousand seven hundred and fifty one-day-old Cobb x Cobb 500 slow-feathering male broilers were randomly allotted to seven treatments with 10 replicates of 25 birds each as follows: control diet (C); C diet with reduction of 60 (C-60), 90 (C-90), or 120 (C-120) kcal AME/kg; C diet with reduction of 120 kcal AME/kg and supplemented with 200 (C-120-200), 300 (C-120-300), or 400 (C-120-400) mg of the enzyme complex/kg. Each g of the enzyme complex corresponded to 200 kilo-Novo -amylase and 350 fungal -glucanase units. On d 40, eight birds were randomly taken from each pen and processed to evaluate carcass and commercial cuts yields. Percent mortality was not affected by the treatments (p > 0.05). Live performance, as indicated by BW gain (BWG) linearly decreased (p 0.05) and FCR linearly increased with the reduction in AME. Birds fed diets supplemented with the enzyme complex showed weekly improvements in BWG and FCR. There were no effects of the treatments on the yield of the carcass or of commercial cuts; however, abdominal fat was significantly lower (p 0.0343) in birds fed the C-120-400 compared to the C-120 feeding program (1.67% vs. 1.90%); all other treatments were intermediate. Average AME equivalence of the enzyme complex varied weekly. Estimations for the entire period were 40, 46, and 56 kcal for BWG and 58, 76, and 99 kcal AME/kg for FCR (p 0.001) for the diets containing 200, 300, and 400 mg enzyme complex/kg, respectively.(AU)

Influence of european quail breeders age on egg quality, incubation, fertility and progeny performance

The influence of age (85, 140, and 270 days) of European quails breeders on the egg quality and hatching, fertility and progeny performance was evaluated. The experimental design was completely randomized in a 3x3 factorial arrangement (females' age x males' age), with ten replicates and six birds per experimental unit (four females and two males). Egg production and quality were determined during 3 periods of 14 days and incubation parameters were evaluated in eggs obtained in five consecutive days. The live performance of the progenies was analyzed until 35 days. There was no effect of male age or any interaction between the age of males and females for the evaluated variable. The female's age influenced egg production, egg weight and chick weight, with better results obtained for 140-d-old breeders. The age of females reduced the hatchability, increased the late mortality in incubated eggs, and had no effect on fertility, total embryo mortality or eggshell structure, when analyzed by electron microscopy. The number of sperm trapped in the outer perivitelline layer (sptz/mm²) was determined in 10 fertile eggs per experimental unit. Young females fertilized by young males (80 days) had reduced sptz/mm². Progeny live performance was not affected by breeder's age. Breeders with 270 days retain fertility; however, their egg production, weight and hatchability of fertilized eggs is reduced. In conclusion, European quail breeders with 140 days of age have better egg quality, hatching and breeding results.

Efficacy and Metabolizable Energy Equivalence of an -Amylase--Glucanase Complex for Broilers

A trial was conducted to evaluate the effects of adding an exogenous -amylase--glucanase complex produced from Bacillus amyloliquefaciens on the growth performance, carcass yield, and relative AME bioequivalence in broilers fed corn-soy diets from 1 to 40 d of age. One thousand seven hundred and fifty one-day-old Cobb x Cobb 500 slow-feathering male broilers were randomly allotted to seven treatments with 10 replicates of 25 birds each as follows: control diet (C); C diet with reduction of 60 (C-60), 90 (C-90), or 120 (C-120) kcal AME/kg; C diet with reduction of 120 kcal AME/kg and supplemented with 200 (C-120-200), 300 (C-120-300), or 400 (C-120-400) mg of the enzyme complex/kg. Each g of the enzyme complex corresponded to 200 kilo-Novo -amylase and 350 fungal -glucanase units. On d 40, eight birds were randomly taken from each pen and processed to evaluate carcass and commercial cuts yields. Percent mortality was not affected by the treatments (p > 0.05). Live performance, as indicated by BW gain (BWG) linearly decreased (p 0.05) and FCR linearly increased with the reduction in AME. Birds fed diets supplemented with the enzyme complex showed weekly improvements in BWG and FCR. There were no effects of the treatments on the yield of the carcass or of commercial cuts; however, abdominal fat was significantly lower (p 0.0343) in birds fed the C-120-400 compared to the C-120 feeding program (1.67% vs. 1.90%); all other treatments were intermediate. Average AME equivalence of the enzyme complex varied weekly. Estimations for the entire period were 40, 46, and 56 kcal for BWG and 58, 76, and 99 kcal AME/kg for FCR (p 0.001) for the diets containing 200, 300, and 400 mg enzyme complex/kg, respectively.

Production aspects of broiler breeders submitted to different drinker types

The objective of this study was of evaluate the influence of different drinker types on the egg production, water intake, mortality, poultry litter relative humidity, egg weight, eggshell percentage, and egg specific gravity of broiler breeders. The experiment was carried out in a commercial farm with 37- to 44-wk-old broiler breeders. A randomized block experimental design, consisting of two treatments (bell or nipple drinkers) with four replicates of 4.000 females each, was applied. Data were submitted to analysis of variance, and means were compared by the test of Student-Newman-Keuls at 5% significance level. Birds submitted to nipple drinkers presented lower water intake (p 0.05). There was no influence (p>0.05) of drinker type on egg production or mortality. Poultry litter relative humidity was lower (p 0.05) under the nipple-drinker system. Birds drinking from bell drinkers produced heavier eggs (p 0.05) between weeks 39 and 40. Hens drinking from bell drinkers laid eggs with higher specific gravity and eggshell percentage. It was concluded that nipple drinkers can be used for broiler breeders during lay.(AU)

Productive performance, eggshell quality, and eggshell ultrastructure of laying hens fed diets supplemented with organic trace minerals.

This study was carried out with the purpose of evaluating the effect of supplementing hens' diets with trace minerals from inorganic or organic sources on the productive performance, eggshell quality, and eggshell ultrastructure of laying hens. Three hundred sixty Hy-Line W36 laying hens between 47 to 62 wk of age were used and distributed in a completely randomized experimental design with 9 treatments, 5 replicates, and 8 birds for each experimental unit. The treatments consisted of a control diet without supplementation of the trace minerals Mn, Zn, and Cu; 4 supplementation levels of these trace minerals from an inorganic source; and the same levels of supplementation from an organic source (proteinates). The supplementation levels in milligrams per kilogram for Mn, Zn, and Cu, were, respectively, 35-30-05, 65-60-10, 95-90-15, and 125-120-20. There was no effect of supplementation of trace minerals on the rate of posture, feed intake, feed conversion, specific weight, and Haugh unit of eggs. However, there was a quadratic effect (P < 0.05) of the levels of trace mineral supplementation on average egg weight and egg mass; the results did not differ regarding the source used. The increase in the levels of supplementation of Mn, Zn, and Cu provided a linear increase (P < 0.05) in the breaking strength and the percentage of eggshell. There was a linear decrease (P < 0.05) in the egg loss and the number of mammillary buttons in the shell. The best results were obtained using diets supplemented with trace minerals from an organic source because these diets provided lower egg loss, higher thickness, and increased strength of the shell. Structurally, organic Mn, Zn, and Cu provided higher thickness of the palisade layer and lower mammillary density. The trace mineral supplementation improved the structural characteristics and the quality of the eggshells.

Production aspects of broiler breeders submitted to different drinker types

The objective of this study was of evaluate the influence of different drinker types on the egg production, water intake, mortality, poultry litter relative humidity, egg weight, eggshell percentage, and egg specific gravity of broiler breeders. The experiment was carried out in a commercial farm with 37- to 44-wk-old broiler breeders. A randomized block experimental design, consisting of two treatments (bell or nipple drinkers) with four replicates of 4.000 females each, was applied. Data were submitted to analysis of variance, and means were compared by the test of Student-Newman-Keuls at 5% significance level. Birds submitted to nipple drinkers presented lower water intake (p 0.05). There was no influence (p>0.05) of drinker type on egg production or mortality. Poultry litter relative humidity was lower (p 0.05) under the nipple-drinker system. Birds drinking from bell drinkers produced heavier eggs (p 0.05) between weeks 39 and 40. Hens drinking from bell drinkers laid eggs with higher specific gravity and eggshell percentage. It was concluded that nipple drinkers can be used for broiler breeders during lay.

Production aspects of broiler breeders submitted to different drinker types

The objective of this study was of evaluate the influence of different drinker types on the egg production, water intake, mortality, poultry litter relative humidity, egg weight, eggshell percentage, and egg specific gravity of broiler breeders. The experiment was carried out in a commercial farm with 37- to 44-wk-old broiler breeders. A randomized block experimental design, consisting of two treatments (bell or nipple drinkers) with four replicates of 4.000 females each, was applied. Data were submitted to analysis of variance, and means were compared by the test of Student-Newman-Keuls at 5% significance level. Birds submitted to nipple drinkers presented lower water intake (p 0.05). There was no influence (p>0.05) of drinker type on egg production or mortality. Poultry litter relative humidity was lower (p 0.05) under the nipple-drinker system. Birds drinking from bell drinkers produced heavier eggs (p 0.05) between weeks 39 and 40. Hens drinking from bell drinkers laid eggs with higher specific gravity and eggshell percentage. It was concluded that nipple drinkers can be used for broiler breeders during lay.