Incorporation of labeled methionine as a tissue tracer in broiler chickens

The objective of this study was to evaluate the process of L-methionine incorporation in the blood plasma, liver, breast muscle, and abdominal fat of 35- to 59-d-old broiler chickens using the carbon stable isotope (12C and 13C) technique for the estimation of methionine requirements. In this experiment, 51 male broiler chickens orally received a solution of L-[13C1] methionine (92 atm % 13C) at 29 µmol/kg live weight/h for 6 h. Three birds were sacrificed for tissue collection at times 0 h (control), 0.5, 1, 2, 3, 4, 5, 6, 12, 24, 48, 72, 96, 120, 144, 168, and 336 h after the administration of the first dose. Tissue L-[13C1] methionine incorporation mass and percentage results were analyzed using Minitab 16 statistical software. Except for abdominal fat, tissue methionine levels gradually increased after the administration of the methionine solution. The calculated half-lives of methionine in the blood plasma, liver, and breast muscle were 2.52, 1.36, and 3.57 h, respectively, suggesting a greater rate of methionine incorporation in the liver, followed by blood plasma and breast muscle. The isotopic dilution showed that 2.81, 4.79, and 23.64% of the administered L-methionine were retained in the blood plasma, liver, and breast muscle, respectively. The methionine requirements of finisher broilers may be estimated using the carbon isotope technique, and approximately 3, 5, and 24% methionine is used for the synthesis of blood plasma, liver, and breast muscle, respectively, at the evaluated dose.

Incorporation of labeled methionine as a tissue tracer in broiler chickens

The objective of this study was to evaluate the process of L-methionine incorporation in the blood plasma, liver, breast muscle, and abdominal fat of 35- to 59-d-old broiler chickens using the carbon stable isotope (12C and 13C) technique for the estimation of methionine requirements. In this experiment, 51 male broiler chickens orally received a solution of L-[13C1] methionine (92 atm % 13C) at 29 µmol/kg live weight/h for 6 h. Three birds were sacrificed for tissue collection at times 0 h (control), 0.5, 1, 2, 3, 4, 5, 6, 12, 24, 48, 72, 96, 120, 144, 168, and 336 h after the administration of the first dose. Tissue L-[13C1] methionine incorporation mass and percentage results were analyzed using Minitab 16 statistical software. Except for abdominal fat, tissue methionine levels gradually increased after the administration of the methionine solution. The calculated half-lives of methionine in the blood plasma, liver, and breast muscle were 2.52, 1.36, and 3.57 h, respectively, suggesting a greater rate of methionine incorporation in the liver, followed by blood plasma and breast muscle. The isotopic dilution showed that 2.81, 4.79, and 23.64% of the administered L-methionine were retained in the blood plasma, liver, and breast muscle, respectively. The methionine requirements of finisher broilers may be estimated using the carbon isotope technique, and approximately 3, 5, and 24% methionine is used for the synthesis of blood plasma, liver, and breast muscle, respectively, at the evaluated dose.(AU)

Phytogenic additives and glutamine plus glutamic acid in broiler diets

The objective of this study was to evaluate the effect of the dietary supplementation of phytogenic additives (PAs) and glutamine plus glutamic acid (Gln/Glu), associated or not, in replacement of antibiotic growth promoters and anticoccidials (AGP/AC) on the performance and carcass yield of broilers. Five hundred male Cobb broilers were housed in an experimental house and randomly distributed into five treatments, with four replicates of 25 birds each. Treatments consisted of a control diet (CD); CD+AGP/AC; CD+Gln/Glu; CD+PAs; CD+Gln/ Glu+PAs. Diets were formulated only with plant feedstuffs, i.e., they did not contain any animal byproducts. Performance data were collected for the accumulated periods of 1-7, 1-21, and 1-42 days of age. Carcass yield and parts yield were determined at 42 days of age. Treatments did not influence performance during none of the evaluated periods. The greatest carcass yield (p 0.05) was obtained in birds in the treatments CD+Gln/Glu and CD+Gln/Glu+PAs relative to CD, but not different from birds in the AGP+AC and PAs treatments, which were not different from the CD treatment. Birds fed the CD+Gln/Glu diet presented greater breast yield (p 0.05) compared with those in the CD and AGP/AC treatments, but there was no difference in comparison with the other treatments. Under the conditions of the present experiment, the dietary supplementation with phytogenic additives and with glutamine plus glutamic acid does not affect the performance, but improves carcass yield and breast yield of broilers.(AU)

Phytogenic additives and glutamine plus glutamic acid in broiler diets

The objective of this study was to evaluate the effect of the dietary supplementation of phytogenic additives (PAs) and glutamine plus glutamic acid (Gln/Glu), associated or not, in replacement of antibiotic growth promoters and anticoccidials (AGP/AC) on the performance and carcass yield of broilers. Five hundred male Cobb broilers were housed in an experimental house and randomly distributed into five treatments, with four replicates of 25 birds each. Treatments consisted of a control diet (CD); CD+AGP/AC; CD+Gln/Glu; CD+PAs; CD+Gln/ Glu+PAs. Diets were formulated only with plant feedstuffs, i.e., they did not contain any animal byproducts. Performance data were collected for the accumulated periods of 1-7, 1-21, and 1-42 days of age. Carcass yield and parts yield were determined at 42 days of age. Treatments did not influence performance during none of the evaluated periods. The greatest carcass yield (p 0.05) was obtained in birds in the treatments CD+Gln/Glu and CD+Gln/Glu+PAs relative to CD, but not different from birds in the AGP+AC and PAs treatments, which were not different from the CD treatment. Birds fed the CD+Gln/Glu diet presented greater breast yield (p 0.05) compared with those in the CD and AGP/AC treatments, but there was no difference in comparison with the other treatments. Under the conditions of the present experiment, the dietary supplementation with phytogenic additives and with glutamine plus glutamic acid does not affect the performance, but improves carcass yield and breast yield of broilers.

Efeito da temperatura ambiente e da idade do frango sobre o valor energético do farelo de soja / Effects of environmental temperature and age of broilers on energy value of soybean meal

Foram utilizados 288 pintos de corte Cobb, distribuídos em delineamento experimental inteiramente ao acaso, em esquema de parcelas subdivididas no tempo, sendo as três temperaturas de criação - fria, termoneutra e quente - as parcelas, e as três fases de avaliação - inicial, crescimento e final - as subparcelas, com seis repetições de seis aves cada. A dieta-teste foi obtida pela substituição de parte da ração basal pelo alimento-teste: 40 por cento do farelo de soja + 60 por cento da ração basal. Foram calculados os coeficientes de metabolizabilidade aparente e verdadeiro da matéria seca, do nitrogênio, do extrato etéreo da dieta-teste e os valores de energia metabolizável aparente e verdadeira (EMA e EMV), e corrigidas pelo balanço de nitrogênio do farelo de soja (EMAn e EMVn). Foram encontrados valores médios de EMAn do farelo de soja para aves criadas em temperatura fria, termoneutra e quente de 2110, 2016 e 2022kcal/kg, respectivamente, e para as fases de criação inicial, crescimento e final de 1840, 2052 e 2256kcal/kg, respectivamente. O valor de energia metabolizável do farelo de soja, os balanços e os coeficientes de metabolizabilidade dos nutrientes da dieta-teste aumentaram com a idade do frango de corte, porém não são afetados pela temperatura ambiente.(AU)

Two hundred and eighty-eight Cobb chicks were distributed in a completely randomized design with a split-plot arrangement with six replication of six chicks each, the main plots were in three temperatures (cold, thermo neutral and hot) and the secondary plot were by phase (initial, growing and final). The test diet was produced by replacing the basal diet with test food: 40 percent soybean meal+60 percent basal diet. The coefficient of apparent and true metabolizability of dry matter, nitrogen, ether extract of the test diet and apparent and true metabolizable energies (AME and TME) of soybean meal were calculated and energy values were corrected for nitrogen balance (AMEn and TMEn) of soybean meal, in kcal/kg, as fed basis. The mean values of AMEn observed for broiler chicks in cold, thermo neutral and hot temperature were 2110, 2016 and 2022kcal/kg, respectively, and the initial, growing and final phases were 1840, 2052 and 2256kcal/kg, respectively. The metabolizable energy values of soybean meal, the balance and coefficients of metabolizability of the nutrients of the test diet increased with the age of broiler; however, they were not affected by environmental temperature.(AU)

Efeito da temperatura ambiente e da idade do frango sobre o valor energético do farelo de soja

Two hundred and eighty-eight Cobb chicks were distributed in a completely randomized design with a split-plot arrangement with six replication of six chicks each, the main plots were in three temperatures (cold, thermo neutral and hot) and the secondary plot were by phase (initial, growing and final). The test diet was produced by replacing the basal diet with test food: 40% soybean meal+60% basal diet. The coefficient of apparent and true metabolizability of dry matter, nitrogen, ether extract of the test diet and apparent and true metabolizable energies (AME and TME) of soybean meal were calculated and energy values were corrected for nitrogen balance (AMEn and TMEn) of soybean meal, in kcal/kg, as fed basis. The mean values of AMEn observed for broiler chicks in cold, thermo neutral and hot temperature were 2110, 2016 and 2022kcal/kg, respectively, and the initial, growing and final phases were 1840, 2052 and 2256kcal/kg, respectively. The metabolizable energy values of soybean meal, the balance and coefficients of metabolizability of the nutrients of the test diet increased with the age of broiler; however, they were not affected by environmental temperature.

Foram utilizados 288 pintos de corte Cobb, distribuídos em delineamento experimental inteiramente ao acaso, em esquema de parcelas subdivididas no tempo, sendo as três temperaturas de criação - fria, termoneutra e quente - as parcelas, e as três fases de avaliação - inicial, crescimento e final - as subparcelas, com seis repetições de seis aves cada. A dieta-teste foi obtida pela substituição de parte da ração basal pelo alimento-teste: 40% do farelo de soja + 60% da ração basal. Foram calculados os coeficientes de metabolizabilidade aparente e verdadeiro da matéria seca, do nitrogênio, do extrato etéreo da dieta-teste e os valores de energia metabolizável aparente e verdadeira (EMA e EMV), e corrigidas pelo balanço de nitrogênio do farelo de soja (EMAn e EMVn). Foram encontrados valores médios de EMAn do farelo de soja para aves criadas em temperatura fria, termoneutra e quente de 2110, 2016 e 2022kcal/kg, respectivamente, e para as fases de criação inicial, crescimento e final de 1840, 2052 e 2256kcal/kg, respectivamente. O valor de energia metabolizável do farelo de soja, os balanços e os coeficientes de metabolizabilidade dos nutrientes da dieta-teste aumentaram com a idade do frango de corte, porém não são afetados pela temperatura ambiente.