The transfer of amino acids and minerals to the egg yolk and to the yolk sac of their progeny is affected by breeder age.

This study aimed to assess the effects of breeder age on egg quality and amino acid and mineral transfer to the egg yolk and yolk sac of newly hatched chicks. Three ages (32, 42 and 52 weeks) of the same commercial flock of Hubbard breeders were studied. A total of 465 eggs were used for each age, with 60 being used for determining egg quality and amino acid and mineral content of yolk, and 405 for incubation period to obtain and evaluate the yolk sac of chicks. Breeders aged 52 weeks had heavier eggs and a higher percentage of yolk (p < 0.05), whereas 32-week-old breeders had higher eggshell percentage and thickness (p < 0.05). The percentage of protein deposited in egg yolk for 52-week-old breeders was higher than that for 32- and 42-week-old breeders (p < 0.05). Percentages of methionine, cysteine, met + cysteine, lysine, threonine, tryptophan, arginine and isoleucine in egg yolk for 32-week-old breeders were higher than that for 42- and 52-week-old breeders (p < 0.05). The transfer from breeder of phosphorus, potassium, calcium, magnesium, copper, iron, manganese and zinc to the yolk of eggs from 32-week-old breeders was greater than that for eggs from 42- and 52-week-old breeders (p < 0.05). Chicks from 32-week-old breeders had greater deposition of phosphorus and calcium in the yolk sac (p < 0.05). Breeder age did not affect the deposition of potassium, magnesium, copper, iron, manganese and zinc in the yolk sac of newly hatch chicks (p > 0.05). It can, however, be concluded that younger breeders deposit more amino acids and minerals in egg yolk, while embryos of older breeders seem to use the nutrients present in the yolk more efficiently during embryonic development.

Hematology and serum biochemistry of broilers at the initial and growth stages submitted to different levels of digestible sulfur amino acids / Hematologia e bioquímica sérica de frangos de corte submetidos a diferentes níveis de aminoácidos sulfurados digestíveis

ABSTRACT: The objective of this study was to evaluate the effect of digestible methionine and cystine (Met + Cys) levels on the hematological and serum biochemical parameters of broiler chickens during the initial and growth stages. For this, 1,800 male chicks of the Coob 500 strain were used, with 900 chicks in the initial phase (1 to 21 days old) and 900 chicks in the growth phase (22 to 42 days old), distributed in a completely randomized design of five treatments with six replicates of 30 birds. The treatments consisted of 0.545, 0.616, 0.711, 0.782, and 0.853%; and 0.514, 0.571, 0.647, 0.704, and 0.761% digestible Met + Cys for "1 to 21" and "22 to 42" days of breeding, respectively. Results showed that digestible Met + Cys levels in broiler feed altered some hematological parameters (erythrocyte, hematocrit hemoglobin, total leukocytes, heterophile: lymphocyte) and serum biochemistry (uric acid, PST, total LDL, and TG). The digestible Met + Cys levels in the diet of broilers affected the hematological parameters and serum biochemistry, especially at higher levels. From the inclusion level 0.761 of Met + Cist in the broiler diet, red blood cells, hemoglobin and hematocrit changes begin to appear.

RESUMO: Teve-se como objetivos neste estudo avaliar o efeito dos níveis de metionina + cistina (Met+Cis) digestível na dieta sobre os parâmetros hematológicos e bioquímicos séricos de frangos de corte na fase inicial e de crescimento. Para isso, utilizou-se 1.800 pintos, machos, da linhagem Coob 500, sendo 900 pintos para a fase inicial (1 a 21 dias de idade) e mais 900 pintos para a fase de crescimento (22 a 42 dias de idade), distribuídos em delineamento inteiramente casualizado composto de cinco tratamentos, com seis repetições de 30 aves. Os tratamentos consistiram em 0,545; 0,616; 0,711; 0,782 e 0,853% e 0,514; 0,571; 0,647; 0,704 e 0,761% de Met+Cis digestíveis para a fase inicial e de crescimento, respectivamente. Os resultados demonstraram que níveis de Met+Cis digestível na alimentação de frango de corte, acarretam alterações em parâmetros hematológicos como: hemácia, hematócrito, hemoglobina, leucócitos totais, relação heterófilo: linfócito; e bioquímico sérico como: ácido úrico, albumina, colesterol total, proteínas séricas totais (PST), lipoproteína de baixa densidade (LDL) e triglicerídeos (TG). Os níveis digestíveis de Met + Cys na dieta de frangos de corte afetam os parâmetros hematológicos e a bioquímica sérica, principalmente em níveis mais elevados. A partir do nível de inclusão 0.761 de Met + Cist na dieta de frangos de corte, começam a aparecer alterações nos glóbulos vermelhos, hemoglobina e hematócrito.