Interactions between lipid source and vitamin A on broiler performance, blood parameters, fat and protein deposition rate, and bone development.

A total of 2622 male broilers were distributed in a 2 × 5 factorial design, using 2 lipid sources (soybean oil and palm fat), 5 levels of vitamin A supplementation (0, 3,000, 6,000, 12,000, and 24,000 IU kg-1), with 10 replicates, and also 1 control diet (CD) for each lipid source used (7 replicates), each experimental unit being composed of 23 birds. During the first 21 d (how were the birds fed) and from 22 to 42 d of age, a redistribution of the treatments was carried out in a 2 × 2 × 5 factorial design: half of the repetitions of each treatment received the diet of the initial treatment, and the others received the CD with its type of lipid source. In the phase from 1 to 21 d of age, the effect of lipid source on feed intake (FI) and feed conversion ratio (FCR), and the effect of vitamin supplementation on FI and weight gain (WG) were observed, with a quadratic response for both variables. At 42 d of age, the lipid source and vitamin A level influenced the FI, whereas the WG and FCR showed interactions between period and the level of vitamin A supplementation. Neither lipid source resulted in blood parameters out of the typical pattern for birds, and the same was observed in relation to dietary vitamin A supplementation. From 1 to 21 d of age, a vitamin A supplementation of 15,585 IU kg-1 was estimated, and at 42 d, 15,527 IU kg-1 and 15,148 IU kg -1 were estimated for the periods 1 to 21 d and 1 to 42 d, respectively.

Quantidade de metionina+cistina digestível para poedeiras semipesadas de 75 a 91 semanas de idade / Nutritional requirement of digestible methionine + cystine for brown-egg laying hens from 75 to 91weeks of age

Determinaram-se as exigências nutricionais de metionina+cistina digestível para poedeiras de linhagem comercial no segundo ciclo de produção de 75 a 91 semanas de idade, utilizando-se 150 aves semipesadas em delineamento inteiramente ao acaso. Estas foram distribuídas em cinco tratamentos, seis repetições e cinco aves por unidade experimental, alimentadas com uma dieta basal contendo 2.859kcal/kg de energia metabolizável e 16,30% de proteína bruta, suplementada com 0,132; 0,173; 0,215; 0,256 e 0,298% de DL-metionina (98%), de forma a proporcionar 0,588; 0,628; 0,669; 0,709 e 0,750% de metionina+cistina digestível na dieta. A inclusão de metionina+cistina obedeceu, respectivamente, às proporções de 67, 72, 77, 81 e 86% com a lisina fixada em 0,872%. Avaliaram-se os consumos de ração e de metionina+cistina, a conversão alimentar por dúzia e por massa de ovos, a taxa de postura, o peso e a massa de ovos, a porcentagem dos componentes dos ovos e a qualidade interna dos ovos e o ganho de peso. A inclusão de metionina+cistina digestível nas quantidades indicadas não exerceu efeito (P>0,05) sobre as características de produção e qualidade interna e externa dos ovos. A exigência estimada foi de 0,588% de metionina+cistina digestível, correspondendo ao consumo de 654,73mg/ave/dia.

This work determined the nutritional requirements for methionine + cystine for commercial hens in the second production cycle from 75 to 91 weeks of age, using 150 brown-egg layer hens in a completely randomized design, distributed in five treatments, six replicates of five hens each and fed a basal diet containing 2859kcal/kg of metobolizable energy, 16.30% crude protein supplemented with 0.132, 0.173, 0.215, 0.256 and 0.298% DL-methionine (98%), in order to provide 0.588, 0.628, 0.669, 0.709 and 0.750% methionine + cystine in the diet. The inclusion of methionine + cystine followed, respectively, the proportions of 67, 72, 77, 81 and 86% with lysine fixed at 0.872%. The feed intake, methionine + cystine intake, feed conversion per dozen eggs and egg mass, percentage of the eggs, egg weight, egg mass, percentage of egg components and internal quality of eggs and weight gain were evaluated. The inclusion methionine + cystine in the amounts indicated had no effect (P> 0.05) on the production characteristics and internal and external quality of eggs. The requirement was estimated at 0.588% methionine + cystine intake corresponding to 654.73mg/hen/day.