Fúlvio Vinícius Foch Furtado

Hatching distribution and embryo mortality of eggs laid by broiler breeders of different ages

This study investigated the hatching distribution of eggs from broiler breeders of different ages in distinct periods of incubation. Eggs were incubated in a single-stage experimental incubator. A number of 3.510 eggs were distributed into 3 treatments with 13 replicates of 90 eggs each. Treatments corresponded to breeder age: young (34 weeks), intermediate-age (44 weeks) and old (72 weeks) breeders. Eggs were transferred to the hatcher at 432 incubation hours, hatching was first checked at 449 hours, after which the number of hatched chicks was counted every 6 hours up to 515 incubation hours. After each count, hatched chicks were removed from the hatcher. Data were submitted to analysis of variance using measures repeated. A significant interaction between breeder age and incubation time was found. The total period required to hatch all incubated fertile eggs was not influenced by breeder age, which, however, affected hatching distribution. Eggs from old breeders hatched later as compared to young and intermediate-age breeders. More than 71% of the eggs had already hatched at 485 incubation hours, and 94% at 491 hours. Eggs laid by old breeders presented higher infertility and total embryo mortality, resulting in lower hatching percentage.

Productive performance of broiler breeder hens fed 25-hydroxycholecalciferol

Foi realizado um experimento com o objetivo de avaliar a suplementacao de 25-hidroxicolecalciferol (25(OH)D3) associado a vitamina D3 em dietas para reprodutoras de frangos de corte. Foram alojadas matrizes Cobb 500 em delineamento completamente casualizado, composto de quatro tratamentos e oito repeticoes de 20 femeas e 2 machos. Os tratamentos experimentais foram constituidos de premixes vitaminicos contendo 2.000 e 3.400 UI/kg racao de vitamina D3 como unica fonte ou 2.000 UI D3 associado a 35 ou 69 mg/t de 25(OH)D3. Nao houve efeito da suplementacao de 25(OH)D3 sobre a producao de ovos durante o periodo de 32 a 67 semanas. A qualidade da casca dos ovos, mensurada por meio da gravidade especifica, melhorou com a suplementacao de 25(OH)D3 em reprodutoras com 60 semanas de idade, independentemente da dose. Nao foi observada diferenca significativa na taxa de eclosao de ovos ferteis incubados nas 54 e 64 semanas de idade das aves. As 64 semanas, houve menor mortalidade de embrioes na terceira semana entre as aves recebendo a dieta com 2.000 UI D3, enquanto, as 67 semanas, houve menor mortalidade na primeira semana de embrioes provenientes de reprodutoras sob suplementacao com 2.000 UI D3 e 2.000 UI D3 + 69 mg 25(OH)D3. A combinacao de 25-hidroxicolecalciferol e colecalciferol teve efeito similar ao das dietas com vitamina D3 como fonte exclusiva sobre o desempenho produtivo de reprodutoras pesadas.