RESUMO
Two experiments were conducted to compare different feed allocation programs from 16 to 26 wk of age and during the subsequent production period on broiler breeder male BW and fertility. In experiment 1, Ross 344 males were randomly assigned to 3 rates (slow, medium, or fast) of weekly feed increase from 16 to 26 wk of age that provided a gradual increase from 85 to 110 g/male/d. Feed allocation was also increased 5 g/ male/d in a single increment at 55 wk of age after fertility had declined. In experiment 2, a 2 x 2 factorial design was used to evaluate the interaction between the slow and fast feeding programs described in experiment 1 in combination with 2 feeding programs (constant or increasing) during the subsequent production period. In experiment 1, the males on the fast feed program exhibited higher mortality after 32 wk of age and lower fertility after 46 wk of age. However, fertility recovered in all treatments after the feed allocation was increased at 55 wk of age. In experiment 2, the constant program elicited lower fertility from 36 to 55 wk. Males that received the slow feed program from 16 to 26 wk of age gained BW more slowly and apparently required less feed to sustain their BW throughout the production period. Increasing male feed allocation during the production period improved fertility.
Assuntos
Ração Animal , Peso Corporal/fisiologia , Galinhas/crescimento & desenvolvimento , Aumento de Peso/fisiologia , Animais , Dieta , Ingestão de Energia , Fertilidade , MasculinoRESUMO
A 2 x 2 factorial experiment was conducted to compare the effects of 2 male broiler breeder feed allocation programs (Concave or Sigmoid) during the rearing period to 26 wk of age and the interaction with dietary CP (12 or 17%) on BW and fertility. From 0 to 2 wk, all birds received a starter diet, after which, pens were randomly assigned to the 4 treatment combinations that ended at 26 wk of age. All males were weighed individually at 4, 8, 12, 16, 22, 26, 28, 32, 36, 40, 48, 52, 56, and 64 wk of age, and fertility was determined weekly from 27 to 32 wk of age and then every 2 wk to 64 wk of age. At 49 wk of age, the male feed allocation for all treatments was increased by 5 g/d. Even when fed the same as Sigmoid program males during the production period, males reared on the Concave feeding program lost BW from 32 to 40 wk of age and exhibited lower BW from 40 to 48 wk of age, which corresponded to a more rapid decrease in fertility. The 17% CP diet increased BW from 8 to 32 wk of age, but no significant differences were subsequently observed. The 12% CP rearing diet improved both weekly and cumulative fertility. A significant interaction between rearing feeding program and dietary CP during the third quartile period showed that the Concave program-17% CP diet combination was most negatively affected. The increase in male feed allocation at 49 wk restored fertility and caused differences among treatments to diminish. These data suggested that BW during the early rearing period did not affect fertility, but an increased BW due to either providing fast feed increments toward the end of the rearing period (Concave) or feeding a 17% CP diet produced males that were unable to sustain fertility after 40 wk of age without an appropriate allocation of feed.
Assuntos
Ração Animal , Criação de Animais Domésticos/métodos , Peso Corporal/efeitos dos fármacos , Galinhas/crescimento & desenvolvimento , Proteínas Alimentares/farmacologia , Fertilidade/efeitos dos fármacos , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Masculino , Fatores de TempoRESUMO
Two experiments were conducted to evaluate the effects of 2 planes (low and high) of cumulative nutrient intake during the rearing period on performance of broiler breeder males. The low cumulative nutrition program supplied 29,580 kcal of ME and 1,470 g of CP, whereas the high cumulative nutrition program supplied 33,500 kcal of ME and 1,730 g of CP to photostimulation at 21 wk of age. Two diets (LoDiet and HiDiet) were used with a single feeding program in experiment 1. In experiment 2, a single diet with 2 feeding programs (LoFeed and HiFeed) was used. In experiment 1, the 2 diets were blended from 21 to 24 wk to provide a gradual transition to a single common laying breeder diet that was fed during the production period. At 21 wk of age in experiment 2, males were divided into light or heavy BW groups to complete a 2 x 2 factorial design during the production period. The high plane of nutrition increased BW, shank length, and comb height during the rearing period, but the differences disappeared after 28 wk of age. Retrospective analysis showed that the heavy males at 21 wk of age in experiment 2 were also the heaviest males at 8 wk of age. Both low plane groups (LoDiet in experiment 1 and LoFeed in experiment 2) exhibited better fertility during late production. A cumulative nutrient intake during the rearing period of 29,580 kcal of ME and 1,470 g of CP was minimally sufficient for subsequent male reproductive performance.