Heat acclimation during incubation and breeder age influences on hatching performance of broilers.
Bildiriler > Tam Metin Bildiri
Yazarlar: Zişan Servet YALÇIN, Metin Çabuk, E. Babacanoğlu, Johan Buyse, Eddy Decuypere, P.B. Siegel
EPC 2006 - 12th European Poultry Conference, Verona, Italy, 10-14 September, 2006, , , Uluslararası, Tam Metin Bildiri
Özet
Heat tolerance of broilers can be changed by exposing eggs to higher temperatures during incubation. The present study measured responses of the chicks, from eggs obtained from 3 different parental ages, to either standard or high incubation temperatures. A total of 1650 eggs were obtained from 3 broiler breeder flocks (Ross 308) that were 32 (younger), 42 (middle aged), and 65 (older) weeks of age. There were 2 flocks for each breeder age. Eggs were divided into 2 groups as 1). Control incubation temperature: eggs incubated at 37.8oC from d 1 to 18 of incubation and 2). High incubation temperature: Eggs were heat acclimated at 38.5o C for 6 hours daily from d 10 to 18 of incubation. The timing of hatching was recorded every 2 h between 464 and 500 h of incubation. Hatchability was determined. At hatch, body weight, rectal temperature, length of beak and third right toe, blood HCO3 level, and organ weights were measured for 10 male chicks/parent age/incubation temperature. Data were subjected to ANOVA. Effects of high incubation temperature on traits measured did not interact with breeder age. As breeders aged from 32 to 65 wk, chick weight, residual yolk weight, yolk free chick weight, absolute liver and heart weights increased. Breeder age did not affect lung weight. An increase in residual yolk sac weight and rectal temperature, and a decrease in liver and heart weights were observed for the chicks from heat acclimated eggs. High incubation temperature had no effect on blood HCO3 level of chicks at hatch. The results showed that although embryos could tolerate to 38.5°C 6h/d from 10 to 18d of incubation without reducing hatching success, there was a delay in hatching time.