Embryonic muscle development and degenerations in broilers
Project no. 899 · Status: Kapanmış · 2018
Summary
The aim of the present study was to investigate the effect of incubation of hatching eggs at temperatures higher than optimum on muscle growth, blood parameters, expression of insulin-like growth factor (IGF-1), vascular endothelial growth factor A (VEGFA) and myogenin genes, muscle degenerations and meat quality in broilers. The study was conducted on two broiler genotypes in order to examine the effect of genetic stock. For this purpose, the eggs were incubated in two incubation temperatures as CONTROL (37.8 ° C between 0 and 18 days) and HEATING (38.8 ° C for 6 h between 10 and 14 days). Cyclical temperature changes did not affect hatchability, but the effect of hatching temperature on chick weight varied according to genotypes. HEATING did not affect the histological properties of the muscle of the chicks. At the hatch, capillary number and plasma T3 and TBARS levels of Ross chicks were higher than those of Cobb. The highest VEGFA gene expression was found in Cobb-HEAT chicks. At slaughter age, while the body weight was the heaviest in the Ross-HEATING group, the weight of the other groups was similar. TBARS level in the liver increased with HEATING at the slaughter age. Genotype x incubation temperature interaction showed that hatching temperature did not affect breast weight in the Cobb group, but HEATING increased breast weight of Ross chickens. While the effect of the genotype on the incidence of white stripes was found to be insignificant, HEATING increased the incidence of white stripes. The white stripe score was higher in Ross-HEATING than Ross-CONTROL. At slaughter age, breast muscle IGF-1 expression was higher in Cobb chickens than Ross and in the HEATING group compared to CONTROL. HEATING decreased fiber number but increased fiber area at slaughter age. In conclusion, the results of the cyclic higher temperatures during incubation may vary according to the genotypes, it did not affect meat quality, but it could cause a slight increase in the occurance of white stripes.