Effect of body weight of laying hens on production traits of broiler parents

Abstract

Certain investigations have been conducted in two broiler breeder flocks of Ross 308 and Cobb 500 hybrids. At the beginning of the production cycle (24 weeks of age), an average laying hens' body weight of 2680.40 g was found in the case of Ross 308 hybrid, and 2697.80 g in the case of Cobb 500 hybrid. During 42nd week of age (the middle of the production cycle), the body weight of laying hens was 3565.10 g (Ross 308) and 3599.05 g (Cobb 500), while at the end of the production cycle (61 weeks of age) the body weight of laying hens of Ross 308 hybrid was 3841.50 g, and 3850.00 g of Cobb 500. Identified differences in body weight of laying hens (17.40 g, 33.95 g, 8.50 g) in certain periods of the production cycle, as well as the difference in body weight of laying hens for the entire production cycle (23.26 g) were not statistically significant (P>0.05). More specific observation of the effect of body weight of laying hens on productive capacity of broiler breeders was determined by calculating the coefficients of phenotype correlation between the indicators studied. Thus, statistically significant (P lt 0.001, P lt 0.01, P lt 0.05) coefficients of phenotype correlation between the body weight of laying hens and the majority of production indicators have been determined, while statistically significant (P lt 0.001, P lt 0.01, P lt 0.05) correlation coefficients between the body weight of laying hens and the intensity of laying capacity for hatching and fertilized eggs have been determined, but for a shorter period of the production cycle.

Ispitivanja su sprovedena na dva jata brojlerskih roditelja hibrida Ross 308 i Cobb 500. Na početku proizvodnog ciklusa (24. nedelja starosti) kod hibrida Ross 308 utvrđena je prosečna telesna težina nosilja 2680.40 g, a hibrida Cobb 500 2697.80 g. U 42. nedelji starosti (sredina proizvodnog ciklusa) telesna težina nosilja iznosila je 3565.10 g (Ross 308) i 3599.05 g (Cobb 500), dok je na kraju proizvodnog ciklusa (61. nedelja starosti) telesna težina nosilja hibrida Ross 308 iznosila 3841.50 g, a Cobb 500 3850.00 g. Utvrđene razlike telesne težine nosillja (17.40 g, 33.95 g i 8.50 g) u određenim periodima proizvodnog ciklusa, kao i razlika u telesnoj težini nosilja za ceo proizvodni ciklus (23.26 g) nisu bile statistički signifikantne (P>0.05). Konkretnije sagledavanje uticaja telesne težine nosilja na proizvodne sposobnosti brojlerskih roditelja utvrđeno je izračunavanjem koeficijenata fenotipske korelacije između ispitivanih pokazatelja. Tako su između telesne težine nosilja i većine proizvodnih pokazatelja utvrđeni statistički signifikantni (P lt 0,001; P lt 0,01; P lt 0,05) koeficijenti fenotipske korelacione povezanosti, dok su između telesne težine nosilja i intenziteta nosivosti priplodnih i oplođenih jaja utvrđeni statistički signifikantni (P lt 0,001; P lt 0,01; P lt 0,05) koeficijenti korelacije, ali za nešto kraći period proizvodnog ciklusa.