Fenotipska povezanost telesne težine nosilja i reproduktivnih osobina brojlerskih roditelja

Examinations were conducted in two flocks of broiler parents' hybrids Ross 308 and Cobb 500. At the beginning of the production cycle (24th weeks of age) was determined that the average hens body weight of hybrid Ross 308 was 2680.40 g, and to hybrid Cobb 500 was 2697.80 g. At 42nd weeks of age (middle of the production cycle) hens body weight was 3565.10 g (Ross 308) and 3599.05 g (Cobb 500), while at the end of the production cycle (61st weeks of age) hens body weight of hybrid Ross 308 was 3841.50 g, and to the Cobb 500 was 3850.00 g. Determined differences of hens body weight (17.40 g, 33.95 g and 8.50 g) in specific periods of the production cycle, and the difference in hens body weight for the entire cycle (23.26 g) weren't statistically significant (P>0.05). Specific consideration of the impact of hens' body weight on reproductive performances of broiler parents was determined by calculating the coefficients of phenotypic correlation among the tested indicators. Thus, between hens body weight and most reproductive indicators of broiler parents were determined statistically very significant (P lt 0.001) coefficients of phenotypic correlation, while between hens body weight and the percentages of chickens feasibility from fertilized eggs were determined significant (P lt 0.001; P lt 0.01; P lt 0.05) correlation coefficients for a slightly shorter period than anticipated 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 nosilja (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 reproduktivne performanse brojlerskih roditelja utvrđeno je izračunavanjem koeficijenata fenotipske korelacije između ispitivanih pokazatelja. Tako su između telesne težine nosilja i većine reproduktivnih pokazatelja brojlerskih roditelja utvrđeni statistički vrlo signifikantni (P lt 0,001) koeficijenti fenotipske korelacione povezanosti, dok su između telesne težine nosilja i procenta izvodljivosti pilića od oplođenih jaja utvrđeni statistički signifikantni (P lt 0,001; P lt 0,01; P lt 0,05) koeficijenti korelacije za nešto kraći period (55. nedelja starosti) od predviđenog proizvodnog ciklusa