Parâmetros genéticos em características morfológicas de bovinos Nelore

This study presents the results of a linearized type appraisal score system given to bulls, at the end of the performance test at the Estacao Experimental de Zootecnia de Sertaozinho, State of Sao Paulo, Brazil. The 364 bulls, that composed the analised sample, were born in 1985, 1986 and 1987 and were 378 days old in average. They were examined under the same criteria utilized in a cattle show judgment. The scores ranged from 1 to 9 being the score 5 atributed to a normal condition in each trait. The simple and genetic correlation between weight at the end of test, hip height and the linear type traits, were also obtained, besides the heritability of each trait. The averages for all the traits were: final weight on test (PPF) 290.3 Kg; hip height (ALTPPF) 1.31 m; forehead width (MA) 5.9; bridge of nose (CHA) 5.1; lenght of ears (ORE) 5.1; lenght of neck (PES) 5.0; size of hump (CUP) 5.0; chest width (PEI) 4.6; lenght of back and loin (DOR) 4.8; body depth (PROF) 4.7: lenght of sheath (UMB) 4.9; pelvic angle (GINC) 4.8; rump lenght (GCOM) 4.8; pelvic width (GTRAS) 4.8; size of sacrum (SA) 5.4; height of tail attachment (INS) 5.6; angle of hind legs (POST) 5.6; lenght of shank (CAN) 4.0 and hair color and skin pigmentation (PEL) 5.4. The highest genetic correlation were those between PPF and GTRAS (0.98); PPF and PEI (0.92); DOR and GTRAS (0.86); GCOM and GTRAS (0.85); PROF and GCOM (0.84); PROF and GTRAS (0.83); DOR and GTRAS (0.79); PROF and PPF (0.79); DOR and PEI (0.77); PROF and DOR (0.76); DOR and PPF (0.75), GCOM and PPF (0.72); GCOM and PEI (0.71); PROF and GCOM (0.66); DOR and ALTPPF (0.57); GCOM and ALTPPF (0.48); and PPF and ALTPP (0.42). The highest heritability estimates were for PPF (0.53); PEI (0.55); PROF (0.65); UMB (0.70). Median estimates were obtained for DOR (0.46) and ALTPPF (0.47).