FR 10. Reproductive characteristics of breeding Brown Swiss x Zebu bulls in Venezuela
In 74 crossbred young bulls, age, body weight (PC), scrotal circumference (CE) and seminal characteristics from puberty (P) to 24m of age were studied. Evaluations were at monthly intervals from 10 through 24m of age. The bulls represented 3 Groups: I) 1/2 Brown Swiss x 1/2 native crossbred (n=15), II) 1/2 Brahman x 1/4 Brown Swiss x 1/4 native crossbred (n=47), and III) 5/8 Brown Swiss x 3/8 Brahman. (n=11). At P all the groups were similar, only sperm concentration (CON) was superior (P < .001) in Group III (143.6 ± 19.4 vs 98.9 ± 4.5). At 24m Group III had different (P < .001) PC (377.8 vs 312.6, 270.2k) CE (31.8 vs 28.7cm) CON (1143.7 ± 158.3.vs 593.3 ± 149.3) and % normal esperm (93.5 ± 4.4 vs 79.3 ± 2.7) than Groups I and II; II; I and II respectively. Increment of Brown Swiss breed until 62 % could improve PC, CE and seminal quality of crossbred bulls in the tropics.