The present study was undertaken to determine the fertility soundness of unselected bulls used for breeding based on a standard breeding soundness evaluation technique (BSE) and trans-scrotal ultrasonography (TSU). A total of 8 bulls, with the mean age of 51⁄2 years (ranged from 31⁄2 8 years) and the mean weight of 651.5kg (ranged from 480-840 kg) were evaluated. Three bulls were Friesian Sahiw...

OBJECTIVE To determine prevalence of infection with tritrichomonas fetus in a bull population; assess influence of age, breed, and grouping; assess effects on measures of cow performance (pregnancy rate, weaning percentage, weaning weight); and estimate test sensitivity. DESIGN Epidemiologic study. ANIMALS 1,383 bulls and records for 28,471 cows bred by these bulls in the immediate past bre...

Genetic evaluations of Holstein bulls for February 1997 through May 1998 were examined to determine the value of more frequent evaluation for quicker identification of bulls with changing predicted transmitting abilities (PTA) and of new bulls of superior genetic merit. Changes in PTA between evaluations that were calculated quarterly rather than semiannually were reduced by 30%. About two-thir...

Current study aimed to evaluate the performance of bulls (1/2 Purunã vs 1/2 Canchim) slaughtered at two ages and three different weights. One hundred and thirteen bulls were divided into two slaughter ages (16 and 22 months) and three different slaughter weights (light, 422 kg; medium, 470 kg; and heavy, 550 kg). The body weight was higher for bulls slaughtered at 16 months. Daily gain, carcass...

Subfertility problems are encountered frequently in the cattle and buffalo bulls commercially maintained for semen production in dairy farms and under field conditions for natural insemination. Reports are scarce on the incidence of subfertility in breeding bulls, especially in India. The objective of the present study was to assess the incidence of the male reproductive anomalies leading to di...

The semen quality during the low (May-July) and the peak (September-November) breeding seasons in 18 Nili-Ravi buffalo bulls varying in age from 3 to 15 years was studied. Ejaculatory volume was higher (P < 0.05) in adult (3.03 ± 0.13 ml) and old (2.86 ± 0.13 ml) than young (2.51 ± 0.11 ml) bulls and during the low (3.44 ± 0.11 ml) than the peak (2.57 ± 0.90 ml) breeding season. Mass activity o...

Introduction Reproductive performance has greater impact on beef economic returns than does either growth rate or product quality (Trenkle and Wilham, 1977). In most cow-calf operations, females still conceive via the natural breeding bull (Godfrey and Lunstra, 1989). Thus the reproductive capabilities of bulls are of paramount importance. These capabilities are largely influenced by one or mor...

The objective of this experiment was to test in vitro embryo production (IVP) as a tool to estimate fertility performance in zebu bulls using Bayesian inference statistics. Oocytes were matured and fertilized in vitro using sperm cells from three different Zebu bulls (V, T, and G). The three bulls presented similar results with regard to pronuclear formation and blastocyst formation rates. Howe...

In this study, the effectiveness of intra-testicular ethanol and calcium chloride administrations was compared for chemical-castration in 12 mixbred young bulls (12-15 months old and 250-400 kg). Ten ml of absolute ethanol or 10 ml of a 30 % calcium chloride solution were administered intra-testicularly in each testicle which were removed with the open surgical technique after 60 days for histo...

The effects of unilateral castration (UC) and induced unilateral cryptorchidism (UCR) on basal plasma luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone, and on the responses of these hormones to gonadotropin releasing hormone (GnRH), were investigated in bulls altered at 3, 6 or 9 months of age. Blood plasma was collected before and after GnRH (200 micrograms) stimul...