Holstein Friesian bulls (n = 75) were used to evaluate the effect of restricted and subsequent compensatory growth on muscular and skeletal growth as well as the recovery of carcass and noncarcass components. Fifteen bulls were slaughtered on Day 0 to provide baseline parameters for carcass and noncarcass measurements. Of the remaining 60 bulls, 30 were fed ad libitum (ADLIB) and 30 were fed a ...

The objectives of the present study were to evaluate the effects of scrotal insulation on sperm production, semen quality, and testicular echotexture in Bos indicus and Bos indicus x Bos taurus crossbred bulls. In one experiment, B. indicus bulls (n=12) were allocated to control and whole-scrotum insulation groups, while in a second experiment, crossbred bulls (n=21) were allocated into control...

AIM The present study compared the testicular cytology and histology between crossbred (Holstein-Friesian [HF] × Tharparkar) and purebred (HF and Tharparkar) bulls to find out differences if any. MATERIALS AND METHODS Four peripubertal bulls from each breed were utilized for the study. Through percutaneous needle aspiration biopsy, Sertoli and spermatogenic cells were extracted, and morphomet...

International Bull Evaluation Service evaluations from May 2005 were examined for country bias by comparing Holstein full-brother families. Countries with > or =25 bulls in multicountry full-brother families were included. The model fit evaluations of US estimated breeding values (EBV) by absorbing full-brother family and producing solutions for country of brothers. For yield and somatic cell s...

Twoand 3-year-old beef bulls were exposed to 25 or 40 beef cows on pasture during a 90-day breeding period. Reproductive performance of bulls by age of bull and size of cow group was evaluated in terms of percentage calf crop. Results indicated that reproductive performance of 2-year-old bulls was higher, but not significantly different (P>.05), than that of 3-year-old bulls. The percentage cal...

To determine whether the accuracy of the genetic evaluations of sires can be assessed by the presence of extreme daughter records, we studied herd-years with records from first-crop daughters of 217 Holstein bulls that were not sampled by artificial insemination (AI) organizations but that later entered AI. The presence of outliers for standardized milk yield was determined within herd-year. Ou...

We tested the hypothesis that expression of sexual behavior in bulls is affected by the manner in which they are exposed to unrestrained, sexually receptive females. Twelve Angus bulls were used in a crossover design involving two treatments, each tested four times for a total of eight tests for each bull. Sexual interactions were quantified for each of four, 30-min periods under the following ...

Sub-fertility is one of the most common problems observed in crossbred males, but the etiology remains unknown in most of the cases. Although proteomic differences in the spermatozoa and seminal plasma between breeds have been investigated, the possible differences at the sperm precursor cells and supporting/nourishing cells have not been studied. The present study reports the differential prot...

Growth and testicular development between 7 and 15 mo of age were evaluated in bulls produced by mating sires of six breeds (Hereford, Angus, Belgian Blue, Brahman, Boran, and Tuli) to Angus, Hereford, and MARC III (four-breed composite) cows. At 12 mo of age, Angus- and Hereford-sired bulls had the heaviest body weight (P < 0.08 to 0.001), whereas Brahman- and Belgian Blue-sired bulls were int...

Records on four bulls and 96 of their progeny born from 2005 to 2011 with pedigree information were used to estimate the impact of bull performance on progeny early growth and the genetic relationships between traits of bull and their progeny. Traits included in this study were metabolic body weight, feed intake and residual feed intake (RFI) for bull performance and birth weight and average da...