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...

The objective of the study was to assess the semen characteristics of Jersey, Mithun and Siri breeds of bulls and to compare the suitability of Tris Eggyolk Citrate and commercial soya lecithin based BIOXcell extenders for cryopreservation of semen from the these breeds of bulls. The mean semen volume was 4.55± 1.57, 4.86±1.33 and 4.83±1.72 ml in Jersey, Mithun and Siri bulls, respectively. Mea...

The aim of this study was to investigate the comparison between some seminal plasma parameters and age of the bull. Concentrations of various biochemical parameters like fructose, glucose, total proteins, albumin and inorganic ions including Na, K and Cl ions of seminal plasma of breeding Sahiwal bulls of different ageswere assessed. Methods: 40Sahiwal bullsdivided into 4 age groups.Semen (2ml ...

The efficacy of active immunization against GnRH as a non-invasive alternative to physical castration was assessed in Hereford × Angus bull calves. Calves were randomly assigned to 1 of 4 treatment groups; unimmunized calves (n = 8), bull calves actively immunized against GnRH (n = 30), or calves castrated at 3 months of age and either non-implanted (n = 9) or implanted with Synovex (n = 9). Im...

Six Holstein (light-muscled type) and six Belgian Blue bulls (double-muscled type) were fed a finishing diet. Average daily gain was 1.36 kg for the Holstein bulls vs 1.24 kg for the Belgian Blue bulls (P less than .05). Holstein bulls consumed more feed (2.3 vs 1.8 kg/100 kg body weight, P less than .001) than the Belgian Blue bulls. The dressing percentage (55.4 vs 65.8%, P less than .001) an...

Three experiments were conducted to evaluate the effects of biostimulation (exposure to bulls or androgenized females) on various reproductive variables in suckled beef cows. Bulls or testosterone-treated cows (TTC) were introduced to cows, randomly allotted to one of four groups, within 72 h postpartum. In Exp. 1, Groups 1 and 3 were exposed to bulls and Groups 2 and 4 were exposed to TTC. In ...

A total of 144 male crossbred calves were allocated to four management treatments (bulls; steers; bulls implanted with zeranol at 100 d of age and re-implanted at 69, 93 and 56 d thereafter; bulls implanted with zeranol at 168 d of age and re-implanted at 93 and 56 d thereafter), and two pre-slaughter shipping treatments (minimum pre-slaughter stress with cattle shipped and slaughtered within 4...

Bull calves (n = 143) were obtained from two strains of Angus and two strains of Hereford cattle for which replacements were selected on the basis of superior feedlot growth performance on either high- or medium-energy diets. From weaning to slaughter at 15 mo of age, bulls were fed either the high-energy (80% grain + 20% forage) or medium-energy diet (100% forage) corresponding to their strain...