This study was conducted at the National Artificial Insemination Center, Ethiopia with an objective of evaluating breeding soundness, effect of age and breed on semen quality and fertility of bulls. The evaluation involved 45bulls (36 breeding and 11 pre-service young bulls) consisting of Holstein Friesian, Jersey, Borana and Cross breeds (Borana X Holstein Frisian). Semen was collected using a...

The present was conducted to separate heparin binding proteins (HBP) of capacitated sperm extracts and determine their relationship with acrosome reaction and semen fertility of bulls (n=30). Fourteen immunoreactive bands in capacitated spermatozoa of bulls (135, 100, 75, 70, 65, 55, 48, 45, 33, 31, 26, 24, 20 and 18 kDa) were detected in western blots following incubation with anti-HBP antibod...

Wild bull Asian elephants spend time in all-male groups. Therefore, managers of ex situ populations increasingly house bulls together. We examined the social interactions five at Denver Zoo, using instantaneous sampling to compare across adolescent and mature bulls, with a history prior integration this group compared no history. Both age significantly affected behavior. Adolescent exhibited mo...

Tonic and phasic dynamics of electroencephalographic (EEG) activities during a continuous compensatory tracking task (CTT) were analyzed using time-frequency analysis of EEG sources identified by independent component analysis (ICA). In 1-hour sessions, 70-channel EEG data were recorded while participants attempted to use frequent compensatory trackball movements to maintain a drifting disc clo...

This experiment was designed to determine 1) if exposure of firstcalf suckled beef cows to mature bulls in the first 30 days, after 30 days, or continuously post partum reduces the postpartum anestrous period and 2) if exposure to bulls alters the first service pregnancy rate. Postpartum first-calf suckled crossbred (Angus x Hereford; Hereford x Angus) cows were randomly assigned to be 1) expos...

Portions of penis and prepuce were collected from 24 bulls with current or recent Tritrichomonas foetus infection. Epididymides were collected from seven of the bulls, and seminal vesicles and prostate were collected from four. Following immunohistochemical staining with two monoclonal antibodies (34.7C4.4 and TF1.15) prepared against T. foetus surface antigens, trichomonads were identified in ...

This study was designed to investigate the characteristics of acrosomal changes during capacitation of bovine spermatozoa in relationship to in vitro fertility of individual bulls. Motile spermatozoa were separated from frozen-thawed semen by a swim-up procedure and capacitated in IVF-TALP medium with or without heparin. The spermatozoa were evaluated in terms of acrosomal changes at 0, 3, 4, 5...

The objective of this study was to evaluate the influence of corn silage (CS) or sugarcane (SC) additions to finishing diets on voluntary intake, apparent digestibility, animal performance, and LM fatty acid (FA) composition in crossbred Holstein × Zebu bulls. Forty-two bulls (initial BW 328 ± 39.2 kg and an initial age of 23.5 mo) were used in this experiment. A completely randomized design wa...

In the present study, thirteen genes involved in the reverse cholesterol transport (RCT) pathway were investigated for their associations with three fat depositions, eight fatty acid compositions and two growth-related phenotypes in a Wagyu x Limousin reference population, including 6 F(1) bulls, 113 F(1) dams, and 246 F(2) progeny. A total of 37 amplicons were used to screen single nucleotide ...

The purpose of the following study was to determine the effects of group size and the male-to-female ratio on the sexual and aggressive behaviors of bulls in the context of serving capacity tests. Tests were administered to two groups of 13 and 14 polled Hereford bulls, respectively, under four test conditions in which the number of bulls and the ratio of males to females was varied. The test c...