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...

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...

The study had two objectives, namely, to estimate the andrological disorders leading to disposal of Karan Fries (KF), Sahiwal cattle and Murrah buffalo bulls and to study the effect of various factors (species/breeds, season of birth and period of birth) on male reproductive parameters. Records on occurrence of subfertility problems and disposal pattern of bulls maintained at the National Dairy...

Fifty-four Holstein bulls were blocked by initial BW (301 +/- 7.4 kg) and randomly assigned to 6 treatments following a 3 x 2 factorial arrangement, with 3 concentrate lipid levels (5, 8, and 11% of DM) and 2 lipid sources (whole canola seed and whole linseed), with the objective of evaluating the possibility of increasing the content of n-3 fatty acids in meat. Concentrates (mostly corn meal) ...

The objectives of this study were to test the interaction of breed (Nellore or Angus) and diet (whole shelled corn [WSC] or ground corn [GC] with silage) on growth performance, carcass characteristics, and ruminal pH of young bulls. Thirty-six bulls (18 Nellore and 18 Angus) with the range in age of 18 to 22 mo and BW of 381 ± 12 kg were used in a completely randomized design experiment with a ...

Postweaning records were collected on 7,428 bulls completing gain tests from 1981 to 1994 at Oklahoma BEEF, Inc. Central Bull Test Station. A total of 3085 bulls (A=806 Angus, B=497 Brangus, H=533 Hereford, P=601 Polled Hereford, C=399 Charolais and L=249 Limousin) completed the 140-day test from 1981 to 1986. From 1987 to 1994, performance data were collected on 4343 bulls (A=2384 Angus, B=487...

The objective was to compare the relative response between rams and bulls in characteristics of LH, FSH and testosterone (T) secretion, during and after long-term treatment with GnRH analogs. Animals were treated with GnRH agonist, GnRH antagonist, or vehicle (Control) for 28 days. Serial blood samples were collected on day 21 of treatment, and at several intervals after treatment. Injections o...

Transcriptome analyses of bovine muscle tissue differing in intramuscular fat (IMF) content identified agouti signaling protein (ASIP) as a promising candidate gene for fat deposition. The protein is secreted from adipocytes and may serve as a signaling molecule in cross-talk between adipocytes and muscle fibers or other cells. Known receptors for ASIP are the melanocortin receptors (e.g., MC4R...