The objective of this study was to determine whether yearling bulls, when pastured with cows, reduced the duration of postpartum anestrus to the same extent as did mature bulls. This experiment was conducted over a 3-yr period. Cows were stratified by parity group to achieve 37% 2-yr-old and 63% mature (> 2-yr-old) cows within each treatment group (approximately 50 cows per treatment per year)....

T evaluation of bulls for breeding soundness is an effective and reliable way to identify bulls that are potentially poor breeders. This management technique can be used to greatest advantage if culling occurs before bulls are turned out with females. Also, the evaluation is an important means available to the producer for predicting bulls with satisfactory to excellent potential. This informat...

Present study analyzed the changes in peripheral blood testosterone concentrations and testicular cytogram in relation to age and semen quality in crossbred males. Three different age groups of crossbred males viz. bull calves (6 months, n = 5), young bulls (15 months, n = 5) and adult bulls (4 to 6 years, n = 8) were utilized for the study. Testicular fine needle aspiration cytology technique ...

A total of 218 yearling Hereford, Angus, Santa Gertrudis and Brahman bulls was evaluated for semen traits and testieular volume at average ages of 16 and 20 months in April and August, respectively, during 2 successive years. Brahman bulls reached puberty at a later age than bulls of the Santa Gertrudis, Hereford and Angus breeds. Santa Gertrudis bulls had the largest testes with the Brahman ha...

There is concern in the beef industry that selecting bulls for feed efficiency based on residual feed intake (RFI) may have a negative impact on bull reproductive performance and fertility. Here we investigated the impact of selection of bulls for low RFI on breeding soundness evaluation (BSE), reproductive performance, and fertility of bulls under natural service in multisire mating groups on ...

Small reference populations limit the accuracy of genomic prediction in numerically small breeds, such like Danish Jersey. The objective of this study was to investigate two approaches to improve genomic prediction by increasing size of reference population in Danish Jersey. The first approach was to include North American Jersey bulls in Danish Jersey reference population. The second was to ge...

Electroejaculation is a reliable method of obtaining a semen sample for a bull breeding soundness examination, but is sometimes regarded as painful. Substance P is a neuropeptide involved in the integration of pain, stress, and anxiety. We hypothesized that substance P is a measure of pain in bulls following electroejaculation. The specific objective was to compare vocalization and plasma conce...

Story in Brief Seasonal differences and growth rates were studied on 60 Hereford and Angus bulls born in the spring and fall calving seasons at Oklahoma State University. Hip height, scrotal circumference and weight measurements were taken over the two IO-month experiments. Season of birth had no influence on scrotal circumference for either Hereford or Angus bulls. Season of birth in Angus bul...

Taurodontism is a rare dental anomaly presented with an aberration of teeth that lacks the constriction at the level of the cemento-enamel junction (CEJ). It is characterized by elongated pulp chambers and apical displacement of bifurcation or trifurcation of the roots, forming a rectangular shape. Whilst, it appears most frequently as an isolated anomaly, its association with several syndromes...

Random samples of cryopreserved, milk-extended semen, collected from 20 Holstein bulls at about 14 mo of age (young) and again at about 4 yr of age (mature), were evaluated at thawing and during 3-h incubation to compare semen quality of young versus mature bulls. Evaluation by differential interference contrast microscopy showed greater proportions of cytoplasmic droplets in semen from young v...