Artificial insemination (AI) subfertility is an indication of failure of AI with frozen-thawed sperm classified as normal by conventional semen examination. Recently, 8 AI-subfertile Japanese Black cattle (S1-S8) were identified using the routine AI test or in vivo fertilization test, which included AI with frozen-thawed sperm of superovulated females and subsequent non-surgical recovery of pre...

Behavioural and endrocrin%gical data on African elephants (Loxodonta africana) are integrated to provide a hypothesis oj the adaptations reflected in the phenomenon of musth in bulls. Occupation oj home ranges, movements. male dominance hierarchies and intra-specific agonistic behaviour are reviewed. Bulls in musth leave their home range, travel far and jast, initiate more contacts with distant...

In some production settings, beef bulls are mixed at the beginning of the finishing period to obtain homogeneous groups to facilitate finishing and to produce more homogeneous carcasses. Given the stress induced by mixing, we questioned whether this practice was profitable. Sixty-four young bulls were finished in groups of four over 8 mo. They were either mixed or unmixed and had either homogen...

Six Hereford bulls from a line selected with an index of body weight and muscling score were compared with six bulls from a control line to determine if increased growth in the selected line was associated with changes in plasma levels of growth hormone (GH), prolactin (PRL) and (or) thyrotropin (TSH). The predictive value of sire hormone data for growth rate of progeny was also evaluated. Bull...

Background: BVD and IBR are contagious viral diseases highly prevalent in Irish cattle. Despite their significant reproductive and economic impact very little is known about the BVD and IBR status of stock bulls (a bull used for breeding purposes). There are still a high proportion of dairy farms in Ireland that rely on the use of a bull for breeding cattle and ensuring the fertility of the bul...

The main goal of this study was to test the effectiveness of two molecules of pheromones identified in the urine of cows in estrus at stimulating sexual function and increasing reproductive capacity of bulls. The trial lasted four weeks and the bulls were divided into two groups (experimental and control) with ten bulls. For this experiment we used an intranasal spray comprising the pheromone m...

this study was performed to determine the effect of copper on growth performance, blood metabolites and claw health in young holstein bulls in a humid area in north of iran. one hundred and two young holstein bulls (initial body weight= 377.3±17.1 kg) were randomly allocated to two treatments in a completely randomized design for 56 days. the treatment groups received: (1) the basal diet of no ...

Thirty-six percent of American Wagyu bulls do not meet the current minimum standards set by the Society of Theriogenology for the breeding soundness exam. In contrast, only 15% of bulls of domestic breeds do not meet the minimum standards. Scrotal circumference measurements of Wagyu are smaller than those of other breeds. The objective of this research was to describe scrotal circumference of W...

The aim of this study was to evaluate the usefulness of trans-scrotal ultrasonography and testicular fine needle aspiration cytology in assessing bulls for breeding suitability. These two techniques were also compared with semen analysis. Bulls presented for breeding soundness evaluation were assessed using all three techniques. The findings of each technique were compared. There was agreement ...

The objective of this study was to evaluate effects of feeding monensin (MON) or a multivalent polyclonal antibody preparation (PAP) against several rumen microorganisms on feedlot performance, carcass characteristics, blood gas profile, and rumenitis of Bos indicus biotype (BT) yearling bulls. The study was designed as a completely randomized design with a 3 × 2 factorial arrangement, replicat...