Sixteen (mean age = 1.1 +/- 0.1 yr; mean BW = 478 +/- 34 kg) Brahman-influenced bulls were used to determine the influence of fescue type on sperm characteristics and serum concentrations of prolactin, cortisol, and testosterone. Bulls were blocked by BW, scrotal circumference (SC), and pregrazing sperm characteristics and randomly assigned to graze toxic endophyte-infected (EI; 4 bulls/pasture...

The breeding soundness evaluation (BSE) was used to evaluate Senepol (Bos taurus) bulls (n = 495) on St. Croix over a 7-year period. Young, unproven bulls (10-26 months of age) and breeding bulls (16 months to 8.5 years) were tested prior to sale or use in breeding. Inbreeding coefficients were determined for a subset of bulls (n = 290). The percentage of bulls passing the BSE increased (P < 0....

Two experiments were conducted to characterize changes in serum hormones prior to and during puberty in bulls and to study effects of castration or shortening the scrotum on these hormonal changes. In the first experiment, four of eight prepubertal bulls (135 days old) and four of eight pubertal bulls (278 days old) were left intact and four of each group were castrated. Two weeks later, serum ...

A survey was conducted to quantify incidence of Beef Quality Assurance (BQA)-related defects in market beef and dairy cows and bulls selling at auction during 2 seasons in 2008. Twenty-three BQA-related traits were evaluated by 9 trained personnel during sales at 10 livestock auction markets in Idaho (n = 5; beef and dairy), California, (n = 4; dairy only), and Utah (n = 1; beef and dairy). Ove...

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 ...

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 bull...

The effectiveness of a program aimed at eradicating carriers of the recessive disorder Complex Vertebral Malformation (CVM) from the population of Holstein-Friesian bulls is reported. Among 1823 bulls, 1268 young and 555 proven bulls were examined. Three hundred and three bulls appeared to be CVM carriers (16.62%). The highest number of carriers occurred in the sons of a CVM sire, 55.51% and 61...

We previously reported that accessory sex gland fluid (AGF) from high fertility (HF) bulls influenced the oocyte-penetrating capacity of cauda epididymal sperm from low fertility (LF) bulls, based on in vitro fertilization (IVF) assays. The present study determined if AGF proteins were associated with these effects. Nineteen IVF assays with 12 bulls were grouped as follows. Group I (n1⁄48): ass...

Excitable cattle are dangerous to personnel and have reduced individual performance. The aim of this study was to 1) identify objective criteria for evaluating bull temperament and 2) examine relationships among temperament, behavior, and performance of bulls during an 84-d performance test. Angus bulls ( = 60) were reared in 6 pens based on BW and age. Pen scores (PS; 1 = docile and 5 = very a...

There is a paucity of data on the beef production potential of Norwegian Red (NOR) compared with 'modern' Holstein-Friesian (HF) cattle. The present study used a total of 64 bulls in a 2 × 2 factorial design study encompassing two breeds (HF and NOR) and two slaughter ages (485; E, and 610; L, days). The mean initial age and live weight of the HF bulls were 179 (s.d. 47.1) days and 203 (s.d. 64...