In dairy cattle breeding, much attention is paid to indicators of the milk quality and technological properties. These are significantly influenced by proteins. Therefore, goal our research evaluate effectiveness creating herds domestic breeds that characterized desired beta- kappa-casein genotypes. To fulfill these tasks, genotyping cows Ukrainian Brown dairy, Sumy intrabreed type Black-and-Wh...

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 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 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...

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 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...

Postweaning growth and pubertal traits were studied in Hereford, Angus, Red Poll, Brown Swiss, Hereford-Angus crossbred (HXA) and Angus-Hereford crossbred (AX H) bulls from 7 through 13 months of age. Pubertal factors characterized included body weight, testicular size, hormone concentrations, sexual aggressiveness and sperm production. Puberty was defined as the age at which a bull first produ...

The first large-scale, international genetic evaluation of Holstein bulls computed by the International Bull Evaluation Service Centre in February 1995 was examined and compared with national evaluations from Canada, Denmark, Finland, France, Germany, Italy, Sweden, The Netherlands, and the US. Assumption of a genetic correlation of 0.995 between all countries and exclusion of bull daughters fr...

The objective was to determine the effects of a recombinant fusion protein anti-GnRH vaccine on testicular development, feedlot performance, and carcass quality of beef bulls. Crossbred beef bulls (n = 58, average weight 306 kg, 9 mo of age), were randomly allocated to two groups and received either an anti-GnRH vaccine (GnRH) or placebo (Control) by intramuscular injection on d 0, 56, and 112....