The effect on prediction accuracy for Jersey genomic evaluations of Danish and US bulls from using a larger reference population was assessed. Each country contributed genotypes from 1,157 Jersey bulls to the reference population of the other. Data were separated into reference (US only, Danish only, and combined US-Danish) and validation (US only and Danish only) populations. Depending on trai...

Many factors affect ruminant carcass and meat quality, and among the genetic and environmental factors, feeding plays an important role in the determination of quality. In a large study, sixty-four German Holstein and German Simmental bulls were randomly allocated to either an indoor concentrate feeding system or periods of pasture feeding following by a finishing period. During this period the...

Sixteen buffalo bulls (Bubalus bubalis) were divided into four age groups, four bulls in each. Bulls in three groups had good semen quality while in one group it was poor. The study was undertaken for a one-year period divided into five seasons. The study revealed an overall seminal plasma testosterone concentration of 0.97±0.12 ng/ml. It was higher (P<0.05) in the 6-10-year-olds, less than 5 a...

Administration of GnRH agonist for an extended period inhibits pulsatile LH release but enhances testicular function of bulls. The mechanism whereby long-term administration of GnRH agonist enhances testosterone concentration in the blood of bulls has not been determined. The aim of this study was to determine whether chronic treatment with the GnRH agonist, azagly-nafarelin, increases blood co...

a deterministic model was employed to simulate various progeny testing programs compatible with the conditions of holstein dairy cattle population in iran. in simulated programs, the selection intensity of bulls was increased by increasing the ratio of cow population in mate with young bulls. selection accuracy in the programs was fixed because of the fixed progeny group. economic efficiency (t...

When female voles were allowed contact with the stud male for only 1 h at the time of mating, 55% exhibited pregnancy failure when exposed to a strange male 48 h later. When females were made psuedopregnant by hormone treatment and vaginal stimulation (i.e. no stud male involved), 87% exhibited luteal failure when exposed to a strange male. It is suggested that the characteristics of the stud m...

The reproductive performance of Angus (A), Polled Hereford (PH) and Santa Gertrudis (SG) bulls was compared when exposed to 40 cows/bull vs 80 cows/two bulls during a 90- to 95-d breeding period on pasture. Cows were A, PH and SG straightbreds and crossbreds of these breeds. Each year, cows were allotted at random within breed composition and age of dam to breeding groups. A replicate consisted...

Objective of the present study was to document the semen producing ability, productive life and genetic ability for lactation milk yield of Sahiwal bulls used for artificial insemination (AI) in Punjab and to find the impact of AI bulls on the improvement of Sahiwal cattle. Data from Semen Production Unit (SPU), Qadirabad, Sahiwal, Pakistan were used for this purpose. A repeatability animal mod...

An experiment was conducted to determine the effects of long-term feeding of cottonseed meal on the reproductive traits of Holstein bulls. Holstein bulls approximately 6 mo of age were placed on the following treatments: 1) soybean meal + corn (CON); 2) cottonseed meal + corn (GOS); and 3) cottonseed meal + 4,000 IU vitamin E x bull(-1) x d(-1) (G+4E). The GOS and G+4E diets were formulated to ...

Recently, Gandomi and Alavi proposed a meta-heuristic optimization algorithm, called Krill Herd (KH), for global optimization [Gandomi AH, Alavi AH. Krill Herd: A New Bio-Inspired Optimization Algorithm. Communications in Nonlinear Science and Numerical Simulation, 17(12), 4831–4845, 2012.]. This paper represents an optimization method to global optimization using a novel variant of KH. This me...