The aim of current study was to investigate the changes in the quality parameters of Holstein bull semen during the heat stress and the effect of feeding a source of omega-3 fatty acids in this period. Samples were obtained from 19 Holstein bulls during the expected time of heat stress in Iran (June to September 2009). Control group (n=10) were fed a standard concentrate feed while treatment gr...

Holstein bulls were assigned to sampling categories (AI stud, AI nonstud, or non-AI) based on bull code, controller number, and age at semen distribution. The AI stud bulls were sampled through traditional progeny-testing programs of 13 AI organizations; AI nonstud bulls had AI semen collection reported by another organization or by multiple organizations. The non-AI bulls had no reported AI se...

The objective of this trial was to determine the effect of breed and long-term dietary linseed addition on composition of fatty acids and expression of some genes involved in the lipid metabolism within subcutaneous (s.c.) adipose tissue of young bulls. Italian Simmental and Holstein bulls (n=16/breed) were fed a corn silage-grass hay diet with or without 8% (DM basis) whole ground linseed. Inc...

the aim of this study was to test the genotypes effect of dgat1 gene on breeding value in iranian holstein milk production traits. for this purpose, 103 semen samples of registered bulls were collected and then genotyped for partial region of dgat1 gene. the studied traits were milk yield (my), fat yield (fy), protein yield (py), fat percentage (fp) and protein percentage (pp). first lactation ...

the present study was aimed to examine the association of bovine follicular stimulating hormone gene polymorphism with sperm quality traits including sperm volume (sv), sperm concentration (spco), total sperm (ts), fresh sperm motility (fsm), total fresh motile sperm (tfms), post thaw sperm motility (ptsm), total post thaw motile sperm (tptms), number of produced payout (npp), number of fresh m...

the objective of this study was to evaluate the importance of environmental and genetic factors affecting semen quality; sperm volume (sv), sperm concentration (spco), total sperm (ts), fresh sperm motility (fsm), total fresh motile sperm (tfms), post thaw sperm motility (ptsm), total post thaw motile sperm (tptms), number of produced payout (npp), number of fresh motile sperm in each milt ejac...

Besides its nutritional value, bovine beta-casein is a source of bioactive peptides called betacasomorphins produced during digestion of raw or processed milk. It was shown that the betacasomorphin 7 originates only from beta-casein variants A1 or B and may be a significant risk factor in human ischemic heart disease, arteriosclerosis, type I diabetes and sudden infant death syndrome. In this s...

Quantitative traits locus for milk production traits has been described on centromeric end of bovine chromosome 14. Reports name the acyl coA: diacylglycerol acyltransferase (DGAT1) gene as a potential candidate gene with dinucleotide substitution (AA to GC) in exon VIII which causes the change of lysine to alanine in amino acid (K232A).The aim of the present study was to estimate the frequency...

A total of 240 Holstein bulls (121 ± 2.0 kg initial BW; 99 ± 1.0 d of age), from 2 consecutive fattening cycles, were randomly allocated in 1 of 6 pens and assigned to 1 of the 3 treatments consisting of different concentrate feeder designs: a control feeder with 4 feeding spaces (CF), a feeder with less concentrate capacity (CFL), and a single-space feeder with lateral protections (SF). Each p...

The objective of this study was to evaluate the influence of corn silage (CS) or sugarcane (SC) additions to finishing diets on voluntary intake, apparent digestibility, animal performance, and LM fatty acid (FA) composition in crossbred Holstein × Zebu bulls. Forty-two bulls (initial BW 328 ± 39.2 kg and an initial age of 23.5 mo) were used in this experiment. A completely randomized design wa...