Random regression models (RRM) are used for genetic estimations of milk traits in dairy cows. RRM utilize data on traits that are repeated during the time, such as milk trait, which allows of the evaluation of the test day production information. In this study, to estimate genetic parameters for milk production trait, test day records (TDR) were collected from the first lactation of Holstein co...

the aim of this study was to evaluate the effect of ecg, pgf2α, and combination of ecg and pgf2α early postpartum on reproductive performance in high producing dairy cows. three hundred sixty eight postpartal holstein dairy cows were divided in 4 groups. cows in groups 1 and 2 received 500 iu ecg on day 8 ± 2 and cows in groups 3 and 4 received saline. cows in groups 1 and 3 received injections...

The nutrient contents of perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.) are reasonably similar. Despite similarities, the lactation performance of dairy cows fed perennial ryegrass has not been compared with the lactation performance of dairy cows fed alfalfa. The present study was implemented to compare the performance of lactating cows fed alfalfa or perennial ryegras...

To evaluate the effects of physically processed flaxseed [ground flaxseed (GFS) and whole flaxseed(WFS)] as a replacement for extruded soybeans on feed intake, milk production, milk composition, milk fatty acid (FA) composition and blood biochemical parameters, nine primiparus Holstein dairy lactating cowsaveraging 495 ± 34.5 kg of body weight (BW) and 70 ± 5 days in milk (DIM) were assigned in...

Kisspeptins (Kps) play a key role in the regulation of GnRH axis and as an anti-metastasis agent by binding with GPR54. Recently, we observed that the expression of GPR54 was higher in the lactating mammary tissues of dairy cows with high-quality milk (0.81 ± 0.13 kg/day of milk protein yield; 1.07 ± 0.18 kg/day of milk fat yield) than in those with low-quality milk (0.51 ± 0.14 kg/day of milk ...

no report has been published on the economical losses associated with errors in oestrus detection in cows under iranian intensive dairy management. the following study was carried out to determine the accuracy of oestrus detection by farmers using artificial insemination in shiraz dairy farms. milk samples were collected from 179 holstein milking cows at the time of artificial insemination. mil...

In order to characterize the expression of genes associated with immune response mechanisms to mastitis, we quantified the relative expression of the IL-2, IL-4, IL-6, IL-8, IL-10, IFN-γ and TNF- α genes in milk cells of healthy cows and cows with clinical mastitis. Total RNA was extracted from milk cells of six Black and White Holstein (BW) cows and six Gyr cows, including three animals with a...

background: cardiovascular system is a very importantorgan that plays a vital role in tissue function. in farm animals,the growth and high milk production depends on function ofcardiovascular system. objectives: cardiovascular health inhigh and low-yielding dairy cows was investigated. methods:fifty 4-year-old high- yielding holstein dairy cows and fifty 4-year-old low- yielding holstein dairy ...

The objective of the current study was to evaluate relationship body condition score (BCS) at 35 d in milk (DIM), production, diseases, and duration dry period with prevalence anovulation 49 DIM then, specifically, each anovular phenotype. We hypothesized that follicular phenotypes, classified based on maximal size follicle, have different etiologies. A total 942 lactating Holstein cows (357 pr...

The objective of this study was to evaluate the associations among milk production, rectal temperature, and pregnancy maintenance in lactating recipient dairy cows. Data were collected during an 11-mo period from 463 Holstein cows (203 primiparous and 260 multiparous) assigned to a fixed-time embryo transfer (ET) protocol. Only cows detected with a visible corpus luteum immediately prior to ET ...