Nutrition has an important impact on the reproductive performance of dairy cattle. Energy is the major nutrient required by adult cattle, and inadequate energy intake has a detrimental impact on reproductive activity of the female bovine. Cows under negative energy balance have extended periods of anovulation. Postpartum anestrus, as well as infertility, is magnified by losses of body condition...

The goal with sexed semen is to produce a calf of a specific sex. Sexed semen is widely available now and many dairy producers are using it to obtain more (and better) heifer calves. Because of its higher cost per dose of semen, combined with a reduced conception risk, sexed semen is primarily recommended for use in virgin heifers. The use of sexed semen varies widely among dairy producers. Som...

The objective of the study was to determine the effect of puerperal metritis prevalence in high yielding Holstein cows on productive (305 days, actual milk yields), reproductive (days to first estrus, days open and services per conception) variables and culling rates. Throughout the study, 2885 dairy records were collected from high yielding private Holstein dairy farm (average milk yield was u...

The diversity of the uterine bacterial composition in dairy cows is still poorly understood, although the emerging picture has shown to be increasingly complex. Understanding the complexity and ecology of microorganisms in the uterus of postpartum dairy cows is critical for developing strategies to block their action in reproductive disorders, such as metritis/endometritis. Here, we used PCR-De...

To evaluate the effect of intramuscular administration of vitamin A in pregnant dairy cows during late stages of pregnancy, on vitamin A status of neonatal calves, a total of 30 cows were randomly selected and divided into three groups; two treatment groups and one control group. Single intramuscular injection of 2000000 IU vitamin A; was carried in 10 dairy cows at 7 months of pregnancy (group...

The purpose of this study was to evaluate the association between milk urea nitrogen (MUN) and fertility of dairy cows using field data. The data came from 24 dairy herds belonging to Ohio Dairy Herd Improvement Cooperative Inc. Reproductive data and MUN measurements from cows that calved between June 1998 and May 1999 and that had been bred at least once were included in the study. Survival an...

skin lesions were found in two 3–4-year-old holstein cows in a dairy farm in shiraz. lesions were distributed mostly around the neck, forelimbs, hindlimbs, and bilateral of midline portion and varied from nodule-like structure to patch with extensive accumulation of crust. skin scraping samples were taken from each animal and direct smears were prepared, stained with giemsa and observed under a...

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...

twelve (experiment i) and four (experiment ii) multiparous dairy cows seronegative to pestivirus were selected and randomly assigned to either a control group which did not become infected or a treatment group in which all cows became infected following intranasal inoculation 9 days before ai. the experimental induction of infection was carried out with 2 ml of non-cytopathic pestivirus (bvd vi...

to estimate the prevalence of subacute ruminal acidosis (sara) in dairy cows, a total of 196 ruminalfluid samples were drawn by rumenocentesis from 10 dairy herds of khorasan razavi province, northeast ofiran. two groups of 12 cows, early lactation and mid-lactation cows were sampled in each dairy herd andruminal ph was determined immediately using a portable ph-meter. a total of 54 cows (27.6%...