The aim of this study was to develop an adapted random regression test-day model for milk urea (MU) and to study the possibility of using predictions and solutions given by the model for management purposes. Data included 607,416 MU test-day records of first-lactation cows from 632 dairy herds in the Walloon Region of Belgium. Several advanced features were used. First, to detect the herd influ...

SUMMARY Lactation milk and fat records of 6,949 daughters, 6,201 different dams, and the contemporary D.H.I.A. herd averages of 2,420 herds were studied, to compare five measures of a dairy site's transmitting ability. They were the daughter average, daughter-dam difference, equal-parent index, daughter-contemporary herd difference, and daughter-contemporary-herd index. The daughters and dams w...

An analysis of dairy herd records to determine the cause of low reproductive efficiency usually leads to the conclusion that problems are centered in one of the following areas: breeding policy (intentionally waiting too long after calving for first service), estrous detection efficiency (missed heats), or conception rate. The challenge is to identify the factors responsible for the problem. On...

Careful antemortem examination and interpretation of findings, assisted by good clinical records, do much to throw light on the nature of vertical fissure in cattle. During an eight month period of investigation, 13 (3.2%) lame cows with vertical fissure out of 52 Holstein cows with different claw fissures were selected for clinical and gross pathological purposes in a commercial dairy farm wit...

The purpose of this study was to determine the prevalence of bovine leukemia virus (BLV) in Khorasan Razavi and Khorasan Shomali provinces which are the main provinces located in the northeast of Iran. Total number of 429 blood samples were collected from industrial dairy herds. The samples were categorized based on province, age (2-3, 4-6, and 7-10 years old), calving (≤ 2, 3-5, and > 5) and h...

Campylobacter jejuni, Campylobacter coli, and Arcobacter spp. were detected in feces of healthy dairy cows by highly specific multiplex-PCR assays. For C. jejuni, at this one-time sampling, cows from 80.6% of farm operations (n = 31) and 37.7% of individual dairy cattle fecal samples (n = 2,085) were positive. Farm management factors were correlated with prevalence in herds in which >25% of cow...

The aim of this study was to gain a deeper understanding of work-related physical and psychosocial exposure and health symptoms of farm staff working in indoor loose-housing dairy systems in Sweden, and to examine possible associations between exposure and health symptoms of farm staff and disease incidence in their dairy herds. A sample of 41 farm owners or managers and 20 directly employed fa...