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...

Hemorrhagic bowel syndrome is a highly fatal intestinal disease of adult dairy cattle with uncertain cause. In a dairy herd in KhorasanRazavi province, Northeast of Iran, two cows showed depression, anorexia, decrease in milk production, ruminal hypomotility, bruxism and dehydration. At necropsy, massive hemorrhage and clot formation was observed within the jejunum and bacterial culture of the ...

OBJECTIVE To estimate potential spread of foot-and-mouth disease (FMD) if introduced from wild pigs in California and to evaluate efficacies of various control strategies. SAMPLE POPULATION Data for California livestock and from hunter surveys on wild pigs in California. PROCEDURES A spatial, stochastic simulation model was used to simulate FMD epidemics that might occur if a dairy or beef ...

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%...

Q fever, a worldwide zoonotic disease caused by Coxiella burnetii, is a looming concern for livestock and public health. Epidemiological features of inter-herd transmission of C. burnetii in cattle herds by wind and trade of cows are poorly understood. We present a novel dynamic spatial model describing the inter-herd regional spread of C. burnetii in dairy cattle herds, quantifying the ability...

OBJECTIVE To estimate seroprevalence of Mycobacterium avium subsp paratuberculosis (MAP) infection among adult dairy cows in Colorado and determine herd-level factors associated with the risk that individual cows would be seropositive. DESIGN Cross-sectional observational study. ANIMALS 10,280 adult (> or = 2 years old) dairy cows in 15 herds in Colorado. PROCEDURE Serum samples were test...

The onset of tetany, when dairy cattle have insufficient magnesium, has a huge impact both economically and on animal welfare. We have previously adapted a model of magnesium dynamics in sheep (Robson et al. 1997) for use with dairy cattle as an aid to understanding aspects of magnesium metabolism which influence the risk of animals contracting tetany (Bell et al. 2005). To estimate this risk i...

Longevity as defined by the Random House Dictionary is “the duration of an individual’s life”. Currently dairy cows average 2.8 calvings in a ‘lifetime (Cassell, 2005). Raising high quality heifers that will express their genetic potential for milk production and allow optimal duration in the milking herd (longevity) is a priority objective to balance the investment of 15-20% of total costs of ...

Introduction It is now widely recognised that reduced fertility in dairy herds is one of the most important factors affecting producer profitability. Roche (2006) has defined the effect of infertility on profitability as: (i) prolonged calving interval with fewer calves and less milk per cow; (ii) increased replacement costs; (iii) increased labour, semen and veterinary bills; and (iv) an exten...