This experiment examined the long-term effects of offering diets containing low levels of dietary phosphorus (P) on dairy cow health, fertility and bone composition, and the effect of dietary P level on nutrient utilisation. One hundred winter-calving Holstein-Friesian dairy cows were offered diets containing either 'high' or 'low' levels of dietary P over a 4-year period. Rations offered durin...

Genetic evaluations provide information to aid in breeding decisions that increase long-term performance of animals and herds. However, to date no study has been undertaken to investigate the accuracy of the Irish maternal genetic evaluations in beef cattle. The objective, therefore, of this study was to quantify the relationship between phenotypic performance and measures of genetic merit for ...

Sischo, W.M., Hird, D.W., Gardner, I.A., Utterback, W.W., Christiansen, K.H., Carpenter, T.E., Danaye-Elmi, C. and Heron, B.R., 1990. Economics of disease occurrence and prevention on California dairy farms: a report and evaluation of data collected for the National Animal Health Monitoring System, 1986-1987. Prey. Vet. Med., 8: 141-156. A stratified random sample of 43 dairy herds in Californi...

Plasma alpha-tocopherol (vit E) and blood selenium (Se) concentrations in February were determined in samples from 314 dairy cows in Norway, selected to provide a representative subset of the Norwegian dairy cow population. Each sample was followed by a questionnaire with information about feeding of the cow at the time of sampling. The results were correlated to herd data and to calving and he...

The effect of shifting calf-weaning age on profiles of energy status (BW, BCS, and rib and rump fat) and reproductive performance of beef cows was evaluated in a 3-yr study. Pregnant and lactating crossbred beef cows (n = 408), mainly of Angus and Hereford breeding, were stratified by age and by sex and BW of their calves and assigned randomly into 2 treatments: weaning at approximately 180 d (...

Mitigation of methane emissions from dairy cattle is a relevant strategy to reduce environmental impact livestock as well increase farm profitability through improvement energy usage. The objective this study was compare how microbiome composition determines concentration (MET) and intensity (MI, ppm CH4/kg Milk) with other traditional proxies (e.g. milk yield conformation traits). A total 1359...

Genetic improvement programs in dairy cattle have until recently focused on increasing net profit by increasing gross income per cow, rather than reducing costs of production [1]. Strong selection pressure on yield traits coupled with management practices aimed at maximizing production may have resulted in undesirable side effects related to decreased fitness [2]. These concerns have been confi...

The objectives of this study were to describe the relationships between milk urea concentrations and nutritional management, production, and economic variables in commercial dairy herds. Dairy Herd Improvement (DHI) test-day milk urea data, production data, and information on ration nutrient composition and feeding management programs were collected over a 13-mo period from 53 commercial Ontari...