Introduction: Although milk production as measured by rolling herd averages has increased markedly for dairy herds in the Western United States over the last decade, reproductive performance of these herds has declined significantly. Average days open have increased by 25 days and fertility has declined as measured by an increase of 0.37 services per conception and first service conception rate...

Differences in conception rate to first service between artificial inseminations (AI) carried out by commercial AI operators (CAI) or do-it-yourself operators (DIY), between natural service (NAT) and AI, between different AI sires, and between fresh and frozen-thawed semen, on Irish commercial dairy farms, were studied using logistic regression. The study comprised 12,933 potential first insemi...

This dissertation summarises the findings of two separate studies relating to the epidemiology of bovine viral diarrheoa virus in New Zealand dairy herds. The objective of the first study was to estimate the distribution and causes of abortion in dairy herds across New Zealand during the 2001/2002 breeding season. A questionnaire survey was sent to all veterinary practices that were listed as m...

BACKGROUND The Swedish control program for salmonella includes restrictions and on-farm control measures when salmonella is detected in a herd. Required control measures are subsidised by the government. This provides an opportunity to study costs for on-farm salmonella control. The aim of this study was to describe the costs for on-farm salmonella control in Swedish cattle herds and to investi...

Salmonella is one of the most serious foodborne pathogenic bacteria in the United States, causing an estimated 1.3 million human illnesses each year. Dairy cows can be reservoirs of foodborne pathogenic bacteria, including Salmonella spp.; it is estimated that from 27 to 31% of dairy herds across the United States are colonized by Salmonella. The present study was designed to examine the occurr...

The following points are important to remember in the quest to achieve a successful dairy reproductive program: • Pregnancy rate is a sensitive and valuable indicator of reproductive performance. • Insemination risk and conception risk are components of pregnancy rate. • Low heat detection accuracy can reduce conception risk and ultimately decrease pregnancy rate. • In an on-going heat detectio...

Bovine rotaviruses isolated from beef and dairy herds in Argentina were serotyped by the immunoperoxidase focus reduction assay as previously described (G. Gerna, M. Battaglia, G. Milenesi, N. Passarani, E. Percivalle, and E. Cattaneo, Infect. Immun. 43:722-729, 1984). Three strains from beef herds were related to the UK and NCDV bovine rotavirus strains defined as serotype 6 (Y. Hoshino, R. G....

from Operation-management factors associated with early-postnatal mortality of US foals, Losinger WC, Traub-Dargatz JL, Sampath RK, Morley PS, Preventive Veterinary Medicine, 47 (2000) 157-175, November 2000. Persistent BVD infection in US beef herds In 1996, testing for BVD persistent infection was carried out on 18,931 spring born calves in 128 beef herds. Of these herds, 76 were randomly sel...

Bovine venereal campylobacteriosis, caused by Campylobacter fetus subsp. venerealis (Cfv), is regarded as one of the major threats to the cattle industry around the world. Abortion and infertility are two important reproductive problems in cows infected with C. fetus subsp. venerealis. Reports on the presence of Cfv are scarce in the cattle, in Iran....