نتایج جستجو برای: dairy herds

تعداد نتایج: 49062  

Journal: :Preventive veterinary medicine 1999
S J Wells L P Garber B A Wagner

The objective of this study was to describe the incidence of papillomatous digital dermatitis in the US (including regional and herd size patterns) and to evaluate specific herd-level management factors associated with high incidence of digital dermatitis in US dairy herds. The study design was a population-based cross-sectional survey. US dairy operations with at least 30 cows in 20 states, re...

2015
Carsten Kirkeby Kaare Græsbøll Tariq Halasa Nils Toft Søren Saxmose Nielsen

BACKGROUND Mycobacterium avium subsp. paratuberculosis (MAP) infections in cattle are generally challenging to detect and cost-effective test strategies are consequently difficult to identify. MAP-specific antibody ELISAs for milk and serum are relatively inexpensive, but their utility is influenced by a number of factors such as herd size, herd composition and diagnostic sensitivity. The sensi...

Journal: :Preventive veterinary medicine 2003
S L Ott R Johnson S J Wells

Bovine-leukosis virus (BLV; also termed 'bovine-leukemia virus') is a retrovirus that primarily affects lymphoid tissue of dairy and beef cattle. Our objective was to investigate the association between BLV infection and annual value of production (AVP) on dairy herds within the United States, as part of the USDA National Animal Health Monitoring System's 1996 dairy study. 1006 herds (in 20 sta...

2005
L. HURKOVA D. HALOVA D. MODRY

Neospora caninum is a protozoan parasite causing bovine abortion all over the world. The aim of this study was to investigate how common N. caninum infection is among dairy herds in the Czech Republic. Bulk milk samples were collected from 495 dairy herds and analysed for the presence of specific antibodies by a commercial N. caninum iscom ELISA. Five out of 495 dairy herds (1.01%) had percenta...

2014
Youcef Mehdi Jean-François Cabaraux Jean-Luc Hornick Louis Istasse

Aim: Monitoring was performed in order to determine the Selenium (Se) status of cattle herds in different agricultural areas in Wallonia (Belgium). Materials and Methods: The study included 114 heifers and 184 cows (82 dairy and 102 beef cows) from 66 cattle farms situated in Wallonia. The Se status was assessed by measuring the glutathion peroxydase in red cells and converting it to the equiva...

2012
Julio Alvarez Andres M Perez Javier Bezos Carmen Casal Beatriz Romero Sabrina Rodriguez-Campos Jose L Saez-Llorente Rosa Diaz Jesus Carpintero Lucia de Juan Lucas Domínguez

BACKGROUND Eradication of bovine tuberculosis (bTB) through the application of test-and-cull programs is a declared goal of developed countries in which the disease is still endemic. Here, longitudinal data from more than 1,700 cattle herds tested during a 12 year-period in the eradication program in the region of Madrid, Spain, were analyzed to quantify the within-herd transmission coefficient...

2002
Jerry D. Olson

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...

2003

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...

2015
Estelle C.C. Ågren Jan Johansson Jenny Frössling Helene Wahlström Ulf Emanuelson Susanna Sternberg-Lewerin

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...

Journal: :Journal of dairy science 2005
T R Callaway J E Keen T S Edrington L H Baumgard L Spicer E S Fonda K E Griswold T R Overton M E VanAmburgh R C Anderson K J Genovese T L Poole R B Harvey D J Nisbet

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...

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