نتایج جستجو برای: dairy cattle herd
تعداد نتایج: 91449 فیلتر نتایج به سال:
Advances in breeding and management resulted in a considerable increase of production traits in Austrian dairy cattle. Besides, low input systems were also established. Possible genotype by environment interactions (G x E) and genetic antagonisms dependent on production level might indicate the need for separate breeding programmes for dairy farms diff ering in management intensity. Th us, G x ...
Premature disposal of female calves before reaching milch herd and undesirable disposal of lactating cows are the major constraints in achieving larger herd size. During the early lactations, younger cows are supposed to give higher milk yield and undesirable disposal of early calvers, thereby, greatly hampers profitability of a dairy farm. Knowledge of the incidence of disposal along with reas...
Mycobacterium avium subsp. paratuberculosis (Map) is the etiological agent of paratuberculosis. In Chile, information about Map isolation from both domestic ruminant and wildlife species has been accumulating, but it has to be extended to other species. The present study focuses specifically on one wild grazing species, the pudu (Pudu puda), one of the less known South American deer considered ...
bovine genital campylobacteriosis is one of the most economically important diseases of dairy cattleresulting in lowered fertility, embryo mortality and abortion, repeated returns to service, reduced pregnancyrates and extended calving intervals. while the occurrence of repeat breeding syndrome and abortions arereported from many iranian dairy cattle farms, little information is available regar...
OBJECTIVE To identify major environmental and farm management factors associated with the occurrence of tuberculosis (TB) on cattle farms in northeastern Michigan. DESIGN Case-control study. SAMPLE POPULATION 17 cattle farms with infected cattle and 51 control farms. PROCEDURE Each case farm (laboratory confirmed diagnosis of Mycobacterium bovis infection) was matched with 2 to 4 control ...
The objective of this study was to characterize opinions and practices of Wisconsin dairy producers about biosecurity and animal wellbeing. Wisconsin dairy producers were surveyed using a mailed questionnaire and responder herds were categorized based on the number of lactating cows: very small herds (< or =50 lactating cows; n = 279); small herds (51 to 100 lactating cows; n = 202); medium her...
Approach and results In April 2006, a dairy cattle herd located in Catalonia was depopulated due to widespread M caprae infection with spoligotype profile SB0416. The herd was repopulated but, in 2009, the same spoligotype was identified, and several possible causes of infection (including the recirculation of the previous infection, purchase of infected animals and contact with other infected ...
OBJECTIVE To evaluate sensitivities at the herd level of test strategies used in the Voluntary Johne's Disease Herd Status Program (VJDHSP) and alternative test strategies for detecting dairy cattle herds infected with Mycobacterium paratuberculosis. DESIGN Nonrandom cross-sectional study. SAMPLE POPULATION 64 dairy herds from Pennsylvania, Minnesota, Colorado, Ohio, and Wisconsin. Fifty-si...
Farm management practices that reduce the prevalence of food-borne pathogens in live animals are predicted to enhance food safety. To ascertain the potential role of livestock bedding in the ecology and epidemiology of Escherichia coli O157:H7 on farms, the survival of this pathogen in used-sand and used-sawdust dairy cow bedding was determined. Additionally, a longitudinal study of mature dair...
We present the building of a discrete event multimodel simulation tool of livestock farming systems, regrouping several mathematical models, and reproducing cattle herd performances through an individual based model. The main goal of this simulator is to study and predict consequences of mastitis occurrences on dairy herds taking into account individual characteristics of animals and seasonal a...
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