نتایج جستجو برای: economic data and performance records from 10 iranian holstein dairy cattle herds
تعداد نتایج: 18034900 فیلتر نتایج به سال:
Mean effective sensitivity for Mycobacterium avium subsp. paratuberculosis infection in cattle herds
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...
Twinning in cattle is a complex trait that is associated with economic loss and health issues such as abortion, dystocia, and reduced calf survival. Twinning-rate QTL have been detected previously on BTA5 in the North American Holstein and Norwegian dairy cattle populations and in a USDA herd selected for high twinning rate. In previous work with the North American Holstein population, the stro...
this study was carried out to study the inbreeding coefficient and its effect on reproductive performance of dairy cows (age at first calving, calving interval and open days) in isfahan province. records of 31,977 (primiparous cows), 36,982 and 51,423 (multiparous cows) for age at first calving, calving interval and open days were used, respectively. the inbreeding coefficients of animals were ...
British breeds of cattle are not so effective as Zebu in extracting nutrients from low-quality roughages, and these breeds differ in their nutrient metabolism and animal physiology. Breeds of cattle may differ in their requirements for Mg. Brahman cows are less susceptible to death from disease and metabolic disorders than are British breeds of cattle, whereas cows with 50% or greater dairy bre...
background: metabolic profiles have been used in efforts to predict pre parturient problems and fertility, to diagnose metabolic diseases, and to assess nutritional status in dairy cows. these profiles may help to confirm the diagnosis of sub clinical diseases, to be aware of possible causes of infertility in the herds, or to monitor improvement in herd animals. objectives: this study investiga...
A seroprevalence study of bovine immunodeficiency virus (BIV) was undertaken on 1,541 serum samples from Holstein cattle from 23 herds, located in different geographical regions of Poland. The analysis was performed using ELISA, with recombinant Gag protein of BIV as antigen. The average BIV prevalence was 4.9% in individual cattle, while the percentage of herds harboring at least one seroposit...
bovine viral diarrhoea virus (bvdv) is an important pathogen of dairy cattle. in this study, bulk milk samples representing a total of 4105 milking cows, from 18 dairy cattle herds in the suburb of mashhad- iran, were tested for presence of bvdv by the use of a nested reverse transcription polymerase chain reaction (nested rt- pcr) assay. non of the cows in the herds had been vaccinated against...
Between 2007 and 2009, the largest human Q fever epidemic ever described occurred in the Netherlands. The source was traced back to dairy goat farms, where abortion storms had been observed since 2005. Since one putative cause of these abortion storms is the intensive husbandry systems in which the goats are kept, the objective of this study was to assess whether these could be explained by her...
In this research test-day records of milk, fat and protein yields of first lactation of 11368 Holstein cows were used to comparison of estimated genetic parameters by restricted maximum likelihood method based on single trait and multiple trait random regression models. These data were collected from 133 herds during 2001 to 2010 by Cattle Breeding and Dairy Product Improvement Center. Herita...
q fever is an important zoonotic disease caused by infection with coxiella burnetii. limited information is available concerning theseroprevalence of coxiella burnetii in iran.a serological survey was conducted to describe the eroepidemiology of coxiellaburnetii infection in dairy cattle in khorasan razavi province located in northeast of iran. 246 dairy cattle from 19 commercial dairy herds th...
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