نتایج جستجو برای: economic data and performance records from 10 iranian holstein dairy cattle herds
تعداد نتایج: 18034900 فیلتر نتایج به سال:
Iodine (I) is an essential element for efficient dairy cow metabolism. Iodine status is however not well known on farms. The objective was to measure milk and plasma I concentrations in a selected group of commercial dairy herds in central Iranian province of Isfahan. During summer of 1999 and winter of 2000, 11 dairy farms were randomly chosen and a minimum of 10 cows were sampled from each fa...
Bovine viral diarrhoea virus (BVDV) causes an economically important endemic disease (BVD) of cattle in Ireland and worldwide. Systematic eradication by detection and removal of infectious (BVDV carrier) cattle has been successful in several regions. We therefore assessed the benefits (disease losses avoided) and costs (testing and culling regime) of a potential eradication programme in Ireland...
the objective of this study was to investigate the effect of inbreeding on lactation performance in holstein cows of iran.the pedigree file contained information of 1,025,281 animals born between 1965 and 2007.lactation performance records from march 2000 to april 2009 comprising 193,501calving events on 123,751 cows in 85 dairy herds were included in the data set. the potential consequent effe...
teachers’ beliefs greatly influence their performance in the classroom, their choice of instructional strategies, their way of controlling the class, their dealing with the students, and their general goals and objectives. one of these beliefs is teachers’ sense of efficacy which is viewed as an important construct and has shown to be positively correlated with students’ achievement (ross, 1992...
Bovine viral diarrhoea (BVD) is a significant drain on efficient and successful cattle production in both dairy and beef systems around the world. Several countries have achieved eradication of this disease, but always through the motivation of stakeholders who accept the benefits of eradication. These include increased cattle welfare and fitness of cattle to withstand other diseases, and decre...
the purpose of the present study was to investigate the relationship between fear of negative evaluation (fne) and communication strategies (css) among iranian efl learners. it was aimed to examine the differences in the use of communication strategies between speakers with high or low degree of fear of negative evaluation. the current study was a case study consisting of 10 english learners at...
introduction cattle are a monotocous species meaning that, under most circumstances, a successful pregnancy results in the birth of one calf. twinning rate has been reported in dairy cows from 3 to 5 percent, which can be influenced by maternal age.the birth of twins is detrimental to the majority of beef and dairy cattle producer. financial loss arising from any of twinning has been reported i...
When linear programming is used to rank sires on daughter profits, coefficients of input are required for representative daughters of each sire. Within herdyear-season regressions of daughter's actual 305-day milk, fat percent, days open, 2-min milk yield adjusted for total yield, total milking time, and body weight at birth and first calving on sire's proofs for production, conformation, milki...
A total of 989,582 test-day records of 160,243 first-parity cows collected from 131 herds of Iranian Holstein dairy cows from 1995 to 2014 by the Animal Breeding and Improvement Centre of Iran, were used to determine the best model for lactation curves of fat to protein ratio (FPR) and somatic cell scores (SCS) in the first lactation. Several mathematical models including the Wood (WD), Wilmink...
to describe proportion and pattern of culling in commercial dairy herds of khorasan razavi province, this survey was carried out from 21st march 2008 to 20th march 2009 in 15 industrialized dairy herds. for each culled cow data related to parity at culling, last calving to culling interval and primary reason for culling were recorded. annual herd exit rate was 20.9%. out of a total of 652 culle...
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