this study was performed to determine the effect of injecting selenium into pregnant heifers at the last stage of gestation on the serum se, cu, zn and fe status of the heifers and their calves. fifty holstein heifers were randomly assigned to one of five treatments. four and two weeks before the expected time of calving, the heifers were injected intramuscularly 10 ml (t1), 20 ml (t2), 30 ml (...

the aim of this study was using bayesian approach via gibbs sampling (gs) for estimating genetic parameters of production, reproduction and health traits in iranian holstein cows. data consisted of 320666 first- lactation records of holstein cows from 7696 sires and 260302 dams collected by the animal breeding center of iran from year 1991 to 2010. (co) variance components were estimated using ...

The aim of this research was to estimate the influence of environmental factors, such as air temperature and milk production, on reproduction traits of primiparous Polish Holstein-Friesian cows. The following reproduction traits were considered: interval from calving to first insemination, interval from first to last insemination, interval from calving to conception, number of inseminations per...

this experiment was conducted to evaluate reproductive indices and provide appropriate solutions to improve the reproductive efficiency of dairy cattle in kermanshah province. with reference to forty-eight dairy industrial herds available at different cities of the province, a questionnaire containing quantitative measures were completed to assessing the reproductive parameters of 5397 dairy co...