نتایج جستجو برای: holstein dairy cattle
تعداد نتایج: 92055 فیلتر نتایج به سال:
Complex vertebral malformation (CVM) is a recently described monogenic autosomal recessive hereditary defect of Holstein dairy cattle that causes premature birth, aborted fetuses and stillborn calves. Guanine is substituted by thymine (G>T) in the solute carrier family 35 member A3 gene (SLC35A3). A valine is changed to a phenylalanine at position 180 of uridine 5'-diphosphate-N-acetyl-glu...
Beef derived from Holstein steers is a significant source of the U.S. beef supply. The nation’s 9.1 million dairy cows in 2003 were 22% of the U.S. cow herd (NASS, 2005). Given the typical breed distribution of dairy cows, calving interval, full-term pregnancy rate, peri-natal calf death loss (NAHMS, 2002), gender distribution, dairy beef placement (80%) and survival to market (94%), it can be ...
Approximately 20% of the beef tonnage produced in the United States is derived from Holsteins, through harvested dairy beef or cull dairy cows (Randy Blach, Cattle-Fax, personal communication). This represents a significant contribution to the U.S. beef supply. More and more large commercial feed yards have seen the opportunity available with feeding Holstein steers. Inherent variation between ...
Mastitis is one of the most serious and costly diseases affecting dairy cattle production. In the present study, effects of a lactoferrin gene polymorphism (intron 6) on milk somatic cell count (SCC) and subclinical mastitis was investigated in 121 Holstein dairy cattle. Two alleles of A and B and two genotypes of AA and AB were found in an EcoRI recognized single nucleotide polymorphism in int...
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...
BACKGROUND Over two decades of observations in the field in South East Asia and Hawai'i suggest that majority of the commercial dairy herds are of black hair coat. Hence a simple study to determine the accuracy of the observation was conducted with two large dairy herds in Hawaii in the mid-1990s. METHODS A retrospective study on longevity of Holstein cattle in the tropics was conducted using...
A high incidence (about 70%) of alteration in endometrial epidermal growth factor (EGF) profile, i.e., loss of 2 peaks on days 2-4 and 13-14, has been linked to a reduced fertility in multiparous repeat breeder Holstein cows. However, the EGF profile in Holstein heifers and other breeds (types) of cattle has not been investigated. In study 1, EGF concentrations were determined using endometrial...
Crossbreeding is a popular tool for genetic improvement of pigs, beef cattle, and other livestock species, but its use in US dairy cattle has been limited for several reasons. The primary reason is the advantage of Holstein cows in milk volume, coupled with a milk pricing system that still tends to reward quantity, rather than quality, in many regions of the country (i.e., through volume premiu...
Excellent reviews of cattle breed comparisons or breed-cross comparisons have been previously reported by Franke (1980), Long (1980), and Marshall (1994). However, these reviews do not contain information on the calving ease, performance, carcass characteristics, or beef palatability of crossbred progeny of Holstein dams sired by different beef breeds. In many countries dairy females are common...
mastitis in cattle is a serious problem which causes considerable economic losses in the dairy cattle herds. the aim of this survey was to identify mycoflorain milk of healthy, clinical and subclinical mastitis of lactating holstein dairy cows. milk samples of 154 holstein dairy cows were collected from 10 dairy cattle herds in suburb of mashhad-iran. the treatment groups included 104 lactating...
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