نتایج جستجو برای: parity holsteins dairy cattle calving during 1997

تعداد نتایج: 1838127  

Nastaran Ahangaran Rajabi, Seyed Abbas Rafat

Objective: The cows that don’t have access to sufficient energy in their ration can get sickness. Milk production has a high priority in metabolism of dairy cows so lactating cows are more prone to get sick This can ruin all the benefits of higher milk yield because of the higher prevalence of the disorders. Methods: Data for this research had gathered from a herd with 1600 Holstein cattle in E...

Journal: :Animal reproduction science 2000
Y T Gröhn P J Rajala-Schultz

The objectives of this presentation are to review results of our previous and on-going research with respect to the risk factors and consequences of poor reproductive performance in dairy cows, and to develop an economic framework to optimize decisions related to dairy cow reproductive performance. To make profitable breeding and replacement decisions, the farmer must account for factors includ...

Journal: :Journal of dairy science 2011
D W Bjelland K A Weigel P C Hoffman N M Esser W K Coblentz T J Halbach

A total of 648 purebred Holstein and 319 backcross Holstein × Jersey dairy cattle were compared for production, reproduction, health, linear type, and growth traits. Animals were born between 2003 and 2009 and were housed in the University of Wisconsin-Madison Integrated Dairy Facility. All animals had Holstein dams; lactating dams were mated to unproven Holstein sires to produce purebred (cont...

Journal: :iranian journal of applied animal science 2015
t. wassie g. mekuriaw z. mekuriaw

the study was carried out at agarfa atvet college dairy farm to evaluate the reproductive performance of holstein friesian× arsi and holstein friesian ×boran cattle. for the study, records compiled from 1983 to 2012 at the agarfa dairy farm were used as original data. the effects of breed, bloodlines, season and parity on the reproductive traits were evaluated. data were analyzed using the gene...

Journal: :Acta Veterinaria Scandinavica 2005
ÅM Sogstad T Fjeldaas O Østerås

Approximately 88% of Norwegian dairy cattle are housed in tie stalls. Free stall housing for all dairy cattle will be implemented within 20 years. This means that the majority of existing stalls will be rebuilt in the near future. Fifty-seven free stall herds of the Norwegian Red breed were randomly selected and 1547 cows and 403 heifers were trimmed by 13 claw trimmers during the late winter a...

Journal: :Animal : an international journal of animal bioscience 2014
D C Wathes G E Pollott K F Johnson H Richardson J S Cooke

The rearing period has a key influence on the later performance of cattle, affecting future fertility and longevity. Producers usually aim to breed replacement heifers by 15 months to calve at 24 months. An age at first calving (AFC) close to 2 years (23 to 25 months) is optimum for economic performance as it minimises the non-productive period and maintains a seasonal calving pattern. This is ...

Journal: :international journal of advanced biological and biomedical research 2014
nastaran ahangaran rajabi seyed abbas rafat

objective: the cows that don’t have access to sufficient energy in their ration can get sickness. milk production has a high priority in metabolism of dairy cows so lactating cows are more prone to get sick this can ruin all the benefits of higher milk yield because of the higher prevalence of the disorders. methods: data for this research had gathered from a herd with 1600 holstein cattle in e...

Journal: :Journal of dairy science 2007
R H Miller H D Norman M T Kuhn J S Clay J L Hutchison

Voluntary waiting period and adoption of synchronized breeding (ovulation synchronization followed by timed artificial insemination) were characterized from 33 million services of Holsteins and Jerseys in Dairy Herd Improvement herds. Calving month, calving year, and parity had large effects on days to first service for both breeds. Holstein cows that calved during March and April were bred lat...

Journal: :Preventive veterinary medicine 1997
W C Losinger A J Heinrichs

In a national survey of US dairy producers, only 2.7 +/- 0.5% of Holstein dairy operations reported achieving recommended target ranges of age < or = 24 months and body weight (BW) > or = 550 kg at first calving. Allowing for wider target ranges, still only 14.6 +/- 1.3% of Holstein dairy operations reported achieving age < or = 25 months and BW > or = 544.3 kg at first calving. Ages of individ...

Journal: :علوم دامی 0
سیروس فراستی دانشجوی دکتری تغذیه دام دانشگاه رازی کرمانشاه و عضو هیات علمی مرکز تحقیقات کشاورزی و منابع طبیعی کرمانشاه سیروس امیری نیا موسسه تحقیقات علوم دامی کشور

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...

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