Interactions of High Milk Yield and Reproductive Performance in Dairy Cows
نویسندگان
چکیده
منابع مشابه
the effects of high non fibrous carbohydrates diet on milk production, inflammation and molecular mechanism of innate immunity in lactating dairy cows
پژوهش حاضر با هدف بررسی اثر جیره حاوی کربوهیدراتهای غیرالیافی زیاد و بروز التهاب در گاوهای شیرده در دو آزمایش جداگانه انجام شد. در آزمایش اول 20 رأس گاو مبتلا به ورم پستان از دو گروه کم تولید و پرتولید (هر کدام 10 رأس) و 20 رأس گاو سالم از دو گروه کم تولید و پرتولید (هر کدام 10 رأس) انتخاب شدند. همه گاوها در دوره دوم و یا سوم شیردهی و در روزهای 80-120 پس از زایش بودند. میانگین تولید شیر در گروه...
Reproductive Success in Dairy Cows: the Linkage of Milk Yield, Nutrition, and Reproduction
During the past several decades, selection for increased milk yield has had a temporal association with declines in fertility and reproductive efficiency in dairy cows. In the US, an average annual decrease of 0.5% in conception rate at first service occurred between 1975 and 1997 (Butler and Smith, 1989; Beam and Butler, 1999). In the UK (between 1978 and 1996) and in Spain (between 1991 and 2...
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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...
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Although the number of dairy farms is decreasing, that of large farms is increasing in Japan. Milk production in Japanese dairy cows has increased from 62 kg/year to 88 kg/year over the last 2 decades. However, Japanese dairy cows are experiencing a sustained decline in reproductive performance, calving intervals, and days open; further, the number of inseminations required for conception have ...
متن کاملInfluence of Body Condition Score on Yield and Composition of Milk in Crossbred Dairy Cows
The study was carried out for a period of 150 days on 120 Holstein Friesian crossbred dairy cows between mid to late lactation to quantify the influence of body condition score (BCS) on yield and composition of milk. Total 12 dairy farms having same housing systems and holding at least 20 crossbred dairy cows per farm between mid to late lactation were selected for this study purposes. BCS of i...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1993
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(93)77662-6