Reproductive Performance of Crossline and Pureline Dairy Heifers
نویسندگان
چکیده
منابع مشابه
Event-time analysis of reproductive traits of dairy heifers.
Data on the reproductive traits of dairy heifers were analyzed using event-time techniques. Traits analyzed were age at first calving (n = 4631), days to first breeding, and days open (n = 1992) during the first lactation. A proportional hazard model was used that included fixed effects of herd-year, year-season, breed type, herd weight, and heifer weight. Body weights were recorded at 390 d of...
متن کاملImproving Dairy Cattle Reproductive Performance
• A calving interval of 13.5 months is an achievable goal that will produce higher daily milk yield and higher milk yield over the length of the lactation. To achieve this goal average days to first service should be <80, yearly 21-day Pregnancy Rates should average >20% and culling for reproductive failure should not exceed 10%. • Management must set standard operating procedures for all aspec...
متن کاملOptimising reproductive performance of beef cows and replacement heifers.
A reproductively efficient beef cow herd is fundamental to meeting the protein and specifically, red meat demand of an ever increasing global population. However, attaining a high level of reproductive efficiency is underpinned by producers being cognisant of and achieving many key targets throughout the production cycle and requires significant technical competency. The lifetime productivity o...
متن کاملThe effect of feeding dairy heifers diets with and without supplemental phosphorus on growth, reproductive efficiency, health, and lactation performance.
The phosphorus requirements for dairy heifers (0.20-0.35%) and endogenous concentrations (0.20-35%) of P in feeds fed to dairy heifers are similar, suggesting that the need for supplemental P in dairy heifer diets may be minimal. Because long-term P feeding studies on dairy heifers are unavailable, 183 Holstein heifers and 182 backcross Holstein × Jersey heifers were offered diets with (SP=0.40...
متن کاملEpidemiology of reproductive performance in dairy cows.
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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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1984
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(84)81590-8