Variance component estimation on female fertility traits in beef cattle
نویسندگان
چکیده
منابع مشابه
Variance component estimation on female fertility traits in beef cattle
The purpose of this review is to define possible breeding objectives for Southern African beef cattle farmers and to review different means of expressing genetic reproductive merit. The breeding objective considered was to maximize the number of calves born or weaned for a given number of cows in a herd under prevailing environmental and management conditions. This is a complex trait that has m...
متن کاملEstimation of variance components for production and fertility traits in Northern Thai dairy cattle to define optimal breeding strategies
Milk production in Thailand has been growing into an important agricultural sector, but it still faces numerous difficulties in environmental constraints. The main intention of this study was to identify significant environmental effects on production and fertility traits to give advices for farm management. Additionally, adjusting records for environmental impact is essential to define appropr...
متن کاملEffect of Sperm Quality of Beef Cattle on Fertility Percentage
Pregnancy rate evaluation of the profitability of any beef cattle operations, the profit or loss is one of the most important factors determining. Emphasis and focus on adequate nutrition and reproductive management beef cattle herd, but, unfortunately, most placed little emphasis on beef cattle operations kept. However, each beef cattle breeding season during a typical cow-calf operation in 15...
متن کاملComparison of Landim and Africander cattle in southern Mozambique: II. Female fertility, reproduction, and beef offtake.
Fertility and reproductive performance of Landim and Africander females were compared using data collected from 1968 to 1981 at the Chobela Research Station in Mozambique. Breeds were managed together and grouped by age and sex, except when separated for breeding. Traits were relative fertility (probability of fertile females calving from the first breeding season), age at first calving, first ...
متن کاملREML Variance-Component Estimation
In the numerous forms of analysis of variance (ANOVA) discussed in previous chapters, variance components were estimated by equating observed mean squares to expressions describing their expected values, these being functions of the variance components. ANOVA has the nice feature that the estimators for the variance components are unbiased regardless of whether the data are normally distributed...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: South African Journal of Animal Science
سال: 2001
ISSN: 2221-4062,0375-1589
DOI: 10.4314/sajas.v31i3.3793