Dairy Cows of High Genetic Merit for Yields of Milk, Fat and Protein - Review -
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...
Evaluation of Various Approaches in Prediction of Daily and Lactation Yields of Milk and Fat Using Statistical Models in Iranian Primiparous Holstein Dairy Cows
In this research, 272977 test day records collected from 659 herds during years 2001 to 2011 by the Iranian animal breeding center were used. In the first section the ability of different models to predict daily milk yield from alternative milk recording was tested. The result showed that a complex model including noon milking time plus the effect of lactation curve of Ali and Schaeffer functio...
متن کاملSelection of Dairy Cows for Economic Merit
Selection of dairy cows for economie merit requires the use of a model for genetic merit that involves the cross-product of the genetic values for milk and milk fa t percentage. A linear and a quadratic index are described as procedures for selection of cows, the linear index being blp.~ + bzp, and the quadratic index being blp,~ + b~_pt + b~p,n 2 + b~p, ~ + b~p.,pt where p~ and pt are the phen...
متن کاملMethod R estimates of heritability for milk, fat, and protein yields of United States dairy cattle.
Heritabilities for milk, fat, and protein yields were estimated from first lactation data used for USDA-Dairy Herd Improvement Association (DHIA) genetic evaluations. Contemporary group assignments and standard deviations within herd-year were determined with the procedure used for national evaluations. Pedigree data were included for animals born since 1970; yield data were included for cows b...
متن کاملGenetic parameter estimates of portuguese dairy cows for milk, fat, and protein using a spline test-day model.
A spline animal model was fitted to 152,103 test-day milk, fat, and protein yield records from 14,423 first-lactation cows. The models included age at calving and the herd-test-month as fixed effects. Model fitting was carried out using Restricted Maximum Likelihood with ASREML. For milk yield, the heritability at 18 d in milk was 0.19, which increased to the maximum estimated value of 0.23 at ...
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: Asian-Australasian Journal of Animal Sciences
سال: 1999
ISSN: 1011-2367,1976-5517
DOI: 10.5713/ajas.1999.1316