Genetic parameters for test-day milk yield, 305-day milk yield, and lactation length in Guzerat cows
نویسندگان
چکیده
منابع مشابه
Estimation of genetic parameters of weekly test-day milk yields and first lactation 305-day milk yield in Murrah buffaloes
Aim: The aim was to estimate genetic parameters of weekly test-day (TD) milk yields and first lactation 305-day milk yield (FL305DY) in Murrah buffaloes. Materials and Methods: The data on 39059 weekly test-day milk yield (WTDY) records during first lactation of 961 Murrah buffaloes calved from 1977 to 2012 and sired by 101 bulls maintained in an organized farm at National Dairy Research Instit...
متن کاملGenetic parameters affecting 180-days standardised milk yield, test-day milk yield and lactation length in Spanish Assaf (Assaf.E) dairy sheep
A total of 42,197 records of test-day milk yield (TDY) and 7654 lactations from 3854 individuals belonging to the Spanish Assaf Assaf.E) breed were analysed using univariate and multivariate models to estimate genetic parameters affecting TDY, total milk ield standardised to 180 days (MY180) and lactation length (LL) in order to asses their possibilities of use in the selection scheme f the Ass...
متن کاملGenetic parameters for first lactation test-day milk flow in Holstein cows.
Genetic parameters for test-day milk flow (TDMF) of 2175 first lactations of Holstein cows were estimated using multiple-trait and repeatability models. The models included the direct additive genetic effect as a random effect and contemporary group (defined as the year and month of test) and age of cow at calving (linear and quadratic effect) as fixed effects. For the repeatability model, in a...
متن کاملGenetic Analysis of Milk Yield in Iranian Holstein Cattle by the Test Day Model
Using monthly test day records the genetic parameters of Iranian Holstein cattle in first lactation were studied. Data of 277400 test-day milk records from 65320 cows and 2210 sires were analyzed by an animal random regression model using restricted maximum likelihood methodology. The model included herd-test-date, interaction between year-season of calving, days in milk (linear and quadratic) ...
متن کاملInterrelationships among ambient temperature, day length, and milk yield in dairy cows under a Mediterranean climate.
We examined the effect of calving month (CM) on the production of milk and milk protein by Israeli Holstein dairy cows located in the main climatic zone of Israel during their third and fourth lactations, and found it to be significant. Cows that calved in December produced the highest milk and milk protein yields, and those that calved in June produced the lowest, 92.8% of the maximum. The com...
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: Livestock Science
سال: 2013
ISSN: 1871-1413
DOI: 10.1016/j.livsci.2012.12.012