Genetic and Phenotypic Parameters for 305-Day Yield, Fertility, and Survival in Holsteins
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 and phenotypic parameters for test day milk yield of Sahiwal cattle in the semi-arid tropics.
A total of 19 376 test day (TD) milk yield records from the first three lactations of 1618 cows daughters of 162 sires were used to estimate genetic and phenotypic parameters and determine the relationship between daily milk yield and lactation milk yield in the Sahiwal cattle in Kenya. Variance components were estimated using animal models based on a derivative free restricted maximum likeliho...
متن کاملApplication of random regression models for genetic analysis of 305-d milk yield over different lactations of Iranian Holsteins
OBJECTIVE During the last decade, genetic evaluation of dairy cows using longitudinal data (test day milk yield or 305- day milk yield) using random regression method has been officially adopted in several countries. The objectives of this study were to estimate covariance functions for genetic and permanent environmental effects and to obtain genetic parameters of 305-day milk yield over seven...
متن کاملGenetic parameters for tunisian holsteins using a test-day random regression model.
Genetic parameters of milk, fat, and protein yields were estimated in the first 3 lactations for registered Tunisian Holsteins. Data included 140,187; 97,404; and 62,221 test-day production records collected on 22,538; 15,257; and 9,722 first-, second-, and third-parity cows, respectively. Records were of cows calving from 1992 to 2004 in 96 herds. (Co)variance components were estimated by Baye...
متن کاملGenetic and Phenotypic Trends of Fertility Traits in Iranian Holstein Cows
A total of 72124 fertility records was used to estimate the genetic and phenotypic trend of fertility traits in Iranian Holstein cow from 1981 to 2007. Fertility traits in this study were: days from calving to first service (DFS), number of insemination per conception (INS), days open (DO), interval between first and last insemination (IFL), calving interval (CI) and success to first inseminati...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1998
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(98)75827-8