Heifers with positive genetic merit for fertility traits reach puberty earlier and have a greater pregnancy rate than heifers with negative genetic merit for fertility traits
نویسندگان
چکیده
منابع مشابه
Relationship of bovine leukocyte adhesion deficiency with genetic merit for performance traits.
Examination of the existence of pleiotropy or linkage of bovine leukocyte adhesion deficiency with other traits and of the impact of removal of the recessive, undesirable allele on genetic progress for those traits has been limited. Frequency of carriers among 6400 Holstein bulls tested was 8.2%; however, reporting was incomplete, and, therefore, the estimate of carrier frequency was biased dow...
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Early lactation parameters are difficult to estimate from commercial dairy records due to the small number of records available before the peak of production. A biological model of lactation was used with weekly milk records from a single Holstein herd to estimate these early lactation parameters and the secretion rate of milk from the average cell throughout lactation. A genetic analysis of th...
متن کاملSelection for Fertility Traits
Introduction Fertility is a very complex trait, difficult to define, to record and to evaluate all the factors that influence fertility. Fertility is strongly influenced by environmental effects and in part by genetics, the male for fertilization and the female for conception. In general, the fertility trait is hereditary but only to a small degree. There does however exist sufficient genetic v...
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The objective of this study was to estimate effects of environmental sensitivity of milk production traits for several environmental parameters and to investigate the impact of combining traits with different environmental sensitivity in an economic index. Variance components and breeding values were estimated for milk, fat, and protein yield, and fat and protein percentage by applying a random...
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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: 2021
ISSN: 0022-0302
DOI: 10.3168/jds.2020-19155