Using AI calving-ease bulls on replacement heifers
نویسندگان
چکیده
منابع مشابه
Genetic evaluation of calving ease for Brown Swiss and Jersey bulls from purebred and crossbred calvings.
The objective of this study was to examine the feasibility of implementing routine national calving ease (CE) genetic evaluations of Brown Swiss (BS) and Jersey (JE) sires that include records of crossbred calvings. Records were available for 11,793 BS calvings, 3431 BS-sired crosses, 65,293 JE calvings, and 7090 JE-sired crosses. Evaluations were performed for each breed using only purebred ca...
متن کاملGenetic parameters for growth, reproductive performance, calving ease and suckling performance in beef cattle heifers
There is considerable concern about the consequences on fitness-related traits of using narrow breeding objectives for production traits. The aim of this study was to assess the potential consequences of selection for growth in French beef cattle breeds by estimating genetic correlations between growth, reproduction, calving and suckling traits of Charolais, Limousin and Blonde d’Aquitaine heif...
متن کاملEstimation of Genetic Parameters for Calving Ease by Heifers and Cows Using Multi-trait Threshold Animal Models with Bayesian Approach
Genetic parameters for birth weights (BWT), calving ease scores observed from calves born by heifers (CEH), and calving ease scores observed from calves born by cows (CEC) were estimated using Bayesian methodology with Gibbs sampling in different threshold animal models. Data consisted of 77,458 records for calving ease scores and birth weights in Gelbvieh cattle. Gibbs samplers were used to ob...
متن کاملCalving day and age at first calving in Angus heifers.
Because of difficulties in data collection and analysis, in most breeds there have been limited ways to evaluate fertility in females on a between-herd basis. The objective of this study was to determine the heritabilities (direct and maternal) for CD (calving day) and AFC (age at first calving) in American Angus heifers and to evaluate the potential for using these traits in genetic improvemen...
متن کاملOptimal breeding strategies for calving ease.
Calving ease is of economic importance in dairy cattle and should be considered in breeding programs. Economic values of direct and maternal calving ease were derived based on cost-benefit analysis and gene flow methodology. Marginal returns from dystocia reduction in primiparous dams were -$43 per phenotypic standard deviation compared with $300 for production. For an average mate, numbers of ...
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ژورنال
عنوان ژورنال: Kansas Agricultural Experiment Station Research Reports
سال: 1986
ISSN: 2378-5977
DOI: 10.4148/2378-5977.3047