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Genetic relationships of fertility traits with test-day milk yield and fat-to-protein ratio in tropical smallholder dairy farms
- Source :
- Animal Science Journal. 87:627-637
- Publication Year :
- 2015
- Publisher :
- Wiley, 2015.
-
Abstract
- The test-day milk fat-to-protein ratio (TD-FPR) could serve as a measure of energy balance status and might be used as a criterion to improve metabolic stability and fertility through genetic selection. Therefore, genetic parameters for fertility traits, test-day milk yield (TD-MY) and TD-FPR, as well as, their relationships during different stages of lactation, were estimated on data collected from 25 968 primiparous Thai dairy crossbred cows. Gibbs sampling algorithms were implemented to obtain (co)variance components using both univariate linear and threshold animal models and bivariate linear-linear and linear-threshold animal models with random regression. Average TD-MY and TD-FPR were 12.60 and 1.15. Heritability estimates for TD-MY, TD-FPR and selected fertility traits ranged from 0.31 to 0.58, 0.17 to 0.19 and 0.02 to 0.05, respectively. Genetic correlations among TD-FPR and TD-MY, TD-FPR and fertility traits, and TD-MY and fertility traits ranged from 0.05 to -0.44, from -0.98 to 0.98 and -0.22 to 0.79, respectively. Selection for lower TD-FPR would decrease numbers of inseminations per conception and increase conception at first service and pregnancy within 90 days. In addition, cow selection based only on high milk production has strong effects to prolong days to first service, days open and calving interval.
- Subjects :
- 0301 basic medicine
media_common.quotation_subject
Fertility
Bivariate analysis
Biology
Genetic correlation
Crossbreed
03 medical and health sciences
Animal science
Lactation
medicine
Selection (genetic algorithm)
media_common
Pregnancy
business.industry
0402 animal and dairy science
04 agricultural and veterinary sciences
General Medicine
Heritability
medicine.disease
040201 dairy & animal science
Biotechnology
030104 developmental biology
medicine.anatomical_structure
General Agricultural and Biological Sciences
business
Subjects
Details
- ISSN :
- 13443941
- Volume :
- 87
- Database :
- OpenAIRE
- Journal :
- Animal Science Journal
- Accession number :
- edsair.doi...........48904b05244afdefc9c60ef82ac17066