Selection Indices for Milk and Fat Yield of Holstein-Friesian Dairy Cattle
Open Access
- 1 January 1959
- journal article
- research article
- Published by American Dairy Science Association in Journal of Dairy Science
- Vol. 42 (1) , 123-126
- https://doi.org/10.3168/jds.s0022-0302(59)90534-x
Abstract
Estimates of heritability, phenotypic and genetic correlations for milk and fat yield and fat per cent were obtained from the single lactation records of 20,024 daughter-dam pairs of the Holstein-Friesian breed. The estimates of heritability were 0.27, 0.57 and 0.24 for milk yield, fat per cent and fat yield respectively. The phenotypic correlations were 0.89 between milk yield and fat yield, -0.20 between milk yield and fat per cent and 0.25 between fat per cent and fat yield. Corresponding genetic correlations were 0.77, -0.33 and 0.34. The above estimates of parameters were used to construct selection indices for milk and fat yield. Results indicated that a selection index for milk yield alone would be expected to be most effective in improving milk and fat yield of dairy cattle.This publication has 5 references indexed in Scilit:
- Selection Indices Based on Milk and Fat Yield, Fat Per Cent, and Type ClassificationJournal of Dairy Science, 1955
- The Variance of the Genetic Correlation CoefficientPublished by JSTOR ,1955
- A Selection Index for Fat Production in Dairy Cattle Utilizing the Fat Yields of the Cow and Her Close RelativesJournal of Dairy Science, 1954
- Genetic Correlation between Type and Production in Jersey CattleJournal of Dairy Science, 1952