engleski

Variance Estimation Of Maternal Lineage Effect On Milk Traits In Croatian Holstein Cattle

The effect of maternal lineage (ML) on milk production traits: milk, fat and protein yield (MY, FY, and PY), fat and protein content (FC and PC) was evaluated in the Croatian Holstein cattle. Data included 102, 961 records for 46, 696 cows calved from January 2000 to July 2015 taken from the Central database of the Croatian Agricultural Agency. Pedigree file consisted of 77, 398 animals. Variance components were estimated by REML method using VCE-6 program. Statistical model included parity, region, and calving season as fixed class effects, while age at first calving was fitted as quadratic regression. Random effects were: interaction herd-year, permanent environment, maternal lineage, and direct additive genetic effect. Identification of ML was based on the pedigree information. The contribution of ML to the phenotypic variance was 2% for FC and PC and 3% for MY, FY, and PY. The estimates of ML for milk traits were within the range of other studies.

milk traits, Holstein cattle, variance components estimation, maternal lineage

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