Additive genetic variance and covariance in some reproduetive disorders in Hungarian Holstein Friesian using multi-trait animal model

Evidence for genetic variance in resistance to tuberculosis in Great Britain and Irish Holstein-Friesian populations

BACKGROUND Here, we jointly summarise scientific evidence for genetic variation in resistance to infection with Mycobacterium bovis, the primary agent of bovine tuberculosis (TB), provided by two recent and separate studies of Holstein-Friesian dairy cow populations in Great Britain (GB) and Ireland. METHODS The studies quantified genetic variation within archived data from field and abattoir...

Genetic Association Analysis of Paratuberculosis Forms in Holstein-Friesian Cattle

A genetic susceptibility to Mycobacterium avium subsp. paratuberculosis (MAP) infections in ruminants has been longtime suspected to exist. Recently, natural infections in cattle have been reclassified into latent and patent forms based on histopathological findings and their associations with immunological and microbiological variables. This study aims to explore whether these newly defined ph...

Additive Genetic Variance

study of some calving parameters in holstein friesian diary cattle in industrial animal husbandries of tabriz

objective of the present study was to determine calving parameters in eighteen large dairy herds of holstein friesian in tabriz. data analysis showed that the mean gestations length were 276.69 ± 6.29, 279.54 ± 8.55 and 271.38 ± 7.34 days in multipara cows and twining pregnancy respectively. percent of premature birth were 24.14% in twining (28 cases out of in 116 births), 9.61% in heifers (114...

Characterizing the evolution of genetic variance using genetic covariance tensors.

Determining how genetic variance changes under selection in natural populations has proved to be a very resilient problem in evolutionary genetics. In the same way that understanding the availability of genetic variance within populations requires the simultaneous consideration of genetic variance in sets of functionally related traits, determining how genetic variance changes under selection i...