Location: Animal Genomics and Improvement LaboratoryTitle: Utilizing variance of gametic diversity in dairy cattle improvement
|SANTOS, DANIEL - University Of Maryland|
|LAWLOR, THOMAS - Holstein Association Usa, Inc|
|MA, LI - University Of Maryland|
Submitted to: Plant and Animal Genome
Publication Type: Abstract Only
Publication Acceptance Date: 1/4/2019
Publication Date: 1/4/2019
Citation: Santos, D.J., Cole, J.B., Van Raden, P.M., Lawlor, T.J., Ma, L. 2019. Utilizing variance of gametic diversity in dairy cattle improvement [abstract]. Plant and Animal Genome. PE0340.
Technical Abstract: Variation in the additive genetic value of gametes coming from individual animals is a parameter that can be estimated and utilized in a dairy cattle breeding program. The variance of gametic diversity can be calculated as a function of the probabilities of transmission of all marker effects for an individual animal. Our data consisted of 1,364,278 Holstein and 164,278 Jersey cattle. All individuals were imputed to a common panel of 60,671 SNPs. Five dairy traits were analyzed: milk (MY), fat (FY), and protein yields (PY) and fat (F%) and protein percentages (P%). SNP marker effects were estimated using a GBLUP model. We used different recombination rates between the markers for the different sexes and cattle breeds. However, the different recombination rate between males and females resulted in little differences between the two sexes for variance of gametic diversity. The estimated variance of gametic diversity for the individual chromosomes varied in average, standard deviation, and amplitude and BTA14 had the largest effect for all traits. Distribution of variance of gametic diversity varied by trait, with PY being more normally distributed, and F%, showing a skewed distribution. The correlation between the variance of the GEBVs of an animal’s progeny with our estimate of variance of gametic diversity for that animal was used as our measure of predictability. As expected, predictability increased as the number of offspring increased, with medium to high predictabiltiy for most bulls. Indicating that predicting variance of gametic diversity could be reliably calculated and used in today’s dairy breeding programs. Correlation of variance of gametic diversity with inbreeding coefficients were negative or close to zero across the traits, the highest correlation observed for PY and the lowest for F%. The correlations of variance of gametic diversity amongst the yield traits were all positive, ranging from 0.31 to 0.92. Correlations between yield and percentage traits were sometimes negative. Selecting dairy cattle with higher variance of gametic diversity can help maintain greater genetic diversity and lead to higher genetic gain over the long term.