Gestation Length In Cattle Research Articles

Genetic and epigenetic architecture of paternal origin contribute to gestation length in cattle

The length of gestation can affect offspring health and performance. Both maternal and fetal effects contribute to gestation length; however, paternal contributions to gestation length remain elusive. Using genome-wide association study (GWAS) in 27,214 Holstein bulls with millions of gestation records, here we identify nine paternal genomic loci associated with cattle gestation length. We demonstrate that these GWAS signals are enriched in pathways relevant to embryonic development, and in differentially methylated regions between sperm samples with long and short gestation length. We reveal that gestation length shares genetic and epigenetic architecture in sperm with calving ability, body depth, and conception rate. While several candidate genes are detected in our fine-mapping analysis, we provide evidence indicating ZNF613 as a promising candidate for cattle gestation length. Collectively, our findings support that the paternal genome and epigenome can impact gestation length potentially through regulation of the embryonic development.

The effect of population size of paternal groups and herds on optimal estimation of the heritability index for gestation length in cattle

Estimation of genetic parameters is a crucial element in the process of population improvement. In the case of farm animals this process is based on a sample which is a subset of the whole population. For this reason it is important to know the effect of the size of paternal groups and of the herd on the accuracy of estimations of these parameters, particularly heritability. The aim of this study was to show the effect of the population size of paternal groups and herds on the accuracy of estimation of the heritability index (h2). The material for the analyses comprised data of Holstein-Friesian cattle born in 2005-2010 and subject to use value assessment in Poland. The trait analysed was gestation length. Calculations using a linear mixed model were performed using the R 3.1.3 platform. The analyses showed that calculations concerning daughters in paternal groups are more accurate when the daughters are in a smaller number of herds, but of greater size. An increase in the size of paternal groups at the expense of their number does not have such a negative effect on the accuracy of the estimate as in the case of a reduced number of small herds. Limiting the estimate to only the largest herds reduces its accuracy.

Modification of gestation length in cattle by the type of environment present at the end of pregnancy

The gestation lengths of cattle are considered in terms of variation due to the month in which calving occurs. The well-known summer decrease in gestation length is re-established but in addition there is a short-term decrease in April which appears to be related to the cattle being put out to grass at a late stage of pregnancy after they have been housed for the winter.