​Body Size Traits and Association with the Genetic Polymorphism of Melatonin Receptor 1A (MTNR1A) Gene in Shuxuan Cattle

Abstract

Background: Shuxuan cattle is one newly cultivated dual-purpose breed in Sichuan province, China, by crossing the indigenous Xuanhan cattle with external breeds. Body sizes have been widely regarded as the important breed characteristics in cattle. The current study was aimed to evaluate the body sizes and its molecular inherite marker for futhure herd improvement. Methods: In the present study, we first investigated a total of 11 body size traits and their overall distribution and pairwise relationships of 169 healthy Shuxuan cattle. Subsequently, the SNP c.A455G of melatonin receptor 1A (MTNR1A) gene were genotyped among 169 Shuxuan cattle and subjected to association analysis with body size traits. Result: We revealed that adult females have the mean withers height of 113.5 cm, body length of 131.8 cm, chest girth of 157.5 cm and hip height of 104.8 cm, respectively. Among all these traits, the highest correlation was observed in withers height and hip height with spearman’s coefficient of 0.85. We found that Shuxuan cattle had an average heterozygosity of 0.5008 and polymorphism information content of 0.3747. Accordingly to the very stringent criterion of Bonferroni multiple adjustments, only chest width was associated with different genotypes of this candidate SNP (P less than 0.05). The results provide an overall profile of the morphological and growth characteristics in Shuxuan cattle.