An evaluation of corticotropin-releasing hormone and leptin SNPs relative to cattle behaviour

Abstract

The purpose of this study was to identify associations between single nucleotide polymorphisms (SNPs) in two genes involved in the hypothalamic-pituitary-adrenal axis and growth, namely corticotropin-releasing hormone (CRH), and leptin (LEP), and measurements of temperament in beef cattle. Four hundred crossbred beef steers were evaluated upon entry into a beef facility using several different measurements of response to handling: subjective score (SS), strain gauge (SG), movement measurement device (MMD) and exit time (ET). The steers were genotyped at the CRH 22C>G, CRH 240C>G and LEP 73C>T SNPs by PCR-RFLP. The SNP genotypes and two-way interactions between LEP and each CRH SNP were analyzed as effects on the various temperament measurements. We found interactions between CRH 22C>G and LEP and CRH 240C>G and LEP with SG. Within this interaction there appears to be a positive effect of one CRH allele (C) within LEP TT animals while in LEP CC the other CRH allele (G) had a positive effect. These interactions, especially between CRH 22C>G and LEP, needs to be confirmed in other populations of beef cattle. It may be possible in the future to select for temperament alongside production goals.