The SLICK hair locus derived from Senepol cattle confers thermotolerance to intensively managed lactating Holstein cows

Abstract

The SLICK haplotype (http://omia.angis.org.au/OMIA001372/9913/) in cattle confers animals with a short and sleek hair coat. Originally identified in Senepol cattle, the gene has been introduced into Holsteins. The objectives of the current study were to determine (1) whether lactating Holsteins with the slick hair phenotype have superior ability for thermoregulation compared with wild-type cows or relatives not inheriting the SLICK haplotype, and (2) whether seasonal depression in milk yield would be reduced in SLICK cows. In experiment 1, diurnal variation in vaginal temperature in the summer was monitored for cows housed in a freestall barn with fans and sprinklers. Vaginal temperatures were lower in slick-haired cows than in relatives and wild-type cows. In experiment 2, acute responses to heat stress were monitored after cows were moved to a dry lot in which the only heat abatement was shade cloth. The increases in rectal temperature and respiration rate caused by heat stress during the day were lower for slick cows than for relatives or wild-type cows. Moreover, sweating rate was higher for slick cows than for cows of the other 2 types. In experiment 3, effects of season of calving (summer vs. winter) on milk yield and composition were determined. Compared with milk yield of cows calving in winter, milk yield during the first 90 d in milk was lower for cows calving in the summer. However, this reduction was less pronounced for slick cows than for wild-type cows. In conclusion, Holsteins with slick hair have superior thermoregulatory ability compared with non-slick animals and experience a less drastic depression in milk yield during the summer.

A Review of Selected Genes with Known Effects on Performance and Health of Cattle

“…Mariasegaram et al (123) reported that the locus responsible for slick hair resided on chromosome 20. Further studies confirmed that the slick hair locus resides on chromosome 20 (124). Dikmen et al (124) indicate that three potential candidate genes are in the region where the slick hair locus resides ( SKP2, SPEF2 , and PRLR ).…”

“…Further studies confirmed that the slick hair locus resides on chromosome 20 (124). Dikmen et al (124) indicate that three potential candidate genes are in the region where the slick hair locus resides ( SKP2, SPEF2 , and PRLR ). Littlejohn et al (125) propose mutations in the prolactin receptor ( PRLR ) on chromosome 20 and the prolactin gene ( PRL ) on chromosome 23, as responsible for the slick hair condition.…”

“…Littlejohn et al (125) indicate that animals with the slick hair condition produced more milk than animals without the condition. Furthermore, Dikmen et al (124) show that Holstein cattle with the slick hair condition produce more milk than Holstein cattle without the condition. This condition in dairy cattle under tropical conditions should be of economic importance if introduced.…”

Rare phenotypes in domestic animals: unique resources for multiple applications

“…In the 1990s, the slick hair haplotype, initially shared by Senepol cattle and a few criollo breeds, was transferred into a Holstein subpopulation, improving the thermotolerance of the animals (Dikmen et al . ). Genetic introgression is obviously easier for traits with simple modes of inheritance.…”

Cellular and epigenetic changes induced by heat stress in bovine preimplantation embryos

“…For example, the slick hair gene initially identified in Senepol (Olson, Lucena, Chase, & Hammond, ) has been associated with greater thermoregulatory ability. Slick‐haired Holsteins were better able to regulate body temperature (Dikmen et al, , ) and milk yield under heat stress than wild‐type Holsteins (Dikmen et al, ).…”