Polymorphisms in the bovine HSP90AB1 gene are associated with heat tolerance in Thai indigenous cattle

Heat shock proteins act as molecular chaperones that have preferentially been transcribed in response to severe perturbations of the cellular homeostasis such as heat stress. Here the traits respiration rate (RR), rectal temperature (RT), pack cell volume (PCV) and the individual heat tolerance coefficient (HTC) were recorded as physiological responses on heat stress (environmental temperatures) in Bos taurus (crossbred Holstein Friesian; HF) and B. indicus (Thai native cattle: White Lamphun; WL and Mountain cattle; MT) animals (n = 47) in Thailand. Polymorphisms of the heat shock protein 90-kDa beta gene (HSP90AB1) were evaluated by comparative sequencing. Nine single nucleotide polymorphisms (SNP) were identified, i.e. three in exons 10 and 11, five in introns 8, 9, 10 and 11, and one in the 3′UTR. The exon 11 SNP g.5082C>T led to a missense mutation (alanine to valine). During the period of extreme heat (in the afternoon) RR and RT were elevated in each of the three breeds, whereas the PCV decreased. Mountain cattle and White Lamphun heifers recorded significantly better physiologic parameters (p < 0.05) in all traits considered, including or particularly HTC than Holstein Friesian heifers. The association analysis revealed that the T allele at SNP g.4338T>C within intron 3 improved the heat tolerance (p < 0.05). Allele T was exclusively found in White Lamphun animals and to 84% in Mountain cattle. Holstein Friesian heifers revealed an allele frequency of only 18%. Polymorphisms within HSP90AB1 were not causative for the physiological responses; however, we propose that they should at least be used as genetic markers to select appropriate breeds for hot climates

Perfil de registros reproductivos de ganado lechero en Uruguay.

RESUMEN:Se presenta un resumen descriptivo de cuatro encuestas llevadas a cabo en los años 2010, 2011, 2013, y 2018 en la cuenca lechera de Uruguay; con la participación de 22 técnicos en promedio/año; en hasta 7 departamentos, involucrando 312 tambos y 81.060 vacas masa. Se registró una consistencia de los índices reproductivos, con una disminución en el número de servicios por concepción y en el intervalo parto concepción en las vacas con el paso de los años. Se remarca la importancia de llevar registros para monitorear y mejorar la eficiencia reproductiva. SUMMARY: A descriptive summary of four surveys carried out in the years 2010, 2011, 2013, and 2018 in the dairy region of Uruguay is presented; with the participation of 22 technicians on average/year; in up to 7 departments, involving 312 dairy farms and 81,060 cows. A consistency of the reproductive indices over the years was observed with decreasing in the number of services per conception and in the interval calving to conception in the cows over the years. The importance of keeping records for monitoring and improving reproductive efficiency is highlighted