O desafio da seleção genética de animais tolerantes ao estresse calórico. O caso do gado leiteiro
Year: 2016
Type: article
Abstract: Exposure of livestock to high heat loads negatively affects animal productivity. In dairy cattle genetic selection to improve tolerance to heat stress (HS) through quantitative approaches has made use of milk production records together with meteorological information for the test date. The main conclusions arrived at by this approach have been: 1) there is genetic variability in individual productive responses to HS; 2) a genotype by environment interaction in productive potential exists between conditions of thermal comfort and stressful conditions, and 3) there is a genetic antagonism between HS tolerance and milk yield. This approach offers the advantage of adding no extra cost to the existing milk recording schemes, but it also has disadvantages. Current milk recording data do not seem to fully capture the productive responses to high heat loads. Moreover, the antagonism between HS tolerance and high milk production may offset the benefits of selection if tolerant animals. are less productive. The use of new tools from phenomics, genomics, and transcriptomics can facilitate accurate selection for heat tolerance without hindering progress in milk yield. New phenotypes for this selection include measures of body temperature and respiration rate together with those of metabolites indicative of heat tolerance detectable in milk by mid-infrared spectroscopy (MIR). The use of commercial DNA chips to perform genome-wide association studies or comparison of whole-genome DNA sequences of animals of heat-adapted and non-adapted temperate climate breeds could also provide useful genomic information. Finally, RNA sequencing combined with the recently discovered possibility of using milk transcription instead of tissue biopsies could help to identify differentially expressed genes under HS and thermally neutral conditions.
Author: Carabaño, María Jesús
Language: Spanish
Subfield: Animal Science and Zoology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
OpenAlex ID: W7221270282