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Genotype-environment interaction between Chile and North America and between Chilean herd environmental categories for milk yield traits in Black and White cattle

Hugo H. Montaldo
Department of Genetics and Biostatistics, School of Veterinary Medicine and Animal Husbandry, National Autonomous University of Mexico, Ciudad Universitaria, 04510, Distrito Federal, Mexico
Abstract :
In order to evaluate the expression of sire genetic evaluations obtained in North America for Chilean
Black and White Cattle, genetic correlations were estimated for milk (MY), fat (FY) and protein
(PY) yields, and for fat (F%) and protein (P%) contents between Chile, Canada and the
US, from
predicted transmitting abilities of common sires in two countries. Moreover, genetic correlations
for the same traits were estimated between herd environmental categories formed according to
MY levels, using bivariate analyses. Genetic correlation estimates for MY, FY, and PY between
Chile-Canada (0.80, 0.61, and 0.70), and between Chile-US (0.79, 0.68, and 0.77), were lower than
values obtained by simulation, assuming sire selection of the best 50%, and were also lower than the
genetic correlations between Canada-USA, which were close to 1, suggesting a moderate genotype
by country interaction. All genetic correlation estimates between countries for F% and P% were
close to 1. No evidence of genotype-environment interaction was found for any trait between High
and Low Chilean herd environmental categories based on MY, (genetic correlation estimates ≥0.96;
not statistically different from 1). Results indicate that a single national dairy genetic improvement
programme incorporating international evaluations could be implemented in southern Chile, rather
than separate programmes for specific herd MY environments. Moderate genotype-environmental
interaction between North American and Chilean environments was found for MY, FY, and PY.
Results from across and within country analyses indicate that sire selection in North America for
milk solids yield will produce relatively high correlated genetic responses for the southern Chile
dairy production system characterized by grazing and a temperate climate.
by country interaction. All genetic correlation estimates between countries for F% and P% were
close to 1. No evidence of genotype-environment interaction was found for any trait between High
and Low Chilean herd environmental categories based on MY, (genetic correlation estimates ≥0.96;
not statistically different from 1). Results indicate that a single national dairy genetic improvement
programme incorporating international evaluations could be implemented in southern Chile, rather
than separate programmes for specific herd MY environments. Moderate genotype-environmental
interaction between North American and Chilean environments was found for MY, FY, and PY.
Results from across and within country analyses indicate that sire selection in North America for
milk solids yield will produce relatively high correlated genetic responses for the southern Chile
dairy production system characterized by grazing and a temperate climate.
Keywords :
across country selection / Chile /dairy sires / genotype-environment interaction / milk yield traits / North America

Date Deposited : 02 Apr 2015 13:59

Last Modified : 02 Apr 2015 13:59

Official URL: http://www.ighz.edu.pl/?p0=5&p1=34

Volume 33, Number 1, - 2015

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