Estudo genético quantitativo do efeito materno em bovinos da raça Nelore

Abstract

The objective was to study the performance of phenotypic progenies through the weights to 120 (P120) and 210 (P210) days of age on the genetic effect of maternal ability by EPDs (Expected Difference in the Progenies) direct to weight (DP120 and DP210), maternal (DMP120 and DMP210) and total maternal (DMTP120 and DMTP210), and evaluate the genetic association of maternal effect for maternal and direct EPDs for weights at 120 and 210 days of age (DDP120, DMP120, DMTP120, DDP210, DMP210, DMTP210) with the reproductive characteristics (DD3P, DDIPP, DDSTAY, DDPAC, DDPE365, DDPE450) and adult weight (DDPAV). To compare the phenotypic performance of the progenies in relation to mothers EPDs mothers considered the formation of classes of EPDs based on quartiles. The selection of the best DP120 produced calves with hiher P120. The selection of the best genetically to DMP120 led to heavier descendants to P120 and P210. The DMTP210 provided an increase in the adult weight, already DMP210 did not increase the DDPAV. It is recommended the selection to DMP120 as selection criterion to increase weight at weaning, because it enables better genetic gains. There is no genetic antagonism between the EPDs maternal and reproductice characterististics and adult weight.