Heat stress during late pregnancy and postpartum influences genetic parameter estimates for birth weight and weight gain in dual-purpose cattle offspring generations.

摘要: Impact of direct heat stress (HS) on genetic parameter estimates, i.e., HS close to the trait recording date, was verified in several previous studies conducted dairy and beef cattle populations. The aim present study analyze impact time-lagged at different periods during late pregnancy (a.p.) postpartum (p.p.) estimates for birth weight (BWT) gain traits (200 d- 365 d-weight (200dg, 365dg)) offspring dual-purpose breed "Rotes Hohenvieh" (RHV). Furthermore, we estimated correlations within across climatic indicators, order proof possible genotype by environment interactions (G×E). Trait included 5,434 observations BWT, 3,679 200dg 2,998 365dg. Time-lagged descriptors were classes mean temperature humidity index (mTHI) number days (nHS) from following periods: 7 d-period a.p. (BWT), 56 a.p., p.p. (200dg 365dg). Genetic parameters via 2-trait animal models, defining same environments as traits. variances heritabilities all increased with increasing mTHI- nHS-classes periods, indicating pronounced differentiation regard utero directly after birth. Similarly, low cold stress, variances, larger than temperate climates. substantially smaller 0.80 G × E observed when considering greater distance. Estimated breeding values (EBV) 10 most influential sires largest records fluctuated nHS-classes. Correlations between sire EBV distant confirmed correlation estimates. Sires displaying stable alterations also identified. Selection those might contribute improved robustness RHV outdoor population genetically.