(Co)variances Between Cattle Postpartum Body Weight and Dairy Traits in a Pastoral System in Chile

Abstract

In Chile, the genetic parameters of dairy cow body weight have not been estimated due to lack of data. The objective of this study was to determine variance components of milk yield traits and postpartum body weight. Data were obtained from a dairy research farm in southern Chile. A multitrait animal mixed repeatability model was used and genetic parameters were estimated using the VCE software. Heritability estimates for yields of milk, milk fat and protein, and postpartum body weight were 0.26 ± 0.011, 0.30 ± 0.011, 0.27± 0.012 and 0.43 ± 0.047, respectively. Genetic correlations for postpartum body weight and yields of milk, milk fat and protein were 0.34, 0.40 and 0.38, respectively. Phenotypic correlations were also positive and generally 10% lower than genetic correlations. It is concluded that the correlations between postpartum body weight and milk yield traits are positive and not very high. The genetic selection to favour yield would increase cow's body weight.

Relationship Between Milk Solids Yield Efficiency and Postpartum Body Weight in a Pastoral Dairy Farm in Chile

“…In a study of Uribe and González (2018), post-partum body weight was genetic and phenotypically associated to yield traits; these associations were positive and low. These authors concluded that as milk and milk fat and protein yields improve, body weight increases due to genetic selection.…”

“…The heritability estimate for postpartum body weight was 0.33 ± 0.05, and falls in the lower range of previous estimates for this trait. Part of the data used in this study was also used in a four-trait animal model by Uribe and González (2018), where the estimated heritability for postpartum body weight was 0.43 ± 0.047. Other estimates of body weight heritability for Chilean dairy cows were not found in the literature.…”