Pre-weaning growth traits of the Hereford breed in a multibreed composite beef cattle population

Abstract

Data from a multibreed composite beef cattle population, managed under intensive irrigated grazing conditions, were used to estimate direct additive heritabilities (h 2 a ), maternal heritabilities (h 2 m ) and maternal permanent environmental effects (c 2 ) for birth weight (BW) and weaning weight (WW) of the calf and cow efficiency of the dam (CE: WW/dam weight 0.75 x 100). Calves born between 1968 and 1993 (n = 52628) had varying levels of Hereford genes, ranging from 0% to 100%, with an average of 19.3%. Direct heritabilities, fitting unitrait models, were 0.72, 0.54 and 0.19 for BW, WW and CE, respectively, with corresponding estimates of maternal heritabilities being 0.14, 0.21 and 0.42. Genetic correlations between direct and maternal effects (r am ) were negative for all three traits, varying from -0.40 to -0.65. Maternal permanent environmental effects were 0.06, 0.12 and 0.11 for BW, WW and CE, respectively. Direct breeding values and maternal breeding values for BW and WW decreased with increasing proportion of Hereford. Direct breeding value for CE increased, while maternal breeding value for CE reached a minimum value at 0.62 proportion of Hereford.

Genetics and environmental trends in growth performance of Horro (Zebu) and crosses of Holstein Friesian and Jersey cattle breeds

“…The higher heritability obtained in this study is in agreement with the findings of Schoeman and Jordaan (1999) and Skrypzeck et al (2000) who found a higher direct heritability estimates of 0.62 and 0.72 for birth weight, respectively. Both authors mentioned that fairly high heritability, arising from large genetic variances due to the multibreed composition of the herd could have been expected, since the population consists of 15 breeds and this effect was not accounted for by the model.…”

The effect of Charolais and Hereford sires and straightbred and crossbred dams on pre-weaning growth of calves

“…For Hereford, the direct additive effect for BW was positive in some reports (Gregory et al, 1978;Schoeman et al, 1993), but negative in other crossbreeding studies (Alenda et al, 1980;Skrypzeck et al, 2000a). Skrypzeck et al (2000b) assessed the contribution of the Hereford breed in the same multibreed beef cattle herd and suggested higher levels of Hereford contributions in crossbreeding for the prevention of dystocia. In another investigation Hereford sires were used also on heifers of other breeds to decrease the incidence of dystocia (Tawonezvi et al, 1988).…”

Evolutionary importance of parental care performance, food resources, and direct and indirect genetic effects in a burying beetle

“…The direct and indirect heritability estimates for mass were of comparable magnitude to those reported for mammals and birds (Cheverud et al ., 1983; Aggrey & Cheng, 1993; Smith & Wettermark, 1995; Skrypzeck et al ., 2000; Neser et al ., 2001). These results suggest that indirect genetic effects of parental care performance generally play an important role in increasing the genetic variance of body mass and size, independently of taxon, and thus accelerate the response of body mass and size to natural selection.…”