Relationships of milk yield and quality from six breed groups of beef cows to preweaning average daily gain of their calves1

Abstract

Milk yield and quality influence calf preweaning growth and ultimately the sale value of the calf at weaning. This study was conducted to evaluate the relationships of milk production and quality of beef cows to calf preweaning ADG in beef cows sired by Bonsmara, Brangus, Charolais, Gelbvieh, Hereford, and Romosinuano and from Brangus dams to determine whether the relationships were homogeneous across cow breed group. Approximately 50 cows/yr were milked monthly for 6 mo in each of the 7 yr of this study. Milk traits were included in models as linear and quadratic covariates along with interactions of the covariates with sire breed. Tests for curvilinearity and homogeneity of regression coefficients indicated the relationship of calf preweaning ADG to milk yield and quality was quadratic and homogeneous across Charolais and Gelbvieh; linear and homogeneous across Bonsmara, Brangus, and Romosinuano; and linear and different from other sire breeds in Herefords (P < 0.05). Exceptions to this were in the regression of calf preweaning ADG on the natural logarithm of somatic cell count (SCC) and milk urea nitrogen (MUN). The relationship of calf preweaning ADG to SCC was quadratic in Brangus (P < 0.05) and linear in Gelbvieh (P < 0.05) with little evidence (P > 0.05) of a relationship in Bonsmara, Charolais, Hereford, or Romosinuano. There was little evidence (P > 0.05) of a relationship of calf preweaning ADG to MUN in any of the sire breed groups. Results from this study confirmed the importance of the influence of milk yield and quality on calf preweaning growth but indicated this influence can depend on the breed composition of the cow. Furthermore, results suggest that breed origin or adaptation may have influenced the relationships of calf preweaning ADG to cow milk yield and quality.

Beef heifer fertility: importance of management practices and technological advancements

“…and an average daily gain of~1.90 lb. per day [27,28], calves born at the midpoint of the second and third 21 d of the calving season would be worth approximately $131 less than calves born on the first day of the calving season. When this number is multiplied by the 1.6 million heifers expected to conceive late in their first breeding season, one can account for over $210 million lost by beef cattle producers due to late breeding heifers.…”

The milk yield of dams and its relation to direct and maternal genetic components of weaning weight in beef cattle

“…This antagonism may cause a decrease in the maternal ability of cows if weaning weight is considered as the only selection criterion (Miller and Wilton, 1999). However, reliable data on cow milk yield are rare in beef breeds because they are not usually milked, and this trait is only indirectly estimated from calf growth rates (Liu et al, 2015), which are also associated with other aspects such as health or management.…”

Comparative composition, diversity, and abundance of oligosaccharides in early lactation milk from commercial dairy and beef cows

“…In addition, the data suggest a functional prebiotic advantage for the OS in beef-source early lactation milk. Assuming that beef OS content in milk is the gold standard for cattle and ad libitum milk consumption for beef calves is approximately 7 kg/d ( Fiems et al, 2008 ; Liu et al, 2015 ) and for dairy calves approximately 9 kg/d ( Jasper and Weary, 2002 ), then a dairy calf fed ad libitum is likely deprived of dietary-source OS. Because many calves are restricted in milk consumption to 4 to 5 kg/d, these calves are severely deprived of dietary-source OS.…”