Comparisons of Crossbred Calves by South Devon, Maine-Anjou and Simmental Sires for some Beef Production Traits:

This study which was conducted in the early 1970s in Alberta, Canada, involved the joining of South Devon (10), Maine-Anjou (2) and Simmental (8) sires to a number of mature Hereford cows (mean age 5.4 years), and the subsequent analysis of the performance of their crossbred calves.

Conclusions:

Despite the faster growth rates and consequent meat yield of the Maine-Anjou sired calves, the authors warn against their use in commercial herds because of the unacceptably high incidence of calving difficulties in mature cows (20%). Nevertheless, they admit that as only two Maine-Anjou sires were used in the study, the results might not be representative of the breed as a whole.

On the other hand, crossbred calves sired by South Devon bulls out of mature Hereford cows did not experience excessive calving problems, while the their eventual carcass characteristics (subcutaneous fat, eye muscle area, marbling and cutability) were as good, if not better, than those of calves from Maine-Anjou and Simmental sires. Their meat yield however, expressed as Kg produced per day, was less than that of the European crosses due to their slightly lower growth rate, but this was compensated for by their tendency to finish earlier.

Reference:

Newman JA, Weiss GM, Schrader B. Comparisons of crossbred calves by South Devon, Maine-Anjou and Simmental Sires for some beef production traits. Can J Anim Sci 1974;54:197-203. Back

Notes:

b. Calving difficulty was significantly (p<0.001) related to the breed of the sire, with South Devon sired calves having the least difficulty. The authors comment that in commercial beef herds, calving ease should be greater than 95%, and that in this respect, neither the Maine-Anjou nor the Simmental would be acceptable. Back

c. Birth weight was also significantly (p<0.001) related to the breed of the sire, with the South Devon calves being the lightest. Bull calves were approximately 1.7Kg heavier than the mean, while heifer calves were 1.7Kg lighter. Back

d. The bull calves were kept intact, and all the calves were weaned at 164 days. Their weaning weights were then adjusted to 200 days. These adjusted 200day weights were significantly (p<0.001) related to the breed of the sire for the bull calves but not for the heifer calves. Back

e. After weaning, the bull calves were placed on a growing ration for approximately three months following which they were managed in a feedlot for just under 200 days. The average daily feedlot weight gain, which was calculated after 91 days on feed, was significantly (p<0.001) related to the breed of the sire with the Maine-Anjou calves having the greatest gains. Back

f. The bull calves were slaughtered at 440 days (14.5 months) following which their carcass data was recorded by grading staff from the Canadian Dept of Agriculture. Although the South Devon sired calves were a little lighter at slaughter, their hot-carcass weights were not significantly less than those of the Maine-Anjou or Simmental sired calves. Back

g. Eye muscle area when corrected for the hot carcass weight was not significantly different between the breeds of calves. Back

h. Subcutaneous fat at the twelfth rib was significantly greater in South Devon sired calves, but was similar in those sired by Maine-Anjou and Simmental bulls. Back

i. Cutability, estimated as the percentage of trimmed, deboned, defatted primal cuts (TDDPC) in the carcass, was not significantly different between the different breeds of calf. Back

j. The weight of trimmed, deboned, defatted primal cuts (TDDPC) per day of age was estimated as: (hot carcass wt) ´ cutability ¸ age at slaughter. The Maine-Anjou calves yielded significantly more meat than did the Simmental and South Devon sired calves (p<0.01). Back

k. Meat colour score was not significantly different between the different breeds of calf. Back

l. Marbling was graded from 1 to 9 as the degree of marbling decreased. South Devon sired calves marbled significantly (p<0.05) better than did the other calves. Back