The relationship between size and efficiency in the beef cow

Author: J.D.G. Steenkamp and C. van der Horst
Year: 1974
Issue: 1
Volume: 4
Page: 81 - 91

The efficiencies of small (<420 kg), medium (455 – 490 kg) and large (>525 kg) size grade Africander cows were compared for reproductive performance of cow, survival rates, growth of progeny and overall profitability. Cow efficiency index (C.E.I.) calculated by expressing the 260-day weaning mass of the calf corrected for month of birth and age of dam, as a percentage of the dam’s metabolic size, is inversely related to cow size. The relationship of cow and calf mass is positive and curvilinear. Calving percentages and survival rates of progeny improved with an increase in size of cow. Large cows were 41 % heavier than small cows but required only 29 % more nutrients for maintenance. Likewise medium cows required 15%more nutrients but were 21% heavier. Mass of female progeny at 2 and 3 years of age and preslaughter mass, carcass mass and carcass grades of steers from the various categories were compared. The economic efficiencies of small, medium and large size cows were assessed, based on an equivalent number of 988 livestock units per area of 6 000 ha, Large and medium size cows were more efficient producers than small cows in terms of beef produced per cow, per livestock unit of 454 kg and per hectare. Relative to small cows = 100, the gross margin for medium size cows was 111,5 and for large cows 126,9.

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