Calving distribution and calf performance data were summarized from the CHAPS (Cow Herd Appraisal of Performance Software) analyses of 61 South Dakota cow herds. CHAPS uses standard beef cow weaning weight records to calculate adjusted 205-day weights and ratios, keep lifetime production records on cows, calculate Most Probable Producing Ability estimates for cows, produce a sire summary and analyze production according to cow age and 21 -day calving periods. The 1990 summary represents 6,771 calves for an average of 110 cows per herd. The average actual birth and weaning weights were 82.2 and 523.2 Ib, respectively, with the average age at weaning 199 days. Overall, 81.3% of the females calved by day 42 of their respective calving seasons, although there was considerable disparity in the percent calved by day 42 between the HIGH and LOW (91.9 vs 62.8%) calving distribution herds. This difference is important since actual weaning weights declined 37 to 60 Ib for each 21 days later that calves were born. In addition to these data for the state summary, CHAP3 provides valuable information for making within herd selection and management decisions.
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South Dakota State University
Copyright © 1991 South Dakota State University.
Boggs, D. L., "Chaps Summary for South Dakota, 1990" (1991). South Dakota Beef Report, 1991. 17.