Likewise, the proper and most meaningful denominator for most cow herd performance measures is the number of females exposed to the bull. When corn is planted, the farmer’s intent is for those seeds to grow and bear fruit. For various reasons including nutrition, poor fertility, venereal disease, etc., some cows may not conceive, and others may lose their calf during the year, but when exposed, the cow-calf manager’s intent was for all exposed cows to produce and wean a calf. If, during the breeding season, 100 cows were exposed to a bull, the ideal hope is that 100 cows will become pregnant, give birth, and raise their calf to weaning. For the commercial cow-calf producer, the “crop” to be harvested and eventually sold is weaned calves, but when were the “seeds” of those calves “planted”? Calves that are born are analogous to seeds that “emerged”, confirmed pregnancies are analogous to seeds that “germinated”, and the ova (eggs) of females naturally or artificially exposed to the bull are analogous to the seeds that were initially “planted”. While the crop farmer realizes that every planted seed will not grow, he/she expects most seeds to germinate, emerge, and grow to bear large ears of corn. Using corn production as an analogy, the farmer selects and plants seed, the seed grows, and the crop is eventually harvested and sold. When calculating a percentage term, selection of the proper denominator (the number located below the line in a fraction) is critically important. When standardized definitions and calculations are used, comparisons can be generated, and herd management strengths and weaknesses can more easily be identified and managed. This creates a management issue, for how can “percent calf crop” be improved if producers have multiple interpretations of what the term implies? In the early 1990’s, this issue was recognized, and a task force that consisted of both producers and academicians were charged with developing standardized definitions for a variety of basic cow herd performance measures including percent calf crop. In fact, when students or producers are asked to calculate percent calf crop from a set of hypothetical herd information, given only their perception of what the term implies, multiple answers are typically generated all mathematically correct.

Each of these mathematical “interpretations” of the term percent calf crop could be justified as a reasonable “definition” of the term. Revised October 2022 Standardized Calculation and Interpretation of Basic Cow Herd Performance Measuresīryan Reiling, Extension Youth Livestock Specialist IntroductionĬommercial cow-calf producers commonly use the term “percent calf crop”, but what does it mean? Does percent calf crop represent the number of calves born relative to the number of cows bred, or perhaps it is the number of calves born relative to the number of cows exposed to a bull? Others might calculate percent calf crop as the number of calves weaned compared to the number of calves born, or the number of cows bred, or the number of cows exposed.

Cow due date calculator