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UNL Extension
Last week we began discussing ways to measure the performance of our beef herd, starting with females exposed, pregnancy percentage, live calving percentage, and calving percentage.
We’ll pick up where we left off looking at death loss percentage, weaning percentage, and pounds of calf weaned.
Once a calf is born and nurses, they have a good chance to survive until weaning. Calf death loss should be low, but losses due to weather during the calving season, such as a blizzard, or health problems like respiratory disease, will impact this number. Calf losses due to calving difficulty and full-term calves born dead are also accounted for.
Death Loss Percentage based on calves born is the number of deaths prior to weaning divided by the number of calves born multiplied by 100.
Death Loss Percentage based on females exposed is the number of deaths prior to weaning divided by the number of females exposed multiplied by 100.
Calves lost to abortions are not accounted for in these measures. Aborted calves are ones lost that have no characteristics of being full-term. Many times, producers do not see aborted fetuses. If the abortion occurs before pregnancy diagnosis, they are diagnosed as not pregnant at pregnancy check.
The greatest loss of potential calves to wean comes from cows not becoming pregnant during the breeding season. Calf losses due to abortion should be one percent of exposed females or less. Calf losses at calving can be as high as 3.5 percent for spring-calving cows if there is a blizzard, freezing rain, etc. Calf losses from calving to weaning, should be low and in the one percent or lower range. It can be higher if the herd encounters respiratory diseases.
Weaning Percent (also known as percent calf crop) is the number of calves weaned divided by number of females exposed multiplied by 100. This percentage is a culmination of all the previous calculations that impact potential calves to wean.
A final measure to calculate is the pounds of calf weaned per female exposed. This is the total pounds weaned divided by the number of females exposed. This measure reflects more accurately on cowherd performance than average weaning weight. This measure increases by weaning more calves and/or increasing weaning weight. Please note if weaning date varies from year to year, you may need to adjust weaning weight to make yearly comparisons.
Weaning weight can be increased by selecting for growth traits in the breeding program, but if replacement females are retained, cow weight will increase over time. A fixed set of forage/feed resources can feed fewer, heavier cows. Weaning weight can also be increased by selecting higher milk EPDs, which is defined as weaning weight due to milk. As milk increases, nutritional requirements for the cowherd increases. Again, a fixed set of forage/ feed resources can feed fewer, heavier milking cows.
Using these indicators, producers can track herd performance over time and see how management and year affect productivity, as well as compare themselves to regional benchmarks. Good records however are key to using these indicators, so plan how your record keeping can be improved next year knowing what indicators to keep an eye out for.
— Ben Beckman is a beef systems Extension Educator serving the counties of Antelope, Cedar, Knox, Madison and Pierce. He is based out of the Cedar County Extension oce in Hartington. You can
reach him by phone: (402) 2546821 or email: [email protected]
