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Ten Things to Consider When Evaluating Moving Calving Date By Aaron Berger, University of Nebraska Extension The severe weather of this last winter and spring has prompted many cow-calf producers to evaluate the potential of moving their calving date to a different time of year. The following are a list of ten things producers may want to think through as they evaluate moving of a calving date. 1. How would the proposed move match cow nutrient requirements with the quantity and quality of available feed resources? Grazed feed is most often less expensive than harvested feed to get into the belly of a cow. Moving time of calving to a time of year that allows for greater use of grazed versus harvested feed can be an advantage economically for feeding the cow herd. The type of cow you have in one season of calving may not fit another season, due to forage quality and nutrient requirements. Moving calving date may decrease supplementation/feeding at certain physiological states, but at the same time increase resource needs at other periods of the year. 186 | JUNE/JULY 2019 2. How would the move impact the quality of feed that is grazed or fed specifically in the window of time from calving through breeding? Cow-calf producers considering a move to calving in later spring, which will result in cows breeding on pasture or range in late summer, will want to evaluate the potential impact of this change on reproduction. Forage quality on pasture and range tends to peak in late May and June and then decline from July on into the fall. Nutrient requirements are the highest at peak lactation, which occurs on average right before the start of breeding. The change in forage quality with higher nutrient requirements can impact reproduction. First-calf heifers and young cows that are still growing may be challenged nutritionally to have adequate protein and energy to achieve acceptable pregnancy rates when on a decreasing plane of nutrition in the period prior to and through the breeding season. Strategic supplementation may be needed right prior to and through the breeding season to help meet nutrient needs and achieve acceptable pregnancy rates especially in higher risk females.