Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Maternal productivity is an important consideration for cow-calf operations. Mature cows have higher reproductive output than young cows, and retaining mature cows longer reduces replacement costs. But most comparisons of rangeland grazing management practices focus on season-long weight gains, particularly for stockers, and have yet to address maternal productivity. We compared three years of cow and calf weight gains by mother age class to inform how patch-burn grazing, continuous grazing without fire, and rotational grazing might affect maternal productivity in an experimental Angus cow-calf herd in central North Dakota, USA. Overall, we concluded that mature cows (those with 4+ calves) on patch-burning and continuously-grazed pastures outperformed cow-calf units on rotational grazing. When we also considered other data that prescribed fire approximately doubled net energy for maintenance, maternal productivity might be greatest among mature cows grazing burned areas, but this needs more examination.

Technical Abstract: Many beef producers in commercial rangelands rely on cow-calf operations. Unlike stocker operations, which typically seek to increase the weight of each animal over a grazing season, cow-calf producers often consider maternal productivity--the efficiency of both a mother cow and her calf--which affects a cows' lifetime reproductive output and longevity. Generally speaking, longer productive lives for cows reduces herd turnover and decreases costs for the producer. As rangeland grazing management strategies are evaluated, it is important to also consider their effects on maternal productivity, not just season-long weight gains. We compared three years of cow and calf weight gains by dam age class to inform how patch-burn grazing, continuous grazing without fire, and rotational grazing might affect maternal productivity in an experimental Angus cow-calf herd in central North Dakota, USA. Overall, grazing management strategy explained variation in weight gain among cows, and dam age class explained variation in calf weight gains, leading us to conclude that mature cows (those with 4+ calves) on patch-burning and continuously-grazed pastures had higher maternal productivity than cow-calf units on rotational grazing. When considered alongside previously-published evidence that burned areas provided approximately twice as much net energy for maintenance, our data suggest that maternal productivity might be greatest among mature cows on patch-burned pastures, but this remains speculative until the actual intake of metabolizable energy for each cow-calf unit can be determined. These findings contribute further evidence of the potential for marginal gains to be found in grazing burned rangeland, with potentially direct positive effects on financial viability of cow-calf operations.