Forage Utilization

Cow-Calf Production from Alfalfa-Grass or Smooth Bromegrass Pastures Rotationally Grazed at Three Stocking Rates

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Abstract

Pastures containing alfalfa-grass or smooth bromegrass were stocked with .6, .8, or 1.0 cow-calf units per acre to compare cow and calf production in rotational grazing systems managed for optimum forage quality. To remove excess forage early in the grazing season, yearling heifers or steers grazed with the cows in each pasture at a stocking rate of .6 ccu per acre for the first 28, 37, and 40 days of grazing in years one, two, and three. Live forage density and days of grazing per paddock were estimated by sward height. Cows, calves, and yearlings were weighed and cows condition scored every 28 days. All cows grazed for 140 days unless forage became limiting. The cows on the smooth bromegrass pasture stocked at 1.0 cow-calf units per acre were removed after 119 days in 1994, 129 days in 1995, and 125 days in 1996. Cows on one of the alfalfagrass pastures stocked at 1.0 ccu per acre were removed after 136 days of grazing in 1996 because of lack of forage. Alfalfa-grass pastures tended to have a more consistent supply of forage over the grazing season than the bromegrass pastures. Cows grazing the alfalfa-grass pastures had greater seasonal weight gains and body condition score increases and lower yearling weight gains than the smooth bromegrass pastures. Daily and total calf weight gains and total animal production also tended to be greater in alfalfa-cool season grass pastures. Increasing stocking rates resulted in significantly lower cow body condition increases and yearling weight gains, and also increased the amounts of calf and total growing animal produced.

Keywords: ASL R1455

How to Cite:

Western, J. M., Russell, J. R. & Berryman, R., (1998) “Cow-Calf Production from Alfalfa-Grass or Smooth Bromegrass Pastures Rotationally Grazed at Three Stocking Rates”, Iowa State University Animal Industry Report 1(1).