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This article in AJ

  1. Vol. 75 No. 6, p. 878-885
    Received: Dec 20, 1982



Central Appalachian Hill Land Pasture Evaluation Using Cows and Calves. III. Treatment Comparisons of per Animal and Hectare Responses1

  1. J. C. Burns,
  2. R. W. Harvey,
  3. F. G. Giesbrecht,
  4. W. A. Cope and
  5. A. C. Linnerud2



The productivity of hill land pastures using cow-calf testers in formal grazing trials is not well documented. This study determined animal response and per hectare productivity of improved hill land pasture [mainly Kentucky bluegrass (Poa pratensis L.), and white clover (Trifoolium repens L.)], crownvetch (Coronilla varia L.), and birdsfoot trefoil (Lotus corniculatus L.) subjected to various pasture and animal management treatments during 6 years of evaluation. Soils ranged from primarily a fine loamy micaceous mesic, Typic Hapludult on the uplands to primarily a fine loamy mixed mesic Hapludult in the low lands. Treatments evaluated in April through June (period 1) consisted of N rates (0, 67, 112, and 224 kg ha−1) and continuously grazed crownvetch. From July through October (period 2) two additional legume rotational treatments and early weaning (0, 67, or 112 kg of N ha−1) were evaluated. Cow and calf daily gain (kg), calf gain (kg ha−1), and total digestible nutrients (TDN) (kg ha−1) from improved hill land pasture (IHP) in period 1 averaged 0.74, 0.97, 156, and 1470, respectively. The respective values for period 2 were 0.13, 0.72, 97, and 1100 and for the season were 0.44, 0.84, 245, and 2420. Cow-calf units were stocked on IHP to average 2.11 ha−1 in period 1, 1.29 in period 2 and 1.54 for the grazing season. Continuous grazing of crownvetch compared with IHP during periods 1 and 2 or rotational grazing of crownvetch and birdsfoot trefoil in period 2 increased only cow daily gain. Calf daily gain in period 1 declined linearly with N rates while calf gain (kg ha−1) and stocking rate increased at a declining rate (quadratic term) at the higher N levels. Maximum calf gain ha−1 occurred at the 224 kg N rate, averaging 109 kg when pastures were stocked at 1.90 cow-calf units ha−1. Calf gain ha−1 was not altered in period 2 by N rates while stocking rate increased linearly. Pasture productivity was increased by N rate in both period? 1 and 2 with 1 kg of applied N ha−1 yielding 2.47 kg of TDN ha−1 (Ŷ = 1507 + 2.47 X) in period 1 and 1.83 kg of TDN ha−1 (Ŷ = 1109 + 1.83 X) in period 2. Early weaning increased calf daily gain, calf gain and TDN ha−1 compared with conventional grazing, but calf daily gains were variable and less than expected.

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