Performance of lambs grazing pearl millet at four levels of herbage allowance
MetadataShow full item record
Knowledge of the quantitative relationship between herbage allowance and production per animal and per unit area of land provides the basis for a successful grazing strategy. A successful grazing strategy implies that an optimum balance between production per animal and per unit area of land has been achieved. The objective of this research was to determine the quantitative relationship between herbage allowance and gain/lamb and gain/ha when grazing Tifleaf I dwarf pearl millet (Pennisetum americanum (L.) Leeke). Levels of herbage allowance were 4, 6 , 9 and 12 kg/100 kg of lamb weight/day. Experimental design was a randomized complete block with three field replications. Experimental grazing lasted 70 days in each of two consecutive summers (1984 and 1985) and rotational grazing with 7-day use and 28-35-day rest was followed, Gain/lamb and per ha was different (P<.05) among allowances. Average gains/lamb over the two years were 65, 68, 90 and 100 g/day for the 4, 6, 9 and 12% allowances, respectively. Gains/ha were 663, 478, 434 and 374 kg for the 4, 6, 9 and 12% allowances, respectively. Gain/lamb was positive and linearly (P<.01) related to level of herbage allowance. The gain/ha-herbage allowance relationship was described by a quadratic equation (P<.05). Gain/ha decreased linearly from the 4 to Q% allowances and leveled off after the S% allowance. After the 3rd-4th day of grazing, intake by lambs was restricted at the 4 and 6% allowances apparently by high fiber content. Final model (R^ = 68) from stepwise regression to estimate daily gain of lambs included the variables (X) sward height reduction by grazing, hemicelluloses after grazing, NDF before grazing, herbage mass before grazing and ADF after grazing. Pearl millet is a good summer pasture for limbs. Based on these findings, grazing dwarf pearl millet at a 6-7% herbage allowance could be expected to provide a reasonable compromise between gain/lamb and gain/ha.