Effect of stocking rate on Rhodes grass-stylo pasture in the northern guinea savanna zone of Nigeria 2. pasture and sheep performance
Mixed pastures of Rhodes grass (Chloris gayana cv. Callide) and Stylo (Stylosanthes guianensis cv. Cook) were evaluated at fi.ve slacking rate, 12, 18, 2 4, 3 0 and 36 rams/ha over five grazing periods at Shika, Nigeria. The pastures were continuously grazed for 154 to 210 days beginning from late rainy into dry season (August to April). Dry matter yields of stem, leaf stem + leaf of C gayana, green material and total herbage declined (P<0.01) as stocking rate and grazing days increased. However, the differences in yields of green material and leaf of C. lgayana at 24 and 30 rams/ha were not significant over the grazing periods. Daily live weight gain (g/head/d) was negatively and linearly related to stocking rate. Mean live weight gains at the lowest and highest stocking rates were + 52 and -1 g/head/d in the second grazing season and 62 and 24 g/head/d in the fifth grazing period. Mean live weight production/ha and optimum stocking rates (OSR) in the first, second, third, fourth and fifth grazing periods were: 61.2kg, 17.8 sheep/ha; 155.5kg; 20.4 sheep/ha; 186.2kg, 24.9 sheep/ha; 129.4kg, 21.2 sheep/ha and 200.2kg, 26.0 sheep/ha, respectively. A curvilinear relationship was obtained between live weight gain/ha and stocking rate. This study indicated that sheep at the highest and lowest stocking rates will need supplementary feeds after 100 and 128 days, respectively, if grazing commenced just before the end of the rain.
Keywords: Stocking rate; sheep; live weight gains: herbage yields; rhodes grass; stylosanthes