Luiz Carlos Vieira Júnior, Luciano da Silva Cabral, Janaina Conte Hadlich, Marina Gabriela Berchiol da Silva
Marandu palisadegrass submitted to different sheep stocking rates: height and leaf: stem ratio
Capim Marandu submetido a diferentes taxas de lotação de ovinos: Altura e relação folha:colmo
The experiment was carried out at the Sheep Experimental Farm of Federal University of Mato Grosso/Brazil, along the months of February to May 2008, during the rainy and the water-dry transition seasons. The area where the experiment were totaled 4500 m2, formed by the Marandu palisadegrass. This area was divided into 45 paddocks of 100 m2. We used 27 lambs Santa Inês (purebred) with 4 months of age and average weight of 22 kg. The lambs were grouped into nine lots of similar weights. The treatments consisted of three stocking rates, 2, 3 and 4 female lambs / paddocks, corresponding respectively to 40, 60 and 80 lambs / ha. Each treatment was represented by 15 repetitions totaling 45 plots, each representing a paddock of 100 m2. The paddocks were managed under the system of intermittent stocking with 7 days of occupation and 28 days of rest. All paddocks had the height measured in 10 points. We used the found height as a criterion for the choice of where to sample the plot residual forage mass. The cutting height was 5 cm in the ground. The samples were weighed and submitted to fractionation: leaf, stem and senescent material. We calculated the leaf: stem ratio, dividing the amount of dry residual amount of green leaves by stem + sheath. The data collected were submitted to variance and regression analysis at 5% significance level. There was a linear decrease as the stocking rate increased for leaf: stem + sheath, and the estimated values of 0.22, 0.17 and 0.11. A similar effect was also observed for the post grazing sward height, where each animal unit added to the stocking rate reduced 0.32 cm in the pasture height. The estimated values were 56.32, 49.50 and 43.34 cm, respectively for 40, 60 and 80 lambs / ha. There was higher areas excluded by the animals, being possible to display high heterogeneity kept in paddocks with lower stocking rate. Both the height of the canopy as leaf: stem ratio increased with the increase in the stocking rate.