Effect of Three Grazing Intervals on Carrying Capacity and Weight Gains Produced by Star Grass Pastures

Abstract

Intensively managed well fertilized Star grass pastures on a steep Ultisol produced similar weight gains and yields of total digestible nutrients (TDN) and of dry forage with similar protein contents when grazed at 14-, 21-, and 28-day intervals over 3 consecutive years. Average weight gains were 1,197 kg/ha/yr; TDN yields were 7,699 kg/ha/yr; dry forage consumed by the grazing animals was 12,930 kg/ha/yr; and carrying capacity was 5.3 273-kg steers/ha. The forage contained an average of 16.8% crude protein and had an apparent digestibility of 62.7%. Average monthly weight gains varied considerably throughout the year but were apprently not related to rainfall (fig. 1). These data show that Star grass pastures can be grazed at intervals varying from 14 to 28 days without affecting their productivity provided that they are grazed no closer than about 20 em from the ground and that they are well fertilized. Grazing no closer than 20 em leaves sufficient photosynthetic area and enough root reserves are maintained to ensure rapid regrowth of the grass after grazing.