Energy and protein contents in pastures at different times of the year and feeding to meet animal nutrient requirements

Abstract

Energy, crude protein and dry matter digestibility of pastures are essential components of quality that influence the voluntary intake of grazing livestock. To be able to meet the nutrient requirements of animals for maintenance, growth, gestation and lactation, pasture quality, quantity and efficient utilisation need to be well managed. Seasonal changes in pasture quality imply that a strategic and tactical approach to grazing management needs to be adopted in terms of herd structure, stocking rate and the use of persistent pasture species that can fill the seasonal feed gap. Pastures grazed in green, leafy vegetative condition have the highest nutritional quality. Growing and lactating animals should have priority access before dry stock due to their high nutrient requirements. Maintaining pasture mass above 1000kg green DM/ha promotes rapid growth and checks against overgrazing. Animal intake and pasture quality decline when the mass exceeds 3000kg green DM/ha, therefore, managing pastures to maintain between 1500-2500kg green DM/ha would enhance maximum cattle performance. Completely depending on pastures alone may not meet the nutritional requirements of lactating animals, particularly energy. Strategic supplementation with high-energy grains will fix this.