Productive performance and nutritional value of Pennisetum purpureum cv. Cuba CT-115 grass at different regrowth ages

Abstract

Grass species forage yield and nutritional value directly affect livestock production performance. They also vary in response to regional climate and soil conditions. Forage yield and nutritional value in Pennisetum purpureum cv. Cuba CT-115 were evaluated at five regrowth ages (30, 45, 60, 75 and 90 d) in three seasons (dry, rainy and northwinds). A completely randomized block design with repeated measures was used, with four replicates per treatment. In all three seasons, maximum height was reached at 75 d: 127.1 cm in the dry season, 151.6 cm in the rainy season and 137.0 cm the northwind season. Forage yield was highest (27.0 t DM ha-1) at 90 d in the rainy season, with a growth rate of 300.2 kg DM ha-1 d-1, 7.3% crude protein and 37.0% in situ digestibility of dry matter. The leaf:stem ratio was highest at 30 d in all seasons, with a 1.65 average value. Crude protein content was highest in the northwind season at 30 and 45 d, with a 15.6 % average value. In all three seasons, digestibility was highest at 30 (mean= 49.3 %), 45 (51.8 %) and 60 d (48.2 %). Based on forage yield, use of P. purpureum cv. Cuba CT-115 grass for open grazing is recommended for cutting at 90 days' regrowth and based on its nutritional quality is recommended for grazing at 60 days' regrowth, both during the rainy season.