Author/Authors :
M.P، Hughes نويسنده Department of Food Production, Faculty of Science and Agriculture, University of the West Indies, St. Augustine, Trinidad and Tobago , , P.G.A، Jennings نويسنده MARJEN Consulting Group, PO Box 314, Spanish Town, Jamaica , , V، Mlambo نويسنده Department of Food Production, Faculty of Science and Agriculture, University of the West Indies, St. Augustine, Trinidad and Tobago , , C.H.O، Lallo نويسنده Open Tropical Forage-Animal Production Laboratory, Department of Food Production, Faculty of Science and Agriculture ,
Abstract :
The objective of this study was to determine the effect of season on sward characteristics and nutritive value of pastures on 5 dairy and 2 beef farms in Jamaica. Pasture samples were collected during the dry, intermediate and wet seasons in 2010. Pasture herbage mass was highest during the dry season. Season affected sward bulk density on all farms (P < 0.05) except Edwards Dairy (P=0.056). Sward bulk density decreased while undisturbed sward height increased from dry to wet season. Season significantly (P < 0.05) influenced crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), cellulose and hemicellulose content on most farms. CP concentration was 8.9-37.9% lower in the dry compared to the wet season. NDF was highest in the wet season (726-789 g kg-1 DM). ADF decreased by 7.3%-14.8% from the dry to wet season. ADL was highest in the dry season (84.1-107 g kg-1 DM) on all farms except FM Jones Dairy and Edwards Dairy.
Cellulose was highest and lowest during the dry (379-413 g kg-1 DM) and intermediate (327-370 g kg-1 DM) season, respectively. Hemicellulose concentration progressively increased from dry to wet season. In vitro organic matter digestibility (IVOMD) was highest (444 - 613g kg-1 OM) in the intermediate season. It is concluded that the nutritive value of Jamaican pastures is highest during the intermediate season and lowest during the dry season.
