G.M.J. HORTON¹ and W.D. PITMAN²

¹Department of Animal Sciences, Rutgers University, New Brunswick, New Jersey and
²Agricultural Research and Education Center, University of Florida, Ona, Florida, USA

Abstract

Three protein-energy supplements and a typical protein fortified mineral supplement were compared with cattle grazing "Ona" stargrass (Cynodon nlemfuensis var. nlemfuensis) pastures during the winter season in Florida. All supplements contained 20% crude protein and consisted of a fortified vitamin-mineral supplement fed ad libitum, a cane molasses liquid feed, and two dry supplements based on either corn or bermudagrass pellets. Pasture was grazed by cattle rotated between paddocks every 28 days at a stocking rate of 3 hd/ha for 140 days.
Herbage dry matter available was similar for all treatments, and decreased from 3360 kg/ha to 1410 kg/ha. Respective daily dry matter and crude protein intake were: fortified mineral, 0.21 kg and 0.04 kg; bermudagrass, 1.32 kg and 0.26 kg; molasses, 1.07 kg and 0.22 kg; corn, 1.30 kg and 0.26 kg. Average daily gains for cattle receiving the fortified mineral supplement, bermudagrass, molasses and corn supplements were 0.01, 0.18, 0.19 and 0.29 kg, respectively. These results indicate that energy was a limiting nutrient in stargrass pastures during the winter. Responses to protein-energy supplements were cost effective under the conditions of this study.