Abstract 20

Wadsworth,-J

Escuela Centroamericana de Ganaderia, Apartado Postal 7, Atenas, Costa Rica.

Tropical-Agriculture. 1990, 67: 1, 37-42; 16 ref.

During the dry season (Jan.-Mar.), 40 Brahman heifers (av. age and weight 22 ñ 1.3 months and 253.7 ñ 3.9 kg resp.) were rotationally grazed on Hyparrhenia rufa pastures or confined and fed whole, fresh sugar cane ad lib. with 1% urea and 0.5 kg rice polishings daily. Animals were considered to be eligible for mating when they attained a weight of 300 kg. At the end of May, when mating for the seasonally-calving herd was to commence, the percentage of heifers eligible for mating was 60 and 5 in the sugar cane-fed and grazed groups resp. An economic analysis showed that feeding of sugar cane could increase net income by $8.85 per livestock unit per yr compared with grazing.