Abstract 514

Ramirez-P,-A

Pastos-Tropicales,-Boletin-Informativo. 1983, 5: 3, 5-7.

Sown meadows of Andropogon gayanus alone or mixed with Centrosema, fertilized initially with P, were grazed continuously during 3 fattening periods of from nearly 200 to over 300 days by zebu cattle at usually 3.3/ha, with free access to water and mineral salts. Forage was more abundant and richer in protein in the rainy season. Daily weight gain was always greater, exceeding 500 g, on mixed pasture than on grass alone, but difference decreased from 65 to 34 and 40 g in periods 2 and 3 as availability and quality of forage deteriorated and proportion of legume, but not number of plants, declined from 40 to 30 then 15% on basis of dry weight of aerial portion of the plants in mixed pasture in the successive fattening periods. In periods 1 and 2 the cattle were sold at the start of the dry season. Sale towards its end in period 3 resulted in daily weight loss of 150 and 96 g on grass and on mixed pasture.