Abstract 511

Laredo-C,-MA

Instituto Colombiano Agropecuario, Tibaitata, Colombia.

Revista-del-Instituto-ColombianoAgropecuario. 1981, 16: 4, 181-187; 20 ref.

Guinea grass swards were rotationally grazed by Zebu cattle with 10 days grazing followed by a 40 day rest period from June 1980 to June 1981 at a stocking rate of 2 animals/ha. Samples of grass were taken in the wet and dry seasons and analysed for cell wall constituents, DM digetibility and DE. There was no difference between seasons in DM digestibility and DE but acid detergent fibre (ADF) and lignin were both higher in the dry season (43.08 and 45.33% and 5.9 and 7.8%, resp.). Linear regressions were not significant but using multiple regression the CP, ADF, cellulose and lignin content significantly affected DM digestibility (R2 = 0.77) and DE (R2 = 0.87).