Abstract 124

Rivera,-B; Vera,-RR; Weniger,-JH

CIAT, Cali, Colombia.

Giessener-Beitrage-zur-Entwicklungsforschung,-I-Symposien. 1988, 17, 243-248; 10 ref.

In trials over 4 years in the Llanos Orientales of Colombia, 45-52 Zebu cross cows and 2 bulls were given various combinations of licks containing 0, 4 or 8% P and grazed on native pastures or pasture in part improved by sowing Brachiaria humidicola/Desmodium ovalifolium or Andropogon gayanus/Pueraria phaseoloides mixtures to provide 900-1800 m2 of improved pasture/animal. Cow liveweights were higher at calving and weaning when given 4% P licks and yearlong access to improved pasture than with either of these conditions alone. There were further wt increases at conception and calving when given the 8% P lick and strategic grazing on improved pastures at critical physiological periods. Abortion and calf mortality percentages were consistently highest when P licks were not available, but weaning percentages were affected more by mating behaviour than by nutritional treatments. Consumption of licks was lowest when areas of improved pasture were available and it was concluded that the provision of such areas with 4% P licks gave the best economic returns.