Milk production from radically improved old fallows in the eastern Free State.

Abstract

Four levels of intensification on old fallows were investigated and evaluated for milk production under dryland conditions. The treatments comprised a control, a low, a moderate and a high level of fertilisation (viz. 0 kg. N/ha & 0 kg P/ha; 50 kg N/ha & 75 kg P/ha; 100 kg N/ha & 30 kg P/ha and 150 kg N/ha & 45 kg P/ha). Cows allocated to the control and low fertiliser levels grazed the existing vegetation dominated by Eragrostis spp. Moderately fertilised plots were oversown with E. curvula cv. Ermelo, while those of the high level were totally replaced by E. curvula cv Ermelo. Concentrate supplementation to cows and conservation of excess pasture were practised during the first three years. During the subsequent two years, no concentrate was fed and a system of put-and-take was applied on all pastures. Results indicated that the low, moderate and highly fertilised treatments outyielded the control by 8, 11 and 1 percent with respect to the mean fat corrected milk (FCM) yield per cow and 112, 190 and 322 percent with reference to the FCM-yield per hectare. The initial stocking rate increased from approximately 0,5 MLU/ha over 112 days of grazing to 1,18; 1,52; 1,85 and 2,82 MLU/ha respectively over 168 days on the four treatments at the termination of the experiment. Concentrate supplementation at one third of the nutritional requirements of the cows, seemed to have had a negligible effect on milk output in this study.

Keywords: cows; dryland; free state; grazing; milk production; pastures; production; south africa; stocking rate; vegetation; yield