THE POTENTIAL OF MAIZE CROP RESIDUES FOR WINTERING SHEEP ON THE EASTERN TRANSVAAL HIGHVELD

Maize crop residues were grazed at three stocking rates, viz. 6, 9 and 12 sheep/ha, for about three months. Total DM yield of the maize crop was about 7500 kg/ha, and consisted of 38,5% grain and 61,5% residues. During harvesting, an average of 338 kg grain/ha was wasted. On average, crop residues consisted of 49% leaves. 31% stems, 3,5% cob leaves, 10% cobs and 6,7% grain. About 39% of the crop residues was removed during the grazing period. Weathering accounted for 21% loss of residual material on an adjacent site that was not grazed. Grain and finer leaf material were almost totally utilized, and oesophageal samples contained between 80 and 90% grain during the first four weeks of grazing. Thereafter, grain content fell sharply, with nutrient and energy content following suit. Stocking rate did not affect mass gains significantly (P less-than-or-equal-to 0,05), but wool growth declined significantly with an increase in stocking rate. Nevertheless, these production parameters were higher with a stocking rate of 12 sheep/ha than with stocking rates of 6 and 9 sheep/ha, when production was calculated per hectare. Production levels were judged to be highly satisfactory, from which it was concluded that sheep may be successfully wintered for up to 1250 sheep grazing days.