THE UTILIZATION OF MAIZE-CROP RESIDUES FOR OVERWINTERING LIVESTOCK - 1 - PERFORMANCE OF PREGNANT BEEF-COWS AS AFFECTED BY STOCKING RATE

Over a three-year period (1986 to 1988), non-lactating, pregnant Susse x beef cows were subjected to grazing maize crop residues over the win ter feeding period at one of three stocking rates [1.75 (LSR), 3.5 (MS R) or 5.26 (HSR) cows/ha]. Cows were blocked by age, live mass and bod y condition score (CS). Grazing commenced on 7 July, 9 June and 9 June and ended on 1 September, 1 September and 10 August in the respective seasons. The respective grazing periods were therefore 57, 85 and 63 days. After 8 weeks of grazing, the cows in the LSR, MSR and HSR treat ments had gained 23.4, 12.8 and 5.3 kg live mass respectively. Cow CS dropped sharply after 8 weeks grazing, irrespective of stocking rate. Overall, 55.4% of the crop residues remained on the lands at the end o f grazing. A higher proportion of grain and leaf (67.2% and 58.7%) was removed from the lands compared to cob and stalk (29.9% and 35.3%).