Selective Grazing by Sheep and Cattle

Studies were made of differences in ability of sheep and cattle to graze selectively alfalfa and trefoil-orchard grass forage. Criteria used to assess the importance of selective grazing were digestibility, forage consumption, total digestible nutrient consumption, weight gains, yields of dry matter and yields of total digestible nutrients. Differences between sheep and cattle were apparent when given alfalfa forage. The sheep selected and consumed from the alfalfa pasture a forage higher in total digestible nutrients and made more gain per unit of total digestible nutrients consumed than did the steers. With the trefoil-orchard grass, however, difference between sheep and cattle in ability to select were not as apparent. It appears that with a low dense forage selective grazing will not have as great an influence as it has with a tall, less dense forage. The steers made better use of the alfalfa soilage because they consumed more feed. The sheep were unable to select the forage desired and this seemed to interfere with feed consumption and hence production. Selective grazing which resulted in refusals to eat the coarse alfalfa stems combined with higher total digestible nutrient content of trefoil-orchard grass forage decreased the importance of differences in dry matter yield between alfalfa and trefoil-orchard grass forage. Even though trefoil-orchard grass produced 58 to 63% the amount of dry matter produced by alfalfa, the ultimate yield in terms of beef and lamb produced per acre showed that trefoil-orchard grass yielded 80 and 89% respectively the yield from alfalfa.