Three studies were conducted to evaluate: 1) rotationally grazed forage for late-summer stockpiling; 2) effects of lactation on self-fed supplement intake; and 3) influence of cow age on hand-fed supplement intake. For the first study, treatments consisted of non grazed, 2X and 3X grazed. Crude protein of forage grazed 3X was greater (P<.10) than non-grazed. Yield of non-grazed forage was greater (P<.10) than forage grazed 2X and 3X. Non-grazed forage displayed the greatest stockpiled yield and grazing influenced quality of stockpiled forage to a small magnitude. Treatments for the second study consisted of non, mid, and late-lactation on two experimental diets. Late-lactation cow BW change was less (P<.10) than non-lactating in both experiments and less (P<.10) than mid-lactating cows in Exp. 1 only. Forage intake for late-lactating cows was less (P<.10) than mid-lactating cows in Exp. 1 and tended to be greater (P=.13) than non-lactating cows in Exp. 2. Self-fed supplement intake was highly variable but not influenced by lactation. Treatments for the third study consisted of five age groups. In yr 1, weight change at d 57 for 11-yr cows was greater (P<.10) than 5-yr cows. In yr 2, weight change at d 28 for 8-yr cows was less (P<.10) than 4, 6, and 10-yr cows and 4-yr cows was greater (P<.10) than 6, 10, and 12-yr cows. At d 56, weight change for 4-yr cows was greater (P<.10) than 6, 8, 10 and 12-yr cows and 12-yr cows was less (P<.10) than 6 and 10-yr cows. Weight change at calving for 4-yr cows was greater (P<.10) than 6, 8, and 12-yr cows. Forage intake of 10-yr cows was greater (P<.10) than 8 and 4-yr cows. Supplement intake of 4-yr cows was greater (P>.10) than 8, 10, and 12-yr cows. Six-yr cows had greater (P<.10) supplement intakes than 12 and 8-yr cows. Three and 4-yr cows displayed the best performance and 4-yr cows consumed the greatest amount of supplement. / Graduation date: 2000

A 2-yr grazing study quantified pasture and animal responses of four forage systems (FS) grazed at two stocking rates (SR; 3 or 6 animals ha-1). Using „Marshall? annual ryegrass (Lolium multiflorum Lam.) and „Durana? white clover (Trifolium repens L.), FS treatments included spatially separated grass and legumes within the same paddock (SS), monoculture grass (MG), monoculture legume (ML), and a binary grass and legume mixture (MIX). Annual herbage mass (HM) was similar among FS at high SR (1900 kg ha-1), but at low SR, grass plots had greater HM (2900 vs. 2000 kg ha-1) than plots of legume monocultures. Animals on SS (1.12 kg) had greater average daily gain (ADG) than ML (0.97 kg), but neither was different from MG (1.08 kg) or MIX (1.00 kg). Low SR animals had greater ADG than high SR (1.09 vs. 0.99 kg). These results indicate that SS grazing system can improve pasture productivity.