Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: July 27, 1998
Publication Date: N/A
Technical Abstract: Plant concentrations of nonstructural carbohydrates vary and highest levels are observed in the afternoon. Previously animals preferred fescue hay harvested in the afternoon over fescue hay harvested in the morning. We tested for variation in ruminant preference for alfalfa harvested within the same 24-h period. Alfalfa was harvested at sundown (PM) and again the next morning at dawn (AM). This was repeated 3 times resulting in 6 hays representing 3 harvests (Hay 1, July PM; Hay 2, July AM; Hay 3, August PM; Hay 4, August AM; Hay 5, September PM; Hay 6, September AM). Three experiments were conducted (Exp. 1, sheep; Exp. 2, goats; and Exp. 3, cattle) with each utilizing six animals. Hays were offered as meals during an adaptation phase. In the experiment each hay pair (15 pairs) was presented to the animals for a meal. Statistical analysis indicated that the animals were basing selection on two criteria. In all three harvests in the three experiments, preference for PM hays was greater than for AM hays (p<.01). Cattle (Exp. 1) preference varied among the three harvests (p<.01) but this effect was not significant for sheep (p=.09) or goats (p=.15). However, (Exp. 3) goats preferred the PM hays more strongly in the second and third harvests than in the first (p=0.01). Shifting the mowing of alfalfa hay from morning to late afternoon was effective in increasing forage preference in ruminant.