While the lambs in the pasture-only group (n=36) have slighter higher ADG (0.436 vs. 0.425 lb/d) than the lambs in the supplemented group (n=37), their gains have been more considerably more erratic. During the acclimation period and before being split into their treatment groups, all the lambs gained an average of 0.543 lbs. per day. During this time, the lambs were grazing a silvopasture, consisting mostly of tall fescue and forbs.
On June 26, the lambs were split into treatment groups. During the first 10 days, the pasture group did not gain any weight, but the next two weeks, the lambs gained an average of 1 lb. per day. Gains dropped off considerably over the next two week period, but were higher the last two weeks. The supplemented group has had more steady gains. Standard deviations were large for both groups early on, but have narrowed in recent weeks.
Each group grazes a five acre system, consisting of four equal sized paddocks. They are rotated each week to the next paddock. Currently, they are grazing the paddocks for a second time. At the start of the study, the pastures were very lush, with a high clover content. It took the lambs some time to adjust to the better quality diet. Initially the lambs grazed the clover and chicory, leaving much of the grass.
It was dry for more than a month, but recent rains have perked the pastures up. They are lush again. Temperatures are also more favorable for grazing. The supplemented lambs are receiving 1 lb. of whole barley per head per day. So far, parasites have not been an issue. FAMACHA© scores have been good and FECs have been low.