Over the course of a long weekend (mid June) when grantee and collaborator were out of town, the sheep heavily browsed trees in the third section of the pasture and escaped through the fence to the previous two sections in search of feed. Browse ranged from isolation (one branch) to heavy (entire tree) and was most significant on the scattered small trees (three to five feet) where leaders were damaged. The damage to the Christmas trees wile significant occurred early enough to allow for regrowth. It is estimated that forty trees were browsed with 30-50% of those trees unmarketable this year.
Additionally, damage occurred on the lower areas of the trees which the yearlings picked as “shade and fly” trees with the larger yearlings causing more breakage. The lower limbs of these trees needs to be removed as they generally browned and died. The cost of the damage from browse and limb breakage is estimated to be approximately $600-$800 and negated any cost savings from not having to manage grassy competition to the trees by mowing.
We view the major browse episode as human error and not reflective of the project. The lower limb damage while significant could be alleviated by allowing access to a well shaded area in each pasture. For our purpose this was not possible.
After the browse event, we replaced the six yearlings with eight ram lambs intended for fall sale and allowed the lambs access to the full acre of the three pastures without smaller paddocks. A small amount of browse occurred when there was sufficient forage but was isolated to three to five small trees. Damage to the trees from the lambs in search of shade was much less compared to the yearlings.
The eight lambs were removed September 8th. Soil samples were taken the following week and showed an increase in P and K. This is believed to be a result of a December 2006 lime application of 1.5 ton per acre.
In the control block, which was maintained with standard practices, labor totaled 5.5 hours. For project purposes, the labor involving management of the lambs exceeded 80 hours. While there is marginal savings on equipment and fuel, the labor expense is far greater and sheep will not replace the mower for Christmas tree management.