The U.S. imported 28.3 million kg of sheep milk cheese in 1998; approximately one-half of total world sheep milk cheese imports. This indicates a potential for growth of the small domestic dairy sheep industry. Profit potential is good with a well-managed 300-head dairy sheep flock estimated to return over $35,000 of net income per year. A dairy sheep research unit was established at our Spooner Agricultural Research Station in 1995. This is the only research facility of its type in North America.
Until recently, there were no dairy breeds of sheep in North America. European dairy sheep breeds of East Friesian (EF) and Lacaune are being evaluated at the Spooner Station. EF-cross ewes produced 92% more milk, 67% more fat, and 69% more protein per lactation than domestic breed (Dorset-cross) ewes (P < .05). In addition, EF breeding resulted in heavier (P < .05) lamb body weights and more (P < .05) lambs produced per ewe compared to Dorset breeding. However, lambs of over 50% EF breeding had lower (P < .05) survival rates than lambs of 50% and lower EF breeding. The Lacaune evaluation is in progress.
Three lamb weaning/ewe milking systems were compared: D30 - lambs weaned from ewes at 30 d of age, ewes milked twice per day from weaning; D1 - lambs weaned from ewes at 1 d of age and raised on milk replacer, ewes milked twice per day from weaning; MIX - lambs separated from ewes overnight and ewes milked once per day in the morning from 1 to 30 d after parturition, lambs weaned at 30 d of age, ewes milked twice per day from weaning. Large (P < .05) differences among D30, D1, and MIX treatments were seen for lactation yields of milk (149, 240, and 205 kg), fat (7.4, 12.3, and 10.2 kg), and protein (7.9, 13.0, and 10.9 kg). Percentage lactation milk fat was less (P < .05) for MIX than for the other two treatments (4.65% vs. 5.02%) due to very low % milk fat (3.24%) from MIX ewes during the first 30 d of lactation.
In another trial, D1 and MIX ewes were supplemented with 100 g/d of rumen bypass fat or not supplemented with fat. Fat supplementation increased (P < .05) % milk fat in D1 ewes but had no effect on MIX ewes. The MIX system is a good compromise system because some milk is obtained from early lactation and the ewes rear their lambs, however, a solution to the low % milk fat while ewes are rearing their lambs needs to be found. Ewes allowed daily grazing of a clover-grass pasture produced 13% more (P < .05) milk per lactation than ewes fed hay in drylot (222 vs.197 kg).