Dairy Sheep Symposium - the Department of Animal Sciences ...

CHOICE OF BREED FOR DAIRY SHEEP PRODUCTION SYSTEMS
David L. Thomas
Department of Animal Sciences
University of Wisconsin-Madison
Madison, Wisconsin
Few decisions can have as much influence on the success of a dairy sheep enterprise as the
decision as to which breed should be milked. The establishment and operation of a dairy sheep
farm requires a greater investment of both money and labor compared to establishment and
operation of a farm for only meat and wool production. Therefore, a breed or breeds of sheep
need to be chosen that can produce enough additional product (milk, meat, and wool) to justify
the increased costs of establishment and operation.
Common Breeds in North America Prior to 1992
Commercial sheep production in North America has been based on the production of meat
and wool from the very beginnings of the industry, with meat production much more important
than wool production. Therefore, selection emphasis has been on traits that result in more
efficient production of meat (e.g. litter size, growth rate, mature size) and wool (e.g. fleece
weight, fleece quality). Adequate milk production and udder health are important traits so that
ewes have enough milk to successfully raise two or three lambs. Indirect selection for increased
milk production has been through selection for heavy lamb weaning weights, and ewes are often
culled for low milk production, estimated from low lamb weaning weights or ewe udder size, or
presence of udder disease. These selection criteria have probably resulted in some, but relatively
small amounts, of genetic improvement over time for milk production.
Dr. William Boylan and his students at the University of Minnesota, St. Paul were the first
research group in North America to compare several North American breeds of sheep for milk
production in a dairy production setting (Boylan et al., 1991; Sakul and Boylan, 1992a; Sakul
and Boylan, 1992b; Boylan, 1995). Results presented in two of their studies are reproduced in
Table 1. Ewes were milked twice per day for approximately 120 days following the weaning of
their lambs at approximately 30 days postpartum. Milk yields are for the machine-milking
period.
Averages for all ewes across the two studies were 138 lb. for milk yield, 6.6% for milk fat
percentage, and 5.8% for milk protein percentage. Average daily milk yields were approximately
1.15 lb. per day over the 120-day lactation period. Romanov ewes had the lowest milk yields in
both studies, and Finnsheep and Lincoln ewes had the second or third lowest milk yields in the
two studies. Romanov and Finnsheep are the most prolific of the breeds found in North America
and have the greatest need for high milk production for lamb rearing, but it appears that this need
has not resulted in high genetic value for milk yield. In the first study (Sakul and Boylan,
1992a), Suffolk, Targhee, and Dorset ewes had above average milk yields and the Rambouillet
ewes were close to average.
In the second study (Boylan, 1995), two additional breeds, the Outaouais and Rideau, were
added. These two breeds were created by Ag Canada at the Agricultural Research Center –
Ottawa by the crossing of several breeds. Both breeds contain a large proportion of Finnsheep