Great Lakes Dairy Sheep Symposium - the Department of Animal ...

EVOLUTION OF THE MILK PRODUCTION AT THE SPOONER AGRICULTURAL
RESEARCH STATION BETWEEN 1996 AND 2004
Yves M. Berger
Spooner Agricultural Research Station, University of Wisconsin-Madison
Spooner, Wisconsin, USA
The year 1996 was the first year of milking sheep at the Spooner Agricultural Research
Station. The total production for this first year was a modest 24,000 pounds of milk from 136
ewes put at milking. In 2004 the total amount of milk produced at the station was 186,000 lbs
with 292 ewes put at milking with an average production per ewe of 755 pounds (331 liters) for
adults and 492 pounds (216 liters) for young ewes in first lactation. This level of production is
becoming very satisfying and rewarding. The tremendous increase of milk, as shown in Figure 1,
has been constant year after year. The greater number of ewes milked, also shown in the same
graph, cannot, by itself, explain this increase. Certainly, many factors contribute to a better
production, all of them with a cumulative effect. Some of the factors can be quantified such as
the amount of dairy breeding, the length of lactation, the weaning systems, but others, such as
feedstuff quality, overall management, and acquisition of a “know-how” are much more difficult,
if not impossible, to measure.
Genetic Composition of the Flock
As shown in Figure 2, the breeding composition of the flock changed drastically from
1996 to 2004. Originally, the starter flock was composed of Dorset-type ewes mixed with some
Romanov or Finnsheep, therefore many ewes that were milked during the first few years had no
or little dairy breeding. The percentage of dairy breeding increased regularly. During the first 3-4
years most of the ewes had less than 50% dairy breeding. The number of ewes with 50% dairy
breeding reached a peak in 2001. These ewes were replaced by ewes with 75% dairy breeding,
which in turn, are now being replaced by ewes with more than 75% dairy breeding.
The East Friesian breed was the first breed used for upgrading using live rams purchased
in the United States and Canada, and frozen semen of Dutch and New Zealand origins. In 1998
the Lacaune was introduced in the United States by purchasing live rams from a Canadian
producer and by purchasing frozen semen from 3 different rams in England. At this time, no
Lacaune could be purchased directly from France. Dorset ewes were crossed with either East
Friesian or Lacaune and all female progenies were kept as replacement. Ewe lambs sired by
Lacaune were bred by East Friesian rams, and ewe lambs sired by East Friesian were bred by
Lacaune rams. The same breeding principle was used every year. In 2004, 85% of the ewes were
crossbreds East Friesian x Lacaune in various percentages with a small percentage of Dorset.
One could expect that most of the increase in the overall amount of milk produced,
would, therefore, be due to the flock being more and more “dairy”. Surprisingly however,
although it certainly contributes, it does not seem to be the most important factor.
Dorset type ewes with no dairy breeding produce the least amount of milk, which is well
illustrated in Figure 3. When crossed with a dairy breed (East Friesian or Lacaune), the milk
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