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

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Chart 1: Milk Production Comparisons
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April May June July August Sept.
2000 (N=126-164) 2001 (N=158-202)
It is important to note that the two years were quite different in terms of nutrition and weather.
In 2000, we were able to feed high quality haylage throughout the ewes’ lactation, while in 2001;
the ewes were strictly on pasture. In 2001, the early season haylage was coarse and not as good as
the previous year’s. Both seasons, the ewes received about two pounds per day of a corn/roasted
soybean mixture. In addition, there were extremes in both heat and humidity on both test dates in
July and August 2001 that negatively affected production.
As noted earlier, we selected to retain ewes that met our calculations for both milk and butterfat
production. It seems that the focus on butterfat production may have yielded some positive results.
However, it is again important to qualify that there is typically a negative correlation between
pounds of milk produced and butterfat percent. Chart 2 illustrates the flock averages of percent of
butterfat comparing year 2000 and 2001.
9.00%
8.00%
7.00%
6.00%
5.00%
4.00%
3.00%
2.00%
1.00%
0.00%
Chart 2: Comparisons of Butterfat
April May June July August Sept.
Butterfat 2000 (N=126-164) Butterfat 2001 (N=158-202)
While we have not been selecting for protein components, there has been a slight desirable
change in protein from year 2000 to 2001 as shown on Chart 3. With the very real possibility of
future milk pricing being based on milk components, we will base ewe and replacement ewe
selection on production of butterfat, protein and total pounds of milk.