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

Presented in Table 3 is the lactation performance of one-year-old ewes in 1996 and 1997, and
two-year-old ewes in 1997. The East Friesian-cross ewes had lactations that were 33 days longer
and produced 115 lb. more milk (1.91 times as much milk), 2.2 kg more fat, and 2.2 kg more
protein compared to the Dorset-cross ewes (P < .05, Table 3). Fat and protein percentage of milk
from East Friesian-cross ewes was approximately .5 percentage units lower (P < .05) compared
to milk from Dorset-cross ewes. As mature ewes and under management systems where milking
started 24 hours postpartum, these same East Friesian-cross ewes had average milk yields of 519
to 572 lb. (McKusick et al., 2001).
In addition, East Friesian-cross lambs had greater growth rates than Dorset-cross lambs, and
East Friesian-cross ewes had greater prolificacy and weaned more lambs per ewe than Dorsetcross
ewes (Thomas et al., 2000). Therefore, sheep of 50% or less East Friesian breeding were
superior to Dorset-cross sheep in milk production, reproduction, and lamb growth. The only
detrimental effect of East Friesian breeding found was reduced lamb survival in lambs of over
50% East Friesian breeding compared to non-East Friesian lambs or lambs of 50% or less East
Friesian breeding (Thomas et al., 2000). It appears that lambs of high percentage East Friesian
breeding are more susceptible to respiratory disease. This also has been reported with East
Friesian and East Friesian-crosses in Greece (Katsaounis and Zygoyiannis, 1986) and France
(Ricordeau and Flamant, 1969).
Table 3. Least squares means for lactation performance of young EFcross
and Dorset-cross ewes
Breed of ewe:
Trait Dorset-cross EF-cross
Number of lactations 76 246
Lactation length, d 92.7 ± 4.2 a
126.2 ± 2.6 b
Milk yield, lb. 125.2 ± 12.1 a
240.0 ± 7.5 b
Fat, % 5.54 ± .07 a
5.02 ± .05 b
Fat yield, kg 3.3 ± .3 a
5.5 ± .1 b
Protein, % 5.42 ± .05 a
4.97 ± .03 b
Protein, kg 3.2 ± .3 a
5.4± .1 b
Log somatic cell count 4.99 ± .09 a
5.03 ± .04 a
a,b Within a row, means with a different superscript are different (P < .05).
Continued experimentation with East Friesian crosses at the University of Wisconsin-Madison
and their performance in commercial dairy flocks in the U.S. and Canada further showed
their superiority for milk production, and most commercial operations moved quickly to crossbred,
high percentage, or purebred East Friesian ewes. A crossbred East Friesian or high percentage
East Friesian ewe is still the most common ewe found in commercial sheep dairies in North
America today.
With the availability of both East Friesian and Lacaune dairy sheep breeding in North
America in 1997, the University of Wisconsin-Madison initiated a study in 1998 to compare
sheep sired by East Friesian rams and Lacaune rams for lamb and milk production under dairy