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

Reproduction. Table 4 compares the reproductive performance of 1/2 East Friesian and 1/2
Lacaune ewes when lambing at approximately one and two years of age. Table 5 presents the
reproductive performance of the various 3/4-dairy breed ewes when lambing at approximately
one year of age and the 1/2 East Friesian and 1/2 Lacaune ewe lambs that were their contemporaries.
Number of lambs born per ewe lambing (average litter size) was not significantly different
among the various breed groups, however, ewes of 1/2 or greater East Friesian breeding gave
birth to slightly more lambs than did ewes of 1/2 or greater Lacaune breeding.
Ewe lamb fertility (percentage of ewe lambs that lambed of ewe lambs exposed) was significantly
greater for ewe lambs of 1/2 or greater East Friesian breeding than for ewe lambs of 1/2 or
greater Lacaune breeding (Table 5), suggesting that East Friesian breeding results in earlier
sexual maturity than Lacaune breeding. Evaluating the information in both tables, there was a
trend for number of lambs born per ewe mated in these young ewes to be greater for ewes of 1/2
or greater East Friesian breeding than for ewes of 1/2 or greater Lacaune breeding. This was due
to the slightly greater litter size and greater fertility of ewes of East Friesian breeding compared
to ewes of Lacaune breeding.
Table 4. Reproduction of F1 ewes produced from East Friesian or Lacaune sires
and non-dairy dams and lambing at one and two years of age
Lambs born per Lambs born per ewe
Fertility, % ewe lambing
mated
Breed group N Mean ± SE N Mean ± SE N Mean ± SE
1/2 EF 95 95.7±2.6 91 1.68±.06 95 1.61±.07
1/2 LA 111 91.3±2.4 100 1.61±.05 111 1.47±.06
Table 5. Reproduction of ewe lambs produced from East Friesian or Lacaune sires
and non-dairy or 1/2-dairy dams and lambing at one year of age in 2001
Lambs born per Lambs born per ewe
Fertility,% ewe lambing
mated
Breed group N Mean ± SE N Mean ± SE N Mean ± SE
1/2 EF 34 97.1±5.1 a
1/2 LA 45 80.0±4.5 b
3/4 EF 23 100.0±6.3 a
1/2 LA 1/4 EF 14 100.0±8.0 a
3/4 LA 14 78.6±8.0 b
33 1.78±.09 34 1.74±.17 a
36 1.53±.09 45 1.22±.10 c
23 1.78±.11 23 1.78±.14 a
14 1.71±.14 14 1.71±.18 a,b
11 1.64±.16 14 1.29±.18 b,c
a,b,c Means within a column with no superscripts in common are significantly different ( P < .05).
Lactation. When looking at the lactation performance of these ewes (Tables 6 and 7), readers
are reminded that these are young ewes (most are one-year-olds, a few are two-year-olds), and a
majority of them nursed lambs for 30 days before being machine milked. Only milk, fat, and
protein obtained from ewes while they were machine-milked was measured. Mature ewes in this
same flock that are milked from 24 hours postpartum have average lactation milk yields of 500
to 600 pounds.