The experiment was carried out to study pre- and post-weaning growth and
fattening potential of lambs. Lambs used were from an earlier experiment to evaluate
effects of feeding management on reproductive efficiency and production rates of
ewes. There were four groups of ewes. The control group was fed according to NRC
recommended allowances from before breeding till the weaning of offspring at the age
of 16 weeks. The three experimental groups were allowed free-choice ad lib
roughage intake throughout. Each of the three experimental groups was offered a
different roughage: ad lib berseem hay, one-third hay plus ad lib rice straw, or ad lib
rice straw with added a commercial molasses-urea mixture, Mufeed. From the end of
breeding till the end of the early pregnancy stage ewes in the three experimental
groups received only the basal roughage. As of the start of the late pregnancy stage
and up to the end of lactation and weaning of offspring they were offered ad lib ground
corn grail1s and cottonseed meal in separate feeders to allow for free-choice intake. The growth of lambs was followed for 16 weeks till weaning. For a period of 12
weeks, between weeks 9 and 20 post weaning, ewe-Iambs were fed to grow as
replacements whereas ram-Iambs were fattened. The NRC recommended
allowances were used. Daily intake and biweekly weights were recorded. The ewe feeding management during pregnancy and lactation had a profound
effect on lamb performance. During the nursing stage and up to weaning, male and
female lambs from the hay-fed ewes were superior in weights and growth rates to the
controls, whereas those from the straw-fed ewes were inferior. The same was true for the growing replacement ewe-Iambs and fattening ram-
lambs up to the age of 10 months. Ewe-Iambs from all groups reached a weight and
age suitable for being joined to rams in intensive production systems at the age of
about 10 months. However, those from the hay-fed ewes were slightly over fat to
attain adult weight at that age. They weighed 44 kg at the age of 10 months. Over
fattening of ewe-Iambs will negatively affect their fertility. In comparison to data cited from the literature for Barki and Ossimi sheep,
results from the present investigation were exclusively superior. It is believed this was
due to the better feeding management of both the dams and their offspring pre- and
post-weaning.