Eighteen weaned Rahmani male lambs with live body weight ( LSW) ranging
from 18 to 20 kg about 4 months of age were divided according to their body weight
into three groups ( 6 lambs each) to study the effect of different levels of dietary
protein on their growth performance, digestibility, rumen liquor and some blood
parameters and the income over feed cost. Each group was fed ration (concentrate
feed mix CFM) containing different levels of protein, but isocaloric for four month.
Lambs in group 1 (G1), group 2 (G2) and group 3 (G3) fed CFM containing 14, 16,
and 18 % crude protein as dry matter, respectively. The results of the animal performance showed that the ADG significantly
increased (P<0.05) when the level of protein increased. Lambs in G3 had higher (P<
0.05) ADG than those in G1 and G2. Daily feed intakes expressed as OM was
slightly higher for G1 flowed by G2 and G3. The results of feed efficiency show that
lambs fed high level dietary protein had the highest values of body gain related to the
unit of DMI and TON The results of nutrients digestibility pointed that increasing dietary protein
improved OM, OM, CP, EE and NFE digestibilites. Crude protein digestibifity
increased as level of protein increased. The same trend has been recorded with
feeding value expressed as TON and DCP. The high level of protein in the ration in G3 were accompanied higher of total
protein (TP), albumin (AL), globulin (GL) and glutamate-puruvate transaminase GPT.
Lambs in G2 had slight higher glutamate-oxaloacetate transaminase GOT than those
in G1 and G3. The differences among treated protein were significant (P<0.05) in TP
and GL on weaning lambs , while the differences among treated protein were non
significant in AL, GOT and GPT on weaning lambs Ammonia - N concentration of rumen liquor tended to increase gradually as a
result of increasing protein level. The highest value was recorded for G3 followed by
G2 while the lowest value for G1. The highest income over feed cost were obtained
from lambs of G3,while the lowest was with lambs of G 1. In view of the obtained results, it could be concluded that increasing protein
level in the ration of weaned lambs improved the animal performance, digestibility,
feeding values and reduce the cost of the product ( meat production) by increasing
the feed efficiency. Furthermore, the level of 18% CP in the ration of weaned lambs is
sufficient for good growth performance during this stage.