EFFECT OF ROSEMARY OR LAUREL LEAVES AS FEED ADDITIVES ON PERFORMANCE OF GROWING LAMBS

hirty males of crossbred Rahmani lambs (Rahmani × Finnish Landrace) were chosen after weaned at 3 months of ages and randomly divided into five similar groups (6 lambs for each) according to their live body weight (20.66 ±0.165 kg) and fed the experimental rations for 20 weeks as an experimental period to investigate the effects of rosemary or laurel herbs as feed additives to lambs rations, on rumen functions, digestibility, some blood parameters and growth performance of growing lambs. Rosemary dry leaves (RDL) or laurel dry leaves (LDL) were added to concentrate feed mixture (CFM) portion of lambs rations at levels of 0, 0.5, 1, 0.5 and 1% as (CFM1, CFM2 CFM3, CFM4 and CFM5, respectively). Each group was assigned randomly to feeding one of experimental rations where R1 (control): received 60% CFM1+40% clover hay (CLH), R2: 60% CFM2+40% CLH, R3: 60% CFM3+ 40% CLH, R4: 60% CFM4 +40% CLH and R5: 60% CFM5 +40% CLH as tested rations. The feed allowances were calculated according to NRC (2007) for sheep. Five digestibility trials were performed to evaluate the nutrients digestibility and feeding values of the experimental rations. Results indicated that the chemical composition of RDL and LDL were contained (6.23, 8.25), (22.72, 23.86), (8.48, 8.41), (53.61, 54.54), (8.96, 4.94) % for CP, CF, EE, NFE and ash, respectively. Essential oil content in LDL was approximately the double of that found in RDL (3.00 vs. 1.6% as fed, respectively). The digestibility of most nutrients and feeding values (DCP) were insignificant improved with increasing the level of RDL and LDL in rations, while TDN value was significantly (P<0.05) improved with increasing the level of LDL in ration compared with that of control one. The rumen liquor pH values were somewhat decreased over 3 and 6 sampling times with increasing the level of RDL and LDL up to 1% in the experimental rations. The vice versa trend was found among dietary treatments respecting and NH3-N and TVFA ́s concentrations where its values were increased with increasing the two herbs levels in the tested rations over the three sampling times. No significant differences among treatments in respect of all blood metabolites except for glucose, total lipid, tri-glyceride, total cholesterol and LDL-c which markedly improved with increased the level of RDL or LDL in rations. Concerning blood plasma TAC, its values significantly increased due to the addition of the two levels of both RDL and LDL into the four tested rations compared to the control ration. Total body gain and daily gain were significantly higher with both tested rations that having the high levels of herbs (R3 & R5) than those of control one, while the other tested rations that having the low level of herbs (R2 & R4) were insignificant higher respecting these growth items, than those of control one. Total DMI and TDNI were markedly increased with increasing the levels of the two herbs (RDL & LDL) in the four tested rations, based on control one, being the high level (1%) of herbs appeared to be more affecting than the low one on feed intake. Economic efficiency was tangibly improved by feeding the tested rations that contained the experimental herbs, especially with that having 1% LDL in comparison with control one and the other tested ones. It could be concluded that feeding on rations contained RDL or LDL (i.e. 1% in adding of CFM), could be recommended for growing lambs due to the positive effect on growth performance and health state in addition to increasing profitability.