This work was carried out on ewes and born kids to investigate the effect of feeding concentrate feed mixtures supplemented with dried Yeast or Matricaria chamomile on body weight changes, nutrients digestibility's, nutritive values of tested diets and growth performance of growing lambs. Some rumen fermentation parameters and blood constituents as well as economical efficiency were studied.
Forty pregnant crossbred ewes (l/2 Fin. X l/2 Rahmani) at late pregnancy (2 months before lambing) with an average body weight of 53.50 + 0.84 Kg and age of 2 years were used in this study.
Ewes were distributed into four similar groups (10 ewes each group) and were randomly fed the four experimental rations as follows:
Ration (T1): Consisted of concentrate feed mixture (control).
Ration (T2): Consisted of concentrate feed mixture supplemented with 50 mg dried yeast/Kg L.B.W/day.
Ration (T3): Consisted of concentrate feed mixture supplemented with 50 mg Matricaria chamomile (M.C)/Kg L.B.W/day.
Ration (T4): Consisted of concentrate feed mixture supplemented with 100 mg Matricala chamomile (M.C)/Kg L.B.W/day.
Wheat straw was offered at 1 % from live body weight as a sole source of roughage for all groups.
After lambing, newly born male and female lambs were taken to study growth performance (12 lambs from each group, 6 males and 6 females) with an average live body weight of 19-20 Kg and were fed the same rations of their dams.
Results obtained revealed that using dry yeast or chamomile as feed additive for growing lambs lead to increase most nutrients digestibility compared to the control ration. Moreover, feeding value expressed as TDN and DCP appeared to be higher (p < 0.05) with tested rations, being 52.63, 56.03, 55.17 and 56.26 % TDN for rations T1, T2, T3 and T4, respectively. Corresponding values of DCP % were 10.55, 11.79, 10.66 and 11.51 %, respectively.
Average daily gains of lambs were 122. 30, 140.82, 140.38 and 127g/day for animals fed T1, T2, T3 and T4, respectively. Animals fed tested rations gained 15.14, 14.78 and 4.62 on advantage with rations T2, T3 and T4, respectively.
Feed efficiency expressed as Kg TDN/Kg gain were 5.64, 5.09, 5.40 and 5.78 Kg TDN/Kg gain for animals fed rations T1, T2, T3 and T4, respectively, being the best for the group fed ration T2 ( supplemented with dry yeast ).
The results also showed that the average of feed cost to produce 1 Kg live body weight were 6.18, 5.50, 5.44, and 6.08 Egyptian Pounds, for groups fed rations T1, T2, T3 and T4, respectively. Consequently, ration T3 attained the cheapest cost to give one Kg gain. The Economic efficiency improved by 20.25, 22.78 and 3.16% for groups fed ration T2, T3, and T4 respectively compared with group fed the control ration.
Results showed that feeding tested rations containing either dry yeast or chamomile were affected fermentation in the rumen. Animals fed ration T2 containing dry yeast attained lower pH value and the highest ammonia-N and total VFA's concentration, while those fed chamomile treatment recorded lower ammonia-N and total VFA's concentration than that fed control ration.
It was also observed that, blood profile was affected by the lasted feed additives. So, total protein and albumin increased with supplemented ration with either dry yeast or chamomile, showing the highest concentration with blood of animals fed ration T4. The same significant trend was observed with other measurements such as glucose, AST and ALT concentrations, while total lipids and cholesterol concentrations tended to be lower with animals fed tested rations, except for those fed T2 with total lipids. Also, it was noticed that the different stages of sampling affected on blood parameters.
Generally, it could be concluded that, using dry yeast and chamomile as feed additives in rations of growing lambs lead to increase most of nutrients digestibility, feeding value and attained higher daily gain. Moreover, the feed additive improved feed efficiency and decreased feed cost per Kg gain with no side effect on ruminal activities and blood parameters.