|Commenced in January 1999||Frequency: Monthly||Edition: International||Paper Count: 16|
A thirty Rahmani weaned male lambs of average body weight (27.28±1.40 kg) were randomly allotted to three similar groups, ten lambs in each, to study the benefit of commercial feed additives Tonilisat (Saccharomyces cerevisiae) and Roemin W2 (Lactobacillus acidophilus, Lactobacillus thermophilus, Bifidobacterium and Lactose) as growth promoters on lambs performance, digestibility, rumen activity and some blood constituents. The experiment lasted about 107 days. Three experimental groups were allotted as control group: received the basal ration, T1 group: received the basal ration supplemented with Tonilisat as (0.5kg/ ton concentrate feed mixture) and T2 group: received the basal ration supplemented with Roemin W2 (1kg/ ton concentrate feed mixture). Our study revealed that addition of Tonilisat significantly increased digestion coefficient of crude protein than that of the control group, Furthermore, the supplementation of Tonilisat or Roemin W2 increased (p<0.05) crude fiber digestibility than control group. Total digestible nutrients and crude digestible protein were not significantly changed between treatments. Retained nitrogen was higher in treated lamb groups than untreated but the different was non significant. Rumen activity of different rations showed that volatile fatty acids concentrations for Tonilisat and Roemin W2 groups were higher than control group, but the differences were not significant. There are no significant changes between groups in tested blood parameters but in T1 group ALT and AST were decreased. Conclusion: Supplementation of the lamb's rations with probiotics had a non significant effect (p<0.05) on blood constituents. While, growth performance and economic efficiency revealed that Tonilisat supplemented lambs had the best average daily gain followed by Roemin W2 treated group in comparison with control group. The best economic efficiency was recorded for T1 which fed Tonilisat followed by control group at whole period.
Plant growth is affected by the osmotic stress as well as toxicity of salt in leaves. In order to study of salt stress effects on stomatal conductance and growth rate and relationship between them as wells osmotic and Na+-specific effects on these traits, four bread wheat genotypes differing in salt tolerance were selected. Salinity was applied when the leaf 4 was fully expanded. Sodium (Na+) concentrations in flag leaf blade at 3 salinity levels (0, 100 and 200 mM NaCl) were measured. Salt-tolerant genotypes showed higher stomatal conductance and growth rate compared to salt-sensitive ones. After 10 and 20 days exposure to salt, stomatal conductance and relative growth rate were reduced, but the reduction was greater in sensitive genotypes. Growth rate was reduced severely in the first period (1-10 days) of salt commencements and it was due to osmotic effect of salt not Na+ toxicity. In the second period (11-20 days) after salt treatment growth reduced only when salt accumulated to toxic concentrations in the leaves. A positive relationship between stomatal conductance and relative growth rate showed that stomatal conductance can be a reliable indicator of growth rate, and finally can be considered as a sensitive indicator of the osmotic stress. It seems 20 days after salinity, the major effect of salt, especially at low to moderate salinity levels on growth properties was due to the osmotic effect of salt, not to Na+-specific effects within the plant.