Effect of TLMM supplementation on growth performance of lambs
The body weights (kg), ADG (g/d) and FCR of lambs were measured at fort nightly intervals. The mean initial body weights (kg) of lambs selected for the experiment were 12.10 ± 0.31Kg. The mean final body weights (kg) were significantly (P<0.05) lower in C group compared to treatment and NC groups. Among the treatment and NC groups, the mean final body weights (kg) were significantly (P<0.05) higher in T2 group, while the difference was not significant among other groups. At the end of the experiment, the body weights (kg) of T1, T2 and T3 groups were found to be 21%, 23% and 18% higher than the control group.
Similar to present findings were observed by
Iqbal et al. (2007) in lambs where maximum weight gain was recorded in animals fed diets containing 3% CT. Similar trend of increased growth in sheep supplemented with CT was reported by
Ngwa et al., (2002). Pathak et al., (2017) obtained similar results of increased body weights in lambs by feeding tannins from
Ficus infectoria and
Psidium guajava leaf meal mixture.
Improved performances have been frequently observed in animals fed with tree leaves
(Leng, 1997). In the present study the body weights of T1, T2 and T3 groups were found to be 21%, 23% and 18% higher than the control group. In consistent with the present findings,
Montossi et al., (1996) observed 23% improvement in live weight gain in lambs grazed on
Holus lanatus (4.2 g CT kg
-1 DM). Similarly, increased live weight gain, carcass weight, dressing per cent was reported in lambs grazed on
L.
corniculatus (34 g CT kg
-1 DM) by
Wang et al., (1996).
Effect on average daily weight gain (ADG) (g/day)
In the present study the mean daily weight gain (g/day) was found to be high in T2 group of lambs (114.31 g/day) followed by T1 group (110.83 g/day), T3 group (105.69 g/day), negative control (97.50 g/day) and the lowest values were recorded in control group (74.03 g/day). The mean average daily weight gains (Table 1) differed significantly (P<0.05) among different treatment groups.
In consistent with the present findings, higher growth rate was reported in kids fed oak leaves based diet
(Singh et al., 1996) and in calves fed on
Q.
semecarpifolia and
Q.
leucotricophora, based diets
(Sharma et al., 2008). Rubzana et al., (2007) also reported that leaf meal supplementation of
Acacia nilotica (52.8 g CT Kg
-1 DM) and
A.
polyacantha (98.3 g CT Kg
-1 DM) showed significant (P<0.05) increase in ADG (114.3 vs 42.9 g/day) in goats.
Effect on feed conversion ratio (kg DMI/ kg gain)
The present study observed significantly (P<0.05) lower feed conversion ratio (FCR) (kg DMI/kg gain) in lambs fed TLMM incorporated TMR containing 3% CT compared to either 2 or 4% levels (Table 2).
The positive response of ADG and FCR for the diets fed at 3% level of CT in the present study gives an indication that the binding effect of tannins was pronounced only at this level which aids in bypassing the protein to the lower gut and subsequently it’s more efficient use for tissue growth. Hence, 3% CT is apparently the optimum level, at which there are enough tannins to exert beneficial effects on performance of lambs. However, the present findings are contrary to the findings of
Dey et al., (2008) who reported that positive impact was evident on the overall performance of lambs supplemented with
F.
infectoria leaves to 1.5% CT in the supplement and decrease in the performance of lambs at 2%. This may be due to the difference in the source of tannins.
Effect on faecal egg count of helminths
TLMM supplementation was found to have significant (P<0.05) effect on the faecal egg counts (Fig 1) and significantly (P<0.05) lower counts were obtained for T2 group, while the difference was not significant among T1, T3 and NC groups. The mean faecal egg counts (Egg per gram) on day 120 of the experiment were reduced by 66.67%, 85.85% and 71.63% in T1, T2 and T3 groups, respectively, when compared with the day one of the experiment.
Reduced FEC have been attributed to both direct reduced fecundity, killing of adult worms,
(Shaik et al., 2006) and indirect effect of CT as dietary supplementation of CT improved the immune function against the GI parasites through enhanced protein supply (higher absorption of amino acids) that is required for the repair and immune response
(Niezen et al., 2002).
Similar to the results reported in the present study,
Heckendorn et al., (2007) observed reduction in daily faecal egg output specific to
H.
contortus by feeding chicory (89%) birdsfoot trefoil (63%) sainfoin (63%) in lambs.
Consistent with the present results,
Valderrabano et al., (2010) reported that feeding of tanniferous forages like sulla, Sainfoin and wormwood has decreased faecal egg excretion by 22%, 54% and 73%, respectively, in sheep.
Minho et al., (2008) and
Marie-Magdalene et al. (2010) also observed reduction in egg counts per gram of faeces and parasite load of
H.
contortus in the abomasum of sheep by feeding tanniferous forages.
The reduced FEC in the sheep decrease the contamination of pasture with infective larvae which in turn results into less infection in the animals grazing on the pasture. Moreover, the mean FECs of the treated groups were much lower than the threshold level, which warrants for anthelminthic medication. Thus, the frequency of using anthelminthic drugs can be minimized. This is especially important in hot and humid climatic conditions like India where frequent medication is the only way to get rid of this menace
(Dutta et al., 2012).
