Effect of Varied Sources of Tannin on Micro-Mineral Bioavailability in Goats Fed Oak Leaves Based Diets

摘要

Eighteen crossbred (CheguxJamunapari) goats (15.99 kg; 7-9 months) were randomly assigned to three groups. The animals were fed a common concentrate mixture as a supplement to three different forage sources (with a concentrate to roughage ratio of 30:70) namely, green grass (PC, Pennisetum clandestinum), oak leaves i.e. Quercus semecarpifolia (QS) and Quercus leucotricophora (QL) with the latter two groups serving as tannin-containing diets while the PC group as a control. The condensed and hydrolysable tannin content of the QS and QL diets was CT 1, HT 3.4 vs. CT 1.9, HT 1.6, respectively. A metabolism trial of six days duration was conducted at 90 d post-feeding. Blood samples were collected on 0, 60 and 120 d of experiment for estimation of serum minerals. The digestibility of DM, CP and fibre fractions were lower (P0.05) in QL than PC and similar with QS. Daily intake and balance of Fe, Mn and Zn was higher (P0.01) in QS and QL groups than the control group. Serum level of Co, Fe and Zn were higher (P0.05) in QS than PC, but at par with QL. Average daily gain was higher in QS and QL as compared to PC. Feed gain ratio was better in QS (22.9 +/- 0.08) than PC (39.5 +/- 0.06), but at par with QL (29.9 +/- 0.04). Overall, the study revealed that goats fed tannin-from QS-based diet showed comparatively better performance than that of QL-based diet. Further, feeding of oak leaves was beneficial in augmenting feed intake, micro-mineral balance and growth performance of goats as compared to animals fed grass based diet.