Effect of Tannin-rich Mimosa pigra Leaf Meal in Molasses-based Blocks on Feed Intake, Rumen Parameters, and Blood Metabolites of Dairy Heifers

| The study was aimed to evaluate the influence of condensed tannin in tannin-rich Mimosa pigra leaf meal (TMLM) as a nitrogen binder in molasses-based blocks (MBB) on feed intake, rumen parameters, and blood metabolites of dairy heifers. Four crossbred Holstein heifers with 328.12 ± 1.96 kg average body weight were assigned in a 4x4 Latin square design to dietary treatments with four different levels of TMLM in MBB at 0, 75, 150, and 300 g/kg dry matter, respectively. Heifers were fed green chopped guinea grass ( Panicum maximum TD58) for ad libitum intake as the basal feed. The feeding trial lasted for 80-d. The results indicated that grass intake, total feed intake, neutral detergent fiber intake, and acid detergent fiber intake significantly increased in response to the advanced degree of TMLM inclusion MBB (P<0.05). However, none of the TMLM inclusions had a significant impact on rumen parameters, blood biochemical profiles, and complete blood counts (P>0.05), except the number of eosinophils (P<0.05). In conclusion, TMLM was beneficial for dairy heifers at 150 g/kg dry matter in MBB to improve feed intake and allow the development of dairy feeding strategies.