Phytonutrient pellet supplementation enhanced rumen fermentation efficiency and milk production of lactating Holstein-Friesian crossbred cows

The objective of this experiment was to investigate the effects of inclusion of dragon fruit peel pellet(DFPP) and dietary non-protein nitrogen (NPN) on nutrients digestibility, rumen fermentation efficiency,plasma antioxidant activity, microbial protein synthesis, milk yield and composition in lactatingHolstein-Friesian crossbred cows. Four animals were randomly allotted to 4 dietary treatments accordingto a 2 ×2 factorial arrangement in 4 ×4 Latin square design. The treatments were as follows: 300 g DMof DFPP t100 g of urea (T1), 300 g DM of DFPP t 200 g of urea (T2), 400 g DM of DFPP t 100 g of urea(T3), and 400 g DM of DFPP t 200 g of urea (T4), respectively. The results showed that intake of ricestraw was increased (P < 0.01) by the DFPP addition. Including DFPP and urea did not affect (P > 0.05) theNDF and ADF digestibilities, but increased the apparent digestibilities of dry matter, organic matter, andcrude protein (P < 0.01). Rumen fermentation process, especially the propionate concentration, wassignificantly increased by the DFPP levels. The plasma antioxidant activity was increased (P > 0.05) withthe addition of DFPP. The DFPP improved (P < 0.01) microbial protein synthesis. The supplementation ofDFPP and urea increased (P < 0.05) milk fat, whereas milk yield and 3.5% fat corrected milk were onlyincreased (P < 0.05) by the DFPP supplementation. Based on these results, addition of DFPP at 400 g/animal per day with urea at 100 g/animal per day improved rumen fermentation, plasma antioxidantactivity, milk yield and milk fat percentage.