Optimized oral supplementation of vitamins improves feed intake and rumen microbial protein synthesis in Deoni cows

Abstract

The present study was conducted to optimize oral doses of fat- and water-soluble vitamins in cattle using in vitro gas production model and to ascertain their effects on dry matter intake (DMI), nutrient digestibility, and rumen microbial protein (RMBP) synthesis. Doses optimized using the in vitro model were 3.66, 6.78, 16.3, 41.1, 3.87, 0.323, 4.12, and 0.055 mg/kg DMI, respectively, for thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folic acid, and B12 and 500 IU/kg DMI for vitamin K. Thirty-two adult, nonproducing Deoni cows (375 ± 13.4 kg body weight, BW) were randomly divided into four equal groups (n = 8) and fed a basal diet (CON) or diets supplemented with in vitro optimized doses of water-soluble (WS), fat-soluble (FS), or both (WSFS) vitamins. The DMI values in WS and WSFS were higher than that of FS (92.6 and 96.17 vs. 82.85 g/kg BW0.75; P = 0.048) but comparable to CON (90.34 g/kg BW0.75). The purine derivative creatinine index was significantly higher in the WSFS group compared to CON (270.3 vs. 224.6; P = 0.035). Oral supplementation of optimized doses of vitamins as derived from in vitro trials improved DMI and RMBP production in Deoni cows.