In vitro study of phosphorus supplementation (sodium orthophosphate, NaH2PO4.2H2O) on degradability and fermentation of rice straw
By: Md. Shad Uddin Mahfuz, M.R Chowdhury, Mohammad Mehedi Hasan Khan, Md. Abdul Baset
Key Words: Phosphorus supplementation, Rice straw, Rumen dry matter degradability, Rumen organic matter degradability, Rumen ammonia nitrogen.
Int. J. Biosci. 9(6), 170-176, December 2016.
Rice straw is the basal feed in some developing countries. Although its availability is abundant but nutritive value and digestibility is very poor. During the last five decades much research has been done to improve the quality of rice straw by using different treatments and supplements. But these treatments have only been partially successful. Therefore, this study was evaluated the effect of sodium orthophosphate (NaH2PO4,2H2O) as a source of phosphorus supplements on utilization of rice straw and rumen fermentation. In-vitro dry matter and organic matter degradability were increased (P<0.002) in all supplemented phosphorus level than control. Dry matter degradability was higher (479 g/kg) with higher level of phosphorus (5.6, g/kg) at 48 hour. Similarly organic matter degradability was higher (438 g/kg) with higher level of phosphorus (5.6, g/kg) at 48 hour. For NH3-N concentration in rumen fluid the effect of phosphorus were decreased (P<0.002) than control but remained at normal range (230 mg/L) for proper rumen function. The effects of phosphorus were also decreased (p<0.021) for pH in rumen fluid. Lowest PH (6.7) was observed at higher level of Phosphorus (5.6 g/kg) in rumen fluid. Sodium orthophosphate can be used as an alternative source of supplement which is not only the source of phosphorus but also act as a source of sodium which is an important mineral helped in maintaining the pH of rumen fluid and microbial growth. As rice straw is deficit in phosphorus, sodium orthophosphate improved its utilization and had an important role in ruminant digestion and metabolism.