Evaluation of MegaFerm Fiber to enhance ruminal fermentation and nutrient digestibility of a total mixed ration using an in vitro gas production measurement system

Abstract Text: The addition of specific feed additives to a total mixed ration (TMR) has the potential to enhance the rate and/or extent of ruminal fermentation and nutrient digestibility.  MegaFerm Fiber (MFF) is an unique blend of nutritional technologies that enhances the ruminal fermentation and nutrient digestion of a TMR fed to lactating dairy cows.  A standard TMR consisting of alfalfa haylage, corn silage, and a grain mix was dried at 55^OC and ground through a ultracentrifuge mill having a 1.0 mm screen.  One g of ground TMR was placed in a 50 um dacron bag, heat sealed, and then placed in a 500 ml Ankom Gas Fermentation Bottle (GFB) to measure rate of gas production and digestion.  Treatments were: Control (C) and MFF fed at 3 rates to equate to a feeding rate of 5, 10 and 15 g/cow/d.  Each treatment was replicated 6 times as individual GFB.  Rumen fluid was collected from a ruminally cannulated lactating dairy cows fed the same TMR.  The rumen fluid was strained through 4 layers of cheesecloth and 20 ml were added with 200 ml of buffer to each GFB.  Bottles were incubated in a circulating water bath at 39 ^OC and gas measurements were collected every 5 minutes for 30 h.  At the completion of 30 h fermentations, dacron bags were removed and dried to calculate dry matter disappearance and then analyzed for NDF concentrations to calculate NDF digestibility.  The rate of gas production was linearly improved (P<0.07) with the addition of MFF to the C TMR (8.0, 8.2, 9.0 and 8.6 %/h for C, and MFF at 5, 10, and 15 g/cow/d, respectively).  The extent of digested dry matter (76.8, 76.7, 75.8, and 75.2%) was similar (P>0.09) for all treatments.  The pH at 30 h was similar for all treatments (6.45, 6.45, 6.46 and 6.49).   The pH decline from 0 to 30 h was similar for all treatments (-0.069, -0.073, -0.097, and -0.089 pH units).  This study demonstrated that MFF can enhance the rate of digestion by increasing the rate of gas production, but the extent of nutrient digestibility was not affected.  The enhanced rate of nutrient digestibility could possibility enhance the milk production of lactating dairy cows

Keywords: Gas Production, Nutrient Digestibility, MegaFerm Fiber