Synchronization of dietary energy and nitrogen availability for microbial protein synthesis in vitro

Isonitrogenous and isocaloric (12% CP and 55% TDN) total mixed rations (9) with roughage to concentrate ratio of 60:40 three each of synchronous (S), medium synchronous (MS) and asynchronous (AS) were formulated. The rate of OM degradation among energy sources was higher (P<0.01) in wheat grain and lower in maize grain while N degradation among protein sources was highest in mustard cake and lowest in formaldehyde treated and straws had lowest (P<0.01) values than all other feedstuffs. S rations resulted in higher (P<0.01) in vitro dry matter (IVDMD), organic matter (IVOMD), TVFA concentration, purine and bacterial N yield and efficiency of microbial protein synthesis, while reduced total gas and methane production than in MS and AS rations. Later rations reduced (P<0.01) acetate to propionate ratio and increased NH₃-N concentration in comparison to S rations. It was concluded that synchronizing the rate of supply of energy and N to the rumen microbes based upon in sacco degradation, improved ruminal fermentation and nutrient digestibility which yielded higher microbial protein synthesis from wheat straw based ration.