Background: In India, there are a variety of unconventional feed resources that can be used in ration of ruminant animals. Among all, the most promising are castor bean, mahua, neem and karanj oil cakes which contains quality nutrients like that of conventional cakes. These unconventional oilcakes (UOC) are rich source of phytochemicals such as glycosides, saponins, tannins, essential oils and other which will help in methane reduction. This study was planned to investigate the effect of feeding unconventional oil cakes combination (Karanj: mahua: 75:25) on methane production through respiration chamber.&nbsp; 
 
Methods: Nine cattle calves aged one and half year old were distributed into three groups (Control, T1 and T2), three in each as per completely randomized block design where one group acted as control and two groups (T1 and T2) were experimental. The control animals were fed with basal diet (concentrate+roughage) and T1 and T2 were fed with basal diet and UOC combination at the rate of 7.5% and 10% of concentrate mixture, respectively. The calves were fed for 120 days and methane was estimated through respiration chamber.&nbsp; 
 
Result: Methane production was significantly (P&lt;0.01) reduced in experimental group, compared to control. Methane production (L/day) measured in control, T1 and T2 was 75.24&plusmn;2.02, 65.90&plusmn;0.97 and 59.85&plusmn;1.55, respectively. Based on the result we concluded that feeding of UOC combination significantly reduced the methane production.

Effect of Feeding of Unconventional Oil Cake Combination on Methane Emission Through Respiration Chamber Study