Protein is one of the most expensive constituents of the ruminant's diet. Under many feeding regimes most of the dietary protein fed to ruminants undergoes extensive modification due to microbial activity in the rumen and the nitrogen used in the synthesis of microbial protein. Consequently, nitrogenous compound with low biological values are upgraded. Conversely a protein having a high availability and biological value in the non-ruminant may be altered in the rumen to lower availability and biological value, or both. (Peter et al. 1971).

The rumen micro-organisms cannot synthesize enough protein to support high level of milk production in lactating cow. Good quality dietary proteins, therefore, should be protected from rumen degradation to improve its bypass value. Different methods have been used to overcome the degradation of protein in the rumen. Of which the two methods i.e. treatment of protein with "Heat" and "Aldehydes" are widely used.

The present study was conducted to determine the bypass values of different vegetable protein meals for ruminants using nylon bag technique on fistulated male buffalo calf. The protein sources were subjected to heating through autoclaving and treated with formaldehyde at various levels. To evaluate their effects, the in situ protein degradation was determined.

It was found that 24 hours incubation in the rumen was the optimum time for digestion of all vegetable protein meals. The data was subjected to statistical analysis only at 24 hours incubation time. Both autoclaving and formaldehyde had significant effect in protecting proteins from rumen degradation of all vegetable protein meals.

Maximum bypass protein value i.e. 97.09 percent of maize gluten meal (60%) was achieved at 1 percent fonnaldehyde treatment as compared with control i.e. 66.82 percent. It was concluded that formaldehyde treatment at 0.5 percent level was better and economical for maximum protein protection of maize gluten meal (60%).The autoclaving treatment of maize gluten meal (60%) for 30 minutes may be considered to be optimum for protein protection. By comparing two treatments it was also concluded that formaldehyde treatment is more effective and economical as compared to autoclaving in case of maize gluten meal (60%).

The bypass protein value of rapeseed meal was observed to be 19.62 percent. The maximum protein protection was observed i.e. 78.0 percent unit increase in bypass protein value at 1.5 percent formalin treatment and this level was found to be the best. Sixty minutes autoclaving of rapeseed meal could be considered the best. While comparing both treatments, formaldehyde treatment was found better than autoclaving.

Maximum rumen undegradable protein (RUP) value of sunflower meal i.e. 79.25 percent was observed at 1.5 percent formalin treatment as compared to control i.e. 7.15 percent. It was recommended that formaldehyde treatment at 0.5 percent level was better and economical for achieving higher RUP value. It could be concluded that autoclaving treatment of sunflower meal for 45 minutes was effective and economical for protein protection. While formalin treatment was noted to be better than autoclaving.

Maximum protected protein value of cottonseed meal was noted to be 50.59 percent at 1 percent formalin treatment as compared to untreated i.e. 20.60 percent. It may be advised that formalin treatment at 0.5 percent of cottonseed meal was optimum and economical to achieve maximum protected protein value. Autoclaving treatment for 60 minutes of cottonseed meal was the best in protecting protein from rumen degradation. It was evident that autoclaving treatment was better than formalin treatment in case of cottonseed meal.