Oil Seed Meals as By-pass Protein Source
The protein digestion in ruminants encompasses microbial transformation of dietary protein in the rumin. A varying portion of feed protein is degraded into peptides, amino acids and ammonia, all of which help in the synthesis of microbial protein. Its synthesis in the rumen is low always on straw based diets. In such situations provision of higher level of by-pass protein in the diet may be necessary to provide adequate protein post-ruminally to enhance the production potential of ruminants.
The by-pass protein contents of important and commonly used oil meals are presented in Table 7. Some of the commonly used oil meals such as soybean meal, coconut meal, and cotton seed meal are considered as good sources of by-pass protein.Feeding trials conducted on lactating cattle fed either paddy straw or finger millet straw as basal roughage have revealed higher milk production when supplemented with by-pass protein sources. However, more studies are needed to arrive at the exact level of by-pass protein supplementation to straw based rations in view of published reports available from western countries where by-pass protein is not added up to 20 kg milk per day.
Crude Protein (%)
By-pass Protein (%)
Cotton seed meal
Mahua seed cake
Groundnut cake (Expeller)
Groundnut cake (Heat treated )
Groundnut cake (Formaldehyde treated)
Rape seed meal
Niger seed cake