The energy value for and nutritive value of para-rubber seed for rats

The digestible (DE) and metabolizable energy (ME) of full-fat and defatted rubber seed meals (FRS and DRS) were determined with weanling albino rats fed diets in which the meals replaced either 20 or 40% glucose monohydrate in the reference diet. The nutritive value of both FRS and DRS included at 10, 20 and 30% of the diet as substitutes for groundnut meal and yellow maize was studied with 56, 28-day-old albino rats of the Wistar strain. The trial lasted 28 days. Nutrient digestion and nitrogen retention were studied at the end of the second week on test. The DE and ME for FRS were on average 24.7 +/- 1.30 and 21.7 +/- 0.80 hy/g dry matter and those for DRS were 15.3 +/- 0.97 and 13.8 +/- 0.46 hy/g dry matter. Incorporation of rubber seed meals at increasing levels in the diet significantly depressed gains and worsened feed/gain ratio (P < 0.01), the diet containing 30% FRS or 20 and 30% DRS being significantly inferior to the control and the diet with 10% FRS or DRS. Significantly (P < 0.01) superior gains but not feed intake and efficiency were obtained for FRS compared to DRS. Percent intake -N retained also decreased with increasing rubber seed levels in the diet. Except for the significantly (P < 0.05) higher crude fibre digestibility of the control diet compared with those containing 20 or 30% FRS or DRS, the digestibilities of other nutrients were not significantly different.