THE DEGRADATION OF OILSEED CAKES AND THEIR EFFECTS ON THE INTAKE AND RUMEN DEGRADABILITY OF MAIZE STOVER GIVEN TO ETHIOPIAN MENZ SHEEP

Six rumen cannulated sheep (26.1 (s.d. 2.24) kg live weight) given mai ze stover ad libitum were supplemented with either sunflower (Helianth us annus) cake (SFC), decorticated cottonseed (CSC) or noug (Guizotia abyssinica) cakes (NGC) with or without crushed maize grain. The 6 X 6 Latin-square experiment studied the degradation properties of the oil seed cakes and their effects and that of maize on the degradation of m aize, maize stover and the composite diet. Seedcakes differed in the d egradability characteristics of dry matter and nitrogen: intercept (a) (P < 0.001); potentially degradable fraction (b) (P < 0.001); rate of degradation (c) (P < 0.001); and the effective degradability (P < 0.0 001). The pooled sum of the degradabilities of the individual ingredie nts were significantly lower than that of mixed ingredients (composite diet) (P < 0.001). The main effects of protein and maize were not sig nificant on the degradation of maize stover. Maize had the tendency to depress the rates of degradation of stover by 0.52 with SFC. Although the protein X maize interaction was not significant on maize stover d egradability, it is important to note that maize had the effect of inc reasing stover degradation rate with CSC and NGC, but a depressing eff ect with SFC. Hence it was concluded that the carbohydrate effect on r oughage degradation rate may vary as a function of the difference betw een the degradation rate of the energy and protein supplements.