Tanzania Journal of Agricultural Sciences 2002, Vol. 5(1): 39-48
A study was undertaken to avaluate the effects of substituting sunflower seed cake with Acacia tortilis pods as a protein source in supplementing Small East African goats fed a basal diet of Brachiaria brizantha hay. Twenty-four growing female goats with mean body weight of 9. 71 = 1.56 kg were used in a growth experiment. Twelve adult bucks were used in a digestibility experiment. In the growth experiment the animals were divided into four groups, each with six animals, while for the digestibility experiment the animals were divided into four groups, each with three animals. These groups were randomly assigned to four supplementary diets containing different proportion of sunflower seed cake and Acacia tortilis pods. In treatments one (T1). two (T2); three (T3) and four (T4) sunflower seed cake was replaced with Acacia tortilis pods at levels of 0.0%, 3.33%, 66.7% and 100%, respectively. The intake of hay and total DM tended to increase with increasing levels of Acacia tortilts pods in the supplementary diet, the highest intake (430 g DM/day) was observed in goats offered supplementary diet T4. The CP intake (49.1 to 58.9g/day) did not differ significantly (P>0. 0.5). among the treatments. The intake of ME was significantly (P<0. 05) lower (3.0 MJ) for animals in T1 than those in T4 (3:7 MJ). In the digestibility trial, no significant (P>0.05) effect on apparent digestibility of DM, OM, CP and NDF on nitrogen utilisation was observed between treatments. In the growth trail, significant (P<0.05) lower growth rate was observed in animals under T1 (20g/day) than those in T3 (32g/day) and T4 (32g/day). Similarly the feed utilisation efficiency for animals in T1 (FCR=18.5) was significantly (p<0.05) lower than those of the animals in T3 (FCR=13.1) and T4 (FCR=13. 5). Replacement of sunflower seed cake with Acacia tortilis pods in the supplementary diets at the level of 66.7% and 100% gave the highest hay and total DM intake, daily live weight gain and feed utilisation efficiency. Therefore, Acacia tortilis pods may be used in place of high cost oil cakes in the feeding of goats.