Proceedings of the 13th ISTRC symposium, Arusha, Tanzania
An experiment was carried out to evaluate the effect of cassava (Manihot esculenta) root meal (CRM) and fish wastes (FW) on the growth of dairy heifers in four rations. The rations were TR1 (66.5 % HM and 31.5 % CSC) TR2 (50 % CRM and 48 % CSC)
TR3 (67.5 % HM and 30.5% FW) and TR4 (51.5 % CRM and 46.5 % FW). Twenty Ayrshire
heifers (average weight 145±8 kg) were randomly allocated to the four rations in a
completely randomized block design. Data was collected on dry matter intake (DMI), weight gain, glucose, Ca, P and protein blood levels. No difference (P>0.05) in weight gain was observed between heifers on TR1 and TR3. Heifers on TR2 showed faster growth rates (P< 0.05) than those in other treatments (i.e. 620 versus 490, 460 and 410 g for TR1, TR3 and TR4 respectively). Correspondingly heifers on TR2 had superior (P< 0.05) feed efficiency (0.116) followed in a descending order by TR1, TR3 and TR4 (0.097, 0.092 and 0.085 kg gain / kg feed. Heifers receiving diets containing
FW had higher (P<0.05) Ca and P than those on CSC. Blood glucose and plasma protein were higher (P<0.05) in heifers receiving TR1 (97.07g/l and 3.3 mmol/l) than those on TR2 (94.86 g/l and 3.0 mmol/l). It is concluded that CRM could be used alone as energy source when combined with protein rich feeds like CSC and FW.