EFFECTS OF ENSILING CASSAVA PEELS ON SOME FERMENTATION CHARACTERISTICS AND THE GROWTH PERFORMANCE OF DJALLONKE SHEEP ON-FARM

Abstract

Two experiments were conducted to determine the effect of ensiling cassava peels on some fermentation characteristics and the growth performance of sheep. In the first experiment, peels were ensiled in mini silos and opened on day 1, 3, 10, 15 and 45 for measurement of pH and for enumeration of lactic acid bacteria, yeasts and moulds. Cassava peels were also either ensiled in large bag silos or were sun-dried and used to formulate two supplementary diets (cassava peels: whole cotton seed; 3:1). In the second experiment, the diets were fed to sheep for 70 d. Nine communal pens containing 5 sheep were randomly allocated to 3 treatments; Control (no supplementation), ensiled cassava peel-based diet or dried cassava peel-based diet. A total of Forty-five Djallonke sheep (11.91 kg; SD = 2.6) were used in the study. Microbial population data, dry matter intake and growth performance data were analyzed by the MIXED model procedure of SAS. In the first experiment, ensiling reduced the pH from 5.65 in the fresh peel to 4.15 after 45 days of ensiling compared to 6.15 in the dry peels. Ensiling increased the crude protein concentration from 45±0.44 g/kg DM in the fresh peel to 52±0.88 g/kg DM in the ensiled peel compared to 46±0.48 g/kg DM in the dried peel. The concentration of neutral detergent fibre was reduced by 19% in the ensiled peel compared to 7% in the dried peel. However, the concentration of hydrogen cyanide was greatly reduced (P = 0.001) by drying than by ensiling the peel. Populations of moulds were greater (P = 0.011) in the ensiled peels than in the dry peels but the yeasts populations did not differ (P = 0.474) between treatments. In the growth performance study, the daily average body weight gain was higher (P = 0.031) for sheep fed the ensiled peel than for those fed the dried peel and those that did not receive any supplementary diet. Total body weight gain was also not significantly different for sheep fed the diet containing the ensiled and dried cassava peel but significantly different from those on the Control. In conclusion, ensiling improved the fermentation characteristics of cassava peels and the growth performance of sheep but the difference in average daily gain of sheep fed the dried compared to the ensiled peel were not significant (p=O.293).