OPTIMUM LEVEL OF UTILIZATION OF COOKED SWEET POTATO MEAL (Ipomoea batatas LAM) IN BROILER CHICKEN DIETS

OPTIMUM LEVEL OF UTILIZATION OF COOKED SWEET POTATO MEAL (Ipomoea batatas LAM) IN BROILER CHICKEN DIETS

Abstract:

Proximate composition of cooked sweet potato meal (CSPM) was determined using AOAC (1990) methods. Four experiments were conducted with two set of birds. The first two experiments were carried out to determine the optimum level of utilization of cooked sweet potato meal (CSPM) in broiler diets and the variety of preference in the second experiments. Two hundred and seventy one-week old broiler chicks (hubbard breed) with an average weight of 93g were randomly allotted to six dietary treatments during experiment 1, with three replicates of 15 birds per replicate in a Completely Randomized Experimental Design. The experimental diets consisted of six levels of weight for weight substitution of maize with CSPM at 0, 10, 20, 30, 40 and 50% respectively. Results showed that at the starter phase birds on 5.4% CSPM diet had higher weights than all the other treatments including the control diet in terms of final weight, total weight gain, daily weight gain and feed conversion ratio. At the finisher phase, significant differences (P>0.05) were noted in the final weight, weight gain, daily weight gain, feed conversion ratio and feed cost as the level of CSPM increased in the diet. Growth performance was significantly depressed even at 10% CSPM replacement for maize. The carcass analysis also showed significant differences (P>0.05) in most parameters, but there was no clear cut trend except for the weight of liver that increased as the level of CSPM exceeded 10%. Dietary inclusion of CSPM significantly reduced the digestibility of DM, CF, EE and ash. Fibre digestibilities decreased linearly as CSPM replacement increased from 0 – 50%, while the ash retention also decreased linearly as CSPM increased from 0 – 30% of maize replacement. There was no mortality at both phases. In the second experiment, three varieties (white, orange and yellow) of CSPM were evaluated for proximate composition and anti-nutritional factors. At starter phase, One hundred and eighty one-week old broiler chicks (Hubbard breed) of mixed ix sex with an average weight of 80g were randomly allotted to four dietary treatments with three replicates of 15 birds each in a Completely Randomized Experimental Design. The experimental diets consisted of diets formulated without sweet potato (control), 10% white-flesh CSPM, 10% orange–flesh CSPM and 10% yellow-flesh CSPM respectively. Performances of birds fed the three varieties of CSPM were better than those of birds fed the control diet at the starter phase, while at the finisher phase, significant (P>0.05) better performance was observed in the control group. They had better live weight, dressed weight, % breast, % thighs, % back cut and % shank than the values for the three varieties of CSPM. Nutrient digestibilities were generally higher in the bird fed control diet. White flesh CSPM based diet had relatively higher digestibility coefficient than orange and yellow flesh CSPM based diets. It was concluded that, broiler chickens at the starter phase can optimally tolerate a maximum of 5.4% CSPM in their diets. White-flesh variety of CSPM supported optimal performance at 10% dietary inclusion level with concomitant reduction in feed cost per kilogram. Further studies are recommended to determine replacement value of CSPM in broiler finisher diets

OPTIMUM LEVEL OF UTILIZATION OF COOKED SWEET POTATO MEAL (Ipomoea batatas LAM) IN BROILER CHICKEN DIETS