DIGESTIBILITY AND NUTRIENT UTILIZATION OF DIFFERENTLY PROCESSED TROPICAL ALMOND (TERMINALIA CATAPPA) KERNEL MEAL AND CAKE BASED DIETS BY CLARIAS GARIEPINUS JUVENILES

Abstract

This study examined the nutrient digestibility and utilization indices of differently processed tropical almond (Terminalia catappa) kernel for Clarias gariepinus juveniles. A total of 420 C. gariepinus stocked at 20 fish /65 litres plastic tank were allocated to seven dietary treatments in triplicates of differently processed almond kernel meal of Raw (RWAM), Boiled (BOAM), Soaked (SOAM), Roasted (ROAM), Mechanically Extracted cake (MEAC), Solvent Extracted cake (SEAC) and control (REFR) diet. Fish were fed at 3% of their body weight twice daily, the excess feed siphoned out after 45 minutes while faecal collection was done 8 hours after every feeding. Apparent digestibility co-efficient of crude protein (ADCP), Gross energy (ADCGE) and dry matter (ADCDM) were calculated from the results of proximate analysis of treatment diets and faeces. Nutrient utilization indices were calculated from records of feeds administered and weights of fish. ROAM had the highest ADCP and ADCGE with 89.03% and 88.51%, respectively, while the lowest were recorded in SEAC (87.06%) and REFR (86.80%) respectively. There were significant differences (p<0.05) between SEAC’s ADCP value and all the other treatments’ values and between SOAM’s ADCP value and BOAM, REFR, ROAM and MEAC’s ADCP values. There were also significant differences (p<0.05) between RWAM’s ADCP value and ADCP values of REFR, ROAM, and MEAC. All the treatments’ ADCGE values significantly (p<0.05) differed from each other. ADCDM was highest in MEAC, 74.54% followed by ROAM, 74.43% and least in SEAC, 72.03%. All the treatments’ ADCDM values significantly (p<0.05) differed from each other. The lowest Feed conversion ratio was observed in ROAM, 1.00 and highest in SEAC, 1.64. ROAM recorded the highest Protein intake (PI) 3.56/100g diet, Protein efficiency ratio (PER) 2.54, Net protein utilization (NPU) 30.74% and Nitrogen metabolism (NM) 210.09 and lowest in SOAM (3.03g/100g diet, 1.60, 27.81% and 176.67 respectively). There was no significant difference (p>0.05) in the PI and NPU values while there were significant differences (p<0.05) between ROAM and the other treatments for PER and NM. Clarias gariepinus can effectively digest and utilize raw and differently processed Almond kernel meal and cake with the JAGST Vol.17 (1) 2016 Digestibility and utilization of tropical almond ©Jomo Kenyatta University of Agriculture and Technology 43 roasted meal and mechanically extracted cake having better nutrient digestibility and utilization indices.