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.
