ABTSRACT
Nutrition is a major factor that determines the growth performance of farmed fish. This may depend on protein content and feedadditives contained in the diet. This study was conducted to evaluate the effects of dietary supplementation of garlic and ginger on the growth performance and immune status of Clariid catfish hybrid (Heteroclarias juveniles).
Six hundred (600) heteroclarias juveniles were allotted at random to 10 treatments namely; treatment 1 (0% ginger and 0% garlic), treatment 2 (1% ginger and 0% garlic), treatment 3 (2% ginger and 0% garlic), Treatment 4 (3% ginger and 0% garlic), Treatment 5 (0% ginger and 1% garlic), Treatment 6 (0% ginger and 2% garlic), treatment 7 (0% ginger and 3% garlic), Treatment 8 (1% ginger and 1% garlic), Treatment 9 (2% ginger and 2% garlic) and Treatment 10 (3% ginger and 3% garlic). Each treatment was replicated three times with 20 fish stocked per replicate. The fishes were fed ad-libitum with a 40% crude protein diet fortified with various inclusion levels of ginger and garlic for 12 weeks during whichgrowth performance parameters and survival were measured. Also, blood samples were randomly collected per replicatefor haematology. The data collected were subjected to analysis of variance and means were separated with Duncan’sMultiple Range Test.
The result showed that fishes fed 1% ginger inclusion level (T2) were significantly different (P > 0.05) in weight gain (63.5g), FCR (1.16), SGR (2.76) and PWG (21.76%) from all other treatments including the control except treatment 8 (1% ginger + 1% garlic) that is similar. Fishes fed diets containing ginger at 1% (T2) and a combination of ginger and garlic at 1% each (T8) were also more efficient in utilizing protein having a PER value of 158.7 and 157.2 respectively and did not differ significantly from each other but significantly different from all other treatments including the control. Fishes fed 1% garlic (T5) in their diets had the highest survival rate with no mortality recorded (100%) and this was significantly different from all treatments. Fishes fed ginger, garlic and their combination in the various inclusion levels were significantly different (P > 0.05) from the control in the major haematological parameters: PCV, Hb, RBC and WBC. Generally, fishes fed with 2% ginger inclusion in their diets (T3) was the best in terms of major haematological parameters: PCV (59%), Hb (16.7g/dl), RBC (4.2 * 1012L-1), MCV (140.5fl) and WBC (16.9 * 109L-1). However, Fishes fed 1% garlic (T5) in their diets performed better than all other treatment in the production of antibodies as shown in the increase of WBC count (16.4 * 109L-1) and Lymphocytes (72%) which shows that garlic, although dose dependent, can increase fish survival and stimulate the immune system. Thus, the combination of 1% ginger + 1% garlic produced better feed utilization, weight gain and survival due to its better immune system and it is thus recommended.
