Nutrition and Health Status of African Catfish Fed Yellow Corn Waste Meal

Abstract

A ten week feeding trial was conducted to investigate the growth performance, haematology and histology of African catfish ( Clarias gariepinus) fed varying inclusion levels of yellow corn waste meal.  A total of one hundred and eighty fingerlings were allotted  to six diets with varying concentrations of  yellow corn waste meal ( 0, 10, 20, 30, 40, and 50%). At the end of the feeding trial the growth performance were determined:   The mean weight gain (MWG),  average daily weight gain (ADWG), percentage daily weight gain (PDWG),  specific growth rate (SGR), average feed intake (AFI), feed conversion ratio (FCR), protein intake (PI), protein efficiency ratio (PER), were significantly different (p>0.05). Highest MWG(13.29g), ADWG(6.19g), PWG(192.33%), SGR(1.54%/day, PER(1.57)  and least FCR (1.59) were recorded in treatment 4 and the least MWG, ADWG,PWG,SGR ( 5.47g, 0.08g 79.05, 0.84) respectively and highest FCR(3.10)were observed  in treatment 6. Hematological parameters such as packed cell volume (PCV), haemoglobin (HB), Red blood cell (RBC), white blood cell (WBC), mean corpuscular volume (MCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC)  recorded were all significantly (P<0.05) different.The highest PCV (37.60, 38.70, 38.30%) and RBC (2.74, 2.98, 3.05) were recorded in treatments 3, 4 and 6 respectively. The highest HB, WBC and lymphocyte count, (13.50g/dl, 154.20 and 59.08) respectively were recorded in treatment 6 respectively. Although, highest MCV (145.90fl) was recorded in treatment 3. The highest MCH (60.80, 63.63,) MCHC (53.80, 57.50) and Platelets (54.00,53.00) were recorded in treatment 1 and 2 respectively. The haematology results therefore, revealed that higher levels of YCWM in the diet of African cat fish did not degenerate to any disease in the blood  Cellular rupture, aggregation of inflammatory cells, vacuolar degeneration in the hepatocyte, focal areas of necrosis and rupture of blood sinusoids that resulted in hemorrhage were characterized. Furthermore, histological examination of liver tissue revealed in plate E shows only a slight difference when compared with  the liver tissue of the fish fed control diet in plate A, although little degeneration and presence of melanomacrophage. The histological result suggests that not more than 40% YCGM should be substituted with maize grain under the conditions tested in this study.Therefore, it can be concluded that maize can be replaced with YCWM at 40% inclusion levels in the diet of African catfish (Clarias gariepinus) without any deleterious effect.

Keywords: Maize, nutrition,  haematology, histology and  African cat fish