Linear growth and blood characteristics of wistar rats fed either milk or fish based complementary foods

BACKGROUND: Information on the effect of different animal protein sources on linear growth is needed to inform specific complementary food recommendations. OBJECTIVE: This study evaluated the effect of milk (COMPIM1) and fish (COMPIM2) based complementary foods on linear growth and blood characteristics using Wistar rats. METHOD: The study adopted completely randomised design involving feeding of COMPIM1, COMPIM2, COMPIM3 (control) and basal diets to weanling rats (8 per group) for 28 days. Length (cm) and weight (grams) measurements were taken once and twice weekly, respectively. Blood samples were subjected to haematological and biochemical analysis. Data was analysed using ANOVA. RESULTS: Rats fed the COMPIM2 diet had significantly (p <  0.001) the highest weight gain (63.50 g). There were no differences in the tail (p = 0.159) and total body length change (p = 0.142) of the rats fed COMPIM1, COMPIM2 and COMPIM3 diets. However, the mean length gain of rats fed COMPIM1 diet was more than that of the COMPIM2 and COMPIM3 groups by 9.8% and 12.6%, respectively. Except for white blood cells count and calcium, blood parameters of the experimental groups were similar. CONCLUSION: The milk diet resulted in better white blood cell counts but similar weight and length gain compared to the fish diet.