The effect of earthworm (Eisenia foetida) meal with vermi-humus on growth performance, hematology, immunity, intestinal microbiota, carcass characteristics, and meat quality of broiler chickens

Abstract

The present investigation was aimed to evaluate the effect of varied amount of earthworm meal (EW) and vermi-humus (VH) on the growth performance of broiler chickens. Three hundred 1-d-old broiler chickens were assigned to 5 starter treatments with 5 pens per treatment, and 12 broiler chickens per pen in a completely randomized design from d 0–14 of the study. Dietary treatments were [per kilogram dry matter (DM)]: control (0g EW and 0g VH/kg of DM), and the diets containing 10g VH/kg of DM supplemented with 0, 10, 20, or 30g EW/kg of DM. At the end of the study (d 42), one representative broiler chicken per pen, close to the average body weight, was selected for blood sampling using a sterile needle and heparinized vacuum tube. The outcomes of the study depicted the greater overall feed intake value in broiler chicken fed the control diet than those fed the diets containing VH or EW or both, and it decreased linearly and quadratically (P<0.05) as the amount of EW supplementation increased. The average weight gain for the chickens was numerically increased as supplementation of EW was increased (linear, P=0.3; quadratic P=0.4). On the other hand, overall feed conversation ratio was slightly greater (P=0.02) in broiler chickens fed the control diet, and it decreased linearly (P=0.03) as dietary EW supplementation increased. Additionally, the serum total protein, albumin, Ca, and P concentrations were lower in broiler chickens fed the control diet, and those variables increased linearly (P<0.05) as dietary EW increased. In like manner, humoral immune response (except heterophil/lymphocyte ratio) and relative weights of immune organs were lower in broiler chickens fed the control diet. Remarkable differences were observed between carcass and ileum characteristics of broiler chickens under treatments. Varied concentrations of EW showed increased total counts of lactic acid bacteria (linear, P<0.05; quadratic, P=0.3) and reduced population of pathogenic intestinal microbiota (linear, P<0.05; quadratic, P>0.05). Similarly, the meat quality of broiler chicken was markedly affected linearly (P<0.05) by the supplementation of increased dietary EW. Briefly, diets containing 30g EW/kg of DM can positively affect the growth performance of broiler chickens and produce meat with better characteristics.