Effect of three organic charcoals as a food additive on ingestion, digestibility, gut weight, evaluation of gut microbiota bacteria level and post-weaning growth in guinea pigs (Cavia porcellus)

In order to evaluate the effect of three biochar powders as a feed additive on the ingestion and digestibility of cavy (Cavia porcellus), a study was conducted at the Animal Production and Nutrition Research Unit (URPRONAN) of the Faculty of Agronomy and Agricultural Sciences (FASA) of the University of Dschang. For these trials, 4 rations were formulated and pelleted containing respectively 0% (control) and 0.8% of organic charcoal powder from cocoa pod husks (CC), cassava peels (EM) and bean tops (FH). 48 female guinea pigs from the first generation of local breed (English) animals weighing on average 450g ± 0.5g and aged about 5 months were used for the evaluation of intake, digestibility, gut weight, gut microorganism level and post-weaning growth. The results showed that, cocoa pod husk and bean hull biochar improved intake of dry matter (29.66 and 29.14 respectively), organic matter (28.14 and 27.65 respectively), crude protein (4.37 and 4.29 respectively) and crude cellulose (5.09 and 5.00 respectively). Biochar improved dry matter digestibility (55.94; 55.56 and 59.59). Bean tops biochar improved digestibility of organic matter (61.16), crude protein (85.18) and crude cellulose (36.89). The small intestine weight of animals fed the biochar (CC, EM, FH) was higher (9.74; 10.12; 9.77) than that of the control ration (8.97). The caecum weight of animals fed with cocoa pod husk charcoal (4.73) or bean husk charcoal (4.35) was higher than that of the control animals (2.88). The cecal weight of control animals was comparable to that of animals fed the ration containing cassava peel biochar (3.16). Compared to the control, the biochar had no effect on colon weight. Incorporating 0.8% of the charcoal into the ration increased the level of gram-positive bacteria (Lactobacilli and Clostridia) in the small intestine of the guinea pigs at the expense of gram-negative bacteria (Enterobacteria). The cassava peel charcoal increased the level of cellulolytic bacteria (Clostridium butyricum: 4.26 CFU / ml) in the cecum and the bean leaf charcoal showed the best balance of intestinal flora between the level of Lactobacilli (3.33 CFU / ml) and Enterobacteria (0.00 CFU / ml) at the end of the test. At 13 weeks of age, the highest average weight of kids was recorded with the ration containing organic bean tops (378.06±20.60g). The highest value of GMQ (2.13±0.38g) and GT (119.75g) was recorded in the batch of animals receiving the FH ration; the lowest value of feed conversion ratio was in the animals receiving the EM ration (1.27). Thus, the incorporation of 0.8% of biochar powder improves the post-weaning growth performance and feed conversion in guinea pigs.