Assessing the potential use of a feed additive based on biochar on broilers feeding upon productive performance, pH of digestive organs, cecum fermentation and bacterial community

Abstract

This study was conducted to assess the influence of supplementing broiler diets with a commercial biochar on productive performance, pH of digestive organs, cecum short chain fatty acid (SCFA) profile and bacterial community. 720 one day-old male Ross 308 broilers were fed with the following diets at starter (1–21 days) and grower-finisher period (22–42 days): control diet (0 g/kg of inclusion on diet of biochar, CTR) or 30 g/kg of inclusion of biochar. Regarding performance results, at the starter period animals fed a diet with biochar showed lower daily weight gain (DWG, P = 0.045) and higher feed conversion ratio (FCR, P = 0.034) but similar feed intake (FI, P = 0.928) compared to CTR. At the grower-finisher period, feeding broilers with biochar promoted an increase on DWG (P < 0.001) and a reduction on FCR (P < 0.001) with similar FI (P = 0.579) compared to CTR. For the entire period of feeding, animals fed with biochar showed an increased DWG (P < 0.001), body weight (P < 0.001) and European production efficiency factor (P < 0.001), a reduced FCR (P < 0.001) and a similar FI (P = 0.577) compared to CTR. Regarding digesta pH of digestive organs the pH of digesta of crop (P = 0.834), proventriculus (P = 0.846), gizzard (P = 0.850), ileum (P = 0.750) or cecum (P = 0.467) were not affected by biochar. Animals fed with biochar showed increased acetic (P = 0.011) and caproic (P = 0.003) contents, and similar propionic (P = 0.724), butyric (P = 0.568), isobutyric (P = 0.436), valeric (P = 0.898) and isovaleric (P = 884) contents compared to CTR. Biochar did not influence cecal bacterial species richness and diversity but altered community structure by increasing relative abundance of [Ruminococcus], Ruminococcus, Blautia and undefined genera (family Ruminococcaceae, Lachnospiraceae and Erysipelotrichaceae) and decreasing Lactobacillus, Coprococcus, Desulfotomaculum, Oscillospira, Clostridium (family Clostridiaceae) and undefined genera (families Lachnospiraceae and Ruminococcaceae). In conclusion although the inclusion on diet of 30 g/kg biochar reduced the productive performance during the starter phase, an enhanced growth of animals during the grower-finisher period was observed, resulting in a greater performance and efficiency of production for the entire cycle without affecting the pH of digestive organs and increasing acetate contents in the caecum. The greater performance could be explained by minor microbiota shifts observed at OTU (Operational Taxonomic Unit) level without disturbing the native beneficial intestinal bacteria as expressed by the retained richness and diversity of the broilers caecal microbiota.