Clostridium autoethanogenum protein inclusion in the diet for broiler: Enhancement of growth performance, lipid metabolism, and gut microbiota

Abstract

This study aimed to investigate the effects of dietary supplementation of the new single-cell protein Clostridium autoethanogenum protein (CAP) on growth performance, plasma biochemical indexes, liver histology, lipid metabolism, and gut microbiota in Cobb broilers. According to the randomized block experimental design, 960 Cobb broilers (1d old) were divided into six treatments with eight replicates of 20 birds each. Six isonitrogenous and isoenergetic diets were formulated with different contents of CAP (0, 1, 2, 3, 4, and 5%) to replace soybean meal (SBM). The results showed that the addition of CAP did not influence liver health when it exceeded 2%. The protein metabolism markers and feed conversion rate increased (P < 0.05), significantly improving the growth performance. When the content of CAP was greater than 4%, it could promote lipolysis without affecting lipogenesis, decreasing the abdominal fat rate. There was no significant difference in MDA between these groups (P = 0.948). The increase of SOD and GSH-Px indicated the enhancement of antioxidant response. Alpha diversity did not significantly differ between groups (P > 0.05). Inclusion of 4% or less CAP led to the increase in beneficial microbiota, the concentration of short-chain fatty acids (SCFAs) such as acetic acid, propionic acid, and butyric acid (P < 0.05), and the concentration of primary bile acids such as cholic acid and goose deoxycholic acid (P < 0.05). While the concentration of secondary bile acids such as taurocholic acid and taurine goose deoxycholic acid was decreased (P < 0.05). These results illustrated that the CAP had a high potential for application in poultry nutrition. In terms of improving growth performance and antioxidant capacity and reducing fat deposition rate, 4% CAP content is recommended.

Dietary supplementation with Clostridium autoethanogenum protein improves growth performance and promotes muscle protein synthesis by activating the mTOR signaling pathway of the broiler

“…Hyperuricemia and gout can be caused by overproduction or reduced excretion of UA (39). Previous study has shown that the inclusion of CAP in diets can increase TP and ALB levels, and UA levels also tend to increase with increasing CAP content (34), which is consistent with the results of the present study. TC and TG are the main lipids in the blood and important indicators of lipid absorption, metabolism, and transport (40,41).…”

“…In the present study, CAP had a significant effect on the lipid metabolism of broilers, as evidenced by the decrease in TG levels. This finding is consistent with the results reported by Wu et al (34) but differs from those observed in aquatic animals (11,27), which may be attributed to species differences.…”

“…However, a high proportion of CAP substitution may lead to a decline in animal production performance (32,33), as well as intestinal and liver damage, and increased mortality (15). Wu et al (34) found that adding the proper amount of CAP in broiler diets improved growth rate and feed conversion efficiency, which is consistent with our findings. Therefore, the function of CAP may be related to the ease of digestion (15,34).…”

“…Wu et al (34) found that adding the proper amount of CAP in broiler diets improved growth rate and feed conversion efficiency, which is consistent with our findings. Therefore, the function of CAP may be related to the ease of digestion (15,34).…”

“…In the present study, including CAP in the diet increased GSH-Px and SOD activities, as well as T-AOC, indicating that the appropriate proportion of CAP can enhance the organism's antioxidant capacity. This finding is consistent with previous studies that have shown CAP's ability to increase antioxidant enzyme activities and improve the organism's antioxidant capacity (30,31,34). Conversely, a high proportion of CAP may impair the organism's antioxidant defense system, leading to oxidative damage (11,17).…”