Search Results (7)

Intestinal health is vital for poultry production, and protein plays a key role in intestinal nutrition. The present study used 16S rRNA gene sequencing and serum metabolomics to investigate the effect of CAP on the cecal microflora structure and serum metabolites in 42-day-old broiler chickens. A total of 480 one-day-old Arbor Acres broiler chickens were randomly divided into four treatments with twelve replicates comprising 10 chickens each, evenly divided by sex. The four groups were basal diet group (CAP0), treatment group 1 (CAP2), treatment group 2 (CAP3), and treatment group 3 (CAP4). The broilers in the CAP0 group were fed a basal diet (without CAP), while those in the CAP2, CAP3, and CAP4 groups received diets containing 2%, 3%, and 4% CAP, respectively. Growth performance results showed that dietary CAP supplementation significantly ameliorated the feed conversion rate (FCR) of broilers at 42 days in the CAP3 and CAP4 groups (p < 0.05). Microbial results revealed that CAP did not alter the dominant microorganisms in the cecum at the phylum, family, and genus levels. LEfSe analysis showed significantly higher relative abundances of p_Desulfobacterota, f_Desulfovibrionaceae, and g_Ruminococcus in the CAP3 group compared to the CAP0 and CAP4 groups. Metabolomic analyses indicated that the effect of incorporating CAP into the diet on serum metabolites primarily focused on organic acids and their derivatives, small peptides, amino acid derivatives, and oxidized lipids. The addition of 3% or 4% CAP to the diet can enhance metabolic pathways such as the citrate cycle (TCA cycle) and arginine and proline metabolism. In summary, incorporating CAP into the diet can increase the relative abundance of beneficial bacteria in the cecum and improve the feed conversion efficiency of broilers by enhancing amino acid and energy metabolism. Full article

The type of protein source in diets has many effects on shrimp. In this study, Litopenaeus vannamei with an initial body weight of 3.68 ± 0.002 g were fed for 8 weeks on three experimental diets (isoproteic: 41.00%; isolipidic: 7.61%) that were formulated using fish meal (FM), Chlorella sorokiniana (CHL), and Clostridium autoethanogenum protein (CAP) as the primary protein sources, respectively. This study examined the growth, non-specific immunity, intestinal digestion, and microbiota of L. vannamei after the feeding experiment concluded. Compared to the FM group, the findings indicate that the weight gain rate (WGR), specific growth rate (SGR), and protein efficiency ratio (PER) of L. vannamei were notably enhanced via dietary CAP. The CHL group exhibited the highest levels of catalase (CAT), phenoloxidase (PO), and superoxide dismutase (SOD) activities in the gills of L. vannamei, whereas the FM group had the lowest levels. Conversely, the malondialdehyde (MDA) content showed the opposite trend. Both dietary CHL and CAP promoted the digestive enzyme activities of L. vannamei, with dietary CAP having a more pronounced promotional effect. An analysis of alpha diversity indicated that the consumption of dietary CHL substantially enhanced the abundance and diversity of microbiota in the intestinal tract of L. vannamei. Furthermore, the dietary CHL significantly increased the colonization of immune-associated beneficial bacteria and inhibited the colonization of pathogenic bacteria in the intestinal tract of L. vannamei, whereas dietary CAP mainly increased the colonization of growth-associated beneficial bacteria. Functional predictions showed that different dietary protein sources affect various metabolic activities and signaling pathways of L. vannamei, and some functions, including signal transduction, cell motility, and the immune system, were significantly enhanced in the CHL group. In summary, both dietary CHL and dietary CAP promoted growth and immunity in L. vannamei compared to dietary FM. The results of this study could be helpful for the sustainable development of shrimp farming. Full article

The study aimed to assess the impact of adding chenodeoxycholic acid (CDCA) to the diet of Litopenaeus vannamei on their growth performance, lipid and cholesterol metabolism, and hepatopancreas health while being fed a low fishmeal diet. Five diets were formulated, one of which contained 25% fishmeal (PC); fishmeal was partially replaced with Clostridium autoethanogenum protein in the remaining four diets and supplemented with 0, 0.03, 0.06, and 0.09% CDCA (NC, BA1, BA2, and BA3, respectively). In this study, four replicates of each diet were assigned and each replicate consisted of 30 shrimp with an average weight of (0.25 ± 0.03 g). The shrimp were fed four times a day for a period of 56 days. The results of this study indicate that the inclusion of CDCA in the diet had a positive impact on the growth performance of the shrimp. The final body weight (FBW), weight gain (WG), and specific growth rate (SGR) of the shrimp in the PC group were similar to those in the BA2 group, and significantly higher than those in the other three groups. The survival rate (SR) was similar among all groups. In comparison to the PC group, the low fishmeal groups exhibited a significant decrease in the crude lipid content of the whole shrimp, as well as the Total cholesterol (T-CHOL), Low-density lipoprotein (LDL-C), and High-density lipoprotein (HDL-C) levels in the hemolymph. Regarding the sterol metabolism, the dietary supplementation of CDCA up-regulated the mRNA expression of intracellular cholesterol transporter 1-like (npc1), 7-dehydrocholesterol reductase (7dhcr), Delta (24) sterol reductase (Δ24), HMG-CoA reductase membrane form (hmgcr), and sterol carrier protein 2 (scp). In the lipid metabolism, the mRNA expression of sterol-regulatory element binding protein (srebp) was significantly down-regulated in the shrimp fed the BA1 diet and the expression of AMP-activated protein kinase (ampk) was significantly up-regulated in the shrimp fed the BA1 and BA3 diets compared to the PC group. The mRNA expression of triacylglycerol lipase (tgl) was significantly up-regulated in the shrimp fed the BA2 diet compared to the NC group. Compared with the shrimp fed the PC diets, the dietary supplementation of CDCA significantly down-regulated the protein expression of SREBP1. The lumen damage in the BA1 group was significantly less severe than those in the NC group. The addition of 0.06% CDCA to low fishmeal diets can improve the growth performance, lipid and cholesterol metabolism, and hepatopancreas health of L. vannamei. Full article

In this study, we present data from an eight-week growth trial with pearl gentian grouper fed either a reference diet (FM) with a fishmeal level of 50%, or test diet wherein 15% (CAP15), 30% (CAP30), 45% (CAP45), and 60% (CAP60) fishmeal was replaced by Clostridium autoethanogenum protein meal (CAP). Results showed that the weight gain and daily feed intake ratio of CAP60 were significantly lower than the FM group. In the serum, compared to the FM group, the content of malondialdehyde (MDA), the activities of alanine aminotransferase in CAP60 and CAP45 groups, and acid phosphatase in the CAP60 group were significantly higher, while the content of total cholesterol in CAP60 and CAP45 groups was significantly lower. In the liver, compared to the control group, the content of MDA in the CAP60 group was significantly higher. 3-hydroxy-3-methylglutaryl coenzyme A reductase in CAP30 to CAP60 groups and farnesoid X receptor in CAP60 were significantly upregulated. In distal intestines, the activities of trypsin and superoxide dismutase of CAP30 to CAP60 groups were significantly lower than the FM group. In conclusion, for pearl gentian grouper, CAP could replace up to 45% of the fishmeal in the feed, while a 60% replacement level will affect cholesterol bile acid metabolism and health. Full article

The purpose of this study was to develop the potential of cottonseed protein concentrate (CPC) and Clostridium autoethanogenum protein (CAP) in the diet of rainbow trout (Oncorhynchus mykiss) by evaluating the effects of substituting fishmeal with a CPC and CAP mixture on growth performance, nutrient utilization, serum biochemical indices, intestinal and hepatopancreas histology. In a basal diet containing 200 g/kg fishmeal (Con), the mixture of CPC and CAP (1:1) was used to reduce dietary fishmeal to 150, 100, 50 and 0 g/kg, to form five diets with the same crude protein and crude lipid contents (CON, FM-15, FM-10, FM-5 and FM-0). Then, the five diets were fed to rainbow trout (35.00 ± 0.05 g) for 8 weeks. The weight gain (WG) and feed conversion ratio (FCR) of the five groups were 258.72%, 258.82%, 249.90%, 242.89%, 236.57%, and 1.19, 1.20, 1.24, 1.28, 1.31, respectively. FM-5 and FM-0 groups showed significantly lower WG and higher FCR than the CON group (p < 0.05). In terms of whole-body composition, such as moisture, crude ash, and crude protein, no significant difference was observed among all the groups (p > 0.05), except that significantly higher crude lipid content was detected in the FM-0 group than in the CON group (p < 0.05). In the FM-5 and FM-0 groups, protein efficiency, protein retention, intestinal protease activity and amylase activity were significantly lower than in the CON group (p < 0.05). Compared to the CON group, the serum contents of glucose and total cholesterol in the FM-0 group as well as MDA in the FM-5 and FM-0 groups were significantly increased, and catalase, superoxide dismutase, and total antioxidant capacity were decreased (p < 0.05). In intestine and hepatopancreas histology, the intestinal villus height in the FM-5 and FM-0 groups and villus width in the FM-0 group were decreased significantly (p < 0.05), while no significant difference in hepatopancreas morphology was observed among all the groups except that some vacuolization was observed in the FM-0 group (p > 0.05). In summary, the mixture of CPC and CAP can effectively replace 100 g/kg fishmeal in a diet containing 200 g/kg fishmeal without adverse effects on the growth performance, nutrient utilization, serum biochemical, or intestinal and hepatopancreas histology of rainbow trout. Full article

Clostridium autoethanogenum protein (CAP) is a new single-cell protein explored in aquatic feeds in recent years. This study investigated the dietary effects of CAP replacing fishmeal (FM) on the growth, intestinal histology and flesh metabolism of largemouth bass (Micropterus salmoides). In a basal diet containing 700 g/kg of FM, CAP was used to substitute 0%, 15%, 30%, 45%, 70% and 100% of dietary FM to form six isonitrogenous diets (Con, CAP-15, CAP-30, CAP-45, CAP-70, CAP-100) to feed largemouth bass (80.0 g) for 12 weeks. Only the CAP-100 group showed significantly lower weight gain (WG) and a higher feed conversion ratio (FCR) than the control (p < 0.05). A broken-line analysis based on WG and FCR showed that the suitable replacement of FM with CAP was 67.1–68.0%. The flesh n-3/n-6 polyunsaturated fatty acid, intestinal protease activity, villi width and height in the CAP-100 group were significantly lower than those in the control group (p < 0.05). The Kyoto Encyclopedia of Genes and Genomes analysis showed that the metabolic pathway in flesh was mainly enriched in the “lipid metabolic pathway”, “amino acid metabolism”, “endocrine system” and “carbohydrate metabolism”. In conclusion, CAP could successfully replace 67.1–68.0% of dietary FM, while the complete substitution decreased the growth, damaged the intestinal morphology and down-regulated the lipid metabolites. Full article

This study was conducted to investigate the effects of Clostridiumautoethanogenum protein (CAP) replacement for fish meal (FM) on growth performance, digestive enzyme activity, humoral immunity and liver and intestinal health in large yellow croakers (Larimichthys crocea). Four experimental diets were formulated by replacing FM with CAP at different levels—0% (CAP0), 15% (CAP15), 30% (CAP30) and 45% (CAP45). Triplicate groups of juveniles (initial weight = 11.86 ± 0.13 g) were fed the test diets to apparent satiation two times daily for eight weeks. There was no significant difference in final body weight (FBW), weight gain rate (WG) and feed efficiency (FE) between CAP0 and CAP15. However, compared to the CAP0, CAP30 and CAP45 significantly reduced FBW, WG and LDR (p < 0.05), while CAP45 significantly reduced FE and PDR (p < 0.05). The whole-body moisture was significantly increased by CAP replacement of FM while crude lipid content was decreased (p < 0.05). No significant difference in crude protein, ash and liver crude lipid was observed among all groups (p > 0.05). Compared to CAP0, CAP30 and CAP45 significantly reduced serum C4 concentration (p < 0.05), and CAP45 significantly reduced serum AKP activity (p < 0.05) but significantly increased LZM activity (p < 0.05). Serum C3 concentration was significantly increased by CAP15 (p < 0.05). In terms of intestinal histology, CAP addition significantly increased the thickness of intestinal villus (p < 0.05), and CAP15 and CAP45 significantly increased the thickness of intestinal muscular (p < 0.05). The addition of CAP significantly reduced serum DAO and D-lactate concentrations (p < 0.05), indicating the intestinal physical barrier was improved. The results of 16S rRNA gene sequencing showed that the intestinal microorganisms of large yellow croakers are dominated by organisms from Proteobacteria, Bacteroidetes and Firmicutes. The addition of CAP reduced the relative abundance of Ralstonia and Christensenellaceae and increased the relative abundance of Paenibacillus. Overall, the optimum level of CAP replacement FM in large yellow croakers feed is 15%, which helps to improve humoral immunity and intestinal health with no adverse effects on growth. However, the 30% and 45% substitution levels adversely affect the growth and humoral immunity of large yellow croakers. Full article