Dietary Supplementation With Didancao (Elephantopus scaber L.) Improves Meat Quality and Intestinal Development in Jiaji Ducks.

Didancao (Elephantopus scaber L.) has been used as a traditional herbal medicine and has exhibited a beneficial role in animal health. This study aimed to investigate the effects of dietary supplementation with E. scaber on growth performance, meat quality, intestinal morphology, and microbiota composition in ducks. A total of 480 Jiaji ducks (42 days old, male:female ratio = 1:1) were randomly assigned to one of four treatments. There were six replicates per treatment, with 20 ducks per replicate. The ducks in the control group (Con) were fed a basal diet; the three experimental groups were fed a basal diet supplementation with 30 (T1), 80 (T2), and 130 mg/kg (T3) of E. scaber. After a 48-day period of supplementation, growth performance, meat quality, intestinal morphology, and microbiota composition were evaluated. The results showed that no differences were observed in the final body weight, average daily feed intake, and average daily gain among the four groups. Compared with that in the Con group, the feed conversion in the T1 and T2 groups was increased significantly; the T2 group was shown to decrease the concentration of alanine aminotransferase in serum; the T3 group was lower than the Con group in the concentration of aspartate aminotransferase and was higher than the Con group in the concentration of high-density lipoprotein-cholesterol. The highest concentration of creatinine was observed in the T1 group. The T2 group was higher than the Con group in the contents of Phe, Ala, Gly, Glu, Arg, Lys, Tyr, Leu, Ser, Thr, Asp, and total amino acids in the breast muscle. Moreover, the T2 group was higher than the Con group in the contents of meat C18:2n-6 and polyunsaturated fatty acid. The concentration of inosinic acid in the T1, T2, and T3 groups was significantly higher than that in the Con group. However, the Con group was higher than the T2 or T3 group in the Zn content. The T2 group was lower than the Con group in the jejunal crypt depth. The T3 group was higher than the Con group in the ileal villus height and the ratio of villus height to crypt depth. In addition, the T3 group had a trend to significantly increase the abundance of Fusobacteria. Compared with the Con group, the T1 and T2 groups displayed a higher abundance of Subdoligranulum. Collectively, dietary supplementation with 80 mg/kg of E. scaber improves meat quality and intestinal development in ducks.

Using Extract From the Stems and Leaves of Yizhi (Alpiniae oxyphyllae) as Feed Additive Increases Meat Quality and Intestinal Health in Ducks.

Yizhi (Alpiniae Oxyphyllae, A. oxyphylla) has been widely used as an important traditional Chinese medicinal herb for centuries. Existing studies have shown that A. oxyphylla has numerous benefits in human and animal health. We hypothesized that extract from the stems and leaves of A. oxyphylla (AOE) as a feed additive may have positive effects on animal health and products. Thus, this study was conducted to evaluate the effects of AOE as a feed additive on growth performance, serum biochemical parameters, intestinal morphology, microbial composition, and meat quality in Jiaji ducks. A total of 240 Jiaji ducks of 42 days old (1675.8 ± 44.2 g, male: female ratio = 1:1) were blocked based on body weight and randomly allocated into four dietary treatments with three replicates that each had 20 duck individuals. The dietary treatments included: basal diet, control group (CK); basal diet supplementation with 30 mg/kg (Y1), 80 mg/kg (Y2), and 130 mg/kg (Y3) AOE, respectively, and lasted for 49 days. The results showed that average daily feed intake from day 42 to day 60 was decreased with the increasing level of AOE (P < 0.05). Compared with the CK group, the groups with AOE supplementation decreased serum LDL-C level (P < 0.05), the addition of 30 mg/kg AOE increased total amino acids, essential amino acids, branched-chain amino acids, nonessential amino acids, and umami taste amino acids (P < 0.05), but decreased selenium and zinc concentrations in breast muscle (P < 0.05). In addition, the supplementation of 30 or 130 mg/kg AOE significantly increased jejunal villus height (P < 0.05) and tended to increase the ratio of villus height to crypt depth in the jejunum (P = 0.092) compared to the CK group. Moreover, the addition of 30 mg/kg AOE showed a higher abundance of genus unclassified Bacteroidales and genus unclassified Ruminococcaceae than the CK group (P < 0.05). Therefore, dietary supplementation with 30 mg/kg AOE increased meat nutrition profile and flavor through promoting amino acid contents in breast muscle, as well as maintained intestine integrity and modulated the microbial composition. In conclusion, AOE as an antibiotic alternative displayed potential in maintaining intestinal health and improving meat quality.

Fatty Acid Content, Flavor Compounds, and Sensory Quality of Pork Loin as Affected by Dietary Supplementation with l-arginine and Glutamic Acid.

To investigate the effect of functional amino acid on meat flavor and eating quality, 60 growing-finishing pigs (Duroc × Large White × Landrace) were dietarily supplemented with or without 1.0% l-arginine, glutamic acid, or l-arginine plus glutamic acid for 2 months. After animals were slaughtered, the muscle fatty acid profile, flavor compounds, and meat sensory quality were comparatively investigated. The results showed that dietary supplementation with arginine, glutamic acid, or arginine plus glutamic acid had little effect on free amino acids, no effect on 5'-nucleotides and meat sensory taste traits, but supplementation with arginine plus glutamic acid significantly increased (P < 0.05) fat accumulation and fatty acid content in muscle, increased (P < 0.05) the formation of multiple fatty acid oxidation-derived volatile compounds, and improved the tenderness, juiciness, and overall eating quality of meat. This study revealed that dietary supplementation with 1.0% l-arginine and glutamic acid could be used to improve meat eating quality in pork production.

Glutamic acid supplementation reduces body fat weight in finishing pigs when provided solely or in combination with arginine and it is associated with colonic propionate and butyrate concentrations.

Changes in the composition of gut microbiota have been proposed as possible causes of obesity. Our previous study showed that glutamic acid (Glu) alone or a combination of Glu and arginine (Arg) decreased backfat thickness in finishing pigs. Therefore, this study aimed to investigate the effects of dietary supplementation with Glu and/or Arg on body fat weight, composition of gut microbiota, and short-chain fatty acid concentrations in the colons of finishing pigs, and to elucidate whether body fat weight was associated with changes in the colonic microbial community and concentrations of colonic metabolites. Sixty Duroc × Large White × Landrace pigs with an average initial body weight of 77.1 ± 1.3 kg were randomly assigned to one of five treatment groups (12 pigs per group). The pigs in the control group were fed a basal diet (BD group), while those in the experimental groups were fed a basal diet supplemented with either 2.05% l-alanine (Isonitrogenous, IS group), 1.00% l-arginine (Arg group), 1.00% glutamate + 1.44% l-alanine (Glu group), or 1.00% l-arginine + 1.00% glutamate (Arg_Glu group). The results showed that dietary supplementation with alanine has no effect (P > 0.05) on body fat weight, while with both Glu and Arg + Glu decreased (P < 0.05) body fat weight and increased (P < 0.05) colonic concentrations of propionate, butyrate, and valerate relative to the BD group. Negative relationships (P < 0.05) were observed between body fat weight and colonic propionate and butyrate concentrations. Compared to the IS group, dietary supplementation with Arg or Arg + Glu decreased (P < 0.05) colonic tyramine concentration. Compared to the IS group, the butyrate concentration increased (P < 0.05) in the Arg_Glu group. Compared to the BD group, the relative colonic abundance of Actinobacteria was higher (P < 0.05) in the Arg_Glu group. The abundances of Lachnospiraceae_XPB1014_group, norank_f_Erysipelotrichaceae, and Roseburia sp. were negatively (P < 0.05) correlated with body fat weight, and the abundance of norank_f_Erysipelotrichaceae was also negatively (P < 0.05) correlated with colonic butyrate concentration. These findings suggest that decreased body fat weight in finishing pigs can be induced by Glu supplementation alone or in combination with Arg. Glu + Arg supplementation was also associated with increased colonic butyrate and propionate concentrations and increased colonic Actinobacteria abundance.

Leucine alone or in combination with glutamic acid, but not with arginine, increases biceps femoris muscle and alters muscle AA transport and concentrations in fattening pigs.

Forty-eight Duroc × Large White × Landrace pigs with an average initial body weight of 77.09 ± 1.37 kg were used to investigate the effects of combination of leucine (Leu) with arginine (Arg) or glutamic acid (Glu) on muscle growth, free amino acid profiles, expression levels of amino acid transporters and growth-related genes in skeletal muscle. The animals were randomly assigned to one of the four treatment groups (12 pigs/group, castrated male:female = 1:1). The pigs in the control group were fed a basal diet (13% Crude Protein), and those in the experimental groups were fed the basal diet supplemented with 1.00% Leu (L group), 1.00% Leu + 1.00% Arg (LA group) or 1.00% Leu + 1.00% Glu (LG group). The experiment lasted for 60 days. Results showed an increase (p < 0.05) in biceps femoris (BF) muscle weight in the L group and LG group relative to the basal diet group. In longissimus dorsi (LD) muscle, Lys, taurine and total essential amino acid concentration increased in the LG group relative to the basal diet group (p < 0.05). In LG group, Glu and carnosine concentrations increased (p < 0.05) in the BF muscle, when compared to the basal diet group. The Leu and Lys concentrations of BF muscle were lower in the LA group than that in the L group (p < 0.05). A positive association was found between BF muscle weight and Leu concentration (p < 0.05). The LG group presented higher (p < 0.05) mRNA levels of ASCT2, LAT1, PAT2, SANT2 and TAT1 in LD muscle than those in the basal diet group. The mRNA levels of PAT2 and MyoD in BF muscle were upregulated (p < 0.05) in the LG group, compared with those in the basal diet group. In conclusion, Leu alone or in combination with Glu is benefit for biceps femoris muscle growth in fattening pig.