This study was to investigate the effects of dietary supplementation with putrescine on the growth performance and meat quality of chickens. A total of 480 eighty-day-old female Wenchang chickens were randomly assigned into four groups, with 8 replications per group and 15 animals per replicate. The chickens in the control group (Con) were fed a basal diet; the 3 experimental groups were fed a basal diet with 0.01%, 0.03%, and 0.05% putrescine, respectively. The experiment lasted for 40 days. The results showed that dietary supplementation with 0.05% putrescine increased (p < 0.05) the final body weight and average daily weight gain, and decreased the ratio of feed intake to the body weight gain of Wenchang chickens. Dietary supplementation with putrescine decreased the concentrations of putrescine, spermidine, and spermine in serum (p < 0.05). The contents of methionine, phenylalanine, lysine, aspartic acid, tyrosine, total essential amino acids, and total amino acids in breast muscle were higher (p < 0.05) in 0.03% and 0.05% groups than those in Con group. However, the contents of undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, arachidic acid, docosanoic acid, tricosanic acid, lignoceric acid, erucic acid, cis-11,14,17-eicosatrienoate, linoleic acid, and total n-6 monounsaturated fatty acids in breast muscle were lower (p < 0.05) in 0.03% and 0.05% groups than those in Con group. In addition, putrescine supplementation decreased (p < 0.05) the ratio of n-6/n-3 polyunsaturated fatty acids in breast meat. Overall, dietary supplementation with 0.05% putrescine enhanced the growth performance and meat quality of Wenchang chickens.

The polysaccharide of Millettia speciosa Champ. ex Benth (MSCP) has antioxidant properties, but its impact on chicken growth and development is not yet known. This study used chlortetracycline as a control to assess MCSP as a feed antibiotic substitute and its effects on Wenchang chicken production, slaughter performance, and meat quality. A total of 576 healthy 80-day-old Wenchang chickens were randomly allocated to six experimental groups. The control group (Control) received a basal diet, while the antibiotic group (CTC) was supplemented with 2 g/kg chlortetracycline (CTC). Four additional experimental groups were administered varying doses of MSCP: 400 mg/kg (MSCP₄₀₀), 800 mg/kg (MSCP₈₀₀), 1600 mg/kg (MSCP₁₆₀₀), and 3200 mg/kg (MSCP₃₂₀₀), respectively. The study discovered that incorporating MSCP and CTC into chicken diets significantly boosted the final body weight and average daily feed intake compared to the control group (p < 0.01), with MSCP notably enhancing average daily weight gain. With the addition of 800 mg/kg MSCP, chicken growth performance is comparable to that achieved with antibiotics in feed. However, it did not impact slaughtering performance (p > 0.05). In addition, MSCP significantly raised the pH after 24 h (p < 0.05) and decreased the yellowness (p < 0.01) of breast muscle. MSCP increased the essential amino acids (EAA) proportion in breast muscle (p < 0.05), EAA to nonessential amino acids (NEAA) ratio (p < 0.05), and diversity of fatty acids while decreasing C20:0 and increasing C18:2N6 and C22:1N9 content. Moreover, MSCP significantly reduced muscle fiber size (p < 0.01), increased fiber density (p < 0.01), boosted MYOD1 expression (p < 0.05), and decreased MSTN expression in breast muscle (p < 0.01). Overall, our study showed that supplementing the diet with MSCP, particularly at a dose of 800 mg/kg, enhanced growth, meat quality, muscle morphology, amino acid content, fatty acid composition, and gene expression related to muscle development in breast muscle. The results indicate that MSCP is a feed additive with the potential to replace antibiotics and improve meat quality, showing promising application potential.

This experiment aimed to study the effects of adding Morinda officinalis polysaccharide (MOP) on the growth, carcass performance and meat quality of Wenchang chickens. A total of 480 eighty-one-day-old Wenchang chickens were randomly allocated into five groups using a completely randomized design, with eight replicates per group (n = 8 per treatment). The control group received a basal diet (CON group), while the experimental group was given a diet with 500, 1000, 2000, and 4000 mg/kg MOP supplements. During the 40 day trial, MOP supplementation did not affect the growth and carcass performance (p > 0.05), but it increased the a* value of breast muscles compared to the CON group. The breast and thigh muscles in the MOP group had significantly lower shear force than those in the CON group (p < 0.05). The MOP groups significantly decreased the muscle fibers’ cross-sectional area and diameter in the breast and thigh muscles of Wenchang chickens compared to the CON group (p < 0.05). The MOP₅₀₀ group notably raised the total number of essential amino acids and total amino acid levels in Wenchang chickens, whereas the MOP₁₀₀₀ group significantly lowered the total SFA concentration (p < 0.05). Collectively, MOP enhances Wenchang chickens’ meat quality, with optimal results at 1000 mg/kg.

The purpose of this study was to investigate the effects of dietary supplementation with copra meal on growth performance, meat quality, and intestinal development in Wenchang chickens. A total of 480 healthy, 80-day-old female Wenchang chickens were randomly allocated to 4 groups, each with 6 replicates of 20 birds. The chickens in the control group (Con) received a basal diet, whereas the 3 experimental groups were fed the basal diet supplemented with 1.5%, 3.0%, or 6.0% copra meal for 40 days. The results indicated that the 1.5% group exhibited higher average daily gain (ADG) and lower feed-to-gain ratio (F/G) compared with the Con group. Additionally, dietary supplementation with 1.5%, 3.0%, or 6.0% copra meal reduced drip loss in both thigh and breast muscles. In the 1.5%, 3.0% and 6.0% group, the contents of C14:0 were significantly induced, and C14:1 were significantly increased in thigh muscle, compared with the Con group. Moreover, the 6.0% group demonstrated significantly greater villus height and villus-height-to-crypt-depth ratio in the jejunum, along with higher levels of propionic and butyric acids in the ileum. At the genus level, Turicibacter abundance was significantly lower in the 6.0% group, whereas Bacteroides and Barnesiella were significantly higher. These findings suggest that dietary supplementation with 6.0% copra meal reduces F/G and enhances meat quality and intestinal development in Wenchang chickens.

The genus Mallotus oblongifolius (MO), a member of the Euphorbia family, exhibits a predominant distribution in Hainan Island and has been proven to possess diverse medicinal attributes. Research indicates that ultramicro-grinding fully exposes the active ingredients of Mallotus oblongifolius, enhancing bioavailability and efficacy, compared to before. Our study investigates the effects of ultrafine powder of Mallotus oblongifolius (MOUP) on Hainan pigs. A total of sixty-four healthy castrated pigs (ternary hybrid pigs, Duroc × Duroc × Tunchang) with comparable initial body weight (BW, 68.06 ± 1.03 kg, 150 days old) were allocated randomly into four groups: the control group (CONT), the antibiotic group (ANTI), the 0.1% MOUP group (PT1), and the 0.5% MOUP group (PT2). There were four replicate pens per treatment with four pigs per pen. The pre-test lasted for 7 days and the formal test lasted for 70 days. The CONT group was fed the basal diet, the ANTI group was fed the basal diet supplemented with 300 mg/kg colistin sulfate, the PT1 group was fed the basal diet supplemented with 0.1% MOUP, and the PT2 group was fed the basal diet supplemented with 0.5% MOUP. The findings of our study indicate that the inclusion of colistin sulfate and MOUP in the diet did not have any significant impact on the production performance or carcass indicators of Hainan pigs compared to the CONT group. However, it is noteworthy that the addition of MOUP to the diet resulted in a significant improvement in the lightness, tenderness, muscle fiber morphology, amino acid composition, and antioxidant activity of the longissimus dorsi muscle, particularly in the PT2 group, compared to the CONT group. In conclusion, the present study has demonstrated that the inclusion of MOUP in the dietary regimen yields enhancements in the meat quality of Hainan pigs, particularly when supplemented at a concentration of 0.5%.

Heat stress adversely affects meat quality and antioxidant status in poultry, and nutritional interventions may help mitigate these effects. This study investigated the effects of dietary DL-methionine supplementation on meat quality, antioxidant capacity, and potential involvement of the Keap1–Nrf2–ARE signaling pathway in heat-stressed Wenchang chickens. A total of 480 healthy 81-day-old chickens were randomly assigned to four dietary treatments supplemented with 0.00%, 0.10%, 0.20%, or 0.40% DL-methionine and subjected to chronic heat stress conditions for 46 days. Dietary DL-methionine supplementation significantly affected meat quality and antioxidant status (p < 0.05). Compared with the other groups, supplementation with 0.20% DL-methionine resulted in increased cooked yield and reduced drip loss in both breast and thigh muscles. It also improved meat nutritional quality by increasing crude protein content, flavor-related amino acids, and polyunsaturated fatty acid proportions while decreasing saturated fatty acid levels. Furthermore, 0.20% DL-methionine increased the activities of superoxide dismutase, catalase, and glutathione peroxidase and reduced malondialdehyde content in breast muscle (p < 0.05). These changes were accompanied by altered expression of genes associated with the Keap1–Nrf2–ARE signaling pathway. Overall, dietary supplementation with 0.20% DL-methionine effectively improved meat quality and antioxidant capacity in Wenchang chickens under chronic heat stress conditions, whereas excessive supplementation (0.40%) showed less favorable effects.