Dietary thymol supplementation promotes skeletal muscle fibre type switch in longissimus dorsi of finishing pigs

Thymol improves the growth performance of blue foxes by regulating the gut microbiota

Introduction

The drawbacks of using antibiotics as feed additives for blue foxes have gradually become apparent; moreover, thymol has wide-spectrum antimicrobial activity and has the potential to replace antibiotics in various animals. However, there are few reports on the effects of thymol on blue foxes.

Methods

This study aimed to investigate the effects of different concentrations of thymol on the growth performance, apparent nutrient digestibility, serum biochemical indicators, intestinal morphology, and gut microbiota of blue foxes. Twenty-four male blue foxes (120 ± 5 d) of similar weight (6.05 ± 0.16 kg) were randomly divided into 4 groups. 0, 100, 200, and 300 mg/kg thymol were added to the basal diets of groups C, L, M, and H, respectively.

Results

Compared with those in the C group, the addition of 100 mg/kg thymol to the diet significantly increased organic matter (OM) digestibility, crude protein (CP) digestibility, immunoglobulin (Ig) A, IgM, the VH of the duodenum, the CD of the jejunum, the VH of the ileum, and the VH/CD of the ileum (P < 0.05) and strongly significantly increased IgG (P < 0.01). The addition of 200 mg/kg thymol to the diet increased the VH/CD of the duodenum (P < 0.05). The addition of 300 mg/kg thymol to the diet significantly increased the VH and CD of the jejunum (P < 0.05). The addition of 200 mg/kg and 300 mg/kg thymol to the diets increased the final weight (FW) (P < 0.05). Adding 100 mg/kg thymol significantly increased the levels of interleukin-4 (IL-4) and catalase (CAT) compared with those in the other groups (P < 0.05). 16S rRNA gene detection revealed that thymol can change the abundances of Bifidobacterium, Fusobacterium, Allobaculum, Streptococcus, Megasphaera, and Lactobacillus in the gut.

Conclusion

The addition of thymol to diets can increase the abundance of Bifidobacterium, Fusobacterium, and Allobaculum, which may contribute to improving the growth performance of blue foxes.

Sow-Offspring Diets Supplemented with Probiotics and Synbiotics Are Associated with Offspring's Growth Performance and Meat Quality

Probiotics and synbiotics supplementation have been shown to play potential roles in animal production. The present study aimed to evaluate the effects of dietary probiotics and synbiotics supplementation to sows during gestation and lactation and to offspring pigs (sow-offspring) on offspring pigs' growth performance and meat quality. Sixty-four healthy Bama mini-pigs were selected and randomly allocated into four groups after mating: the control, antibiotics, probiotics, and synbiotics groups. After weaning, two offspring pigs per litter were selected, and four offspring pigs from two litters were merged into one pen. The offspring pigs were fed a basal diet and the same feed additive according to their corresponding sows, representing the control group (Con group), sow-offspring antibiotics group (S-OA group), sow-offspring probiotics group (S-OP group), and sow-offspring synbiotics group (S-OS group). Eight pigs per group were euthanized and sampled at 65, 95, and 125 d old for further analyses. Our findings showed that probiotics supplementation in sow-offspring diets promoted growth and feed intake of offspring pigs during 95-125 d old. Moreover, sow-offspring diets supplemented with probiotics and synbiotics altered meat quality (meat color, pH_45min, pH_24h, drip loss, cooking yield, and shear force), plasma UN and AMM levels, and gene expressions associated with muscle-fiber types (MyHCI, MyHCIIa, MyHCIIx, and MyHCIIb) and muscle growth and development (Myf5, Myf6, MyoD, and MyoG). This study provides a theoretical basis for the maternal-offspring integration regulation of meat quality by dietary probiotics and synbiotics supplementation.

Effects of dietary supplementation with different levels of palygorskite-based composite on growth performance, antioxidant capacity, and meat quality of broiler chickens

This study was conducted to investigate the effects of different levels of palygorskite-based composite (PBC) on growth performance, antioxidant status, and meat quality of broilers. A total of 320 one-day-old mixed-sex Ross 308 broiler chicks were allocated to 1 of 5 groups with 8 replicates of 8 birds each, and given a basal diet supplemented with 0, 250, 500, 1,000, and 2,000 mg/kg PBC for a 42-day trial, respectively. PBC quadratically increased feed efficiency during the late and overall experimental periods (P < 0.05). Compared with the control group, 1,000 mg/kg PBC increased feed efficiency during the overall period (P < 0.05). PBC linearly increased serum total superoxide dismutase (T-SOD) activity at 21 d and glutathione peroxidase (GSH-Px) activity at both 21 d and 42 d (P < 0.05). Compared with the control group, PBC supplementation, regardless of its level, increased 21-day serum SOD activity (P < 0.05). The 21-day serum GSH-Px activity was increased by PBC when its level exceeded 250 mg/kg (P < 0.05). PBC linearly increased 42-day total antioxidant capacity (T-AOC) activity, but linearly decreased 42-day malondialdehyde level in liver (P < 0.05). An addition of PBC, irrespective of its level, increased 42-day hepatic T-AOC activity (P < 0.05). PBC quadratically increased 45-min yellowness value and linearly increased 24-h pH value, but quadratically decreased 24-h lightness value and linearly and quadratically reduced 24-h drip loss in breast muscle (P < 0.05). Compared with the control group, the 24-h drip loss of breast muscle was decreased by PBC, regardless of its dosage (P < 0.05). An addition of PBC linearly increased 42-day T-AOC and T-SOD activities of breast muscle (P < 0.05). Compared with the control group, muscle T-SOD activity was increased by PBC, regardless of its administration level (P < 0.05). These results suggested that PBC could improve growth performance, antioxidant capacity, and meat quality of broilers, and its recommended dosage is 1,000 mg/kg.

Effect of dietary resveratrol supplementation on muscle fiber types and meat quality in beef cattle

In order to investigate the effect of dietary resveratrol supplementation on muscle fiber types and meat quality in beef cattle, a feeding experiment was undertaken. Longissimus lumborum, Psoas major and Semitendinosus muscles were collected 24 h post-mortem from two groups of cattle, which were fed with a total mixed ration (Control - CON) or supplemented with resveratrol (5 g/animal/day, RES) for 120 d before slaughter. The results showed that dietary resveratrol increased the gene expression of MyHC I and enhanced the proportion of type I fibers in three muscles. The cooking loss and Warner-Bratzler shear force of all muscles during aging for 21 days were decreased. However, the increased proportion of type I fibers resulted in a darker initial color, but did improve color stability, as the a* value of RES samples was lower initially but higher in the later stage of aging. This study indicates the supplementation potential of resveratrol for beef cattle for tenderness and color stability.

Probiotics and Synbiotics Addition to Bama Mini-Pigs' Diet Improve Carcass Traits and Meat Quality by Altering Plasma Metabolites and Related Gene Expression of Offspring

This study evaluated the effects of maternal probiotics and synbiotics addition on several traits and parameters in offspring. A total of 64 Bama mini pigs were randomly allocated into the control (basal diet), antibiotic (50 g/t virginiamycin), probiotics (200 mL/day probiotics), or synbiotics (500 g/t xylo-oligosaccharides and 200 mL/day probiotics) group and fed with experimental diets during pregnancy and lactation. After weaning, two piglets per litter and eight piglets per group were selected and fed with a basal diet. Eight pigs per group were selected for analysis at 65, 95, and 125 days of age. The results showed that the addition of probiotics increased the average daily feed intake of the pigs during the 66- to 95-day-old periods and backfat thickness at 65 and 125 days of age, and that the addition of synbiotics increased backfat thickness and decreased muscle percentage and loin-eye area at 125 days of age. The addition of maternal probiotics increased the cooking yield and pH45min value at 65 and 95 days of age, respectively, the addition of synbiotics increased the meat color at 95 days of age, and the addition of probiotics and synbiotics decreased drip loss and shear force in 65- and 125-day-old pigs, respectively. However, maternal antibiotic addition increased shear force in 125-day-old pigs. Dietary probiotics and synbiotics addition in sows' diets increased several amino acids (AAs), including total AAs, histidine, methionine, asparagine, arginine, and leucine, and decreased glycine, proline, isoleucine, α-aminoadipic acid, α-amino-n-butyric acid, β-alanine, and γ-amino-n-butyric acid in the plasma and longissimus thoracis (LT) muscle of offspring at different stages. In the LT muscle fatty acid (FA) analysis, saturated FA (including C16:0, C17:0, and C20:0) and C18:1n9t contents were lower, and C18:2n6c, C16:1, C20:1, and unsaturated FA contents were higher in the probiotics group. C10:0, C12:0, and C14:0 contents were higher in 65-day-old pigs, and C20:1 and C18:1n9t contents were lower in the synbiotics group in 95- and 125-day-old pigs, respectively. The plasma biochemical analysis revealed that the addition of maternal probiotics and synbiotics decreased plasma cholinesterase, urea nitrogen, and glucose levels in 95-day-old pigs, and that the addition of synbiotics increased plasma high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total cholesterol concentrations in 65-day-old pigs and triglyceride concentration in 125-day-old pigs. The addition of maternal probiotics and synbiotics regulated muscle fiber type, myogenic regulation, and lipid metabolism-related gene expression of LT muscle in offspring. In conclusion, the addition of maternal probiotics and synbiotics improved the piglet feed intake and altered the meat quality parameters, plasma metabolites, and gene expression related to meat quality.