Thymol in the intestinal tract of broiler chickens after sustained administration of thyme essential oil in feed.

Plant compounds occurring in phytogenic feed additives are involved in different pharmacological activities in the animal organism. Since the digestive tract acts as a first line of defence against foreign compounds, it is necessary to outline its response to dietary supplementation with bioactive plant components. Little information is available on the bioactivity of thymol as the main bioactive compound of Thymus vulgaris L. essential oil (TEO). The main objective of the present study was to provide a detailed view of the concentrations of thymol in plasma and the content of individual intestinal segments (duodenum, jejunum, ileum, caecum and colon) of broiler chickens after 4 weeks of dietary supplementation with different TEO concentrations. 32 one-day old Ross 308 hybrid broilers were randomly divided into four dietary treatment groups (0.00%, 0.01%, 0.05%, 0.1% w/w of TEO in the diet). Thymol concentrations in the duodenal chyme presented around 7% on average from the thymol amount administered in the feed. A significantly increased thymol amount was observed after 0.1% TEO addition to the diet compared with 0.01% TEO enrichment in the duodenal wall and gut content of jejunum, ileum, caecum and colon (p < 0.05). Thymol levels in the colon were significantly higher than in the ileum and about 1.7 times higher on average than those in the caecum. Significant coefficient of correlation was observed between thymol concentrations in plasma and feed, gut content of all intestinal segments as well as duodenal wall. Our results point to intensive thymol absorption in the initial sections of the digestive tract. In the current study, the role of intestine in biotransformation of thymol was observed, and it would be desirable to investigate whether thymol itself or thymol metabolites are responsible for beneficial effects in intestine.

Identification and quantification of thymol metabolites in plasma, liver and duodenal wall of broiler chickens using UHPLC-ESI-QTOF-MS.

In the present study, we aimed to develop a method for thymol sulfate and thymol glucuronide determination in plasma, liver and duodenal wall of broiler chickens after feeding with a Thymus vulgaris essential oil at the different concentrations (0.01, 0.05 and 0.1% w/w). UHPLC coupled with accurate-mass QTOF-MS was used for identification and quantification of thymol metabolites. Novel Waters Oasis Prime HLB solid-phase extraction cartridges were applied to sample clean-up with extraction recoveries ranged from 85 to 92%. The presence of thymol glucuronide was confirmed by MS software according to molecular formula, score, mass error and double bond equivalent. In terms of validation, calibration curves of thymol sulfate were constructed in matrix samples with linearity from 3.91 to 250.0 ng/mL and correlation coefficients were within the range of 0.9979-0.9995. Limits of detection were 0.97, 0.29 and 0.63 ng/mL and limits of quantification were 3.23, 0.97 and 2.09 ng/mL for plasma, liver and duodenal wall, respectively. Intra-day and inter-day precision expressed as relative standard deviation were <4.35%. To highlight, thymol metabolites were directly detected for the first time in liver and duodenal wall and this method was shown to be successfully applicable for investigation of thymol metabolism in chickens after thyme essential oil ingestion.

Evaluation of a Dietary Grape Extract on Oxidative Status, Intestinal Morphology, Plasma Acute-Phase Proteins and Inflammation Parameters of Weaning Piglets at Various Points of Time.

Reports of the underlying mechanisms of dietary grape extract (GE) in overcoming weaning challenges in piglets have been partly inconsistent. Furthermore, evaluations of the effects of GE at weaning in comparison to those of widely used therapeutic antibiotics have been scarce. To explore the mode of action of GE in selected tissues and plasma, we evaluated gut morphology, antioxidant and inflammation indices. Accordingly, 180 weaning piglets were allocated to three treatment groups: negative control (NC), NC and antibiotic treatment for the first 5 days of the trial (positive control, PC), and NC and GE (entire trial). The villus surface was positively affected by GE and PC on day 27/28 of the trial in the jejunum and on day 55/56 of the trial in the ileum. In the colon, NC tended (p < 0.10) to increase crypt parameters compared to PC on day 55/56. The PC group tended (p < 0.10) to increase catalase activity in the ileum and decrease Cu/Zn-SOD activity in the jejunum, both compared to NC. There were no additional effects on antioxidant measurements of tissue and plasma, tissue gene expression, or plasma acute-phase proteins. In conclusion, GE supplementation beneficially affected the villus surface of the small intestine. However, these changes were not linked to the antioxidant and anti-inflammatory properties of GE.

Potential of Grape Extract in Comparison with Therapeutic Dosage of Antibiotics in Weaning Piglets: Effects on Performance, Digestibility and Microbial Metabolites of the Ileum and Colon.

Enteric diseases in piglets, such as post-weaning diarrhea (PWD), often require antibiotic treatment of the entire litter. Grape polyphenols may help overcome PWD and thereby reduce the need for antibiotics. The potential of a grape extract (GE; continuous in-feed supplementation) on performance of weaning piglets, compared with both negative (NC; corn-based diet) and positive control (PC; NC + in-feed antibiotic (amoxicillin) in a therapeutic dosage for day 1-day 5 post weaning) was assessed. Apparent total tract digestibility (ATTD) and microbial metabolites were also evaluated on two sampling points (day 27/28 and day 55/56). We assigned 180 weaning piglets (6.9 ± 0.1 kg body weight (BW)) to 6 male and 6 female pens per treatment with 5 piglets each. Animals from PC showed higher BW on day 13 compared with NC and GE, and a tendency for higher BW on day 56 (p = 0.080) compared to NC. Furthermore, PC increased the average daily feed intake in the starter phase (day 1-day 13), and the average daily gain in the early grower phase (day 14-day 24). Overall, GE improved the ATTD at the same level as PC (ash, acid-hydrolyzed ether extract), or at a higher level than PC (dry matter, organic matter, gross energy, crude protein, P). There were no effects on microbial metabolites apart from minor trends for lactic acid and ammonia. Dietary inclusion of GE may have beneficial effects compared to therapeutic antibiotics, as frequently used at weaning.