A botanicals-based microencapsulated feed additive protects weaning piglets during a challenge with Escherichia coli LPS

     

At weaning, pigs develop significant stress with long-lasting effects on their performance and health. Botanicals include a wide variety of bioactive molecules able to control inflammation and oxidation. The aim of the study was to investigate the ability of a microencapsulated thymol-based blend of botanicals (BOT) to support piglets’ performance and health during an LPS inflammatory challenge. To examine this, 72 weaning pigs were divided in 24 pens and assigned to 3 experimental groups: a negative control (CTR−), a positive control (CTR+), and a group treated with BOT (BOT+). After 14 d, CTR+ and BOT+ received the inflammatory challenge, consisting of two 30-µg/ kg BW intraperitoneal Escherichia coli O55:B5 LPS injections, 48 h apart. One pig per pen was then sacrificed on d 21, and all the remaining on d 28, to collect samples for gene expression analysis. In the challenge week (d 14–21), BOT significantly improved BW (P = 0.02) and ADG (P = 0.04) compared with CTR+, with trends confirmed also for the final week (d 21–28) and across the last 2 weeks (d 14–28). BOT also increased ADG in the first 3 weeks of the study (P = 0.04). Moreover, during d 14–21 and 14–28, FCR was deeply impaired in CTR+ (+0.36 and +0.24 points vs. CTR−, respectively), but BOT re-established values in line with CTR− (P ≤ 0.05). In the overall period, ADG and final BW tended to be increased by BOT at levels closer to CTR− (P = 0.09), with numerical improvements also for FCR. Gene expression analysis in liver showed that BOT lowered the inflammatory activation caused by the challenge at d 21 and 28, with reductions in TLR4, TNFα, and IL-6 (P < 0.05). Moreover, BOT modulated the expression of several antioxidant enzymes, such as GPX2, SOD1, SOD2, and CAT. To conclude, BOT helped weaning piglets to face an inflammatory challenge improving performance parameters and overall health. Its mechanism of action counteracted stress by controlling inflammation and enhancing the oxidative response. BOT can be proposed as a nutritional supplement to support pigs at weaning.

Key Words: Botanicals, inflammation, oxidative stress, liver, piglets.