Effects of the Supplementation of Essential Oil Mixtures on Growth Performance, Nutrient Digestibility, Immune Status and Microbial Community in Weaned Piglets

Abstract

Since essential oils—such as cinnamaldehyde, thymol, carvacrol, and eugenol—have antibacterial, antioxidant, and anti-inflammatory properties, this study aimed to examine the supplementation of different essential oil mixtures together with 1600 mg/kg zinc oxide (ZnO) on growth performance, incidence of diarrhea, serum immune indices, fecal volatile fatty acids, and microflora structure in weaned piglets. A total of 240 weaned piglets (Duroc × Landrace × Yorkshire) with an average body weight of 8.85 ± 0.21 kg were randomly allocated to 30 pens (6 pens per diet, 4 males and 4 females per pen). Five different experimental diets were prepared and administered for 28 days: (i) a control diet (C), a corn–soybean basal diet without antibiotics, ZnO, or a supplementation of growth promoters; (ii) a control diet with 400 mg/kg essential oil mixtures 1 (EOM1); (iii) a control diet supplemented with ZnO at 1600 mg/kg (Z); (iv) a diet incorporating the Z diet with the addition of essential oil mixtures 1 at 400 mg/kg (ZOM1); and (v) a diet incorporating the Z diet with the addition of essential oil mixtures 2 at 400 mg/kg (ZOM2). During day (d) 14–28 and d 1–28 of the experiment, the average daily gain (ADG) in piglets in the ZOM1 and ZOM2 groups were higher (p p p p p p = 0.05) acetate concentration in feces on d 14. Principal co-ordinates analysis (PCoA) showed significant differences (p p Prevotella (p < 0.1). Therefore, EOM1 combined with 1600 mg/kg ZnO tends to reduce diarrhea incidence, tends to improve the fecal microbial community structure and growth performance of weaned piglets, and has the potential to replace pharmacological dosages of ZnO.

Keywords

• essential oil
• zinc oxide
• fecal microbial communities
• weaning piglets