Effects of Supplemental Phytoncide Instead of Zinc Oxide on Growth Performance, Apparent Nutrient Digestibility, Blood Profiles and Fecal Microflora in Growing Pigs

Zinc oxide as growth promoters and an antidiarrhea drug was widely used in the pig industry. However, the excessive excretion of zinc in the pig’s manure cause environmental problems. This study aimed to evaluate the effect of phytoncide (terpene), Korean pine extract as phytogenic feed additive (PFA), instead of zinc oxide on growth performance, apparent nutrient digestibility, blood Profiles and fecal microflora in growing-finishing pigs. A total of 120 grower pigs [(Landrace x Yorkshire) x Duroc] with an average initial body weight (BW) of 24.48 ± 1.62 kg. Dietary treatments: positive control (PC, basal diet + 0.3% Zinc oxide) and basal diet + 0, 0.5% or 1.0% phytoncide. The data were analyzed using the GLM procedure of SAS (SAS Institute, 1996) as a randomized complete block design. Pen served as the experimental unit. Linear and quadratic polynomial contrasts were used to examine effect of dietary treatment (without zinc oxide supplement: 0, 0.5% and 1% of phytoncide in the basal diet). Variability in the data will be expressed as the standard error of means (SEM) and P<0.05 was considered to be statistically significant. Results indicated that during 1-3 weeks, 3-6 weeks, and overall phase, compared with basal diet treatment, the ADG of growing pigs tended to be increased in phytoncide treatment and was significantly increased in PC treatment (p<0.05). During 3-6 weeks, and overall phase, pigs fed the PC diet showed improvement in average daily feed intake, compared with basal diet treatment as trend. The pigs received phytoncide diet significantly (P=0.027) increased the digestibility of DM compared with basal diet. The concentration of aspartate transaminase (AST) was reduced (P=0.047) in pigs receiving 1.0% phytoncide diet (32 U/L), compared with basal diet (40 U/L) at week 3. Meanwhile, the growth performance, digestibility of nutrients, and Lactobacillus and E.coli of pigs received phytoncide diet have no significantly change compared with PC diet. Otherwise, no difference was observed in fecal microflora among treatment (P＞0.05). Conclusion that the pigs fed 0.3% phytoncide diet could increase the digestibility of nutrition and reduce the risk of liver damage in growing pigs. All those suggests that phytoncide may be used as an environmentally friendly factors treatment instead of zinc oxide without excreting excessive zinc.