PS3-5. Effects of Different Additives Replacing Zinc Oxide on Performance, Fecal Score, and Incidence of Diarrhea in Weaned Piglets

Abstract Zinc oxide (ZnO) at pharmacological doses (1000 to 3500 ppm) controls diarrhea and improves the performance of weaned piglets. However, due to the environmental impact caused by zinc excretion (Zn), this practice has been restricted. Thus, this experiment evaluated the performance, fecal consistency (FC), and incidence of diarrhea (ID) in weaned piglets fed with low levels of Zn as zinc proteinate (ZnProt-Bioplex® Zn), mannan-rich fraction (MRF-Actigen®), and proprietary blend of sodium butyrate, prebiotic components, and minerals (Viligen™ (VIL)), as substitutes for pharmacological ZnO, all provided by Alltech Inc., São Pedro do Ivaí, PR, Brazil. A total of 275 mixed-sex piglets (Landrace × Large White, PIC 337 × DanBred 90), weaned at 21 days of age, were allocated in a CRD with 5 treatments, 11 replicates of 5 animals. The treatments were: T1 – Basal diet (BD) + pharmacological ZnO (3000 ppm and 2000 ppm in phases 1 and 2, respectively) + Zn sulfate (100ppm Zn) in all phases (ZnOF); T2 – BD + ZnProt (100ppm Zn) (ZnProt); T3 – BD + ZnProt (100 ppm Zn) + 800 g/ton MRF (ZnProt+MRF800); T4 – BD + ZnProt (100ppm Zn) + 800 g/ton MRF + 600 g/ton VIL (ZnProt+MRF800+VIL600); and T5 – BD + ZnProt (100ppm Zn) + 800 g/ton MRF + 1200 g/ton VIL (ZnProt+MRF800+VIL1200). Diets were fed in three phases (0–11d; 11–21; 21–42 days post weaning), with ad libitum access to feed and water. The variables evaluated were final body weight (FBW), average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR). During the first 7 days of each phase, individual pig FC was evaluated using the scale: 1 = solid; 2 = semi-solid; 3 = semi-liquid; and 4 = liquid. Diarrhea was defined as scores 3 or 4 for two consecutive days. Data were subjected to ANOVA and means compared using Tukey’s and Dunnett’s tests at a 5% level of significance. Piglets receiving T5 showed higher FBW, ADG, and ADFI during days 0–11, 21–42, and 1–42 (P 0.05), and lower FCR in the initial period compared to T3. Additionally, T5 showed improved performance compared to T1 in FBW, ADG, and ADFI across different phases according to Dunnett’s test. T1 promoted better FC during days 2-8 and 12-18, and lower DI between days 2-8 (P 0.05). During days 12-18, T1 presented the lowest DI; however, T5 presented intermediate DI (Tukey), but superior to T1 by Dunnett's test (P 0.05). Between days 22 and 28, no significant differences were observed. In conclusion, the combination of ZnProt, MRF, and double-dose VIL (ZnProt+MRF800+VIL1200) is a promising alternative to pharmacological ZnO, providing performance benefits and potential mitigation of diarrhea, and should be further evaluated in combination with other strategies.