Comparative study of the effects of high- versus low-dose zinc oxide in the diet with or without probiotic supplementation on weaning pigs' growth performance, nutrient utilization, fecal microbes, noxious gas discharges, and fecal score

Abstract This study was conducted to determine the effects of high- versus low-dose (3000 vs. 300) zinc oxide (ZnO) in combination with or without a probiotic complex (0.1%) on weaned piglet production efficiency, nutrient absorption, fecal bacterial counts, noxious gas emissions, and fecal score. A 42-day experiment included 180 crossbred weaned piglets [Duroc × (Yorkshire × Landrace); 28 days old; 6.61 ± 1.29 kg] and four dietary treatments. An HZ (high ZnO) diet increased body weight at week 6, average daily gain at week 3, week 6, and overall period, and gain-to-feed ratio (G:F) at week 3 compared with an LZ (low ZnO) diet. G:F tended to increase with the LZP (LZ with probiotic) diet compared with the HZP (HZ with probiotic) diet at week 1. Escherichia coli count decreased by HZ diet compared with the LZ diet. In addition, E. coli count decreased and Lactobacillus count increased with the HZP diet compared with the LZP diet. There was no effect of treatment on nutrient digestibility, noxious gas emission, and fecal score. No interactive effect was seen between ZnO and probiotic. Therefore, high-dose ZnO inclusion improved growth performance and probiotic addition improved fecal microbiota, but no synergistic effect was found from ZnO and probiotic complex interaction.