Comparative effects of low zinc oxide dose with or without probiotics relative to high zinc oxide dose on the performance, nutrient digestibility, blood metabolites, and noxious gases emission in weaned piglets

The objective of this study was to assess the effects of low-dose zinc oxide (ZnO) supplemented with or without probiotic complex compared with pharmacological ZnO (3000 mg kg(-1)) on the performance, digestibility, blood metabolites, fecal Lactobacillus and enterobacteria counts of weaned piglets. One-hundred and twenty crossbred piglets were randomly allocated to three treatments based on their initial body weight (BW). Treatments consisted of corn - soybean-meal-based basal diet supplemented with 3000 mg kg-1 ZnO as positive control (ZH), basal diet supplemented with 300 mg kg-1 ZnO as negative control (ZL), and ZL + 0.1% probiotic complex (ZLP). At the end of the experiment, fecal samples were collected by direct rectal massage to determine nutrient digestibility, Lactobacillus and enterobacteria counts, and gas emission, whereas blood samples were taken via jugular venipuncture for determination of blood metabolites. The BW of piglets at week 6, and the average daily gain (ADG) at week 6 and during overall period were higher (P < 0.05) in pigs fed ZH diet compared with those fed ZL diet. The supplementation of ZLP increased the ADG during week 6 and overall making it comparable with ZH diet (P < 0.05). However, other parameters described above were comparable with ZH in pigs fed ZLP diet.