Probiotic, paraprobiotic, and hydrolyzed yeast mixture supplementation has comparable effects to zinc oxide in improving growth performance and nutrient digestibility in weaned piglets

Abstract A total of 150 21-day-old weaned piglets [(Yorkshire × Landrace) × Duroc] were randomly assigned to 3 groups based on average initial body weight (6.96 ± 0.21 kg) to evaluate the effects of dietary supplementation of probiotic, paraprobiotic, and hydrolyzed yeast mixture (PPY) on growth performance, nutrient digestibility, fecal bacteria counts, fecal calprotectin contents, and diarrhea rate in a 42-day experiment (phase 1: days 1-14; phase 2: days 15-42). There were 10 replicate pens per treatment with 5 pigs per pen (three gilts and two barrows). The experimental diets were a basal diet, without additive (CON), a basal diet supplemented with pharmacological levels of zinc oxide (ZnO; TRT1), and an experimental treatment including PPY (TRT2). Pigs in TRT1 were provided with a basal diet + 3000 mg/kg (as fed) ZnO during phase 1, and a basal diet during phase 2. Pigs in TRT2 were provided with a basal diet + 200 mg/kg (as fed) probiotic for a final concentration of 2 × 109 colony forming units (CFU)/kg diet + 800 mg/kg (as fed) paraprobiotic + 10 g/kg (as fed) hydrolyzed yeast mixture during phase 1, and a basal diet +100 mg/kg (as fed) probiotic + 400 mg/kg (as fed) paraprobiotic mixture during phase 2. Pigs in TRT1 and TRT2 tended to be heavier at day 14 and were significantly heavier at day 42 than CON pigs. Growth rate during days 1-14, 15-42, and 1-42 was similarly affected by treatment while feed efficiency was unaffected by treatment in the first 14 days but was significantly higher for TRT 1 pigs between 15-42 and 1-42 days with TRT2 being intermediate. Apparent nitrogen and energy digestibility were both significantly higher for pigs on TRT1 and TRT2 compared with the CON. There were no significant differences in any parameters measured between TRT1 and TRT2. Therefore, we demonstrated that PPY supplementation had comparable effects as ZnO on nutrient digestibility and the performance of weaned piglets.