Effect of drinking a metabiotic feed additive on the growth of calves

The administration of the investigated metabiotic feed additive to calves demonstrated a positive impact on growth performance. The inclusion of this additive into the diet, which comprised culture fluids with metabolites from Bacillus pumilus B-13250 and Kluyveromyces lactis in a 50:50 ratio, resulted in a statistically significant increase in the live weight of the experimental group compared to the control group. By the end of the first month, the experimental calves were heavier by 4.5 kg (7.2 %, p < 0.05). This difference increased to 7.6 kg (9.3 %, p < 0.05) at the end of the second month and reached 15.2 kg (14.7 %, p < 0.001) by three months of age. The average daily gain (ADG) during the initial application period (0–1 month) was significantly higher in the experimental group by 123.8 g (20.3 %, p < 0.01). From the first to the second month, the ADG remained significantly elevated by 100.0 g (16.2 %, p < 0.01), and between the second and third months, the ADG in the experimental group was 995.2 g, which exceeded the control by 257.1 g (34.8 %, p < 0.001). Furthermore, the calf survival rate was 100 % in the experimental group, compared to 90 % in the control group. The specific metabolite ratio from B. pumilus and K. lactis also positively modulated the gut microbiota in the large intestine, leading to a 6.7 % increase in mesophilic aerobic and facultative anaerobic microorganisms, a 93.5 % rise in lactic acid bacteria, alongside a 52.2 % reduction in coliform bacteria and a 16.7 % decrease in microscopic fungi.