Abstract: This study aimed to investigate the application effects of compound probiotic fermentation liquid in pig production, focusing on its impacts on growth performance and environmental improvement. In trial 1, 110 pigs were randomly divided into control and experimental groups. The experimental group received drinking water supplemented with 2% compound probiotic fermentation liquid. The results showed that the average daily weight gain of pigs in the test group increased by 7.68% (P<0.01) and the feed-to-meat ratio decreased by 7.89% (P<0.01) compared with that of the control group, indicating that the composite probiotic fermentation bacterial solution significantly enhanced the growth performance of fattening pigs. A total of 4 080 pigs were selected from six units in trial 2, with 2 040 pigs in the control and test groups, respectively. The experimental group was provided with drinking water supplemented with 2% of a composite probiotic fermentation liquid, while the control group received normal drinking water. The results showed that the ammonia concentration in the experimental group decreased by 35% (P<0.01) compared to the control group, indicating that the compound probiotic fermentation liquid effectively improved air quality. The aim of this experiment was to study the effects of adding compound probiotic fermentation liquid to the drinking water of pigs on the growth performance of pigs and the concentration of ammonia in the house, with a view to providing data support for the application of probiotic complexes in animal husbandry, improving the efficiency of farming, and decreasing the negative impacts of pig farming on the environment.

Key words: pig, compound probiotic, fermentation liquid, growth performance, ammonia concentration