2.1 Experimental design and feeding management
A total of 27 Bamei pigs with similar weights (21 kg ± 0.15 kg) and good levels of health were selected and randomly divided into three treatments at the Gansu Provincial Farming and Animal Husbandry Breeding Farm, Jingtai County, Gansu Province, China. Three replicates per treatment were carried out with three pigs per replicate (Table 1). The test period used spanned June 24, 2019, to November 20, 2019, encompassing a pre-trial period of seven days and a normal trial period of 150 days. The pig house was thoroughly cleaned before the test and disinfected. Throughout the test period, pigs were immunized at the times specified by the farm and were able to freely drink water and eat. The management conditions for each group were the same; disinfection was carried out every Friday and the pig house was cleaned at 09:00 and 16:00 each day.
Table 1 Dietary protein level