illustrates the frequency distribution of piglet pre-weaning mortality. As can be seen from thefigure, 62.1% of the litters had a piglet pre-weaning mortalityrate of 0–10 and 18.1% of the litters had a piglet pre-weaningmortality rate of 11–20%. Among all the litters, 19.8% hadpiglet pre-weaning mortality greater than 20%. Characteristicsof the litters with a pre-weaning mortality rate of 0–10, 11–20,and > 20% are demonstrated