Mong Cai pigs had shorter villi, smaller villus width and
greater crypt density in the ileum than LY pigs [41].
These differences in gut morphology can be explained
by differences in digesta transit time and gut microbial
activity [42]. A major part of the digested nutrients are
absorbed in the proximal small intestine. This together
with a rapid digesta passage and low microbial activity,
results in less exposure to digesta components compared
with the situation in the more distal small intestine. The
MC pigs had a longer total tract mean retention time of
solids than the LY pigs [37] allowing for longer contact
between digestion products and absorptive surfaces [32].
Based on existing data, it appears reasonable to assume
that different breeds can have different digestive capacity
and will as a result show different response to the same diets
in terms of nutrient utilization and performance.