MEKARN Conference 2010
The aim of this study was to evaluate the effect of piglet age and dietary fiber level on the gut environment and the development of intestinal bacteria in local [pured-breed Mong Cai (MC)] and exotic [Landrace x Yorkshire (LY)]. The experiment diets contained maize meal, fish meal, soybean meal, rice bran and cassava meal and were calculated to contain 100 g (low fiber diet) and 200 g (high fiber diet) NDF kg-1 DM. The piglets were killed at the age of 30 days (weaning, 20 days after solid feed introduced) and 60 days (30 days after being given the low and high fiber diets). The digesta contents of the different intestinal segments (ileum, ceacum, colon) were collected to determine pH, organic acids (lactate, acetate, propionate and butyrate) and count for number of bacteria (lactic bacteria and cellulolytic bacteria). As age of animals and fiber level in the diets increased, the population of lactic and cellulolytic bacteria in all intestinal sites increased (p < 0.05), but the population of lactic bacteria in the ceacum was not affected by dietary fiber level (p > 0.05). The age effected on pH, total OA, the molar proportion of individual organic acid in all segments of the intestine (p < 0.05), however the molar proportion of SCFA (of total OA) and propionic (of SCFA) in the ceacum and the molar proportion of acetic acid (of SCFA) in the ileum were not different significant between the ages of 30 days and 60 days (p > 0.05). There was an interaction between age and breed for the molar proportion of acetic acid in the ceacum and colon and the molar proportion of propionic acid in the colon.
The high fiber level resulted in decreased pH and increased content of total organic acids in all segments of the intestine (p < 0.05). Furthermore, the high fiber level resulted in an increased (p <0.05) molar proportion of lactic acids (of total OA) in the ileum, cecum and colon and a decreased molar proportion of acetic acids (of SCFA) in the ileum and ceacum. MC pigs had a higher molar proportion of lactic acids in the ileum and lower molar proportion of lactic acids in the ceacum and colon than LY pigs (p < 0.05), whereas the reverse was true for molar proportion of short chain fatty acids (SCFA) at these site.
In conclusion, the different ages and diets containing different fiber levels resulted in the differences in the development of lactic and cellulolytic bacteria, and pH, lactic acid and short chain fatty acids in the intestinal segments of MC and LY pigs.