The study was conducted to investigate the effects of graded dietary inclusion levels
of betaine on ileal and total tract nutrient digestibilities and intestinal bacterial fermentation
characteristics in piglets. A total of 8 barrows (BW 7.9 kg) was fitted with simple T-cannulas at the
distal ileum. The animals were randomly allocated to 1 of the 4 assay diets with 2 pigs per treatment in
4 repeated measurement periods. The assay diets included a basal diet based on wheat, barley and
soybean meal alone, or supplemented with a liquid betaine product at dietary levels of 1.5, 3.0, or 6.0
g betaine kg–1
diet (as–fed). Ileal digestibilities of dry matter (DM) and neutral detergent fiber (NDF)
increased both quadratically and linearly (P<0.05), and ileal digestibility of glycine increased linearly
as dietary betaine level increased (P<0.05). Moreover, there were linear increases in the concentrations
of ileal D–lactic acid (P<0.05), indicating intensified intestinal bacterial activities as dietary betaine
level increased. At the fecal level, total tract crude protein (CP) digestibility increased quadratically
(P<0.05), and digestibility of amino acids (AA) tended to increase quadratically (P=0.06 to P=0.11),
except for proline (P>0.05), as dietary betaine level increased. The increased bacterial degradation of
CP and AA in the large intestine coincides with the linear increase (P<0.05) in fecal diaminopimelic
acid concentrations, indicating enhanced intestinal bacterial growth with increasing dietary betaine
levels. In most cases, there was a response in the variables that were measured up to 3.0 g betaine per
kg diet, whereas increasing the betaine level from 3.0 to 6.0 g betaine per kg diet had no additional
effect. It can be concluded that dietary betaine stimulates microbial fermentation of fiber in the small
intestine, leaving less fermentable fiber to reach the large intestine and therefore, increased microbial
degradation of protein in the large intestine may occur.
Keywords: piglets, betaine, digestibility, bacterial fermentation, microflor