Augustine et al.
(1997) reported that betaine caused a significant reduction
in intestinal intracellular invasion by E. tenella
or E. acervulina sporozoites as compared with control
chicks. As for the methyl donor function of betaine, it
is believed that damaged tissues require more methyl
groups than healthy tissues (Chiang et al., 1996). Klasing
et al. (2002) concluded that increased chemotaxis
of monocytes and nitrous oxide release by macrophages
may explain the improved intestinal pathology when
betaine was fed during the coccidia challenge.
The orthogonal polynomial contrasts showed linear
reductions in the digestibility of fat, mean AA, and
starch with increasing total lesion scores. Of these nutrients,
fat digestibility was found to be the most influenced
by the intestinal damage. For each unit increase
in total lesion score, digestibility of fat was reduced by
16% compared to mean AA and starch, which were reduced
by 3.8 and 3.4, respectively.
In conclusion, our results support previous findings
that supplementation with natural betaine reduced the
impact of coccidia challenge on intestinal lesion scores
and positively affected nutrient digestibility and feed
efficiency in broilers. Increasing intestinal lesion scores
were associated with reductions in nutrient digestibility.