Nutritional implications of pectins in chicks in relation to esterification and origin of pectins

An experiment was conducted to examine the effect of feeding high-methylated (HM) and low-methylated (LM) pectin on performance and physiological characteristics in broiler chicks. Two levels each (1.5 and 3%) of HM citrus pectin (HMC), LM citrus pectin (LMC), or HM sugar beet pectin (HMS) were added to a semi-purified basal diet. The experiment was conducted in battery brooders, and chicks received the diets as pellets from 6 to 27 d of age. The inclusion of LMC or HMS in the diet had little or no effect on the performance of chicks; however, when HMC was added to the diet growth and feed utilization were reduced significantly (P < 0.05). Water intake and water:feed ratio were increased (P < 0.05) after inclusion of all three pectin products in the diet. The effect on water consumption was more pronounced in the HMC-containing diets than in the LMC or HMS diets, and was dose-dependent. In vitro viscosity was increased significantly by incorporating HMC or LMC into the diet, whereas HMS had no effect on this parameter. Waterholding capacity of the diets and the excreta were increased significantly by including one (P < 0.05) of the three pectin products in the diet. The concentration of some of volatile fatty acids (VFA) in the cecal chyme was markedly decreased (P < 0.05) by feeding HMC, whereas LMC had no effect (P > 0.05) on the concentration of VFA. In contrast, inclusion of HMS in the diet significantly increased the concentration of VFA in the cecal content (P < 0.05) dose-dependently. Based on the results of the present study, it can be concluded that the effect of dietary pectin on chick performance is dependent on the degree of carboxyl groups that is esterified, the origin of the pectin product, and the amount added to the diet.