Effect of enzyme supplementation and acidification of diets on nutrient digestibility and growth performance of broiler chicks

Abstract

Two experiments were conducted to examine the effects of alpha-galactosidase supplementation and acidification of diets on nutrient digestibility and growth performance of broiler chicks. In experiment 1, dietary treatments consisted of feeding a low-energy basal diet (2.74 Mcal of ME/kg) alone, the basal diet supplemented with 1,724 units of alpha-galactosidase per kg, the basal diet supplemented with 2% citric acid, or the basal diet supplemented with both. alpha-Galactosidase significantly increased feed intake, weight gain, AME(n) of the diets, and retention of CP and neutral detergent fiber (NDF) (P < 0.05). Citric acid significantly increased the retention of DM, CP, and NDF, but decreased feed intake and weight gain. The greatest values for DM and NDF retention and for AME(n) were obtained with the combination of alpha-galactosidase plus citric acid. In experiment 2, chicks were fed diets with 2 levels of energy (2.74 or 3.11 Mcal/kg), 2 levels of citric acid (0 or 1.5%), and 2 levels of alpha-galactosidase (0 or 1,724 units/kg) in a 2 x 2 x 2 factorial arrangement of treatments. alpha-Galactosidase significantly increased the reducing sugar concentration in the crop content, whereas citric acid decreased the pH and increased the reducing sugar concentration in the crop content. Citric acid decreased the gain to feed ratio in the absence but not in the presence of alpha-galactosidase. The data from these studies indicate that acidification of diet improves the efficacy of alpha-galactosidase.

Phytogenic additives and organic acids in broiler chicken diets

“…These results corroborate the studies of Pirgozliev et al (2008), who observed AMEn improvement in young broilers fed diets supplemented with fumaric acid and sorbic acid, and also corroborate studies conducted by Ao et al (2009), in which citric acid increased the metabolizable dry matter and crude protein. However, Hernández et al (2006) observed no differences in the metabolization of total and ileal dry matter and crude protein in the 16 to 21 day-old period in broilers fed two levels of formic acid.…”

“…The broilers fed diets supplemented with organic acids and not supplemented with PA had higher GEMC, DMMC, NMC and EEMC values (P<0.05), in comparison with those fed diets without the additives, partially corroborating Ao et al (2009), who found that citric acid increased dry matter and crude protein metabolizability. However, when the birds were fed a combination of phytogenic additives and organic acids, they had lower NMC in comparison with those without organic acids supplementation and with PA supplementation.…”

“…Another alternative to APE are organic acids (OA), which have shown positive results in poultry production, for reducing the intestinal pH and bacterial growth intolerant to pH changes (Pirgozliev et al, 2008;Ao et al, 2009), thus providing better intestinal health for the bird to obtain maximum nutrient absorption. Additionally, undissociated organic acids can penetrate the lipid membrane of the bacterial cell and decrease intracellular pH, which leads to death (Ricke, 2003), in addition to stimulating pancreatic secretion and providing better intestinal villus integrity (Dibner & Buttin, 2002).…”

Using Exogenous Enzymes to Increase the Nutritional Value of Soybean Meal in Poultry Diet

“…The results indicated that the TME n of low oligosaccharide soybean meal was significantly higher than that of conventional soybean meals. Ao et al (2009) reported a significant increase of AME n of corn-soybean meal diet by dietary supplementinggalactosidase. However, Irish et al (1995) removed up to 90% oligosaccharides from soybean meal using either ethanol extraction or exogenous -galactosidase.…”

“…In other studies, they added enzymes in broiler diets and fed broilers for 21 d. Increases in chick growth rate and digestibility that were similar to those recorded in previous study were obtained when protease and -galactosidase were included in the diets. Ao et al (2009) did two trials to investigate the effects of -galactosidase supplementation and acidification of diets on nutrient digestibility and growth performance of broiler chicks fed corn-soybean meal diet. The data showed that dietary supplementation of -galactosidase significantly increased feed intake and weight gain of broiler chicks, which was further approved by increased AME n of the diets and digestibility of CP and NDF.…”