The energy sparing effect of guanidinoacetic acid alone or in conjunction with exogenous enzymes in broiler diets

Abstract

Feed is the most expensive input in poultry production systems accounting for approximately 70% of the total production costs, with maize and soybean meals contributing the bulk of raw material ingredients used and influence the costs of broiler feed. The aim of this study was to evaluate whether guanidinoacetic acid (GAA) would provide a metabolic compensation to reduced dietary apparent metabolisable energy (AME) by acting as a backup to adenosine triphosphate (ATP) shortage and if such compensation will have a synergistic effect in the presence of nonstarch polysaccharide degrading enzymes (NSPases). Another aim was to evaluate whether NSPases would improve growth of broilers receiving reduced energy in the diet through their effect on feed digestibility. A growth performance trial was conducted using 1920 broiler chickens placed in a 96-pen environmentally controlled broiler facility. Guanidinoacetic acid was included in the feed at 600 g/ton as the commercial product CreAMINO® (Alzchem, Germany) which contains at least 96% GAA, whereas the commercial product Rovabio Advance® (Adisseo, France) was included at a level of 50 g/ton as a source of NSP degrading enzymes. The study consisted of six maize-soybean dietary treatments with 16 replications each. The Positive Control diet was formulated as a standard commercial diet with 2900, 3000 and 3050 kcal/kg (11.70, 12.02 and 11.97 MJ/kg) AME in the starter, grower and finisher phase diets, respectively) without any of the test additives. A Negative Control (NC1) diet contained 65 kcal/kg (or 2%) AME less than the Positive Control. The NC1 diet was then supplemented with either NSP degrading enzymes (Rovabio Advance®) or GAA (CreAMINO®). A second Negative Control (NC2) diet contained 130 kcal/kg (or 4%) AME less than the Positive Control. The last of the treatment diets was similar to the NC2 diet but supplemented with both the test feed additives simultaneously. The test additives were supplemented during the starter, grower and the finisher phases of growth. There was a drop in production performance for the broilers that received NC1 and NC2, evident by significant reductions in body weights and increased feed conversion ratios. Supplementation of NC1 with CreAMINO® significantly improved the body weights of broilers. . No benefit, however, was observed for the NSPase that was included in the diets. It is suggested that CreAMINO® has the potential to contribute at least 65 kcal/g (0.272 MJ/kg) AME in the diet of broilers.