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.
