title: Effects of Protease Addition and Replacement of Soybean Meal by Corn Gluten Meal on the Growth of Broilers and on the Environmental Performances of a Broiler Production System in Greece.
abstract: An experimental study was conducted to examine the combined effects of adding a dietary protease, reducing the levels of soybean meal (SBM) and introducing corn gluten meal (CGM) in the ration of a group of broilers reared on a commercial Greek farm. Five hundred forty chicks were divided into three dietary treatments with six replicates of thirty birds each. The first group (Control) was fed a conventional diet based on corn and soybean meal, containing 21% w/w crude protein (CP). The second group (Soy-Prot) was supplied a corn and SBM-based diet containing a lower level of CP (20% w/w) and 200 mg of the protease RONOZYME® Proact per kg of feed. The third group (Gluten-Prot) was fed a diet without soybean-related constituents which was based on corn and CGM and with CP and protease contents identical to those of the diet of the Soy-Prot group. Body weight, feed intake, feed conversion ratio (FCR), intestinal microbiota populations and morphology, meat quality and cost were evaluated. Furthermore, a partial life cycle assessment (LCA) was performed in order to assess the potential environmental performance of the systems defined by these three dietary treatments and identify their environmental hot-spots. The growth performance of the broilers supplied the Soy-Prot diet was similar to the broilers supplied the Control diet. However, the broilers which were fed the Gluten-Prot diet at the end of the trial showed a tendency (P≤0.010) for lower weight gain and feed intake compared to those of the Control diet. When compared to the Control group, lower counts of C. perfringens (P≤0.05) were detected in the ileum and cecum parts, and lower counts of F. necrophorum (P≤0.001) were detected in the cecum part of the birds from the Gluten-Prot group. The evaluation of intestinal morphometry showed that the villus height and crypt depth values were not significantly different (P>0.05) among the experimental groups for the duodenum, jejunum and ileum parts. No significant differences (P>0.05) were observed in the quality of the breast and thigh meat and in the feed cost per kg body weight gain for the total duration of the growth period between the Control and Gluten-Prot broiler groups. The LCA suggested that the ammonia and nitrous oxide emissions due to litter handling constitute the farm level hot-spots for the Acidification and Eutrophication Potentials of the Control and Soy-Prot systems and the Global Warming Potential of the Gluten-Prot system, respectively. The Latin American soybean production and domestic corn production and lignite mining are important off-farm polluting processes for the studied life cycles. The Soy-Prot and Gluten-Prot systems both performed better than the Control system in nine of Environmental Impact Category Indicators assessed, with the respective differences being generally larger for the Gluten-Prot system. The environmental impact estimates are regarded as initial, indicative figures due to their inherent uncertainty. Overall, the results could be considered as positive indications in the effort to sustainably replace the conventional, soybean-dependent control diet in the specific broiler production system.
authors.affiliation: Laboratory of Nutrition, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Ilias
authors.identifier: http://orcid.org/0000-0003-3145-3734
authors.initials: I
authors.lastname: Giannenas
authors.affiliation: Research Institute of Animal Science, ELGO-Dimitra, Paralimni Giannitsa, Pella, Greece.
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Bonos
authors.affiliation: Laboratory of Agricultural Engineering and Environment, Institute for Research and Technology of Thessaly, Centre for Research and Technology Hellas, Volos, Greece.|Laboratory of Agricultural Constructions and Environmental Control, Department of Agriculture Crop Production and Rural Environment, School of Agricultural Sciences, University of Thessaly, Magnisia, Greece.
authors.forename: Vasileios
authors.initials: V
authors.lastname: Anestis
authors.affiliation: Laboratory of Microbiology and Infectious Diseases, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Filioussis
authors.affiliation: Laboratory of Agricultural Engineering and Environment, Institute for Research and Technology of Thessaly, Centre for Research and Technology Hellas, Volos, Greece.
authors.forename: Dimitrios K
authors.initials: DK
authors.lastname: Papanastasiou
authors.affiliation: Laboratory of Agricultural Engineering and Environment, Institute for Research and Technology of Thessaly, Centre for Research and Technology Hellas, Volos, Greece.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bartzanas
authors.affiliation: Laboratory of Pathology, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Papaioannou
authors.affiliation: Department of Agricultural Technology, Division of Animal Production, Technological Institute of Epirus, Arta, Greece.
authors.forename: Athina
authors.initials: A
authors.lastname: Tzora
authors.affiliation: Department of Agricultural Technology, Division of Animal Production, Technological Institute of Epirus, Arta, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Skoufos
mesh_terms: D000821:Animal Feed; D000822:Animal Husbandry; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight; D002432:Cecum / Q000382:microbiology; D002645:Chickens / Q000254:growth & development; D004032:Diet / Q000662:veterinary; D004044:Dietary Proteins / Q000378:metabolism; D005983:Glutens / Q000737:chemistry*; D006115:Greece; D007421:Intestine, Small / Q000382:microbiology; D008018:Life Cycle Stages; D064307:Microbiota; D010447:Peptide Hydrolases / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D013025:Glycine max / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry*
chemical_list: D004044:Dietary Proteins; D005983:Glutens; D010447:Peptide Hydrolases