Effect of glycosaminoglycans on the structure and composition of articular cartilage and bone of broilers

This study aimed to assess the influence of glycosaminoglycan (chondroitin and glucosamine sul-fates) supplementation in the diet of broilers on the expression of matrix metallopeptidase 9 (MMP-9) and metallopeptidase inhibitor 2 (TIMP-2) genes, the syn-thesis of proteoglycans, collagen type II and chondro-cytes, bone and cartilage macroscopy, bone mineral densitometry, bone breaking strength and mineral pro-file. A completely randomized design was carried out in a 3 & POUND; 3 factorial scheme (3 levels of chondroitin sulfate: 0.00, 0.05, and 0.10%; and 3 levels of glucosamine sul-fate: 0.00, 0.15, and 0.30%), totaling 9 treatments. At 21 and 42 d of age, broilers were slaughtered, and tibias and femurs were collected for evaluation. There was an interaction (P < 0.05) of sulfates for the expression of MMP-9 and its inhibitor TIMP-2 in femur articular car-tilage, as well as for the number of chondrocytes, colla-gen type II and proteoglycans in tibia articular cartilage, bone and cartilage macroscopy and mineral profile (P < 0.05), with better results obtained with the inclusion of chondroitin and/or glucosamine sulfates in the feed. In conclusion, chondroitin and glucosamine sulfates can be used in broiler diets in order to favor the development of the structure of the locomotor system (bones and joints), thus preventing locomotion problems.