Glycosaminoglycans and vitamin C in ovo and the feeding of broiler chickens influence bone and cartilaginous histology

Abstract The objective of this study is to evaluate the effect of in ovo feeding and dietary supplementation with glycosaminoglycans (GAGs) and vitamin C, on the bone and cartilage histology of broiler chickens. A completely randomized factorial design (2 x 2) was used, with two treatments during incubation (noninjected eggs and eggs injected with 4 μg of additive/100 μL of water on the fourth day of incubation), and two treatments during rearing (diet without additive and diet with 0.74 g of additive/100 kg of feed). Each 100 g of in ovo additive contained 30 g of chondroitin sulfate, 30 g of glucosamine sulfate, and 5 g of vitamin C, while each 100 kg of feed contained 30 g of glucosamine sulfate, 24 g of chondroitin sulfate, and 20 g of vitamin C. On day 43 of rearing, the number of chondrocytes in the cartilage, osteocytes, and periosteal osteoblasts in the tibial diaphysis, and tibial diaphysis thickness were evaluated. An interaction (P < 0.05) between the factors was observed. Greater diaphysis thickness and osteoblast numbers were observed in broilers fed with 0.74 g of additive/kg without in ovo injection, as well as in those that received 4 µg of additive in-ovo, and no additive in the diet. On the other hand, the use of the in ovo and dietary additive resulted in a reduction in the number of osteocytes. It was concluded that in ovo feeding or dietary supplementation with vitamin C and chondroitin and glucosamine sulfates during broiler rearing benefited bone and cartilage development.