RESUMEN
The purpose of this study was to determine if in ovo feeding and rearing with glycosaminoglycans and vitamin C could influence bone and cartilage macroscopy, mineral composition, mineral density and surface area, bone breaking strength, and bone histology in broilers. Fertile eggs from breeders (Cobb) were either uninjected or injected with 4 µg of additive/100 µL water on day 4 of incubation. Every 100 g of in ovo additive contained 30 g of chondroitin sulfate, 30 g of glucosamine, and 5 g of vitamin C. After hatching, the chicks from both incubation treatments were submitted to additional treatments during the growth phase from 1 to 42 D of age (diet without and with 0.74 g of additive/kg of feed). Every 100 kg of feed contained 30 g of glucosamine sulfate, 24 g of chondroitin sulfate, and 20 g of vitamin C. A completely randomized factorial design (2 × 2) was applied. The data were submitted to variance analysis using the general linear model procedure of SAS (SAS Institute). In ovo feeding with 4 µg of additive plus dietary supplementation with 0.74 g of additive/kg of feed resulted in the highest cartilage weight of the femur proximal epiphysis in birds (P = 0.0098). The highest ash, phosphorus and calcium percentage, mineral density and mineral composition were identified for femur and tibia in the following treatments: in ovo feeding plus diet without additive during rearing, or uninjected eggs plus dietary supplementation during rearing. In ovo feeding with 4 µg of the additive reduced (P = 0.0008) the number of chondrocytes in the proximal epiphysis of the tibia cartilage and increased (P < 0.0001) the number of osteocytes in the tibia diaphysis of broilers. We conclude that in ovo feeding or dietary supplementation during broiler rearing with glycosaminoglycans (chondroitin sulfate and glucosamine sulfate) and vitamin C benefits the development of bird bones and cartilage, and may represent a solution to bone problems in broilers.
