Efeitos da suplementação de 1,25-Dihidroxicolecalciferol glicosídeo em frangos de corte provenientes de matrizes de diferentes idades suplementadas com o mesmo aditivo

Abstract

A total of 1,152 Ross 308 AP chicks were used in all trials, distributed in a 2 × 3 factorial design, considering 1,25(OH)₂D₃-G supplementation in breeder hens (0 or 100 mg/kg) and different supplementation levels in broilers (0, 50, and 100 mg/kg) up to 21 days of age. In Trial I (30-week-old breeders), intestinal histomorphometry and gene expression were evaluated at 21 days, while tibial dyschondroplasia was assessed at 42 days. Broilers from breeders supplemented with 100 mg/kg of 1,25(OH)₂D₃-G showed higher hatch weight, better feed conversion, improved intestinal histomorphometry, and higher carcass yield. However, this supplementation did not increase calcium and phosphorus deposition in the tibia, resulting in lower bone strength. In Trial II (46-week-old breeders), 1,25(OH)₂D₃-G supplementation in breeders led to heavier broilers at hatch and better bone health at 21 days, with higher calcium and phosphorus deposition and greater tibial breaking strength. Additionally, it increased the expression of calbindin D28K, interleukin 10 (IL-10), and interleukin 1β (IL-1β) in the jejunum. Broilers supplemented with 50 mg/kg had greater phosphorus deposition in the tibia, while those receiving 50 or 100 mg/kg showed higher IL-10 levels when derived from supplemented breeders. In Trial III (46-week-old breeders), supplementation of 1,25(OH)₂D₃-G in breeders resulted in broilers with higher hatch weight, increased villus height, greater absorption area, and a higher villus:crypt ratio in the jejunum at 42 days. These broilers also had lower serum calcium concentration, greater calcium and phosphorus deposition in the tibia, greater tibial breaking strength, and increased expression of calbindin D28K, IL-10, and IL-1β at 42 days of age when derived from breeders supplemented with 100 mg/kg. Furthermore, broiler supplementation with 100 mg/kg of 1,25(OH)₂D₃-G promoted greater weight gain and improved immune response at 42 days. In Trial IV (62-week-old breeders), supplementation with 1,25(OH)₂D₃-G resulted in broilers with higher hatch weight, better feed conversion, and increased levels of calbindin D28K, IL-10, and IL-1β at 21 days. In Trial V (62-week-old breeders), maternal supplementation with 100 mg/kg of 1,25(OH)₂D₃-G led to broilers with higher hatch weight, fewer tibial dyschondroplasia lesions, and increased expression of calbindin D28K, IL-10, and IL-1β at 42 days. Additionally, broilers supplemented with 100 mg/kg of 1,25(OH)₂D₃-G during the growth phase exhibited improved feed conversion, reduced crypt depth, increased villus height, larger absorption area, higher villus:crypt ratio, and increased expression of IL10 and IL-1β at 42 days. The interaction between breeder and broiler supplementation demonstrated that broilers from supplemented breeders had higher levels of alkaline phosphatase, IL-10, and IL-1β when also supplemented with 100 mg/kg of 1,25(OH)₂D₃-G at 42 days. In conclusion, 1,25(OH)₂D₃-G supplementation in breeders consistently resulted in heavier broilers at hatch. However, the effects on broiler growth varied depending on breeder age and supplementation levels during the growth phase. Therefore, while supplementation in breeders proved to be a viable strategy to enhance early broiler development, supplementation during the broiler growth phase should be carefully evaluated to determine its actual effectiveness and cost-benefit in production.