Effects of dietary 25-hydroxycholecalciferol and vitamin D3 on performance, meat yield, bone characteristics, innate immune response and gene expression of Ross 308 broilers grown on reused or fresh litter

• Author / Creator

  Fatemi, Seyed Abolghasem

• The effects of dietary 25-hydroxycholecalciferol (25OHD3) and vitamin D3 (D3) on performance, meat yield, bone characteristics, innate immune response and gene expression of broiler chickens grown on Reused and Fresh litter were investigated. Experimental diets were fed to Ross 308 chicks (n=512) for 41 d in a 4 x 2 factorial arrangement with 8 pens/treatment. Diets were: vitamin D3 at 2,760 IU/kg feed (D; Control); 25OHD3 at 2,760 IU/kg feed (25OHD); D3 at 2,760 IU/kg plus 25OHD3 at 2,760 IU/kg feed (D+25OHD); or D3 at 5,520 IU/kg feed (Dx2); each diet was fed to broilers grown on either fresh (Fresh) or reused (Reused) pine shavings to increase bacterial exposure. Dietary 25OHD3 alone relative to vitamin D3 at the same level of inclusion resulted in increased leg meat yield at processing (d 42), decreased broiler performance in the fresh litter at 12, and decreased breast meat yield at processing. Supplementation of 25OHD3 at 2,760 IU/kg feed relative to vitamin D3 reduced acute phase proteins at d 41 and increased villus width, crypt depth and tended to increase villus surface area at the same day. However, deeper crypts could result in increased gut maintenance energy requirement, which could have been the reason for lower breast meat yield at processing. In addition, dietary supplementation of 25OHD3 as a complete or partial replacement for vitamin D3 increased bone quality by increasing bone mineral density and tended to increase bone breaking strength throughout the 41 d experiment. Dietary 25OHD3 reduced inflammation in post-hatch and older birds as indicated by reduced serum concentration of α1 acid glycoprotein in broilers at d 41; haptoglobin tended to be decreased at d 12 relative to birds fed D. Moreover, 25OHD3 alone increased the expression of genes involved in muscle synthesis and adaptive immunity relative to vitamin D3 at the same level of activity in broilers at d 12. However, 25OHD3 alone decreased the expression of genes involved in amino acid biosynthesis and transport as compared to vitamin D3 at the same level. Reused as compared to Fresh litter resulted in reduced broiler performance, breast meat yield, and bone mineralization and strength in post-hatch broilers. Reused litter resulted in decreased villus surface area and villus height to crypt depth ratio, and increased crypt depth in post-hatch broilers relative to Fresh litter. Plasma haptoglobin concentration increased at d 41 and tended to increase at d 12 in birds reared on Reused litter in comparison to those on Fresh litter. In addition, expression of genes involved in the inflammatory response increased when birds were reared on Reused relative to Fresh litter at d 12. Therefore, increased crypt depth, which is associated with increased gut maintenance requirements, and systemic inflammation in post-hatch broilers reared on Reused relative Fresh litter may explain the reduced broiler performance, and bone characteristics in this group. In this study, supplementation of 25OHD3 as a complete or partial replacement for vitamin D3 relative to vitamin D3 alone did not affect breast meat yield relative to vitamin D3, but it increased bone mineralization and development and reduced inflammation through the 41 d experiment. In conclusion, dietary supplementation of 25OHD3 is more effective in broilers production and immune response when birds are reared in a challenging environment.

• Subjects / Keywords

  • Broiler chickens
  • Reused or fresh litter
  • Dietary 25-hydroxycholecalciferol

• Graduation date

  Fall 2016

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3KH0F43X

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.