Effects of dietary combination of 25-OH-D3 and canthaxanthin on performance, meat yield, bone characteristics and antioxidant status of broilers housed under commercial and experimental conditions

• Author / Creator

  Lozano, Carlos

• The effects of 25-hydroxy vitamin D3 (25-OH-D3), canthaxanthin (CX), alone and in combination on broiler performance, meat yield, oxidative status, skin colour and bone characteristics were evaluated in a field trial in Colombia and also under controlled experimental conditions in Canada. The effects of regional and housing conditions on performance, meat yield and bone characteristics were also assessed. In the field trial, one whole broiler cycle of 4,922,130 broilers of both sexes (reared separately) of two commercial broiler strains (A and B) was followed from placement to processing. Birds were fed with a Control diet containing vitamin D3 at 4,000 IU per kg of complete feed, and a treatment diet (MaxiChick®, MC) containing CX at 6 mg, 2,760 IU of 25-OH-D3, plus the Control level of vitamin D3 from 0 to approximately 21 d of age. Additionally, 53% of the males also received 1.0 g per kg of complete feed of marigold extract (MG) from approximately d 22 to processing age. Strain A had lower FCR and higher weights and yield of carcass, whole breast, breast fillet, and thighs than strain B, but BW and feed intake were similar. MC reduced yield of most of the carcass traits, especially in strain A. Males fed MG had higher feed intake and FCR than males not fed MG. During the fifth week of age, MG increased weight gain and reduced FCR, especially in strain A. During the same period, in males not fed MG, MC reduced weight gain and increased FCR. MG increased weight gain but increased mortality in males fed MC. From d 29 to d 35, MC reduced mortality, but not in males fed MG. Males fed MG had higher breast weight, and weight and yield of carcass, drumstick, and thigh than males not fed MG. MG reduced skin lightness and redness, but increased yellowness. Bone breaking stress was increased and bone breaking strength was nearly increased (P = 0.0768) by MC. MC increased bone breaking strength only in strain B birds. The regional and housing analysis showed that most differences in broiler traits were related to differences in environmental temperature. In controlled conditions, birds were fed one of seven diets: Control (2,760 IU of vitamin D3/kg of feed from d 0 to 40); 25D (2,760 IU 25-OH-D3 /kg of feed from d 0 to 40); CX (Control + 6 mg/kg CX from d 0 to 40); 25DCX (25D diet + 6 mg/kg CX, from d 0 to 40); 25D-Early (25D diet from 0 to 19 d; Control diet thereafter); CX-Early (CX diet from 0 to 19 d; Control diet thereafter); 25DCX-Early (25DCX diet from 0 to 19 d; Control diet thereafter). Diets containing CX increased BW and reduced FCR at d 11 and had a tendency to increase Pectoralis major weights (P<0.1) at 19 and 39 d. CX increased redness and yellowness of shank and breast skin, and breast muscle; especially when fed during the full grow-out period. The presence of CX reduced malondialdehyde concentrations of liver samples at 11 and 19 d. At d 19, an increased trabecular bone cross sectional area at 30% of total femur length from the proximal epiphysis evidenced a synergy between 25-OH-D3 and CX. At d 39, 25D-Early and 25DCX-Early increased bone breaking strength relative to the other treatments. It was concluded that broiler productivity was strongly strain-dependent. The increased productivity at early ages in the treatments containing CX and in birds fed MG was likely due to an increased antioxidant status. The increased bone quality in birds fed MC, 25D-Early and 25DCX-Early was likely due to the inclusion of 25-OH-D3 and it confirms the higher biopotency relative to vitamin D3 at early ages. Both active compounds in MC may positively influence livability and bone formation through different metabolic pathways. Therefore, dietary MC has the potential to increase profitability by increasing the number of saleable birds at processing age, but also may increase bird welfare.

• Subjects / Keywords

  • Yields
  • Canthaxanthin
  • Bones
  • Broilers
  • Performance
  • 25-OH-D3
  • Tomography
  • Antioxidants
  • Fields

• Graduation date

  Fall 2014

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R36M32

• 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.