Quantitative evaluation of 1-alpha-hydroxycholecalciferol as a cholecalciferol substitute for broilers

Area of Science:

• Animal Nutrition
• Poultry Science
• Nutritional Biochemistry

Background:

• Cholecalciferol (D3) is an essential vitamin for broiler chickens.
• The efficacy of vitamin D metabolites as dietary substitutes for D3 requires thorough investigation.
• Young broilers have specific nutritional requirements that influence vitamin D metabolism and efficacy.

Purpose of the Study:

• To determine the effectiveness of 1-alpha-hydroxycholecalciferol (1alpha-OHD3) as a dietary substitute for cholecalciferol (D3) in young broilers.
• To compare the bioavailability of 1alpha-OHD3 relative to D3 under controlled experimental conditions.

Main Methods:

• Two experiments utilized corn-soybean meal diets deficient in D3 but meeting other NRC (1984) nutrient requirements.
• Ross x Ross broiler chicks were fed varying levels of D3 and two sources of 1alpha-OHD3 for 16 days.
• Data analysis included body weight, plasma calcium, rickets incidence, and bone ash percentage, employing slope ratio analysis for bioavailability assessment.

Main Results:

• Slope ratio analysis indicated a bioavailability of 1alpha-OHD3 relative to D3 ranging from 1.88 to 21.2.
• Percentage bone ash provided the most precise measure of efficacy in both experiments.
• 1alpha-OHD3 demonstrated significantly higher efficacy compared to D3 across multiple criteria.

Conclusions:

• 1-alpha-hydroxycholecalciferol (1alpha-OHD3) is approximately eight times more effective than cholecalciferol (D3) in meeting the nutritional requirements of young broiler chickens.
• The findings support the potential use of 1alpha-OHD3 as a highly effective vitamin D source in broiler diets.
• Bone ash percentage is a reliable indicator for assessing the bioavailability and efficacy of vitamin D compounds in poultry.