Related Experiment Videos
Phosphorus studies in pigs. 2. Assessing phosphorus availability for pigs and rats
P P Ketaren1, E S Batterham, E B Dettmann
1NSW Agriculture, Wollongbar Agricultural Institute, Australia.
The British Journal of Nutrition
|July 1, 1993
Summary
This study determined phosphorus (P) availability in feed ingredients for pigs and rats. Results show P availability varies by ingredient and assessment method, highlighting the need for precise evaluation in animal nutrition.
Area of Science:
- Animal Nutrition
- Nutrient Bioavailability
- Agricultural Science
Background:
- Accurate assessment of phosphorus (P) bioavailability in feed ingredients is crucial for optimizing animal diets and reducing environmental P excretion.
- Previous studies have shown variability in P availability estimates depending on the animal model and response criteria used.
Purpose of the Study:
- To determine the P availability in soya-bean meal and field peas for grower pigs using a slope-ratio assay.
- To establish optimal conditions for a slope-ratio assay in rats to assess P availability and evaluate rats as a model for pigs.
Main Methods:
- Pigs (20 kg) were fed diets with varying levels of P from monosodium phosphate (MSP), soya-bean meal, or field peas for 35 days.
- Bone variables, body P concentration, and retention were used as criteria for P availability in pigs.
- Experiments with rats investigated dietary P levels, Ca:P ratios, and response criteria (growth, bone ash, bone bending moment) for P availability assays.
Main Results:
- P availability estimates for soya-bean meal and field peas in pigs varied significantly based on the criteria used (e.g., bone variables vs. body composition).
- Mean P retention from MSP, soya-bean meal, and field peas in pigs was 0.74, 0.33, and 0.21, respectively.
- Optimal conditions for rat P assays included 1.8-3.5 g/kg dietary P, Ca:P ratios of 1.3-6.2, and using bone ash or femur bending moment as criteria. Rat P availability for soya-bean meal was estimated at 0.81.
Conclusions:
- Phosphorus availability in feed ingredients is highly dependent on the chosen assessment criteria and animal model.
- Rats may serve as a potential model for P availability assessment, but species differences in estimates (e.g., soya-bean meal) require further investigation.
- Precise methods are needed to accurately determine P bioavailability for efficient animal nutrition and sustainable agriculture.