Phosphorus utilization in starter pigs fed high-moisture corn-based liquid diets steeped with phytase

Area of Science:

• Animal Nutrition
• Swine Physiology
• Enzyme Technology

Background:

• Phytase supplementation in swine diets enhances phosphorus (P) availability and utilization.
• Pre-treatment of feedstuffs, such as steeping, may further optimize phytase efficacy.

Purpose of the Study:

• To evaluate the efficacy of steeping high-moisture corn (HMC) with phytase in phosphorus-deficient liquid diets for starter pigs.
• To assess the impact of phytase addition and steeping on nutrient digestibility, mineral retention, and bone characteristics.

Main Methods:

• A total of 384 weaned pigs were fed HMC-based liquid diets with varying phytase levels (0, 62.5, or 125 FTU/kg) with or without a 24-hour steeping period.
• Nutrient digestibility (DM, OM, CP, P, Ca) was assessed using titanium dioxide marker.
• Body composition, metacarpal characteristics, and mineral content in digesta and urine were analyzed post-mortem.

Main Results:

• Phytase addition increased the soluble P:total P ratio in duodenal digesta and improved P and Ca retention in the empty body.
• Steeping HMC with phytase enhanced DM and CP digestibility but did not improve P digestibility.
• Metacarpal P and Ca content and breaking strength were improved with phytase, with no significant benefit observed from steeping.

Conclusions:

• Exogenous phytase improves calcium and phosphorus retention in starter pigs fed P-deficient HMC liquid diets, irrespective of steeping.
• Steeping HMC with phytase provided limited additional benefits regarding nutrient digestibility and overall pig performance.
• Further research may explore optimal steeping conditions or alternative pre-treatment methods to maximize phytase benefits.