Lysine requirement of weaned piglets.

Area of Science:

• Animal Science
• Nutritional Biochemistry
• Swine Production

Background:

• Lysine is the primary limiting amino acid in pig diets, essential for growth.
• Accurate lysine requirements are vital for optimizing pig health, production efficiency, and minimizing nitrogen excretion.
• Lysine needs vary with pig age, sex, genetics, and environmental factors.

Purpose of the Study:

• To determine the standardized ileal digestible (SID) lysine requirements for weaned piglets (5-30 kg).
• To achieve this through a comprehensive literature review and meta-analytical approach.

Main Methods:

• A systematic literature review identified 41 relevant experiments from 344 initial studies.
• Meta-analysis employed linear, quadratic, and linear-plateau models to analyze the impact of SID lysine on piglet growth.
• Data from 206 treatment means were analyzed to assess average daily gain and feed efficiency.

Main Results:

• Regression analysis indicated a consistent linear increase in average daily gain and feed efficiency with rising SID lysine levels.
• Breakpoint analysis using linear-plateau models was inconclusive, suggesting optimal levels likely exceed those commonly tested.
• The study indicated that optimal SID lysine requirements may surpass 1.3 g SID lysine per MJ net energy.

Conclusions:

• The findings suggest that current SID lysine levels in piglet diets may not be sufficient to maximize growth performance.
• Further research is recommended to explore the optimal SID lysine to crude protein (CP) ratio in piglet diets.
• Diet formulation might benefit from focusing on the SID lysine:CP ratio rather than solely on SID lysine per unit of feed or energy.