Supplemental lysine for sows nursing large litters

Area of Science:

• Animal Science
• Swine Nutrition
• Reproductive Physiology

Background:

• Sow lactational performance is critical for litter survival and growth.
• Meeting the nutritional demands of sows nursing large litters is challenging.
• Lysine is an essential amino acid influencing protein synthesis and growth.

Purpose of the Study:

• To evaluate the impact of supplemental lysine on the lactational performance of sows nursing large litters.
• To determine optimal lysine levels in diets based on corn or sorghum and soybean meal.
• To identify potential limiting amino acids at higher lysine supplementation levels.

Main Methods:

• A cooperative experiment with 501 litters across four stations.
• Sows were fed diets with .60%, .75%, or .90% lysine.
• First-parity sows nursed ≥9 pigs; older sows nursed ≥10 pigs.
• Sows were monitored for three parities.

Main Results:

• Increasing lysine from .60% to .75% quadratically improved mean pig weights at birth and 21 days.
• No significant effects on sow body weight, backfat loss, or feed intake were observed.
• A treatment x station interaction indicated varying responses to lysine based on grain source (corn vs. sorghum).

Conclusions:

• A 13% CP corn-soybean meal diet with .60% lysine is inadequate for sows nursing large litters.
• Supplemental synthetic lysine beyond .15% additional lysine may not be beneficial due to other amino acid deficiencies.
• Optimizing lysine levels requires consideration of the grain source and potential co-limiting amino acids.