Effect of dietary lysine level on lipogenesis in broilers

Area of Science:

• Animal Nutrition
• Poultry Science
• Biochemistry

Background:

• Lysine is a crucial amino acid for broiler growth and meat quality.
• Dietary lysine levels significantly impact broiler performance and carcass composition.
• Understanding lysine requirements is essential for optimizing broiler production and reducing fat deposition.

Purpose of the Study:

• To determine the optimal dietary lysine concentration for male and female broilers during the finishing period.
• To investigate the effects of varying lysine levels on growth performance, abdominal fat proportion, and hepatic malic enzyme activity.
• To elucidate the relationship between lysine intake, fat deposition, and metabolic enzyme activity.

Main Methods:

• Feeding 8 experimental diets with varying lysine levels (7-14 g/kg) to broilers from 3-7 weeks of age.
• Measuring growth performance (feed intake, body weight gain, feed conversion ratio).
• Assessing abdominal fat proportion and hepatic malic enzyme activity (malate dehydrogenase with decarboxylating EC 1.1.1.40).

Main Results:

• All measured parameters, including growth, fat proportion, and enzyme activity, varied significantly with dietary lysine concentration.
• The lysine requirement for minimum abdominal fat was higher than for optimal growth rate or feed conversion ratio.
• Hepatic malic enzyme activity correlated with abdominal fat proportion, suggesting a role in fat metabolism regulation.
• Excessive lysine beyond the requirement did not further reduce fat deposition.

Conclusions:

• Dietary lysine concentration critically influences broiler performance and fat deposition.
• The optimal lysine level for minimizing abdominal fat in broilers is higher than that for maximizing growth or feed efficiency.
• Malic enzyme activity is a potential indicator of lysine's role in regulating fat metabolism, but excessive lysine does not enhance fat reduction.