Dietary protein effects on hen performance and nitrogen excretion

Area of Science:

• Animal Science
• Nutritional Biochemistry
• Environmental Science

Background:

• Dietary nitrogen management is crucial for reducing ammonia emissions in poultry operations.
• Crude protein (CP) levels in feed directly influence manure nitrogen content.
• Optimizing CP in laying hen diets can mitigate environmental impact.

Purpose of the Study:

• To determine the minimum crude protein (CP) content in laying hen diets based on performance criteria.
• To evaluate the impact of varying dietary protein levels on ash:nitrogen ratios in manure, eggs, and hens.
• To assess the relationship between dietary protein and nitrogen excretion in poultry.

Main Methods:

• Egg-type hens were fed diets with 13, 15, or 17 g of protein per day, with controlled essential amino acid intake.
• Performance criteria including egg production and feed intake were monitored.
• Manure, egg, and hen composition, specifically ash and nitrogen content, were analyzed.

Main Results:

• Egg production and egg mass were unaffected by dietary protein levels (13-17 g/d).
• Hens fed lower protein diets (13 g/d) consumed more feed.
• Manure nitrogen content significantly decreased with lower dietary protein, ranging from 3.98% to 5.68% dry matter.

Conclusions:

• Laying hen diets can be formulated with reduced crude protein without compromising egg production.
• Lowering dietary protein effectively reduces nitrogen excretion in manure, a key factor in ammonia emission control.
• Dietary strategies can be employed to manage nitrogen content in poultry manure, aiding environmental sustainability.