Metabolizable energy values determined with intact and cecectomized roosters

Area of Science:

• Animal Nutrition
• Poultry Science
• Digestive Physiology

Background:

• Accurate determination of the metabolizable energy (ME) of feed ingredients is crucial for optimizing poultry diets.
• The role of the cecae in nutrient and energy metabolism in roosters is not fully understood in the context of ME determination.

Purpose of the Study:

• To compare the accuracy of ME determination using intact versus cecectomized White Leghorn roosters.
• To evaluate the impact of cecal fermentation on energy and nitrogen excretion in roosters.

Main Methods:

• Mature White Leghorn roosters (intact and cecectomized) were used in a comparative study.
• Fasting and excreta collection protocols were employed to measure energy and nitrogen balance.
• A specific diet (85% corn, 15% soybean meal) was force-fed to assess apparent metabolizable energy (AME) and true metabolizable energy (TME).

Main Results:

• No significant differences in energy and nitrogen excretion were observed between intact and cecectomized roosters during fasting.
• Cecectomized roosters exhibited greater energy and nitrogen excretion compared to intact roosters when fed the test diet.
• Calculated AME, TME, AME(n), and TME(n) values were higher when determined using intact roosters.

Conclusions:

• Intact roosters provide more reliable data for determining the energy content of feed ingredients for commercial poultry flocks.
• Cecal function influences the excretion of energy and nitrogen, impacting ME calculations.
• The study recommends the use of intact roosters for precise feed ingredient energy evaluation.