Energy Expenditure and Maintenance Requirements in Non-Pregnant First-Parity Sows

Area of Science:

• Animal Science
• Nutritional Physiology
• Swine Metabolism

Background:

• Accurate energy requirements are vital for optimizing swine production and minimizing waste.
• Previous estimates of maintenance energy (MEm) may not reflect the needs of modern sow genetics.

Purpose of the Study:

• To determine the energy expenditure (EE) and heat production (HP) of non-pregnant sows under different feeding regimens.
• To re-evaluate and propose an updated maintenance energy requirement (MEm) for non-pregnant modern sows.

Main Methods:

• Five non-pregnant sows were housed in respiration chambers and fed either 1.0 or 2.0 times their estimated MEm for one week each.
• Energy intake and heat production were measured, with feeding strategies including small, frequent meals and a single large meal.
• Body weight changes and respiratory quotient (RQ) were monitored to assess energy balance and substrate utilization.

Main Results:

• Sows fed 1.0 MEm experienced negative energy balance and weight loss, while sows fed 2.0 MEm gained weight with RQ > 1, indicating fat deposition.
• Heat production was significantly higher during feeding periods (small or large meals) compared to post-absorptive periods.
• The study identified a proposed MEm of 506 kJ ME/kg^0.75 for non-pregnant modern sows.

Conclusions:

• The feeding strategy and energy intake level significantly impact energy expenditure and body composition in sows.
• The proposed MEm provides a more accurate nutritional guideline for non-pregnant modern sows.
• Further research can validate these findings across different sow genotypes and physiological states.