Dietary Calcium and phosphorus levels for reproducing sows

Area of Science:

• Animal Science
• Nutritional Physiology
• Reproductive Biology

Background:

• Sow reproductive performance is influenced by dietary mineral levels.
• Calcium (Ca) and Phosphorus (P) are critical for bone health and reproductive function in swine.

Purpose of the Study:

• To evaluate the effects of three dietary Ca/P ratios on reproductive performance and bone metabolism in gilts over three parity cycles.
• To determine optimal Ca and P intake for maintaining bone homeostasis in lactating sows.

Main Methods:

• Thirty-six gilts were fed diets with varying Ca/P levels (.65/.50, .80/.60, .90/.70%) during gestation and lactation.
• Reproductive parameters, milk Ca and P, progeny bone histopathology, and sow bone ash were analyzed.
• Sows and progeny were sampled at various stages of gestation, lactation, and postpartum.

Main Results:

• No significant differences were observed in sow reproductive performance, litter outcomes, or milk Ca and P concentrations across dietary treatments.
• No histopathologic bone lesions were found in progeny.
• Sow bone ash analysis indicated demineralization in lactating animals, with greater loss in rib, vertebrae, and humerus compared to the femur.

Conclusions:

• Dietary Ca/P levels tested did not affect reproductive performance or milk mineral content.
• Lactating sows undergo bone demineralization, indicating a need for adequate mineral intake to maintain bone homeostasis.
• An estimated daily intake of 50-55 g Ca and 40 g P is suggested for lactating sows to preserve bone health.