Effects of different dietary P levels on performance and bone health in weaned piglets

Phosphorus (P) belongs to the essential elements in animals` nutrition and is responsible among others for performance and bone health in weaned piglets. Nowadays, phosphorus achieves an economic relevance due to limited resources of this element. Therefore, aim of the present study was the evaluation of effects of different phosphorus levels in the diet on the performance and bone structure and composition as well to assess bone health in weaned piglets.

Diets based on wheat, barley and soybean meal with varying levels of soluble phosphorus (0.30 / 0.47 / 0.66 % in dry matter) were fed to piglets from weaning (28 days p.n.) until slaughter (64 days p.n.). Within this time, body weight gains, feed intake, feed conversion rate, blood parameters and fecal quality were evaluated. The right femur of the slaughtered piglets was scanned with a Skyscan 1076 micro-CT. Trabecular bone mineral density (BMD), cortical tissue mineral density (TMD) and specific microstructural parameters were determined as well. The structure of the bone was examined using a scanning electron microscope (SEM) coupled with an energy dispersive X-ray spectroscopy (EDX).

Feeding a diet with a soluble phosphorus level of 0.66% resulted in a decreased feed intake and lower body weight gains and higher feed conversion rates in consequence. Serum concentration of inorganic phosphate, calcium and magnesium decreased in this group, too. A reduction of the phosphorus level in the diet to 0.30% did not result in an insufficient BMD of the bones. According to preliminary biomechanical results, bony strength seems not to be influenced by any of the tested diets.

A reduction of the phosphorus level in diets for weaned piglets below usual recommendations was not combined with negative effects on the bone structure and should be discussed to spare phosphorus resources.

Disclosure of Interest: None Declared.