INFLUENCE OF DIFFERENT FEED PHOSPHATE ON MECHANICAL PROPERTIES OF SWINE BONE TISSUE

Abstract

The function of the highly complex structure such as the human skeletal system is possible by the appropriate construction and properties of bone tissue. Bone tissue, due to its design, is a material that continuously adapts its mechanical properties and structural response to the smallest change in load condition. Bone should be viewed as a twophase composite material, consisting of a collagen matrix with low elasticity and HA crystals with high elasticity modulus. The main mineral components of these crystals are Ca and P. The degree of digestibility of P compounds is affected by many factors, which include, type of feed, breed and species of animals, amount of vitamins and probiotics, and the ratio of Ca vs. P. The primary feed used in swine feeding is grain, which is also the main source of P that has in the form of phytate. This form of phosphorus is very difficult absorb as molecules of phytic. Consequently, in neutral pH phytate forms sparingly soluble complexes with amino acids, sugars and divalent metal cations, thus reducing its absorption. Amount of P supplied with the feed, even when supplemented by microbial phytase, does not cover the requirements of extensively growing pigs. The most frequently commercial products which are intended to supplement deficiencies are 1, 2 and 3-calcium, calcium-sodium, sodium-calcium-magnesium. Studies in literature (Jongbloed, 2000) present that the best results in swine nutrition is obtained when one or disodium phosphate is used. The main goal of this study was to determine the mechanical properties and elemental content of bone tissue derived from pigs fed with forage with different amounts of Ca and P. In addition, the study was to determine the fodder value of the new dicalcium phosphate feed (n-DCP) produced by the Gda sk Phosphate Fertilizer Plants' Fosfory Ltd. according to patent No. P-369805, when compared to monocalcium phosphate, calcium and sodium.