Glueless bone meal in the nutrition of nursing sows

Mineral nutrition of pigs is limited chiefly by the lack of inorganic phosphorus. In the experiment, in which a total of 800 sows and 6,674 piglets were involved, replacement of dicalcium phosphate (DCP) by glueless bone meal (VKM) in the KPK S feed mixture for suckling sows was tested. The feed mixtures given to the sows differed from each other in the sources of phosphorus supply. The inorganic phosphorus portion consisted of 1.8 per cent DCP in the control group, and of VKM in the test group. Two variants of the tested feed mixtures with different proportions of VKM (1.8 per cent and 2.8 per cent) were studied in the experiment. The initial VKM portion (1.8 per cent) statistically significantly lowered the mean phosphorus content in the feed mixture (by 16 per cent), had an undesirable influence on the proportion of inorganic and native phosphorus (32.8:67.2), and conclusively reduced the phosphorus content in the milk of the tested sows (by 18 per cent). When more VKM (2.8 per cent) was added to the feed given to the test group, the effect of feed phosphorus was as high as in the control group. VKM introduction influenced significantly neither the parameters of sows' performance, nor the phosphorus and calcium content in the selected body tissues. Metabolic comparison confirmed a generally higher digestibility of phosphorus (by 6.52 per cent) and calcium (by 6.87 per cent) in the feed mixture with DCP. Analysis of VKM showed lower mean values of the contents of cadmium (-0.378 mg/kg), lead (-0.009 mg/kg), in comparison with DCP. After replacing the phosphate compounds in the feed mixtures (DCP:VKM = 1:1), the price of the tested mixture is the same as the price of the control mixture. Compensation of the phosphorus content by increasing the VKM proportion by 1 per cent increased the price of the complete feed mixture KPK S by 30 crown per one tonne.