A statistical study of the interrelations between certain mineral constituents of the blood of dairy cows

Authors

• Pellervo Saarinen Agricultural Research Centre, Department of Animal Husbandry, Tikkurila, Finland

DOI: https://doi.org/10.23986/afsci.71341

Abstract

A statistical study of interrelations between some blood minerals was made on the basis of 330 arterial blood samples collected from 16 herds. The mutual dependence of five variables, calcium (x1), sodium (x2), the total excess of cations (x3), chlorine (x4), and inorganic phosphorus in the blood (x5), was investigated simultaneously. For this purpose the coefficients of partial correlation were calculated and the dependence of each mineral studied was expressed as a linear function of the others. If the effects of all the minerals studied were taken into consideration simultaneously the inorganic anions in the blood showed a slight positive correlation with the blood calcium or vice versa, r14;235 = +0.1353 and r15;234= +0.1717. The phosphates appeared to be proportionately more effective than the chlorides. No reciprocal relationship was noticed between calcium and inorganic phosphorus in the blood of dairy cows Blood chlorine and inorganic phosphorus in the blood were reciprocally related, r45;123 = —0.1746; hence it is concluded that an excessive feeding of chlorides can remove phosphorus from the blood and affect the requirements. Blood sodium and chlorine were fairly closely correlated, r24;135 = +0.7022, and the possibilities of removing one oi these elements from the blood by feeding the other in excess appear to be limited. Regarding the positive effects asserted to be obtainable with chlorides in maintaining the blood calcium at high level the study has given a fairly positive result. If, however, the excess of cations in he blood is maintained simultaneously at a normal level the effect of chlorides on the blood calcium appears to be very slight and in practice some other methods may be preferable.