RESISTANCE TO DISEASE

Timaru Herald, Volume CXLV, Issue 21090, 16 July 1938, Page 15

RESISTANCE TO DISEASE

SCIENTIFIC INVESTIGATION THE CASE OF PEDIGREES Important information from America strengths the case for only using sires which are the progeny of cows that have proved by a long succession of annual tests that they possess natural power of resistance to disease. The American case is the report of a scientific investigation into the reason why some cows are resistant to contagious abortion. The investigation showed that resistance is a definitely inherited characteristic. Examination of the blood of cows that re-

sisted abortion showed that they had high powers of resistance—or, as the investigators themselves put it—the blood had high killing power, while the blood of cows which aborted when exposed to infection had invariably little or no killing power. The bactericidal power of the resistant cows was so great that one cubic centimeter of her blood (about one-thousandth of a quart) killed 8000 abortus organisms. All the evidence went to show that the killing power of the blood was “a

specific and definite phenomenon.” If further research work proves this interesting American investigation to be correct a certain means of controlling abortion is at the farmer’s com- | inand. There are cows in many a | New Zealand herd that have given satisfactory production over a long ' series of years, up to 15 years, and have bred regularly every year. These | are the cows to breed from, and in the case of pedigrees the only cows to be chosen as matrons of a herd sire.