INBREEDING QUESTION.

New Zealand Herald, Volume LXVII, Issue 20561, 12 May 1930, Page 3

INBREEDING QUESTION.

DIVISION OF OPINION*

TASK FOR THE ' EXPERT*

In every part of the world wherfi csre-. ful breeding ,is practised the'old argument for and against inbreeding inviriably crops up. Some, principally scientific men, arguo against inbreeding and utterly condemn it, while others, especially skilled breeders, argue in favour of it. Tho American Sheepbreeder journal strongly condemns the practice of it, and declares that, many of tho foremost breeders of the United .States have bred the flocks in-and-in to such an extent in order to establish type that they have almost ruined the constitution of their flocks and brought theai to a condition in which they arc tho easy and helpless prey to internal parasite:and other diseases. Tho opponents of tho system point to such facts as Iho ultimate barrenness of the celebrated strain -of Mr. Bates' Shorthorns, although the geneial experiences of Collings, Bakowell and Price all went to show that inbreeding could bo carried out for many years without the occurrence of any more than tho usual percentage of barren animals. No doubt, intensive and rich feeding; of domestic animals is responsible for some barrenness, and there is probably far more danger from overfeeding thau from inbreeding. Examples in Human Race. Tho American writer " Huth," in his book on the, marriage of near-i:o-!:in, says Dalgety's Review, showed that in some fishing villages in very, healthy localities such as the north-west of Scotland and the north of France, the practice. of close inter-marriage, hut limited to first cousins has prevailed for hundreds of year', and careful investigations disclose no ill effects arising from it. " Huth" showed that it was difficult, in small communities to avoid close marriage because it was an absolute necessity for a fisherman to have a wife who understood the mending of nets and the preparation of fish for market On this account tho men had to chooso their help-mates from their own community, and this soon resulted in every family becoming related by marriage. Another example iu the human race of very close inter-marriag-j was the ancient Egyptian dynasty. For three hundred years this house inter-married with no apparent ill effects., as Cleopatra, the last of the race, was, by ail accounts, a perfect specimen of womanhood. On the other hand the New York State Medical Society found that there was distinct evidence to show that close marriage promoted or intensified tho tendency to some diseases. Importance of Selection. With these differences of opinion for and against inbreeding the conclusion is reached that selection is vastly more important, because it has been definitely shown that no ill effects are produced when both parents are perfectly healthy and normal, but on the other" hand, it has been equally as definitely shown that, inbreeding will intensify bad qualities just as much as it will fix good ones. All this only goes to show that inbreeding when practised by unskilled breeders is very dangerous, but in the hands of a skilled man. desirable characteristics may be fixed quickly. This has been demonstrated most ablv by such 'artists as Bakewell with his Leicesters, Bates with his Shorthorns, aiid many Australian breeders who have shown that by careful selection combined with breeding, remarkable results may be obtained. • In conclusion it may be said that in-and-in breeding is a necessity where rapid improvements are aimed at, and when these improvements are to be fixed, but the ordinary breeders who possess no particular skill should avoid inbreeding .if they wish to retain a sound constitution in their flock or herd. In other words, leave the inbreeding to the recognised skilled stud breeder, and if this is done no ill effects need be feared.