IN-BREEDING.

Waikato Times, Volume 112, Issue 18808, 2 December 1932, Page 12

IN-BREEDING.

EVIDENCE IN FAVOUR. fi MATTER FOR PAST-MASTERS. Bull sales arc coming on and buyers arc studying pedigrees which is necessfirv as though an animal with a pedigree may he wortliless to breed from, one without one is certainly so. hvery effort is being made to increase toe average production of our daii> hcids, though possibly in-breeding _ is not practised to any extent. thc're ate many reasons why it should not become general, ‘the principal of which Is that (he mating of two closely related animals intensifies with remarkable rapidity any conslitulional weakness or physical defect common to hoth parents. On the other hand inbreeding is the short cut to success under the guiding hand of the skilful breeder, as it allows of valuable qmlJlics being transmitted intact and undisturbed by any mixture of outside blood. For instance, the mating of a hull with his high-producing daughters is po| only safe, hut advisable, provided that both are of robust constitution. The male progeny of such a union would he- much more prepotent than a hull bred in Ihe ordinary way, and the breeder could with great advantage use a hull so bred on seieeled cows of his own herd.

in-breeding has linen practised by every noted stock breeder, and it is on record thal ihe Polwarth Hock of Border Leiccslers never had fresh blood introduced for a whole eintury. The last breeder of the name, however, provided a climatic outcross by keeping a portion of the dock on a farm In the Lolhians. where soil and conditions were different from Mertoun.

To digress shortly a striking example of I lie value of a climatic outcross is furnished in pigeon breeding. A fancier in France continued inbreeding until his birds ceased to be prolific, and iie then established another breeding station in England with Ihe result that the birds from the French stock again bred freely. Sir

John Scabright, Ihe famous poultry authority, says: “The evil effects of close inter-breeding may tie checked, or quite prevented, by 'the related individuals being 'separated for a few generations and exposed to different conditions of life.”

According to these views, two herds might be kept in different districts and in-breeding carried on safely for an indefinite period. The Colling Bros.’ greatest success in breeding Shorthorns was the famous bull Comet, the produce of daughter and sire, and his darn the produce of dam and son, while his sire was bred from brother and sister. Here, therefore, was a case of intensive in-breeding leaving the most prepotent and valuable sire in Shorthorn history.

The shepherds along Hie Cheviol Hills have evolved the finest race of sheep-dogs in Die world largely through close in-breeding with one particular strain, and ihe result is that, 90 per cent of the winners in sheepdog trials, not only in Britain hot all over the dominions, can lie traced back to one dog. the St. Simon among Hie sheep-dogs of the Empire. Such is ihe prepotency and transmitting power of in-bred stock that there is not even yet a single flock of Border Leicester sheep of any note Hie pedigrees of which aro clear of Polwarth blood. There are many , instances In the human family where (lie inter-mar-riages of close relations have been carried on for many generations without any ill-effecls; as. for instance, on Pitcairn Island and Iceland. The Claddngh in Cahvay have had no outside blood for close on a century, and though I heir numbers arc small they are a hardy, 'robust people. Professor Mnhal'fy refers lo Cleopatra as “a speaking instance of Ihe falsehood of a prevailing boli'T Hint ihe inlcr-mar-rlage of near relations produces a decadence in the bum an race.” Much evidence can therefore he adduced to prove Mint excellent results can l>o obtained by in-breeding, but we must keep in mind that all qualities, good and had. in Mic mated animals arc intensified by Mi is method of reproduction. Thus a slight physical failing may result in a near approach to deformity in Uni offspring, and a mild form of constitutional weakness lead lo serious trouble in the in-bred family. i

In wild animals there is no sueii lliing as selection except Nature’s taw, Ihe survival of the 111.tost, and il is only by following on Die lines of Nature. Die greatest of all teachers, that breeders can make a success of in-breeding. Choose only animals of outstanding merit, as though intensified perfection is most desirable. It Is difficult enough lo gel away from mediocrity without i's being deliberately intensified by in-breeding, a praclicc which can, nfler all is said and done, only be safely attempted by past-masters in the breeder's art.