DAIRY INDUSTRY.

New Zealand Herald, Volume LXV, Issue 20080, 18 October 1928, Page 5

DAIRY INDUSTRY.

PEDIGREE AND IN-BREEDING. PREPOTENCY IN SIRES. IMPROVEMENT OF STOCK.

BY H.B.T.

A .short time ago a. dairy farmer was showing mc his pedigree bull, and, with much pride, remarked that its blood could be traced back many generations to one outstanding cow of the breed. Afterwards he si lowed mo the pedigree, and it was all he had claimed in length and origin. Ilut- when I questioned this farmer regarding (lie qualities of the bull* parents, grandparent and great-grand-parents, he knew so little about them that I gathered that none of the cows had been outstanding performer:; in recent generations. This man failed to recognise that the value of pedigree does not depend on ils length, or even on its origin, but on the length of time during which no inferior animals have been included, and on the continuous improvement of the stock produced. With domestic animals the most important forebears are those extending back to the great-great-grandparents. Those four generations arc all-important, and the list of their merit is that each succeeding generation should be 'f not superior to its predecessor. With dairy cuttle, there are only two factors which should concern the practical breeder, and these are production and heaith.

Proportion of Qualities Transmitted. Unless in-brccding or line-breeding has been resorted to, any animal has only one-sixteenth of the blood of any particular great-great-grandparent in its veins, but it has half the blood of each of its parents, a-quarler of the blood of each grandparent, and so on in diminishing influence. Hence the further back in tho pedigree (he outstanding sire or dam figures the less value it has.

Over 150 years ago, Robert Bakewell realised that there was only one method of rapidly improving stocks, so that the virtues of tho parents would not be dissipated, but would be concentrated in tho offspring. lie was the first English stock breeder who intelligently undertook inbreeding to attain this end, and succeeded to such an extent that his name has lived through the years, and his breed of sheep has been the foundation of the most valuable flocks to-day. Thomas Batis, the great breeder of Shorthorn cattle, records in his memoirs that " Mr. Bakewell lias not had a cross (from any breed than his own) for upward of 20 years; his best stock have been bred by tho nearest affinities; yet they have not decreased in size, neither are they less hardy or more liable to disorders; but, on the contrary, have kept in a progressive state of improvement."

Use of Line-Bred Sires. This concentration or intensification of food qualities in any animal produced either by in-breeding, line-breeding, or selective "mating is what the farmer must look for in any sire, with which lie hopes to improve the productiveness of his Jherd or flock. It does not matter what method is employed in breeding to secure this concentration of qualities, provided they are accompanied by sound constitution and health. It will, therefore, be seen how necessary it is for everv purchaser of a pedigreed sire to study these two features in the history of the forebears of his stock for at lea'st four generations. I stress the "four generations," for where line or in-breeding has been employed, the blood is again mathematically the same as the great-great-grandsire or dam of that generation; and, further, if the animal'is the result of close breeding for four generations and has not developed any constitutional weakness, it can be accepted that both the animal in question and the stock from which he is descended are sound.

Fear of In-breeding. Even to-day many breeders fail to secure rapid improvement in the quality of their stock because they believe that no bull should bo used in the same herd for more than three years, or no ram for more than two years, for fear of inbreeding. Certainly, in-breeding practised by the average farmer, who cannot detect the signs of constitutional weakness in his animals, can have the most disastrous effects, for, if there are weaknesses present in tho parents, he will certainly intensify them in the progeny; but for the intelligent stud breeder, nothing will serve him so well as in-breeding. The dairy farmer who is purchasing a pedigreed bull with tho object of improving a mixed herd cannot do better than buy one which is lino or in -bred, for at least four generations, in which all the females'have been heavy producers and have exhibited no signs of constitutional weakness. Such a bull is usually very prepotent in regard to production, and will effect more improvement in the herd than will one which is not linebred or in-bred.