IN-AND-IN BREEDING

New Zealand Mail, Issue 1315, 13 May 1897, Page 5

IN-AND-IN BREEDING

ITS BENEFITS AND INJURIOUS RESULTS DISCUSSED. [By J. A. Craig, Winconsin, U.S.A.] lb may be said, in brief, that the beneficial effects of in-and-in breeding are that it is of material assistance in evolving and maintaining a type, it intensifies characteristics, and it is conducive, to quality. It does not follow with surety that because animals are related that they are of similar type. Oftentimes brothers and sisters illustrate extremes in appearances, but it is none the less true that there is likely to be more similiarity between animals that are closely related than between those that are distantly so. It is this liability to variation, even among close relations, that keeps the principle of selection to the fore, without any respect to the method of breeding that is followed. In the evolution of a new breed of sheep, in and-in breeding is a necessity for the purpose of fixing a type from diversified material, and to strengthen characteristics so that they may be prepoteut over all other influences ; hence in the establishment of all the breeds of sheep there was a time when in and-in breeding was absolutely necessary, and the breeders in making the breeds had to follow it. In reference to the comment that in-and-in breeding is the road to quality, ‘here is no doubt as to its effectiveness in that direction, but it is usually a refinement that indicates weakening of the constitution. A thin skin, light bone, and fine hur are the evidences of such quality, and these are indicative of a lack of constitution. The injurious results that follow clo-e in-and-in breeding ere tendencies towards weakness of constitution, and all the disfigurements in appearance that this implies, together with infertility. In my estimation,’these are the source of the most baneful troubles that ma'y reduce a flock. Weakness in constitution means the most favourable conditions for the introduction of all diseases that sheep are likely to have. To indicate how susceptible in-and in bred animals are to defects and diseases, let me cite one instance that has occurred in my experience. A ram of excellent type was used on grade ewes. The best ewe lambs were retained, and owing to force of circumstances, these were bred to their sire. A defect in the ram that had escaped me asserted itself in the second generation. The ram was slightly crooked in his hind legs, and the lambs in the first generation failed to show this defect, because of the counter influence of the ewes ; but in the second generation the lambs when quite young were so deformed and weak in their hock that they were almost helpless.