STUD-STOCK BREEDING.

New Zealand Journal of Agriculture, Volume XXVII, Issue 3, 20 September 1923, Page 157

STUD-STOCK BREEDING.

Mr. W. Perry,

ADVICE REGARDING SHEEP.

Paper communicated to the New Zealand Board of Agriculture by

“ Penrose,” Masterton

It is with a feeling of diffidence that I consent to give an opinion on breeding of stud animals. The experience I have had has been wholly with long-woolled sheep, and I am of opinion that methods that will work out quite well when breeding Merino sheep, on account of their purity and evenness of type, will not be satisfactory with long-woolled sheep.

Having been in charge of a Lincoln flock for forty years, a Romney flock for sixteen years, and an English Leicester flock for ten or twelve years, it has given me a very good opportunity of following different methods of breeding and watching results, and has practically brought me to the conclusion that none of the systems, such as in-and-in breeding, line-breeding within the same line of blood, line-breeding with unrelated families, or consistent outcrossing, can be followed exclusively when breeding long-woolled sheep. Undoubtedly close breeding or keeping within the same blood is the only way to produce great and valuable sires, but there are limitations beyond which the breeder must not go. Great judgment is required in this matter to know when the danger-line has been reached. The loss of vitality comes on gradually and is not easily detected ; the wool-covering is affected as well.

There is a lot of literature on breeding,' and most of the writers quote the pedigrees of champion animals as being closely inbred ; but nothing is known of the percentages of failures the breeders of . those animals had in their matings.- . There is no straight. road to success. With all the advantages possible, it is not so difficult to reach a high standard with a flock as to maintain it.

There are several recognized methods of breeding — (i) In-and-in breeding ; (2) line-breeding with distant strains of the same blood ,; (3) line-breeding with distinct families ; (4) outcrossing, which means continuous change of blood.

The method of outcrossing is very misleading to the young breeder. If he is careful to select sires similar in appearance to his flock he will apparently produce some useful-looking-animals at first, but the more fresh blood he introduces the more uneven will be- the result. I had this experience when I first started with Lincoln sheep, ‘ and did not do any good until the method, of line-breeding was adopted. Rams bred on the outcross principle are no good to the stud breeder, and very little better for the ordinary flockmaster. Sheep bred in . this way are much like the crossbred: they mature quicker than the line-bred sheep, and at two-tooth they, look very promising, but do not last and the result of mating.them with crossbred ewes will be anything but satisfactory. Any one who has read and studied Mendel’s

laws of heredity will quite easily understand why the outcrossing methods cannot lead to any great success.

There is no question that many breeds ; have been made by the method of in-and-in breeding, which means the mating of nearly related animals ; but once a breed is established there does not seem so much need to practise it to any great extent. It is decidedly useful, if one procures an outstanding sire, to mate a few nearly related ewes of the same family and ; type, ■ the progeny of which, if successful, would be very valuable ; but to continue would, I think, only be courting trouble. Before attempting to inbreed it is necessary to have an intimate knowledge of the history of the animals to be mated. I have tried mating in this way with varying success ; in one particular instance the result was a decided success.

Line-breeding with distant strains of the same blood is the ideal system. By selection leading faults can be eliminated, family lines can be established, and a flock, if large enough, can be carried on a number of. years on these lines improving all the time. But there comes a time when, if some fresh blood is not introduced, the young sheep will be slower to mature and harder to get into condition, and will show less covering on their points and a general falling-away in vigour. I had this happen with my Lincoln flock, and if a flock is allowed to go too far it takes quite a time, to bring it back to normal. To avoid this happening, a safe method is to purchase a few outstrain ewes, use the home ram on them, and if the results are satisfactory use the half-blood through the flock. It may be that selection has •something to do with slow maturity after a flock becomes closely bred for some years. A good sire in either the Lincoln or Romney breeds must have a lasting fleece — i.e., it should grow good wool until four or five years old. A sheep which will carry sound wool until that age is invariably a very firm-fleshed animal and free from excessive fat. . These animals are a little slower in coming to maturity, and the more you inbreed them the more you intensify the slowmaturing qualities.

Line-breeding with distinct strains of blood is no doubt a safe method for the beginner, but the great difficulty is to get a number of separate strains of blood of equally good quality and alike in type to start with. It would take years to bring a flock bred in this way to anything like evenness.

To be successful at stud breeding a . person must have a natural gift for observing the good and bad points and the general characteristics of each animal; by so doing he will know all his best animals by sight, which is of great assistance when dealing with the flock.

The safest method the young breeder can adopt is to make up his mind on the type of sheep he would like to breed, select his stock from the breeder whose sheep come nearest to this ideal, and continue doing so as long as the parent flock continues to be up to standard. As time goes on, if he is a keen observer of his animals, he will be able to analyse them at a glance. When this stage is reached, success should crown his efforts. Suitable climate and soil for the particular breed are essential; good judgment in selecting and mating, and good judicious feeding are all necessary before success can be obtained.