The evolution of British cattle and the fashioning of breeds/Speculations
XII
SPECULATIONS
It is not the purpose of this book to deal fully with the principles of stock-breeding, but some phases of the question raised by the preceding chapters might be referred to with interest at least. It cannot have escaped the notice of any one who has read the last few chapters how large have been the parts played by crossing and inbreeding in bringing our British breeds of cattle to their present position. At the same time, it must be admitted that it is not clear that everything accomplished has been due to the action of those two factors. There may still be something more—there may still be the constantly accumulating change which Darwin believed in, although it is hard to think that changes which formerly took thousands and thousands of years may now be induced by man's action in two or three centuries; and there may also be De Vries's mutations or organic "jerks," the results of changed conditions in food, climate, or any other form of environment. So far these questions must be left undecided; but it seems impossible to account for the extraordinary milking powers of some animals and the beef-producing powers of others without the assistance of Darwin or De Vries or somebody else. Did any Dutch cows produce twelve hundred gallons of milk a year, or did any Dutch bullocks weigh thirteen or fourteen hundredweights at less than two years old two hundred years ago; or if they did not, could they have done so provided they had received similar treatment to that received by their descendants in Britain to-day? To answer these questions is of course to answer the former ones; but as we have no data before us to answer these, the former must also remain undecided.
These remarks lead to another phase of the same question, namely, Is it possible, without crossing, to endow a set of animals with characters which none of them already possess? For example, is it possible, without crossing, to make the North Devon as large as the Shorthorn, or as black as the Aberdeen- Angus? If Darwin's theory be correct, then it might be possible, but how long would it take? If De Vries's organic jerks occur, it may also be possible, but who is to have the patience to sit down and watch for them? On the other hand, it must be remembered that the origin of all our improved breeds has been in the selections of such men as Bakewell and his kind, of unparalleled judges as we have called them; and that when the originally selected type had been steadied or fixed by inbreeding, the breed as a whole was gradually graded up to their standard by persistent mating with the selected type.
Within the above question lies another much smaller to a breed but larger to many an individual breeder: Is it possible for a second class herd to be raised to the first class without recourse to the assistance of first class stock? Again the answer must be the same: that it may be done; but in how many years, or in how many lifetimes? Few, if any, of our first class herds have been raised in this way. Some may have been raised by continued infusion of the highest into lower types—by grading, as it is called—but most of our great stock-breeders date their entry into the highest ranks from the time they acquired the highest class of stock and commenced to eliminate the lower.
Among stock-breeders generally there is a very strong aversion to in-breeding, although it was the method of the great pioneers and is still the method in a modified form, called line breeding, among breeders of the highest class. The origin of this aversion would be difficult to trace, although it has been frequently suggested to have been biblical. It existed in Bakewell's day and how long before we do not know; but if it existed in much earlier days it is difficult to see how farmers were able to make their practice agree with their theories. Nature herself seems to have no special aversion to the practice. The wild bull keeps possession of his own glen and his own herd till he is ousted perhaps by some stranger from across the hills, but more likely by his biggest brother or his eldest son who so far has been kept at a distance by the fear of his parent's horns. According to some authors the evils of in-breeding are almost innumerable: barrenness, lack of size, milk, constitution, hair, and so on; tuberculosis, rheumatism, leanness, fatness, long legs, short legs, brainlessness, and every other form of retrogression. Families and tribes that once had the highest reputation are now no more, nearly extinct, or relegated to an inferior position. But would the type that was best half a century ago be the best to-day? Have not some that formerly were less regarded now found favour? Besides when a tribe or type gets into a prominent position, and its individual members rise in money value and so get into the hands of wealthier men but poorer judges, who is to see to their proper mating, and the elimination of such animals as are below the standard? And when animals whose money value is large get into the possession through inheritance or otherwise, of poorer men but better judges, how are these men to determine whether their purse or their taste is to prevail? In the face of some of the preceding chapters and these considerations, in-breeding must escape the charges against it with at least the Scots verdict, not proven. When once a breed has been established, however, that is to say, when it has reached such a degree of steadiness that it can be called "pure," the need for in-breeding is greatly decreased.
But what of the future? Does the past offer any guide? Previous to the discovery of Mendel's work, the dictum of the past as to the conditions for success in cattle-breeding would have been—
(i) A good judge.
(ii) Good stock.
(iii) Line breeding with old-established and in-breeding with new breeds.
(iv) Ruthless elimination of the unfit.
But although Mendelism would not alter the dictum it would increase the breeder's power by increasing his knowledge of the working of Nature's laws. Already in this paper such of the Mendelian knowledge as is yet known with regard to cattle is referred to. So far that knowledge is not great, and it is largely concerned with comparatively unimportant matters, like colour, for instance; but as the signs by which Mendelian characters can be identified become better known, it is hoped that information about much more important matters than colour may be gathered. And, when this happens, things that now come and go in the most mysterious manner will be under the cattle - breeder's control.
Perhaps the best way to make the possible power of Mendelism clearer is to consider what signs ought to be looked for in reference to a matter of some considerable importance, namely, milking capacity. This capacity varies enormously, a fact which in itself suggests a Mendelian phenomenon. Some bulls have a reputation for leaving good milking, others for leaving poor milking, stock: another circumstance pointing to the same conclusion. If milking capacity be a Mendelian phenomenon, then the way in which it will show itself will depend upon whether the hybrids between high and low milkers are intermediates or masqueraders. It must be remembered that other factors interfere with milking capacity as such alone. The cow's size, age, and health might be mentioned, for instance. If these other factors can be eliminated, then, if the hybrids are intermediates, there will be three grades of cows, viz. high grade, medium, and low grade. The cows' grade being manifest by their yield of milk, the difficult part of the problem is to determine the grade of the bull; and for this there is only one test, the test of breeding. He is either high grade, middle, or low grade. The following, table will show the grades of stock each grade of bull should get with each grade of cow: —
| High grade stock. % |
Middle grade stock. % |
Low grade stock. % | ||
| High grade bull with high grade cows should get | 100 | — | — | |
| „„middle grade cows | „ | 50 | 50 | — |
| „„low grade cows | „ | — | 100 | — |
| Middle grade bull with high grade cows | „ | 50 | 50 | — |
| „„middle grade cows | „ | 25 | 50 | 25 |
| „„low grade cows | „ | — | 50 | 50 |
| Low grade bull with high grade cows | „ | — | 100 | — |
| „„middle grade cows | „ | — | 50 | 50 |
| „„low grade cows | „ | — | — | 100 |
But the greatest difficulty of all perhaps is that a bull's grade is not known till he is at least five or six years old. How is this to be overcome? The pioneers adopted two methods; they kept their bulls till their grades, so to speak, were known—Hugh Watson's Old Jock won the sweepstakes at the Highland Society's Show at Perth when he was ten years old—and they bred from closely related animals. The former method was safest; the latter placed the chances on the right side, for there is a higher probability of the same characters being carried by near than by distant relations. But, just as the AberdeenAngus breed has been gradually made hornless, so, by constantly selecting the breeding stock—the bulls are the most important—from high grade cows a whole breed could be raised eventually to the highest milking capacity.
If the hybrids between high grade and low grade milkers were masqueraders, then apparently there would only be two grades of cows; but two-thirds or so of one of the grades would be masqueraders. The difficulty again would be to find a bull that was pure high grade. Again there is only one test, the breeding test; and in this case it might be summed up shortly by saying that if a bull is pure high grade, his daughters from both kinds of cows ought all to be high grade milkers.
One other character might be suggested, as an example. It has been found that the short legs of animals of North Devon type are dominant to the long legs of the Kerry. The same seems to be the case among Shorthorns and Aberdeen-Angus. That is, short-legged Shorthorns and Aberdeen-Angus are dominant to long-legged ones. That being so, there occurs in these breeds occasionally a long-legged animal, just as a red animal sometimes appears among Aberdeen-Angus. Bred to a short-legged beast, this animal's progeny will be short-legged, but not pure. It will be a masquerader. If it be a bull and put to short-legged cows, the progeny will also be short-legged, but half their number will be impure. If that bull be followed by another of similar character, a quarter of his progeny from the previous bull's daughters will be long-legged.
These are only two characters that might be looked into, but there are others of importance which might be suggested, viz.:—
The capacity for fat production in milk;
The capacity for fatness and leanness;
The presence and absence of black noses;
The Shorthorn and the Aberdeen-Angus shape of rump;
Thickness and thinness of skin;
Longness and shortness of face;
The shape of the horns;
A strong as against a weak constitution.
The subject must be left as it stands until future research has shown us still further into Nature's ways.