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Show 120 GOOD FROM CROSSING-. CHAP. XVl l. of experience has convinced him that when two nearly related. animals are quito sound in constitution, in-and-in breeding docs not induce degeneracy ; but he adds that he "does not pride himself on breeding from tho nearest affinities." In France tho Naz flock has been bred for sixty years without tho introduction of a single strange ram.10 Nevertheless, most great but~cders of sheep have protested against close interbreeding prolonged for too great a length of time.U Tho most celebrated of recent breeders, Jonas Webb, kept five separate families to work on, thus "retaining the rct]_uisito distance of relationship between tho sexes." 12 Although by the aiel of careful selection tho ncar interbreeding of sheep may be long continued without any manifest evil, yet it has often been the practice with farmers to cross distinct breeds to obtain animals for tho butcher, which plainly shows that good is derived from this practice. J'lfr. Spooner sums up his excellent Essay on Crossing by asserting that there is a direct pecuniary advantage in judicious cross-breeding, especially when the male is larger than the female. A former celebrated breeder, Lord Somerville, distinctly states that his half-breeds from Ryolands and Spanish sheep were larger animals than either the pure Ryclands or pure Spanish shoop.13 As some of our British parks are ancient, it occurred to me that thoro must have been long-continued close intcrbroccling with tho fallow deer ( Cerv~~s duma) kept in them; but on inquiry I find. that it is a common practice to infuse now blood by procuring bucks from other parks. Mr. Shirloy,14 who has carefully studied the management of deer, admits that in some parks there has been no admixture of foreign blood from a time beyond the memory of man. But he concludes "that in tho end " the constant breeding in-and-in is sv.rc to tell to the disadvantage of " the whole herd, though it may take a very long time to prove it; '' moreover, when we find, as is very constantly tho case, that the intro" duction of fresh blood has been of the very greatest use to deer, both "by improving their size and appearance, and particularly by being of " service in removing the taint of ' rickback,' if not of other diseases, to "which deer arc sometimes subject when tho blood has not been "changed, there can, I think, be no doubt but that .a judicious cross " with a good stock is of the greatest consequence, and is indeed essential, " sooner or later, to tho prosperity of every well-ordm·ed park." Mr. Moynell's famous foxhounds have been adduced, as showing that no ill ef:Iects follow f]:om close interbreeding; and Sir J . So bright ascertained from him that he frequently bred from father and daughter, mother and 1° For the case of the 1\:Icssrs. Brown, see 'Gard. Chronicle,' 1855, p. 26. For the Foscote flock, 'Gard. Chron.,' 1860, p. 416. For the Naz flock,' Bull. de la Soc. d'Acclimat.,' 1860, p. 477. 11 Nathusius, 'Rindvieh,' s. 65; Youatt on Sheep, p. 495. 1 ~ 'Gard. Chronicle,' 1861, p. 631. 13 Lord Somerville, 'Facts on Sheep ancl Husbandry,' p. G. Mr. Spooner, in 'Journal of Royal Agricult. Soc. of England,' vol. xx., part ii. See also an excellent paper on the same subject in 'Gard. Chronicle,' 1860, p. 321, by :Mr. Charles Howard. H 'Some Account of En"'lil:lh Deer Parks,' Ly hvelyn P. Shirle;, 18G7. CnAP. XVII. EVIL FROM INTERBREEDING-. 121 son, and sometimes even from brothers and sisters. Sir J . Scbright, however, doclarcs/5 that by brooding in-and-in, by which he means matching brothers and sisters, he has actually seen strong spaniels become weak and diminutive lapdogs. The Rev. W. D. Fox has communicated to me tho case of a small lot of bloodh01mds, long kept in the same family, which had become very bad brooders, and nearly all had. a bony enlargement in the tail. A single cross with a distinct strain of bloodhounds restored their fertility, and dxovc away tho tendency to malformation in the tail. I have heard the particulars of .another case with bloodhounds, in which tho female had to be held to the male. Considering how rapid is tho natural increase of tho dog, it is difficult to understand the high price of most hi~hly improved breeds, which almost implies long-continued close interbreeding, except on tho belief that this process lessens fertility and increases liability to distemper and other diseases. A high authority, :1\Ir. Scrope, attributes the rarity and deterioration in size of the Scotch deerhound (the few individuals now existing throughout the countl·y being all related) in largo part to close interbreeding. With all highly-bred animals there is more or less difficulty in getting them to procreate quickly, and all suffer much from delicacy of constitution; but I do not pretend that those effects ought to be wholly athibuted to close interbreeding. A great judge of rabbits 16 says, "the long-eared does are often too highly bTed or forced in their youth to be of much value as breeders, often turning out banen or bad mothers." Again : "Very long-eared bucks will also sometimes prove barron." Those highly-bred rabbits often desert their young, so that it is necessary to bavo nurse-rabbits. With Pig_s there is more unanimity amongst breeders on the evil e:fl'ects of close interbreeding than, perhaps, with any other large animal. Mr. Druce, a great and successful breeder of the Improved OxfOTclshires (a crossed race), m·ites, " without a change of boars of a different tribe, but of the same breed, constitution cannot be preserved." 1\Ir. Fisher Hobbs, the raiser of the celebrated Improved Essex breed, divided his stock into three separate families, by which means he mailltainod the breed for more than twenty years, " by judicious selection from the thTee distinct fam,ilies ." 17 LOTd Western was the first importer of a Neapolitan boar and sow. "From this pair he bred in-and-in, until the breed was in danger of becoming extinct, a sure result (as 1\fr. Sidney remarks) of in-and-in breeding." Lord Western then crossed his Neapolitan pigs with the old Essex, and made the first great step towards the Improved Essex breed. Here is a more interesting case. J'lfr. J. Wright, well known as a breeder, crossed 18 the same boar with the daughter, granddaughter, and groat-granddaughter, and so on for seven generations. The xesult was, that in many instances the offspring failed to breed; in others they produced few that lived; and of the latter many were idiotic, without sense 15 ' The Art of Improving the Breed,' &c., p. 13. With respect to Scotch deer-hounds, see Scrape's ' Art of Deer Stalking,' pp. 350-353. 16 'Cottage Gardener,' 1861, p. 327. 17 Sidney's edit. of Youatt on the Pig, 1860, p. 30; p. 33, quotation from l\'lr. Druce; p. 29, on Lord Western's case. 18 'Journal, Royal Agricult. Soc. of England,' 1846, vol. vii. p. 205. |