THE INHERITANCE OF HORNS IN CATTLE. SOME FUt~THE:~ DATA. B~z A. D. BUCHANAN SMITH. A~d,mal B~'eedin9 Resec~'eh Depa~'t'men4 Unive,rsi~y of Edinbu~9 h. (With One Plate and Four Text-figures.) Wm~N tile writer :first :heard of certain exceptions to the well-estab- lished rule of simple dominance of the polled condition in earle, he paid littIe attention to them. Further records of such exceptions, however, were encountered, and it was then felt that the subject merited fuller consideration. The following report concerning such exceptions came from two main smtrees: from Northern Rhodesia, where the crosses concerned were Aberdeen-Angus bulls and native cows, and from England, where Crosses involving the Park Cattle, between their two types and various other breeds, appeared to give anomalous resuRs. A. RttO.DES:[ANNATIVE CATTLE. For precise information regarding the case in Northern Rhodesia, the writer is indebted to N_r R. A. S. ~Iacdonald, M.R.C.V.S., of the Veterinary Experimental Station, Chilanga. His facts relate mainly go two cases, and are as follows: 1..In a herd of Angoni and hfashukulumbwe cows, the majority of which were pure native bred (though a few showed slight traces of Hereford or Shorthorn blood, bug none had any Aberdeen-Angus blood), a p~e bred registered Aberdeen-Angus polled bull was placed (see photograph). The cows were alI horned, ani[ in colour were red, red- and-white or dun. There were practically no blacks. FiRy-one of g.heir progeny so produced were traced as under: 27 heifers all compleSely polled. 9 bulls all completely polled. 15 bulls mostly with distinct horns or buds. All were completely black with the exception of a few white ~aces. This was the case in 120 such calves. 2. In another herd, a pure bred registered Aberdeen-Angus btdl (polled) was mated to native cows, all of which possessed the typical 3(16 [-[or~8 in Cattle heavy horn. In this ease, all f;he progeny were completely black, practi- cally all the heifers polled, and practically all the males with buds, short drooping horns, or ordinary short horns. It was found diNcuR to obtain more detailed information as regards exact munbers, and rather than obtain figtu'es which could not be guaranteed to be correct, it was considered advisable merely to give the bare outline of facts. The following conclusion concerning these two herds, which are typical of several others, may, i~herefore, be con- sidered indubitable and has been confirmed by correspondence: That a registered Aberdeen-Angus bull (polled) when mated to the native cows of Northern iRhodesia (horned) produced calves, all the heifers being polled and withou~ scars, and the majority of the bull calves possessing horns of various shapes, .a few being only scurred, and a very few being polled. As the cattle of Northern l~hodesia are being rapidly "graded" up, it is tmlikely that the native breed will retain their purity much longer. Andsince it seemed improbable that more exact facts were likely to be obtained, or that the reciprocal cross was likely to be made, it is con- sidered advisable to record these facts as they stand. The conclusion, therefore, is that in rantings with the indigenous cattle of Africa, horns are inherited as a sex-Iimited character; that ~s to say that the factors for their expression, are either dominant in the male and recessive in the femaIe, or otherwise governed by sex. Sinces in the ordinary domesticated breeds of cattle, the polled condition behaves as a simple dominant to the horned, and since there was ~ome blood of domesticated breeds in certain of the native cows used in this cross, it would appear logical to presmne that either the sex-limited transmission of horns, or the simple dominance of the polled condition, is the rule in cattle, and the one condition may be altered to ~he other by the action of one or more pairs of modifying factors. A point worth noting in this connection is that although ~his cross reveals a sex difference in )espec~ of horns, castration of the males does not appear to modify the horns to any great extent, as is the case in other animals whose horns are modified or conditioned by sex, e. 9. sheep (Narshall and Hammond, 1914), though Arkell (1912) shows this to be not so marked in the case of Merinos. B. PAP~I(CATTLE. The report concerning the other exception to the rnle of simple dominance of the polled condition in cattle, came from the Wild White A. D. BUOt{ANAN Sm'rn 367 Park Ca~le breeders in ~heir opera,ions towards bee formation of ~he domesCicaied breed of Park @stale. Since 1923, the writer has been in Couch wigh several breeders in an effort go obtain daga regarding ghe inheritance of coat colour in crosses of Park Cattle and[ other breeds. AC first, no record was taken regarding the inheritance of horns, as the figures appeared merely go be abnormal ratios. But, since practically nil the breeders with whom contact was made had obtMned qniCe nnexpec~ed ratios of horned and[ polled calves, resulting from certain crosses, iC was considered a,dvisable Co obtain some fro:Chefreliable data. The dabs which follow were obtained from Sir Claud Alexander, Ba,rt., of FaygaCe, Sussex, and Nit A. H. L. Bohrmann, F.Z.S., of Ide Hill, Keng, both of whom are leading breeders of Park @attic, and reeognised authorities on the breed. Before tabulating their experiences, ig musg be staged Chat there are, at the very leas$, ewe disCincg types of Wild White Park Ca~Cle which form ~he foundation stock for these experiments. These are called the horned and the polled. The horned were formerly ~he more common in ~he notch and wesg of Great Britain, and are now best represented by ghe Chiilingham Herd in Northumberland belonging to ~he Earl of Tankerville, and ~he @adzow1 herd in Scotland, the property of the Duke of I-Iamilton. The former herd has had very ligCle, if any, addition of foreign blood within ~he pas~ ewe huncked years. The latter is no5 qnige so pure, yet has a definite type, though some West I-Iighland blood has been in~rodueed in~,o ig as well as some Chillingham. The 1 Of ghis herd, t~{r Brown, Ohamberlain go ghe Duke of Hamilton, reported about ~he year 1886, f~haL "The cows seldom have horns" (8~orer, 1879, p. 339). This was corroborated by Sir John Orde of Iiihnory, u ~fgegilllvray (in his prize essay), and R[r Ohandos- Pole-@ell. The latter in Oegober 1874 fmmd ghe herd engirely horned. Sir John Orde sugges~ sghag bhe herd acquired horns after ghe ingrodnetion of a Highland bali (SCorer, pp. 341-845}. (See also Auld, 1888, pp. 507-508.) The earliest Mmwn reference to ghis herd being potled is in 1809 when a local poeg, l~oberg Burns of tic,mitten, in the note go his poem, "Cadzow Casgle," dedieaf~ed go Sir Wal~er Seo~, wrote ~llag'~4e bulls ~hen in use were mostly "humble" (i.e. polled) and ~ha~, some of ~he cows had "/~ne moony horns." Sir Wglger Beobg himself in his early poem, "Cadzow C~slAe," wriggen a year or ~wo previously, bug dealing wi~h evengs of ghe year 1569, describes the death of a wild bull "wigh black hoof and horn," despi~e f.he fac~ ~ha~ he was well acqnMnged wigh polled eagtle, and a friend of ~[r Hugh Wagson, one of ghe founders of Aberdeen-Angus eaggle. As the original wild Caledonian e~ttle were undoubtedly horned, ig would appear as ghongh ghe Cadzow herd became polled eigher by a mutagion or ghe infusion of polled blood, imssibly after ~he Oromwellian period, when, a~ ~r Brown says, ig was "nearly extirpgged." Ig is suggesgive tha~, according ~o Burns, in 1809 ghe bulls were polled and cows horned, where~s on ghe evidence of Iager aughorigies, e.g, h{r Brown, ~he females were more fre- quengly polled. TMs mighg indicate ghat polled blood was ingroduced through ghe bulls ~bout bhe beginning of bhe sengury, jusg as bhe honied blood was several decades Inter. 368 Horns in Uatt[e :Fig. I. :Horned :Park bull from the Char~ley I-Ierd, "Fayg~te :Brace." Though ma~ed to many polled cows, this bull left only one polled calf, and ~h~ a twin to a horned cMf. (:By courtesy of Sir Claud Alexander, Bart.) (Figs. 1-4 by courtesy of her ~. A. S. ~Iaedonald, ~f.t~.O.V.S.) Fig. 2. "FaygM;s C4ar~er," a ~ypieM horned P~rk cow by a horned Park bull, and out of a polled cow from ~ pure polled herd. (Photograph by the owner, Mr A. H. L. ]3oln,m~nn,) A. D. BlJm-iAm~.~ S~H,r~t o69r b Fig. 3. Horned heifer, out, of a horned Shorthorn-Ayrshire eow by ~ polled Park bull. This bull, when mated to a pedigree Shorthorn cow, produced a polled calf. (Photo- graph by Mr A. }:L L. Bohrmanm) iFig. 4. I{orned blIll (14~ monghs old) by a horned Park bull (whi~o wigh black points) and out of an Aberdeen-Angus cow (polled, bh~ek). (Photograph by Mr J. Cob.) 370 fIo,r~s i'~ 6~c~ttle Ghartley herd, now belonging to the Duke of Bedford, is also horned. It contains some Longhorn bl.ood (introduced after removal from Chartley go Wobm'n). The polled Wild Park @attle were ioeat~ed chiefly in the middle and eastern counties of England.