IBREEDING TO NORTHERN DANCER THROUGH MIXED-SEX STRAINS BELOW PAR

By Roger E. Lyons
Originally appeared in Owner Breeder journal June, 1998

        No topic in thoroughbred breeding is more pervasive at the present time than inbreeding. The conjecture that certain configurations of the male and female strains of male and female ancestors will optimize a mare’s productivity is especially appealing because it means that a formula for inbreeding can be used to identify the one stallion who most comprehensively completes the pattern. The task is a simple one, really. All that a breeder must do is select a stallion whose ancestry fills out the pattern.
        The central claim made for these patterns of inbreeding is that they have a uniform effect, regardless of the ancestors involved. This contradicts the principle that different ancestors have different effects, that the maintenance of hybrid values depends upon a variety of influence. Breeders should be mindful that the names they use to fill out the pattern are not mere place-markers. They are not merely functions of a formula. Rather, they are thoroughbred ancestors of vastly differentiated potential.
        In a random model of breeding all ancestors would offer the same opportunities for inbreeding, but observation of successful cases indicates that different ancestors suggest different models of optimal expression. Some otherwise influential ancestors are simply not suitable for inbreeding. Inbreeding to others can be favorable, but only when descending through certain of their offspring. Whatever stock might be placed in patterned inbreeding must take into account the optimal expressions of particular ancestors.

THE SEX OF STRAINS
        How effective it is to inbreed to Buckpasser, for example, is a controversial question. It depends on what you make of the quality and quantity of the 34 SWs so inbred. But, when you consider that 76 percent of these SWs are inbred through all-female strains, then you get a message concerning how Buckpasser might fit into an inbreeding pattern. The main point to be made about this is that, on the whole, Buckpasser’s females were superior to his males. Not a single SW is inbred to Buckpasser through all-male strains. A further warning is implied by the fact that, of the eight SWs inbred to Buckpasser through mixed-sex strains, seven are colts. This does not seem a favorable model of inbreeding when you consider that your prospect of getting a colt is only 50 percent.
        Nashua’s profile is similar to that of Buckpasser, with 65 percent of the SWs inbred to him through all-female strains and none through all-male strains.
        Of all of the ancestors that might comprise the nearest inbreeding, Rough’n Tumble is possibly the most versatile, meaning, in part, that virtually all of the male and female strains through which he descends combine at least tolerably with one another. In fact, inbreeding through mixed-sex strains occurs in 75 percent of the 71 SWs inbred to him, 10 percent of these SWs involving three strains.
        Raise a Native contrasts especially with Buckpasser and Nashua in that, of the 127 SWs inbred to him, only 33 percent involve a female strain at all. That only two SWs are inbred to Raise a Native through all-female strains suggests that his female strains are, on the whole, vastly inferior to his male strains, Real Quiet notwithstanding (Meadow Blue is an uncharacteristically viable female strain of Raise a Native).

NORTHERN DANCER'S MALE STRAINS
        In view of the high frequency of Raise a Native’s male strains, it is remarkable that Northern Dancer, the most important contemporary subject of nearest inbreeding, is even more radically oriented towards male strains. Only 21 percent of the 420 SWs inbred to him involve mixed-sex strains. Only four SWs are inbred to Northern Dancer through all-female strains.
        Just how superior his male strains have been is underlined by our last survey, conducted in 1995. We compared Northern Dancer inbreeding in a Keeneland September auction sample with its occurrence in a SW population. In the auction sample we found that 38 percent of the cases of inbreeding to Northern Dancer involved mixed-sex strains, compared with 20 percent in the SW population. That is to say, the commercial opportunity of inbreeding to Northern Dancer through mixed-sex strains far exceeded performance.
        Given the unpredictable variety of thoroughbred influence, the only amazing thing about this is that commercial breeders would have expected so much of the female strains. The female ancestors through whom Northern Dancer descends to contemporary runners, like the female strains of most notable ancestors, are inferior to the male strains that breed his influence forward. Everything about Northern Dancer’s record points to that fact--his extraordinary record as a sire of sires, his less exalted record as a broodmare sire, and his undistinguished record as a broodmare sire of sires. If you can resist all of the unsubstantiated claims you have heard about the benefits of inbreeding through strains of opposite sex, then logic must prevail upon you to avoid inbreeding to Northern Dancer when a female strain is involved.
        There are exceptions, of course. As is suggested in Table I, Fanfreluche, Royal Statute, and Sleek Dancer do seem to stand above the rest of the female strains. That said, inbreeding should only involve the best strains available, and the best strains of Northern Dancer are mostly male.

NINJINSKY II PLUS ?
        One other major demurrer is in order concerning the use of female strains. In our 1995 survey, 50 percent of Northern Dancer inbreds involved Nijinsky. That proportion has fallen--and significantly--to 45 percent, most of the difference occurring very recently. Other strains are apparently stepping up to approximate his function. We also noted in passing that, when a female strain was used, Nijinsky’s frequency dropped significantly. Nijinsky’s aversion to female strains is even more pronounced in our most recent survey. When the 146 cases of Northern Dancer inbreds involving Nijinsky are removed from the SW population of Northern Dancer inbreds, then the level of inbreeding through mixed-sex strains among those that are left rises from 20 percent to 35 percent, almost what it was in our auction group. This happens because 91 percent of the SWs that involve Nijinsky are inbred through all-male strains--that is, when Nijinsky is involved, the frequency of inbreeding through mixed-sex strains is one-fourth that of the rest of the Northern Dancer inbreds, at only nine percent. This is clear evidence that a stallion with a female strain of Northern Dancer is an especially low-percentage choice for a mare with the Nijinsky strain, and vice versa.
        The web site of Jack Glengarry, a New Zealand bloodstock consultant, warns that inbreeding through all-male strains "can lead to plodding colts," but "the filly foals can be quite exciting." If so, then shouldn’t at least a majority of the SWs inbred to Northern Dancer involving the Nijinsky strain and another male strain be fillies? In fact, only 44 percent of them are fillies. Since colts among the Northern Dancer inbreds have a majority of only one SW, Nijinsky combined with another male strain actually decreases the proportion of fillies.
        Coincident with this, note that in Table II, the Nijinsky-Storm Bird combination is one of the most frequent crosses among Northern Dancer inbreds. This was predicted by Ken McLean back in 1986. None had occurred as of our last survey, and I committed the indiscretion of theorizing about this. On a professional level, I am taught a lesson in the fundamental conservatism of science: never try to push a theory farther than it will go under its own power. At a more personal level, I am reminded of the old blues song, "Don’t Make Your Move Too Soon."
        McLean is vindicated. But what was wrong with my theory reveals something important about the broader context of Northern Dancer influence, which will be the starting point of next month’s episode. The lesson here is that, when inbreeding in accordance with a pattern of gender distribution, the particular ancestors involved are crucial. The natural proclivities of a particular ancestor, especially as regards the strains through which the ancestor is optimally expressed, may not fulfill the requirements of the larger pattern.

Table I: Most frequently occurring strains (4+)

Strain			SWs	Male	Female

Nijinsky II		146	78	68
Lyphard			91	48	43
Danzig			38	22	16
Vice Regent		34	14	20
Nureyev			29	16	13
Be My Guest		22	11	11
Sadler’s Wells		20	12	8
Northfields		19	8	11
Fanfreluche		17	10	7
Storm Bird		14	6	8
The Minstrel		13	4	9
Try My Best		11	6	5
Sovereign Dancer	8	4	4
Royal Statute		8	4	4
Lomond			8	0	8
Viceregal		6	3	3
Sleek Dancer		6	3	3
Secreto			6	4	2
Northern Taste		6	5	1
Dancing Count		6	2	4
Topsider		5	1	4
Northern Answer		5	3	2
Far North		5	3	2
Fairy King		5	5	0
Rose Red		4	3	1
One For All		4	1	3
Lauries Dancer		4	1	3
Grand Chaudiere		4	2	2
Dixieland Band		4	1	3
Cool Mood		4	3	1


Table II: Most frequently occurring combinations (3+)

Strains				Occurs

Nijinsky II - Lyphard		38
Nijinsky II - Danzig		14
Nijinsky II - Nureyev		12
Nijinsky II - Vice Regent	9
Lyphard - Danzig		8
Nijinsky II - Storm Bird	7
Nijinsky II - Northfields	6
Lyphard - Sadler’s Wells	6
Nijinsky II - Sadler’s Wells	5
Lyphard - Nureyev		5
Lyphard - Be My Guest		5
Nijinsky II - Be My Guest	5
Nureyev - Northfields		4
Nijinsky II - Lomond		4
Vice Regent - Cool Mood		4
Nijinsky II - Secreto		3
Nijinsky II - Sovereign Dancer	3
Nijinsky II - Northern Taste	3
Lyphard - Try My Best		3
Lyphard - Lomond		3