This article describes research conducted in 2008 and which appeared in my first book about Fell Ponies. More information about the book can be found at the end.
Considerations for a Rare Breed
The Fell Pony population worldwide continues to grow, and from a rare-breeds perspective, the breed is considered to be recovering. Nonetheless, Fell Ponies are still considered rare by the Rare Breeds Survival Trust in England and the American Livestock Breeds Conservancy.
One of the challenges rare breeds face is a limited gene pool because of population bottlenecks in their history. The Fell Pony has had at least two such bottlenecks, generally at the times of the two world wars. (1) To maximize the genetic diversity that remains in the breed, it can be helpful to identify bloodlines that are becoming rare within the breed and develop conservation strategies for them.
The Search for Unrelateds
The search for rare bloodlines isn’t just a conservation strategy, however.Over the past several years as I have conversed with master breeders, searching for suitable outcrosses has often been a topic of discussion.These breeders are looking for ponies unrelated to their stock to continue their breeding program.The problem is generally posed in terms of a need for a stallion, as the breeders wish to continue their mare lines.They are always on the lookout for ponies of sufficient quality from unused lines to breed to their newest fillies and sometimes to their oldest mares.When I visited Cumbria in 2005 and 2006, I was fortunate to see first hand the results of these breeders’ searches for unrelated blood lines.In my research since then in the stud books of the Fell Pony Society, the ponies I saw then have shown up as having rare blood lines.
Rare for a Reason?
As I’ve researched rare bloodlines, other ponies that I’ve seen in person have also shown up as having rare bloodlines. They, however, have led me to ask a number of questions. For instance, have these bloodlines become rare for good reason? Have breeders left these bloodlines behind intentionally? Were the ponies in those lines straying from the breed standard? To my eye, the few ponies I’ve seen in this category were not good examples of Fell Ponies. Perhaps their bloodlines are best left behind. These examples point out the importance of considering the quality of the pony as well as the status of its bloodline before deciding to undertake conservation measures.
Equines present special challenges for breed conservation because they take so long to reproduce. In addition, some of the most common faults in the Fell Pony breed – coarse heads, long backs and poor shoulder or hind leg conformation - take many generations to correct. When a pony with a rare bloodline has one of these faults, is it worthy of the multi-decade effort it could take to improve the pony’s line and continue to include it in the breed? Would enough genetic diversity remain to justify the time and effort?
From a rare breeds standpoint, it is important to consider preserving rare bloodlines. In general, I trust the decisions of long-time breeders in England regarding leaving some bloodlines behind. Nonetheless, knowing which ponies have these rare bloodlines is important. Some breeders may learn of the value of their breeding stock from a rare bloodlines perspective. Perhaps others will become interested in evaluating some of the ponies as potential outcrosses and considering whether their contribution to the breed is worthy of a conservation effort.
One tool that can be used to identify rare bloodlines is the Mean Kinship analysis. Mean Kinship (MK) is a calculation that measures the relatedness of a particular pony to the rest of the ponies in a given population. The Fell Pony Pedigree Information Service of raresteeds.com provided numerous mean kinship analyses for the breed. When considering rare bloodlines, one of these analyses is of particular interest: the breeding population in a particular year - the sires and dams of a particular foal crop. This analysis indicates both which ponies represent rare bloodlines but also which ponies have been chosen by breeders as being worthy of being bred. The last year for which this analysis was available was 2007.
A low MK value means low relatedness to the rest of the population, hence a rare bloodline. The table on page 15 lists the sires and dams of the 2007 foal crop that have a low MK value and therefore represent a rare bloodline.
There is one case when a low Mean Kinship may not mean a rare bloodline. If a particular pony is itself inbred, meaning it has the same pony in its pedigree multiple times, it can have a low MK value. The low MK value results from the fact that the pony has few relatives (because of replication of ancestors) to compare to the rest of the population. Therefore, its low MK value doesn’t necessarily mean it has rare bloodlines. To sort these ponies out, it is important to also look at each pony’s inbreeding coefficient (IC). A high inbreeding coefficient indicates repetition within the pedigree, and a low inbreeding coefficient means the pony has lots of diversity in its history. Therefore, for a pony to have rare bloodlines, it must have both a low MK value and either a low IC value or in the case of a high IC value, few replications of common ponies within its pedigree.
One pony in the 2007 parents list has this combination of a low MK value and repetition of a common pony in its pedigree: Wellbrow Pegasus. (2) Pegasus is very line-bred on Tebay Campellton Victor, a relatively common stallion. Therefore, while Pegasus is unrelated to a significant portion of the Fell Pony population, he is not a representative of a rare bloodline because of the common stallion in his pedigree.
Limitations of MK Analysis
In the Fell Pony, analyses based on pedigrees have their limitations. In some cases, a pedigree ends just a few generations back; pedigree depth can be limited for a number of reasons, including the inspection scheme used a few decades ago. Another challenge is the veracity of the pedigrees themselves. From the first day I encountered Fell Ponies, I’ve been warned that the pedigrees on older ponies may not be accurate for a variety of reasons. So analyses like MK and IC based on pedigrees must be considered with these limitations in mind. There may be rare bloodlines within the breed that do not show up in pedigrees, and there may be ponies with supposedly rare bloodlines that are actually quite related to the rest of the population. Most long-time breeders in Cumbria understand the realities behind Fell Pony pedigrees. Here again is a reason why I put a lot of trust in the decisions that long-time breeders have made to use certain ponies in breeding programs and to leave other bloodlines behind.
Keeping in mind that certain bloodlines may be rare for a reason and that Mean Kinship analyses have limitations, there were some interesting patterns that emerged during my research:
· Several prefixes were common in the pedigrees of ponies with low MK values. The four prefixes I saw frequently in the pedigrees of ponies with rare bloodlines were: Greenfield, Hades Hill, Sleddale and Waverhead.
· One Lownthwaite pony, Starturn, shows up quite often as an ancestor to ponies with rare bloodlines. At right is a table showing other ponies that frequent pedigrees of ponies with rare bloodlines. The table also shows the percentage of the 2007 foal crop with this pony in its pedigree. Starturn is the only mare in the list.
· Several ponies from the Kerbeck stud crossed my path during my research, and they usually went back to the stallion Frizington Duke, who appears rarely in most Fell Pony pedigrees.
· Greenfield Gay Lad appears in the list of ponies with rare bloodlines himself, as do some of his progeny who are being used as breeding stock. Gay Lad often passes his rarity to his offspring.
· Two long-time Fell Pony studs located in Northumberland have more than one pony on the list of rare bloodlines: the Dene ponies bred by Mrs. Ailie Newall, and the Linnel ponies bred by the Charlton family. Mrs. Newall’s mare lines go back to the very early Linnel ponies bred by the Charltons, and the recent Linnel ponies of the Charltons often have the stallion Linnel Romany Boy in their pedigrees or Sleddale stud lines. The breeding stock of both these Northumberland studs has generally not traveled back to Cumbria to mix in with the majority of the breed’s population. This has led to the Dene and Linnel ponies generally having distinct bloodlines from the rest of the breed.
· Three of the ponies on the list reside in North America: Lownthwaite Monarch and Hades Hill Freya, imported by the Laurelhighland Stud in Pennsylvania, and Ravenscairn Selkie at the Braeberry Stud in Oregon.
Examples of Conservation Breeding
While conserving rare bloodlines is important for maximizing the gene pool in a rare breed, it is also important for making outcrosses available to breeders, as my conversations with master breeders have shown. To accomplish this second objective of conserving rare bloodlines, maintaining the rarity of those bloodlines is important so that they can serve as useful outcrosses into the future. Maintaining the rarity of those bloodlines is accomplished by breeding the rare bloodlines to each other rather than to more common bloodlines, which would dilute them. There are two notable examples of this strategy in the list of ponies with rare bloodlines.
Waterstolls Beauty II is an example of two rare bloodlines crossed to preserve rarity. Her sire is Greenfield Gay Lad, also in the rare bloodlines list. Her dam, Waterstolls Beauty, made the rare bloodlines list when she was being bred a decade ago. Beauty’s dam is from the Greenfield stud, ponies from which repeatedly show up in pedigrees with rare elements. Her sire, Waverhead Rob, is on the list of ponies that show up in pedigrees with rare elements.
The second example takes a different approach to conserving rarity: linebreeding. Greenhead Alfred’s parents are half-brother and half-sister; his grand-dam on both sides was Boltonabbey Blackbird, herself on the rare bloodlines list when she was being bred several years ago.
The Art of Rare Breeding
Breeding high quality animals is an art, especially when breeding is constrained by a closed stud book and a written standard as the Fell Pony breed has. Producing high quality animals within the context of a rare breed takes that art to a higher level. Consistently producing high quality over time requires finding suitable outcrosses, which in a rare breed is challenging because the gene pool is already limited. The work of identifying rare bloodlines that can supply outcrosses is time-consuming. Then the quality of those outcrosses must be assessed. Improving the quality of the outcrosses without losing their genetic diversity is one more hurdle that is especially challenging in equine breeds because of their long reproductive cycle. Long-time breeders of the Fell Pony have been making trade-offs between relatedness and quality since their involvement with the breed began. It will be up to thoughtful breeders of the Fell Pony to determine if the ponies on the rare bloodlines list presented here are worthy of a conservation effort for the genetic diversity they represent.
Note on footnotes: raresteeds.com no longer exists but the data is in possession of the author.
Murray, David Anthony. The Fell Pony: grazing characteristics and breed profile – a preliminary assessment. 2005, Earthwatch Institute, p. 42, citing Dr. Gareth Thomas’ PhD dissertation.
Pedigrees of ponies with low MK and high IC were reviewed and replications identified. Greenhead Alfred and Wellbrow Pegasus were the only ponies in this class in the 2007 parents list.
Courtesy Fell Pony Pedigree Information Service of raresteeds.com.
This list compiled from Sires and Dams with foals in 2007 that have low MKs and low ICs and more than four generations in their pedigrees.Courtesy raresteeds.com Fell Pony Pedigree Information Service
This article appears in the book Fell Ponies: Observations on the Breed, the Breed Standard, and Breeding, available internationally by clicking here.