The Highland Pony, an Endangered Breed?
Prompted by the decline in the number of Highland Pony foals born in 2000, I decided to undertake research into breeding patterns of Highland Ponies. My detailed examination is of the years 1991 to 2000, with a less detailed examination of each previous decade. My sources are the studbooks and indices. I have included foals which are on the appendix registers which were sired by licensed stallions.
The object of this research is to evaluate how the genetic composition of the breed is affected by the declining population numbers and by past breeding patterns. Not only is the level of in breeding in the population significant, but also the contribution made by prolifically used stallions and the number of stallions and breeding mares sired by these prolific stallions. This is such a huge task that I cannot evaluate all these factors in full. Thus, I have selected to examine the contribution to the breed by stallions, since they can have a more dramatic influence, being able to sire several foals in a year, rather than the one foal produced per year by a mare.
The uses of a breed dictate what and how many are bred. The Highland Pony was originally used as an all-purpose pony in the Highlands and Islands of Scotland, where it had evolved into a hardy, sturdy, sure-footed animal. It was used as an agricultural animal, as a deer pony and general workhorse. After the Second World War, the Department of Agriculture set up the Knocknagael stud to improve the breed by standing quality stallions in each area for the use of the crofters.
The Highland Pony's traditional uses declined with the advent of the tractor and by the 1950's, the ponies were being sold off in vast numbers. A few of the sporting estates retained their stock, but even there, mechanisation eventually usurped the place of the Highland Pony. Trekking, which began in the 1950's, gave a new purpose to the breed.
Nowadays, the ponies are used in several fields and disciplines, such as breeding, in-hand showing, riding, dressage, driving, jumping, endurance riding, Le Trec and as good all round family ponies.
Registration records began in the 1880's. The Highland Pony Society was set up in 1923, although ponies continued to be registered through the National Pony Society until the 1960's.
The Highland Pony Society does not dictate which stallions should be used for breeding and stallions need only pass veterinary inspection to be licensed. (A stallion inspection scheme of the early 1990's caused much bitter controversy amongst breeders and was eventually scrapped). Stallions can be licensed from the age of two to four years. Mares can first be mated at three years.
It is not possible to give a total population number for the breed. The average number of foals per year from 1991 to 2000 was 339, an increase on the 1983 - 1992 Index book, where the average was 232 foals. Colt and filly foal numbers over the ten-year period are approximately 50%. From 1991, the number of foals born gradually increased from 308 to a maximum of 427 in 1994, declining to 216 in 2001. (See table 1 below). It is of concern that since 1994, when 427 foals were born to 407 in 1995; 412 in 1996; 314 in 1997; 302 in 1998; 285 in 1999; 265 in 2000; to a low of 216 in 2001.
The ages of breeding stock are important. The majority mares used for breeding are nine years old and over. (See Table 1 below). Since fertility declines at fifteen years, this leaves a breeding window of six years for each mare. The time lapse in breeding can be attributed to mares being used initially for riding and other disciplines. Stallions however can be found to be breeding over two decades.
The number of stallions siring foals has increased from 82 in 1991 to 103 in 2000. There has also been a marked increase in the number of stallions siring only one foal per year from 23 (28% of stallions used) in 1991 to 45 (43.68 %) in 2000. The number of licensed stallions on the 2001 list is 220, which prompts one to wonder about the use of these 117 extra stallions.
Family size is a significant factor in any breed. One stallion (Stallion A) dominated the breed in the 1990's, siring 116 foals from 1990 till 2000. In one year alone, he sired 16 foals, the highest number to be sired by any stallion in one year over the ten-year period. Of the 116 foals, four have been licensed as stallions, with no full brothers entire.During the period, this stallion's sire (Stallion B) was also still breeding. He produced seventy foals in the ten year period, of which ten colts were licensed, three being full brothers.
The sire of stallion B (Stallion C) was also prolific and left five stallions, two of which were full brothers. Thus the influence of Stallion C is present in nineteen stallions, which must be a significant contribution to present day breeding. It is fortunate, however, that none of these stallions is particularly in-bred.
The maximum number of foals sired by one stallion in a year has declined. (See table 2 below). From 1991 to 1994, Stallion A sired the maximum of 13 foals in each year. In 1995 and 1996, he was the sire of 16 foals and in 1997, there were 10 foals by him. The maximum number of foals sired by one stallion (a sire unrelated to Stallion A) in 2000 was 7.
Another important consideration is the generation interval of sires and dams. The latest year for which we can determine how many foals were subsequently used for breeding is 1996, as colts can be licensed up till the age of 4 years and mares can produce their first foals at that age. In 1996, 402 foals were born, of which 202 were fillies and 200 were colts. Of the fillies, at the age of four years, only 11 (5.45%) produced foals in 2000. Of the colts, 17 (8.5%) were licensed as stallions.
In 1995, 37 mares, (9%) aged four years old, produced foals. There were 407 foals that year and so 370 breeding mares were older than four years old. This trend has continued throughout the ten year period with 129 mares (48.67 %) breeding in 2000 having being born before 1991 136 (51.32 %) mares breeding in 2000 were more than 9 years old.
Stallions tend to be used from the year in which they are licensed, thus producing their first foals at the age of three, four or five. However, the breeding period for stallions is longer (in some cases more than twenty years) than that of mares, whose fertility declines after the age of fifteen and stallions produce more foals than mares.
The Rare Breeds Survival Trust has registered the Highland Pony Breed on the vulnerable register. One of the criteria used is that there should be at least six distinct male bloodlines. This is defined as a bloodline which has no ancestors in common with another in the last four generations (i.e.: back to and including great grandparents). The vulnerable list is the third category of registration with RBST and requires that there should be at least 600 breeding mares, but it is not clear whether this means the actual number of mares breeding or the number available to breed.
Having researched the bloodlines of all stallions which sired foals in 2000, I have discovered that there is not even one distinct male bloodline in Highland Ponies. Having looked back at the pedigrees of the founders of the breed, I discovered that the ponies are now less closely bred than previously. Only a very few studs use inbreeding, although many practise line breeding back to a successful sire or dam. (I have not researched the dam lines of foals and obviously it is probable that some are line bred or in bred).
In considering breeding patterns it is necessary to look at the contributions of ancestors and founders of the breed. The Highland Pony breed was indigenous to the Highlands and Islands of Scotland and became the workhorse of these areas, being used by crofter and landowner alike. Obviously there was breeding stock, but the first registered pony was Highland Laddie, foaled in 1880. Nearly every pony in existence today will have Highland Laddie at least once in its pedigree. Herd Laddie and Glen Bruar were notable and prolific sons of Highland Laddie. Other stallions being used at this time were Rory O' the Hills, foaled in 1897, and Roderick, foaled in 1893, by the Crofter, out of Poolewe. At the beginning of the 20th century, inbreeding was common.
The Congested Districts Board was founded in 1898 and supplied stallions to the crofters. Some crosses were with Arabs, Fells, Dales, Clydesdales and Hackneys. When these sires proved unpopular, the Board thereafter provided Highland Pony sires which stamped the type of the ponies of that time. The Board was superseded by the Department of Agriculture for Scotland, which set up the Knocknagael Stud initially on Skye, and latterly at Beechwood, Inverness. Atholl (by Herd Laddie and out of a Herd Laddie daughter), Braemore and Roderick were the sires used.
Beechwood's foundation mares were May Dew, a Glen Bruar daughter, and her full sister May Mist. The stallions Faillie Diamond and Faillie Rover were out of these mares respectively. Macpherson by Atholl and Fender Laddie by Bonnie Laddie (by Herd Laddie) were also used. The stud was dispersed in the 1970's.
The 1930's to 1960's were dominated by two famous studs, Derculich and Glenearn, both of which made a large contribution to the breed through Iain of Derculich and Glenearn Ambassador.
In the present day, three studs, Whitefield, Croila and Dene, dominate by force of numbers. Of the stallions which sired foals in 2000, 35% were of Whitefield bloodlines and 22% of foals had a Whitefield sire or dam. 10% of foals had a Dene sire or dam and 6% a Croila sire or dam. These studs produce the largest number of stallions, some of which are full brothers.
A disproportionately high number of stallions has been licensed since 1996 and this could be explained by their use as ridden animals rather than breeding animals. A surprising fact to emerge is that a large number of stallions sired only one foal in each year. The number of stallions siring only one foal in a year has changed from 23 (7.46 % %of foals bred in that year) in 1991 to 32 (7.8 %) in 1995, whilst in 2000, there were 45 (16.98 %).
The maximum number of foals sired by one stallion in 2000 was 7, and by far the majority of stallions sired only one foal. This contrasts with 1995, when one stallion sired 16 foals and 1991, when one stallion sired 14 foals.
To conclude: The genetic characterisation of the Highland Pony population is at risk of losing some of its genetic diversity as a result of falling population numbers, the unequal use of sires and the unbalanced contribution made by founder animals and ancestors. The low amount of inbreeding bodes well for the breed and the mating of closely related individuals seems to be avoided in most cases. The present trend of using ponies as riding ponies has resulted in a decline in breeding numbers and the age at which mares start breeding is getting later. The number of licensed stallions has increased but it can only be assumed that many are used as riding animals and do not produce many or any foals. The stallions which sire only one foal per year do add to the genetic diversity of the breed as a whole.
The Foot and Mouth epidemic had a significant effect on number of foals produced in 2001 (240) and thought must be given to incentives to breed foals in the future. Stallion owners are now less likely to stand their animals at public stud because of such factors as Foot and Mouth and the work involved in serving in-hand.
In-breeding does not appear to be a problem within the breed of today, but the contributions of greatly used bloodlines may at some future date cause problems. The diversity of the gene pool is greater nowadays than it was a century ago.
It is understandable that breeders wish to produce quality animals with specific traits and if a mating is successful, then to continue with that mating. It is a truism that success breeds success. One cannot expect breeders to use unpopular stallions, as it is possible that they are unpopular because they do not produce quality foals or alternatively these stallions are unavailable to visiting mares. This is where human interest comes into conflict with the good of the breed. I do not condemn this, but merely draw this to the attention of the reader.
One consideration must be that in selecting to breed for certain characteristics, such as pretty heads, for example, we reduce the chances of preserving other characteristics, such as fertility. A major worry should be the disproportionate use of particular sire lines and this could lead to a loss of genetic diversity within the population.
The popularity of the breed as ridden animals has been increasing over the past decade, but with the decline in the number of foals bred, there may soon be a situation where demand will outstrip supply and potential buyers may then look to purchase other native breeds.
If the breed is to continue to thrive, an increase in the population is only part of the answer. The population must retain and increase genetic diversity if it is to survive in the future. If breeding practices were modified to maintain equal family size, giving each sire and dam an equal chance of contributing genetically to the breed, this would conserve genetic diversity. Inbreeding should be avoided and line breeding should not be practised to any great extent. We should increase the number of breeding males, which would increase the ratio of males to females and this would help to maintain diversity in the breed.
An endangered breed - perhaps. Certainly a vulnerable one!
TABLE 1: numbers of foals bred, with distributuion of ages of mares and stallions being bred from.
Key: f=foaled; in 1991 and 1992, colts could only be licensed up till three years old, thereafter up till 4 years old; the stallions licensed % is the number licensed expressed as a percentage of the number of colts (% rounded up); likewise the % number of mares bred from.
|TABLE 2:distribution of stallions siring foals