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E p i c e n t r e
Issue 3

Breeding in the New Millennium

Breed Societies and Studbooks for the Native Pony breeds have been established over the last 110 years: -

Each breed society has various standards and different rules for the registration of foals within their studbooks. In some breeds the registration of a foal and its identification thereafter is very much up to the breeder, but the Exmoor Pony Society has always insisted on inspection of foals and branding. This has produced a studbook which for the purpose of a genetic study of the breed is by far the best.

An initial stochastic analysis of the EPS studbook for 1997 showed that in 3834 records there were only 8 birth discrepancies and 14 parents without a record. It was for this reason that the Exmoor Pony population was chosen by the Roslin Institute for a study. The work was carried out by Sneha Maroo under the supervision of Dr. John Woolliams a leading quantitative geneticist.

The study revealed that although the average coefficient of relationship between animals in each year was found to be increasing, as expected, the rate of inbreeding has been reduced and become more stable since breeding herds have been established off the moor over the last 28 years. However Genetic Bottlenecks have occurred in the past due to the overuse of certain sires, this causes a sudden increase in inbreeding two generations later.

Updating the studbook to 1998 reveals that to date 4,009 ponies have now been registered, of these 1,009 females and 230 males have bred. Of the 230 males 30 have had only 1 foal - mistakes perhaps, but not to be ignored 12/13 only had one foal but he was Caractacus, he had 31 progeny including Crackshot, he had 65 progeny including Heatherman, who in turn had 95 progeny and 336 grand-progeny. Analyses such as these illustrate one reason for the narrow founder base of the present pedigrees.

Only too often a breeder regards his stallion of having done well by having many progeny, not realising that using the stallion even on an infinite number of mares reduces the Effective Population of his herd to 4. To date the two stallions which have sired over 100 foals are Golden Gorse (23/69) with 148 and Dazzling Boy (85/32)with 102. Other records are: -

In 1998 the studbook indicates that of the ponies which have bred and are alive now there are 491 mares and 93 stallions ( although only 64 stallions appear to have sired foals in 1998).

Potential stallions are inspected at 2 to 3 years of age. The standards for this inspection must be maintained but at the same time we must be prepared, that to progress without the risk of genetic bottlenecks, to increase the number of stallions available to breeders.

The way forwards for the EPS is to "level the playing field". If we regard the breeding female population as 500 then we should aim at about 100 working stallions - not much different from now. In order to solve the overuse of certain stallions, and their use into old age, the number of foals they produce should be limited. For each stallion all foals born must now be presented for inspection. The EPS could pay premiums on the foals which pass inspection for the first 25 foals put forwards, thereafter the EPS pays no further premiums for foals from that stallion and recommends he be castrated.

Such a regime would ensure a broad genetic base for the breed to flourish during and indeed to survive the next millennium.

Written by Alex.N.Copland

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