New Observations’ by Robyn Petrie-Ritchie (From DS Newsletter 52)
A record 98 persons eagerly assembled in the Dolphin Hotel, Bovey Tracey on 31 October 2014. Robyn was born and bred on Dartmoor and now farms with her partner Steve Alford near Throwleigh. She has a BA Masters Degree in Equine Science and recently completed her Research Masters MSc thesis on the ponies of Dartmoor at Duchy College/Plymouth University.
Robyn spent hours on the moor observing groups of ponies in all winds and weathers to acquire data relating to equine birth control which is a key issue on Dartmoor. She commented that although the
market for ponies has changed dramatically in recent years (due to new laws relating to export etc) management practice has essentially remained the same. Her study combined interviews with pony keepers with close observation of the behaviour of ponies. Hoof prints of ponies on Dartmoor dating to around 1600 BC were found in excavations on Shaugh Moor in the late 1970s. A cast was made of them (now in Plymouth Museum) and Robyn’s measurements revealed that they are the same size as those of
her own ponies today. There are three key types of pony on Dartmoor: The Dartmoor Hill Pony – of mixed breed, colour and size, but present for hundreds of years.
The Registered Dartmoor Pony – maintained for more than 100 years with a traceable pure pedigree.
The Heritage Dartmoor Pony (Dartmoor Pony Heritage Trust) – unregistered as ‘pure’ but generally fits the breed standard and is capable of improvement to registered status.
Fifty-one farmers / pony keepers from all areas of Dartmoor were interviewed, including a mix of Hill Pony, Registered and Heritage pony breeders within the sample. A semi-structured interview was used by Robyn with a dictaphone. Valid and reliable data was obtained from respondents. Ninety-two per cent of her interviewees recommended that management practice needed to change. Sixty-nine per cent were in favour of stallion removal, twenty-one per cent were against stallion removal and ten per cent were unsure.
Among suggestions and opinions were: • if all registered stallions (Dartmoor Commoners’ Council
have 150 registered) were DNA tested, then the unwanted progeny could be tested and the disposal costs of offspring shared. • stallions which have a well-established territory should be gelded. They will still retain their lairs/lears and keep off other young colts.
• Dartmoor Commoners’ Council have statutory and legal obligations to which they are not adhering. Stallion removal should not be an option – it should be enforced.
• either attempt stallion removal or watch the next generation give up keeping ponies.
• Dartmoor Commoners’ Council has made a huge effort to clear up unmarked animals, but they now need to enforce stallion removal which will in turn reduce the number of unwanted young stock including the rogue colts.
• if the New Forest pony keepers have more than halved their foal crop with their system, then why can we not do something similar? A few breeders suggested that there should be a ‘clear period’
for ponies on Dartmoor just as there is for cows and sheep, when all ponies would be required to be removed between certain dates. This action would allow for management such as worming
to take place and to make sure that all animals had been removed. Some pony keepers raised concerns over what effect stallion removal will have on the behaviour of the herds, with changes in behaviour potentially impacting upon the livestock and ecology of the moor. In 2011 the Dartmoor Commoners’ Council had conducted their own survey which showed that 76% were in favour of stallion removal for a structured period (e.g. two years) and 23% were not in favour of this idea.
For her behavioural study, Robyn observed three distinct pony
a) a herd of mares ‘on the pill’, running in an enclosed area witha vasectomised stallion.
b) a herd of mares with no stallion.
c) a herd of mares on the contraceptive drug Improvac®, running with a proven stallion. Although the drug was trialled on the ponies it is not yet fully licensed for use in equines.
• An ethogram of codes was developed (recording movement, grazing, sleeping etc) after an initial observation of two hours on each group, in order to assemble a catalogue of behaviours prior to the full study.
• A total of 1,858 equid hours were observed.
• The result was a giant spreadsheet which included all the behaviours such as grazing, drinking, covering etc.
• In studying the ponies so closely Robyn had a mixed reaction from them. Some became emotionally attached to her and would frequently come up to her showing affection.
• The behavioural data for analysis was collated in Excel and transferred into Minitab (version 17) for statistical analysis.
• The Kruskall-Wallis test was used to investigate differences in behaviour of the three mare groups. Mann-Whitney tests were used to compare the behaviour of the two groups with stallions.
There were some key questions relating to each group. In Group A
• Was there a reduction in foal numbers?
• Did the stallion maintain weight?
• Were normal behaviours demonstrated? The mares that were ‘on the pill’ running with a vasectomised stallion had fewer foals. However, some foals were born because the owner had intentionally covered some mares off the moor with their own stallion.
In Group B
• Did mares leave their lairs?
• How many unwanted foals annually?
The mares living without a stallion in general didn’t leave their lairs which proved that a stallion is not necessary to keep the mares in certain areas. However, there was still a problem with unwanted foals because they were covered by other people’s stallions.
In Group C
• Herds can remain as they are, running with a stallion?
• Long term effects?
With this group where the mare was on Improvac® and running with a proven stallion, the vasectomised stallion did maintain his body condition and the herd displayed normal behaviours.
The practice of sterilisation means there is a danger of losing all the genetics in the group. With mare contraception there can be several inconsistencies, especially if continuity is broken with incorrect timescales of administering the drug. Robyn’s research results clearly supported the view that there
should be a policy of NO BREEDING ON OPEN COMMONS and she felt that the Dartmoor Commoners’ Council should initiate removal of stallions from the commons. However, this may be
hard to implement and there are still many issues to address, but there is little reason not to encourage such a change. Benefits would include:
• breeding to your own individual market
• reducing interference between hill, heritage and registered breeders.
• eliminating over-breeding
• increasing welfare standards
• ensuring numbers are maintained
• ensuring genetic traceability
Robyn hoped that her work will be used as a catalyst for discussion and as a basis of scientific evidence to underpin a management system suited to all breeders, in order to ensure that a physically and behaviourally healthy equid population is maintained on Dartmoor without unwanted foals.