Extracted from ATR It has been one of the most enduring theories in horse racing over the decades, but new research has debunked the theory that fillies and mares improve on the racecourse when they are pregnant. In an article published in the Thoroughbred Daily News, regular At The Races contributor Kevin Blake conducted extensive research covering seven years of British and Irish racing which identified 443 fillies and mares that raced while pregnant. " It starts of with: "With those individuals having had over 1,500 starts while in-foal, the research revealed that their win strike rate was 11.7% lower than the win strike rate of every three-year-old and older fillies and mares in the same time period. The article suggests that not only does this very much contrast with what the racing public are likely to have expected, it also contrasts with what would have been statistically expected." What a load of cobblers. Doesn't prove a thing "The research also revealed that just 15.1% of the in-foal fillies and mares produced career-best efforts while pregnant, with just 2.9% of them improving by 10lb or more. Similar results were found when the research was extended to National Hunt runners in the same period." Again, what a load of cobblers. So what % of all the non pregnant fillies/mares (or colts/geldings/horses for that matter) produced a career best in the same period? Nearly 3% of those pregnant improved by 10lb or more "The conclusion of the article is that not only is the theory that fillies and mares improve when pregnant highly likely to be a myth, but there is even a possibility that being in-foal could well have a negative influence on racing performance." Some conclusion that A mare is pregnant for anything from 320 to 370 days. At what stage were these raced? All at the same stage? What were their odds when running; were they fancied? Were they running at their optimum distance on their favoured going. So many questions. How they can conclude anything from that I don't know, other than some fillies/mares might improve performance and some won't, depending on all sorts of circumstances. Obviousy one cannot expect all fillies/mares to improve when pregnant. Common sense. Waste of bloody time.
All? How far through the pregnancy could be a bit tricky for the non pregnant. And it doesn't say what % of all the non pregnant fillies/mares achieved career best performance over the same period. Or how many non pregnant fillies/mares improved by 10lb or more in the same period? What % of pregnant mares actually race and why? What % don't race and why? Too many missing facts and reasoning to take this seriously. As I said it's common sense to not assume that all pregnant fillies/mares will improve performance during pregnancy. So they are trying to disprove something that doesn't need disproving. Half baked study and a waste of time
The issue I've always had with people wanting the status of in foal mares to be declared is that at what stage do you consider her in foal? You can't get a positive scan any earlier than 12 days after covering, though more likely to be 16, but does the embryo really have much impact on the mare's system at that early stage. From a breeding perspective you don't consider a mare safely in foal until 40 days after covering - usually referred to as PD40 in stud records. So if we chose 40 days as the cut off point for declaration, what will people say if a mare who is less than 40 days pregnant wins a Race?
The general population have a 40% higher strike rate than those in foal so it's most likely that more than 2.9% of them have risen ten pounds or more over the same lenght of time.
Just out of interest what level of mares would hold a service or skip their next heat and not reach full maternity?
11.7%/ 8.29% The difference in strike rates between the fillies and mares in foal and the general population.
I'm probably not on my best form as I have a stinking cold but you've lost me there mate. Of course, we have no idea how those in foal that didn't race would have fared. Do we know what % of those pregnant raced in foal in the period and at what stage they were in foal when they raced?
Those percentages are what the conclusion of the study have been determined by. We don't know those that didn't run but because they didn't run I can't see their relevance. There is a cut off date which in foal horses can't run. If those who have run in foal have worse strike rate than the general population I cant see any reason why an in foal horse could be deemed to have a better chance. Of coarse there are exceptions but these would be in the minority.
I'd say the average is about 70% would reach full-term - that's the aim of most stallion owners. Obviously there is a higher conception rate but pregnancies are lost for a variety of reasons. There are no available statistics for the number of coverings needed per mare as again it's dependent on lots of factors. I think at the time they quoted that Frankel got 126 of his 133 first book of mares in foal but that produced (from memory) 108 foals.
My apologies for having a go at a half baked article by ATR. I should have read the full article as it explains some of the things that weren't mentioned in the ATR article. I know they added a link to the full article but (stupidly) I didn't notice and just read the ATR piece. I think they would have been wiser to either copy the entire article or none of it I have no idea why there was such a myth and I still maintain that it is common sense to not assume that fillies/mares, in general, improve due to being pregnant. Some will some won't and this could be influenced by any number of circumstances, probably best left for a top vet from Newmarket to explain. Personally, if I had a mare in foal I wouldn't dream of racing it The full article is very interesting and explains how the data has been sensibly sifted to ensure there is no bias towards non pregnant fillies/mares. It does prove that not all fillies/mares improve during pregnancy; but surely that didn't need proving. It also proves that some do, and by a considerable margin As far as I am concerned it wasn't necessary to prove something which was common sense but the results were very interesting. For instance I was surprised that so many fillies/mares actually improved more than 10lbs and absolutely amazed that one improved by 22lbs. What we don't know is if the same improvement would have been made had they not been pregnant.
Because of my interest in the Royal Studs I've known of 2 fillies that 'seemed' to improve once in foal. The first was a filly called Albany who Hern found difficult to train because she kept getting in season. Her form figures were 343 as a 2yo and she generally seemed to flatter to deceive. As a 3yo she was put in foal and won her first race as a 3yo (Sandleford Priory Stakes at Newbury: an Oaks Trial). She ran in the Oaks but didn't stay (ran a good race but finished 5th). After that she ran in 2 Group races (over 10f) in France winning one of them and being 2nd in the other. The other filly was Starlet. She was a promising 2yo but didn't do much as a 3yo. As a 4yo she was put in foal and won a whole set of races including a Group 2 in Germany as well as being 2nd in both the the Nassau and Sun Chariot. Huntingdon (Hastings-Bass) who trained her is one of the proponents of getting these fillies in foal. I can't believe that putting a filly in foal improves the performance of the filly per se. But it may iron out other problems, as in the case of Albany.
The BHA Add a few more facts which backs up the conclusion made in the ATR article " 1. Mares In Foal There is a dearth of peer-reviewed scientific studies on this topic. Informed Veterinary opinion was that known effects were that pregnancy removed the variation in behaviour seen through the oestrus cycle. Weatherbys and the Authority’s Racing Department considered the record of all in-foal mares with handicap ratings that participated in Flat races between 1997 and 2007. This analysis was produced by referring to subsequent foaling records. During the period, 370 such mares were identified and their handicap ratings, pre and post covering, were compared. The analysis identified that once the mare was in foal: • The rating of 109 of the 370 mares (29%) increased, thereby indicating that the mare had improved; • The rating of 17 of the 370 mares (5%) remained unchanged; • The rating of 244 of the 370 mares (66%) declined, thereby indicating that the mare had deteriorated. When considering the performance of all 370 mares, on average, each mare’s handicap rating declined by 2.96lbs once in foal, with the median decline being 3lbs. Arguably the most significant finding, however, was that the handicap rating of just 32 mares (8%) increased by 7lbs or more once they were in foal and that, therefore, for every mare that shows marked improvement once in foal, there will be at least nine mares which experience no such noteworthy improvement in performance. Indeed, the analysis would suggest that the performances of two-thirds of mares will deteriorate once they are in foal. The fact of pregnancy is one thing, what it is likely to mean in terms of performance, at least on this analysis, differs between horses." A reason why some mares improve during pregnancy "It is well known that being in season can detrimentally affect both the behaviour and racing performance of fillies. Thus, the fact that fillies cease to come into season once they are in foal is considered a significant positive offshoot of pregnancy in a racing filly. As well as that, the calming effect of the hormone progesterone which is produced during pregnancy could also have a positive impact on racing performance."
It's never something I've ever really taken into consideration as a punter. I've heard people say it makes a mare run faster. The actual evidence as you've posted Ron doesn't really support the theory though. I think it's purely coincidental if a mare wins and she happens to be in foal. Horses ratings go up and down all the time.
Precisely Shergs. Maybe those that did improve were the ones who had "women" problems before the pregnancy. That might be worth knowing
