How blood and heart rate readings help trainers
A“blood reading” or “blood picture” is a term often used by trainers when assessing the well-being of a horse in the build up to a race, but there have not been many articles written in laymen’s terms which explain what this means.
Each trainer has his own methods and some will regard blood readings as an important part of a horse’s preparation, others place less importance in it and others don’t do them at all.
A “heart rate” is another measurement which can be taken but this is not a common practice.
The Paul Lafferty yard used blood readings extensively and Sean Tarry often uses heart rate readings.
The information about bloods readings in this article was gleaned largely from an interview with Lafferty’s assistant Roy Waugh and the information about heart rate readings is from Sean Tarry.
Athletic performance in thoroughbreds, as in humans, is interlinked with oxygen supply.
Haemoglobin, an iron-containing protein within the red blood cell, carries oxygen to the rest of the body and the more haemoglobin present the more that can be carried. Haemoglobin levels are raised by exercise. The aim of training is to stress the system, so that bone marrow makes more red blood cells and accompanying hemoglobin for the workload.
Short, sharp work is the best way to increase haemoglobin levels.
There are two important measurements to be taken in assessing the efficiency of oxygen transportation in a horse’s blood, the haemoglobin levels and haematocrit. The latter is also known as the Packed Cell Volume (PCV).
To ensure adequate tissue oxygenation, a sufficient haemoglobin level must be maintained. The amount of haemoglobin in whole blood is expressed in grams per deciliter (g/dl). The normal haemoglobin level for horses at rest is 8-19 g/dl.
The haematocrit or PCV measures the percentage of red blood cells in blood. A normal PCV reading for horses at rest is between 3248%. Lower than 30% may indicate anemia. When the blood sample is taken it is separated into three parts, red blood cells, plasma and buffy coat. The buffy coat is essentially the layer between blood cells and plasma that contains most of the white blood cells and platelets. An abnormally high white blood cell count indicates an infection.
When the number of red blood cells is too large there is a traffic jam effect and blood flow is restricted.
Haem-concentrating
This is termed haem-concentrating and is chiefly associated with intact males.
Gelding is the usual solution. Long, slow work can also help.
Haemo-concentration is an unknown term in most racing countries, but is well-known in South Africa. The reason for this is likely due to South African trainers’ tendency to do short, fast work on heavy tracks, which can cause a rapid production of red blood cells and haemoglobin.
Trainers would ideally be looking for a haemoglobin level of from 13,5 to 15 for a horse at rest and a PCV reading from 40 to 43.
An important difference in the physiology of horses and humans is that a horse’s spleen holds approximately a third of its total red blood cells and these are held in reserve until mobilised through exercise, stress and excitement. This is a common physiological design in flight animals, who require a sudden burst of energy to escape from predators. It also explains why a good temperament is so vital in racehorses. Those who get worked up before the race or during the running are releasing some of their splenic blood and wasting their oxygen reserves. However, those who are able to relax until asked for an effort in the straight will still have something in the tank in the final stages and this often makes the difference between victory and defeat.
The horse's physiology is also one of the reasons a measurement of hemoglobin and red blood cell content in horses at rest can’t always be exact as even the anticipation of the needle can cause excitement and the consequent release of the splenic blood.
Therefore, trainers tend to take the measurement after fast work at which stage the splenic blood will still be in the system.
However, the expected levels will then change.
A good reading for hemoglobin after fast work would be from 23 to 24,5 and a good reading for PCV would be from 72 to 75.
These readings can be a valuable aid to trainers. If the levels are too low a couple of days before a race, the horse will have no chance and might as well be scratched. However, if there is still two or three weeks to the race the levels can be raised by short, sharp work.
The levels become more important as an indicator the longer the race is and in Johannesburg, where the air is thinner due to the high altitude, they become even more important.
Those who place importance in heart rates usually take these readings after fast work. A profile of a horse’s heart rate and recovery rate is created over a period of time. When a race is approaching the heart rate and recovery rate readings are compared to the markers on the profile to assess how well the horse is in this regard. BARGAIN buy Mystic Journey held off the might of the Godolphin stable to record a sensational victory in the inaugural AllStar Mile at Flemington on Saturday.
The three-year-old filly only bagged her spot in the A$5 million (R50millon) race via a wildcard earned through her Australian Guineas win two weeks ago, but she established herself as among the best of her age with this victory, holding off Hartnell and favourite Alizee in a thrilling finish.
Mystic Journey encapsulated the spirit of the All-Star Mile as she was just an A$11,000 (R110 000) purchase but had gradually forced her way to the top shelf. The A$2.25m (R22.25millon) prizemoney for first place took her earnings beyond $3m (R30 million).
Trainer Adam Trinder said: "She's a filly on an upward spiral and we don't know where the bottom of her is.
"We'll protect her, look after her and she might be able to take over the mantle of Winx."