Post by bellajack on Apr 1, 2007 21:30:42 GMT -1
.The Royal Veterinary College Laminitis Conference. March 24th 2007
Part 4.
Nutritional Countermeasures to Laminitis.
The speaker for this section was:
Pat Harris MA PhD DipECVCN Vet MB MRCVS
Bibliography in Part 1 - 2nd post.
This will concentrate on 2 main areas:
1) How to reduce the intake of rapidly fermentable material.
2) Nutrients and managemental strategies that may reduce insulin resistance
1) Reducing Intake.
We need to be able to identify the that are high in those components that, under certain conditions,tend to be rapidly fermented to produce, in particular, excess lactic acid, which lowers Ph of hind gut, increases gut permeability, kills bacteria and aids the release of undesirable substances.
A number of terminologies have been used which can be confused:
Water soluble carbohydrates (WSc). These include simple sugars and fructan, but not starch.
Nonstructural carbohydrates (NSc)
The material within the feed which can potentially be rapidly fermented to lactic acid and includes simple sugars, fructan and starch.
The amount of starch that is rapidly fermented rather than digested varies on the amount fed and whether it has been processed. If cereals are to be fed to animals which may be prone to laminitis, unprocessed corn or barley should be avoided, even in small amounts. Oat starch is usually efficiently digested, regardless of processing.
One large feed of unprocessed cereal can result in clinical signs of laminitis within 40hrs.
Even horses used to being fed grain should be fed less than 0.5 kgs per 100kg bodyweight, cereal in one meal.
Pasture.
Research has shown that a bolus of fructan at between 7.5 - 12.5 g/kg bodyweight will reliably produce laminitis, even in a breed not believed prone to the condition.
Many people restrict the time horses have access to grass but preliminary data suggests that they can eat up to40% of their daily dry matter intake in 3hrs of turnout, so just restricting time may not be enough.
For current advice on reducing turnout effectively see Part 1, 2nd post.
2) Reducing Insulin Resistance.
EXERCISE.
A survey showed a high proportion of acute laminitis cases in the 'no regular exercise' category.
Exercise and exercise training have been shown to have numerous benefits including enhanced insulin sensitivity.
Maintaining and if possible increasing the level of activity of horses prone to laminitis would be advantageous, especially if they are obese as well.
OBESITY.
It has been well recognized that obese horses are more prone To laminitis.
It is likely that the risk for laminitis in obese horses is due to the development of insulin resistance (IR).
The syndrome of obesity, IR and laminitis is sometimes referred to as 'equine metabolic syndrome' or peripheral Cushings syndrome.
The link between obesity, insulin sensitivity, and vascular dysfunction is currently under investigation.
Horses are usually overweight because they have stored excess calories as fat ie been overfed relative to their activity level.
Horses turned out to pasture at certain times of the year may be getting several times their calorie requirement.
DIET.
Insulin sensitivity has been found to be affected by diet as well as exercise.
Adaptation to high carbohydrate diets is associated with decreased insulin sensitivity as large fluctuations in glucose and insulin following meals high in sugar may supply inappropriate signals of energy availability to the glucose regulatory system, thereby altering insulin sensitivity of the tissue and may result in changes in metabolic signaling both within and between cells.
It is important to note that certain pastures at certain times of the year can result in marked fluctuations of blood glucose and insulin in a similar way to the feeding of large cereal based meals.
It has been suggested that there may be a progression of IR in laminitis prone horses from compensated IR (insulin sensitivity greatly decreased but made up for by increased insulin secretion), being a predisposing factor in healthy but possibly genetically predisposed horses, to a decompensated IR later in the course of the disease.
It would seem advisable to choose diets that result in low glycaemic and insulinaemic responses.
Feeding a fibre based diet, using oil as an energy source if required for the more athletic horse, has the potential to improve glucose tolerance and insulin sensitivity, as well as , perhaps more importantly for exercise performance,improve metabolic flexibility.
DIETARY SUPPLEMENTS.
There have been few, if any, controlled trials that have tested interventions with dietary supplements, feed additives, or drugs, to prevent laminitis.
The streptogramminn antibiotic 'Virginiamycin' (I think this 'Founderguard') has been used and marketed to prevent pasture induced laminitis by preventing the overgrowth of gramm-positive bacteria. However it is not thought to be effective in all cases and is only available under special licence in Europe.
Areas needing exploration include increasd anti-oxidant supplementation, hind gut buffers, and agents that block the over activation of MMPs.
Current important area of interest is around nutrients or nutraceuticals to counter the development of IR or the effects of being IR.
Two discussed:
Cinnamon.
Cinnamon bark has been reported to act in man as a stimulant astringent to the stomach with antimicrobial, antispasmodic, antioxidant, antidiarrhoea, calmative and antiparasitic properties with a potential natural insulin sensitising action. In man 1gm /day could have significant effects on fasting glucose concentrations.
Tests suggest that cinnamon extract may play a role in blood glucose levels by improving insulin sensitivity, or the release of insulin, or by slowing the absorption of carbohydrates.
This may be a fruitful area for evaluation in laminitic horses where IR is involved.
Cinnamon also contains proanthocyanidins which may improve vascular health and have substantial antioxidant activity - potentially of additional benefit to laminitics.
Magnesium.
May have a role in modulating the action of insulin.
No data yet available to confirm that additional supplementation over and above that currently recommended will affect insulin sensitivity but should ensure all horses have an adequate intake particularly those prone to laminitis.
Take Home Message
Base horses diet on forage/fibre, not sugar/starch.
Feed a broad-spectrum vitamin and mineral supplement to horses on a restricted diet, and ensure an adequate and balanced supply of magnesium.
Do not starve or prevent from eating for long periods in an attempt to reduce bodyweight, and make all dietary changes slowly.
Maintain or increase regular exercise.
Plan an active weight management programme for overweight animals; Meadow hay at 2% current bodyweight for 6 weeks.
Meadow hay at 1.5% current b/w for 6 weeks.
Meadow hay at 1.5% target b/w for 6 weeks.
With increased exercise wherever possible.
Maintain a moderate condition score - between 4 and 5 on 9 point scale.
Get forage analysed and try to feed a forage with less than 10% NSc. Soaking hay in clean water for 30mins will significantly reduce sugar content.
Follow turnout advice given in Part 1, 2nd post.
Part 4.
Nutritional Countermeasures to Laminitis.
The speaker for this section was:
Pat Harris MA PhD DipECVCN Vet MB MRCVS
Bibliography in Part 1 - 2nd post.
This will concentrate on 2 main areas:
1) How to reduce the intake of rapidly fermentable material.
2) Nutrients and managemental strategies that may reduce insulin resistance
1) Reducing Intake.
We need to be able to identify the that are high in those components that, under certain conditions,tend to be rapidly fermented to produce, in particular, excess lactic acid, which lowers Ph of hind gut, increases gut permeability, kills bacteria and aids the release of undesirable substances.
A number of terminologies have been used which can be confused:
Water soluble carbohydrates (WSc). These include simple sugars and fructan, but not starch.
Nonstructural carbohydrates (NSc)
The material within the feed which can potentially be rapidly fermented to lactic acid and includes simple sugars, fructan and starch.
The amount of starch that is rapidly fermented rather than digested varies on the amount fed and whether it has been processed. If cereals are to be fed to animals which may be prone to laminitis, unprocessed corn or barley should be avoided, even in small amounts. Oat starch is usually efficiently digested, regardless of processing.
One large feed of unprocessed cereal can result in clinical signs of laminitis within 40hrs.
Even horses used to being fed grain should be fed less than 0.5 kgs per 100kg bodyweight, cereal in one meal.
Pasture.
Research has shown that a bolus of fructan at between 7.5 - 12.5 g/kg bodyweight will reliably produce laminitis, even in a breed not believed prone to the condition.
Many people restrict the time horses have access to grass but preliminary data suggests that they can eat up to40% of their daily dry matter intake in 3hrs of turnout, so just restricting time may not be enough.
For current advice on reducing turnout effectively see Part 1, 2nd post.
2) Reducing Insulin Resistance.
EXERCISE.
A survey showed a high proportion of acute laminitis cases in the 'no regular exercise' category.
Exercise and exercise training have been shown to have numerous benefits including enhanced insulin sensitivity.
Maintaining and if possible increasing the level of activity of horses prone to laminitis would be advantageous, especially if they are obese as well.
OBESITY.
It has been well recognized that obese horses are more prone To laminitis.
It is likely that the risk for laminitis in obese horses is due to the development of insulin resistance (IR).
The syndrome of obesity, IR and laminitis is sometimes referred to as 'equine metabolic syndrome' or peripheral Cushings syndrome.
The link between obesity, insulin sensitivity, and vascular dysfunction is currently under investigation.
Horses are usually overweight because they have stored excess calories as fat ie been overfed relative to their activity level.
Horses turned out to pasture at certain times of the year may be getting several times their calorie requirement.
DIET.
Insulin sensitivity has been found to be affected by diet as well as exercise.
Adaptation to high carbohydrate diets is associated with decreased insulin sensitivity as large fluctuations in glucose and insulin following meals high in sugar may supply inappropriate signals of energy availability to the glucose regulatory system, thereby altering insulin sensitivity of the tissue and may result in changes in metabolic signaling both within and between cells.
It is important to note that certain pastures at certain times of the year can result in marked fluctuations of blood glucose and insulin in a similar way to the feeding of large cereal based meals.
It has been suggested that there may be a progression of IR in laminitis prone horses from compensated IR (insulin sensitivity greatly decreased but made up for by increased insulin secretion), being a predisposing factor in healthy but possibly genetically predisposed horses, to a decompensated IR later in the course of the disease.
It would seem advisable to choose diets that result in low glycaemic and insulinaemic responses.
Feeding a fibre based diet, using oil as an energy source if required for the more athletic horse, has the potential to improve glucose tolerance and insulin sensitivity, as well as , perhaps more importantly for exercise performance,improve metabolic flexibility.
DIETARY SUPPLEMENTS.
There have been few, if any, controlled trials that have tested interventions with dietary supplements, feed additives, or drugs, to prevent laminitis.
The streptogramminn antibiotic 'Virginiamycin' (I think this 'Founderguard') has been used and marketed to prevent pasture induced laminitis by preventing the overgrowth of gramm-positive bacteria. However it is not thought to be effective in all cases and is only available under special licence in Europe.
Areas needing exploration include increasd anti-oxidant supplementation, hind gut buffers, and agents that block the over activation of MMPs.
Current important area of interest is around nutrients or nutraceuticals to counter the development of IR or the effects of being IR.
Two discussed:
Cinnamon.
Cinnamon bark has been reported to act in man as a stimulant astringent to the stomach with antimicrobial, antispasmodic, antioxidant, antidiarrhoea, calmative and antiparasitic properties with a potential natural insulin sensitising action. In man 1gm /day could have significant effects on fasting glucose concentrations.
Tests suggest that cinnamon extract may play a role in blood glucose levels by improving insulin sensitivity, or the release of insulin, or by slowing the absorption of carbohydrates.
This may be a fruitful area for evaluation in laminitic horses where IR is involved.
Cinnamon also contains proanthocyanidins which may improve vascular health and have substantial antioxidant activity - potentially of additional benefit to laminitics.
Magnesium.
May have a role in modulating the action of insulin.
No data yet available to confirm that additional supplementation over and above that currently recommended will affect insulin sensitivity but should ensure all horses have an adequate intake particularly those prone to laminitis.
Take Home Message
Base horses diet on forage/fibre, not sugar/starch.
Feed a broad-spectrum vitamin and mineral supplement to horses on a restricted diet, and ensure an adequate and balanced supply of magnesium.
Do not starve or prevent from eating for long periods in an attempt to reduce bodyweight, and make all dietary changes slowly.
Maintain or increase regular exercise.
Plan an active weight management programme for overweight animals; Meadow hay at 2% current bodyweight for 6 weeks.
Meadow hay at 1.5% current b/w for 6 weeks.
Meadow hay at 1.5% target b/w for 6 weeks.
With increased exercise wherever possible.
Maintain a moderate condition score - between 4 and 5 on 9 point scale.
Get forage analysed and try to feed a forage with less than 10% NSc. Soaking hay in clean water for 30mins will significantly reduce sugar content.
Follow turnout advice given in Part 1, 2nd post.
