0.5 can adjust the pelvis score if it differs by 1 or more points from the back or neck scores to obtain the condition score. Huntington (1992) Figure 2.
Condition scores for horses. Step 2: Determining the nutritional requirements of various classes of horses When developing a ration for your horse, it is necessary to know their specific nutrient requirements.
Once you have determined the horse’s weight, you can now determine their nutrient requirements.
Special consideration is needed when feeding different categories of horses.
Mares The cost of full drought feeding a breeding mare for six months during late pregnancy and lactation is 70% more than for a dry mare.
Considerable cost savings can be made by not breeding.
When making decisions about breeding mares in a drought several points should be kept in mind: • Condition score: chances of successful reproduction decline rapidly as condition score falls below 2.
Also remember if mares are overweight the chances of conception diminish.
If mares are below the critical condition score, it may be best not to breed them.
Apart from the extra energy required to return them to a reasonable condition score, the mare’s nutritional requirements will increase substantially during pregnancy.
Severe under nutrition may result in an under grown foal or may result in some growth abnormalities such as DOD and OCD (refer to RIRDC publication Developmental Orthopaedic Disease in Horses by Janine Aldred). • Roughage should be available to supplement a drought-fed grain ration during later stages of pregnancy and in early lactation to aid and maximise digestion of feed • Weaning early will allow mares to run as dry mares, this will reduce feed requirements as mares will be managed as maintenance stock.
Stallions During a breeding season stallions require more energy than other mature horses.
Stallions are usually kept in small individual paddocks.
A maintenance level of nutrition for stallion’s will suffice during the non-breeding season.
Young stock Young horses require between 90 and 120% of the energy required for the maintenance of a mature horse.
Young stock can recover from a check in growth, but it is unadvisable to continue this for a prolonged period of time.
The potential and quality of young stock should be evaluated and it may be best to sell horses that are of poor quality and lack potential.
Weaners Early weaning can reduce feed costs and simplify management of both mares and foals.
As previously discussed, the important factors when weaning are an absolute minimum of 10 weeks of age and a minimum liveweight of 140 kg (500 kg mature weight).
The use of high quality rations and good management are also important.
In a normal season, the growth target for weaners would be to achieve 75% of their mature (4-year-old) weight by 18 months of age.
Some later compensatory growth is possible after a short check in growth.
To enable compensatory growth adequate nutrition must be provided.
Severe under-nutrition of young stock can cause numerous growths and health disorders and must be avoided.
Yearlings Yearlings if not being shown or prepared for yearling sales are usually produced under low input management systems.
Generally, in a normal year quality pasture is sufficient for growth at acceptable rates.
During drought pasture quality and quantity will rapidly decline.
Frequent checks of the pasture and the condition of the yearlings should be made.
If the condition score of the young stock falls below 2 supplementary feeding should take place.
Maintenance This category generally involves idle horses that are doing little or no work.
These horses should be frequently checked to observe their condition.
If no pasture is available pasture hay should suffice.
If horses fall below a condition score of 2, it will take about the same amount of energy to gain 1 kg of body weight as it does to maintain the horse for a day.
In other words, it takes twice the amount of feed to gain 1 kg than for maintenance.
Thus it is more economically viable to maintain a horse at condition score of 2 than to let it fall below this score.
Working horses Working horses include racing, eventing, showjumping and show horses or any other type of horse that is performing at a medium or high level of energy requirements.
These horses will require various levels of supplementary feeding from high energy rations for racehorses to low energy rations for show horses.
Many of these horses have their nutritional requirements satisfied by supplementary feeding, therefore drought often does not result in a change in diet for these animals, unless certain feeds become too expensive or unavailable.
Diets that include pasture will require roughage as the pasture diminishes.
During drought, it may be feasible and more economic to spell working horses and thereby reduce their nutrient requirements.
Ponies Compared to large horses, ponies generally can survive on very little feed.
Grass hay will provide ponies with adequate nutrition during drought conditions.
Generally, the main cause of concern for ponies is laminitis (founder) when the drought breaks and they graze the new green pasture. Total energy requirements Feed energy is a major requirement and normally the first limitation during a drought.
The energy derived from digested feed is used to maintain body functions, foetal growth, milk production or body weight increase.
Energy is termed as Metabolisable Energy (ME).
It is standard practice for ruminants (sheep and cattle) to describe energy value of feeds and energy requirements in units of ME (energy units).
For horses, as they are not ruminants Digestible Energy (DE) is used.
This is calculated by: DE = ME/ 0.82 and is expressed in Megajoules per Kilogram (MJ). Table 3 is a summarised chart of nutrient requirements for horses developed by the NRC (Nutrient Requirements Council).
NRC charts cater for all sizes and categories of horses.
In the further reading section of this book, there are references for these charts so you can view the full range of nutritional requirements. Table 3.
Daily energy and protein requirements for different categories of horses. Type of horse Mature weight (kg) Daily gain liveweight (kg/day) Digestible energy (DE) (MJ) Crude protein (g) Weanling (4 months) Weanling (6 months, moderate growth) Weanling (6 months, rapid growth) Yearling (12 months, moderate growth) Yearlings (12 months, rapid growth) 18 months old 2 years old Maintenance Pregnant (9 months) Pregnant (10 months) Pregnant (11 months) Lactating (foaling to 3 months) Lactating (3 months to weaning) — The introduction of weeds can be a problem with buying in feed and samples should be inspected carefully for weed seeds.
It is not always possible to detect a potential problem or even to refuse a feed on these grounds during times of drought.
One way to minimise a potential weed problem is to restrict feeding out of any suspect fodder to a limited number of paddocks.
During times of drought, grain prices tend not to rise significantly as compare to roughage.
It is therefore advisable to store good quality roughage as this can save you a large amount of money and stress trying to find quality roughage for your horses when demand will be at its greatest.
When storing feed it is always best to minimise wastage such as making storage areas vermin proof and store feed out of the weather.
Grain can easily be stored in silos and this ensures grain is protected from vermin and the weather.
Fodder is harder to protect from the elements and should be stored elevated from the ground and undercover.
If this is not possible tarpaulins should be used to protect the fodder.
There is likely to be some loss in fodder and this must be calculated into your feed budget. Chapter 3 MANAGING HORSES DURING DROUGHT When to start feeding The commencement and cessation of feeding, the level of supplementation and the introduction strategy are all-important components in feeding during drought.
Feeding too early or too long can waste feed while commencing too late or stopping too soon can result in increased costs in feeding to gain weight, illness or even death.
Often the greatest problems occur after the drought has broken, especially if the weather turns cold.
It pays to remember that unlike fire or flood when horses may have to suddenly rely on hand feeding alone, the onset of a drought is usually gradual.
Drought conditions rarely deteriorate to the stage where no grazing is available and horses have to rely solely on hand feeding.
Experience from previous droughts indicates that more paddock feed is available than would first appear.
Horses can scavenge quite a bit of feed from sparse dry pasture.
The presence of paddock feed early in a drought makes it easier to get horses accustomed to drought rations before they have to be fed close to full rations.
The presence of paddock feed can have its down sides, with the gradual onset of drought owners can miss a gradual loss in condition.
These horses are frequently disadvantaged right through the drought.
Feeding should be started well before the horse drops condition.
It may take some time before they become accustomed to hand-feeding and begin eating their entire ration.
If horses have lost too much condition before feeding has begun or before they readily accept grain, it may be hard to raise their liveweight back to desirable levels.
This is particularly applicable to weanlings that were not fed supplements when grazing with their mothers.
Table 7 provides target condition scores.
Horses that are in excess of these condition scores can be allowed to lose some weight and condition at the start of a drought.
This weight loss should be controlled.
A drop in weight and condition over a number of weeks to the condition score target, will save feed.
Horses can safely lose up to 5 kg on average a week for this period of weight loss.
The period of controlled weight loss can coincide with the feeding of introductory rations. Table 7.
Suitable condition scores for horses during drought.
Category Maintenance Weanling Yearling Pregnant mare Lactating mare Condition score 2 2/3 2 2/3 2/3 Introducing horses to hand-feeding Horses have to be introduced to hand-feeding gradually as a sudden change in diet can cause colic or founder.
If possible, educating horses onto feed should be started while there is still reasonable paddock feed.
Train horses that have not been fed before by including previously fed horses in the herd to encourage the inexperienced horses to feed.
Untrained horses are best educated in small paddocks.
Whilst this may sound unfamiliar to most recreational horse owners, station horses or young horses on large studs may never have been supplementary fed before.
A new ration should be started at the rate of up to 2 kg per head per day for adult horses (1 kg for weanlings) and increased slowly to the full ration over a two-week period.
Once the equivalent daily rate is reached the introduction period can stop.
If you witness some ‘shy feeders’ amongst your group.
You should move them into another paddock so that they can obtain the same ration as the rest. Monitoring The management of horses during drought depends on knowing how the animals are faring.
The best way to know how horses are going is to weigh them.
In most cases this will be virtually impossible.
The easiest way to monitor is to condition score using the scale as mentioned previously.
Monitoring condition can prevent unnecessary feeding and ensure horses do not fall below a condition score of 1 before being fed as well as identify which horses are not getting enough to eat. Breaking routine or changing feed If a break in the normal feeding routine occurs through delay in the availability of supplies, do not resume feeding the full ration when supplies become available.
Begin feeding again daily, on about half-rations, and build up to the full ration over a few days before returning to the normal routine.
In drought changes in feed are likely due to shortages and prices and this requires careful management.
It is especially important to avoid sudden changes in the ration.
Horses, which have become accustomed to one type of grain, cannot immediately adjust to another.
Deaths can result from a sudden switch of feed.
Even the same grain type obtained from a different source has caused problems.
It is desirable to estimate early in the program how long supplies will last.
This will allow time for planning of a gradual changeover from one feed to another.
If it is necessary to use a different grain arrange the supplies early and mix the old grain with the new, gradually increasing the concentration over at least four days. Deciding when to stop feeding Using a rule of thumb based on condition score, stops feeding when stock remain at a condition score of 2 after the drought breaks.
Feeding should be reduced gradually.
In previous droughts many studs have experienced their greatest problems/ losses during the period immediately following the drought-breaking rains.
Prolonged periods of rain can induce horses to loose appetite and can cause health problems mentioned later in this manual.
The emergence of new pasture growth can cause colic in horses.
Often people think the drought is over when the rain arrives, however it can take some time for pastures to recover.
This time varies greatly depending upon the time the drought ends, and the severity of the drought.
A very general indication for the time taken for pasture to recover would be about 2 months.
In most circumstances, horses should be kept confined to restricted feeding areas until adequate pasture is available.
Allow increasing grazing time each day until full grazing is provided after 6 to 7 days.
Allowing immediate full grazing will lead to digestive disorders. Chapter 4 FEEDING IN HORSE CONTAINMENT AREAS During a drought the risk increases of losing valuable soil as ground cover is reduced.
If grass cover is reduced below 500 kg of dry matter per hectare or 1- 2cm, wind may start to blow soil particles away causing erosion and loss of valuable nutrients and topsoil.
Bare areas will also be more prone to erosion and weed infestation once the break finally occurs.
Another potential loss is newly improved pastures, which may be vulnerable to overgrazing.
Pastures that you have invested money and time in establishing can be lost if continuously overgrazed and should be among the first paddocks to be considered for destocking.
Perennial based pastures should be de-stocked before annual based pastures Feeding horses in containment areas provide an opportunity to take the pressure off susceptible parts of the farm/stud.
Containment areas are yarded sections where horses are lot fed.
For the horse industry lot feeding would consist of horses in smaller paddocks or in many cases ‘day yards” with very limited access to pasture.
This may already be normal practice for some small horse owners due to limited land availability.
The main reasons for considering feeding horses in containment areas are: • • • • • To protect areas vulnerable to erosion To protect vegetative cover of pastures Where weeds in bought feed are of concern Where stock are losing weight on full drought rations in paddocks To facilitate stock feeding, watering, monitoring and handling — • • • • Treatment of colic: Treatments used by veterinarians may vary markedly depending on the type of colic.
Treatment used may use drugs and or mineral oil drenches to surgery in severe cases of blockage and intestinal disorders.
If a horse requires surgery the sooner you get your horse to a surgery the better chance it will have of survival.
Prevention of colic: Poor worm control is the most common cause of colic.
During drought horses can be grouped together and reinfestation may occur.
Regular parasitic treatment and a program to reduce worm intake will minimise the problem.
Your veterinarian can advise you on an worm control program.
In a period of drought, many of your horses will be in a small containment area, if you worm one, worm all your horses.
Also, if horses are in a containment area, remove manure as quickly as possible, (every 2 days).
Care of your horses teeth to prevent them from becoming too sharp or worn will ensure that they can properly chew dry feed; this will reduce the likelihood of large masses of roughage building up in the intestinal tract.
Ensure that there are no foreign objects in the horses feed.
Avoid giving horses a large feed or drink immediately after strenuous exercise as this could bring on a mild case of spasmodic colic.
Change feed gradually over 7– 14 days and do not let your horse gorge on grain.
This is extremely relevant in a time of drought.
If you have to change your horses diet, do it slowly and ensure your horse is getting enough quality roughage. When the break in the drought occurs and there is likely to be a lot of new ‘green pasture’ and your horses may be at risk from sand colic.
This is because horses are grazing low to the ground and the young plants root system is not developed so the roots as well as some dirt is consumed by the horse. Chronic copper poisoning This is caused by long-term excessive intake of copper in the diet, which may be caused by grazing Paterson’s Curse or Heliotrope.
Liver damage can be associated with copper build up.
The disease is brought on by some form of stress (for example, nutritional or lactation stress). Founder (laminitis) The risks of founder will greatly increase when supplementary feeding has to take place.
This is very common in ponies as they require a lot less nutrient for maintenance than large horses.
This problem is usually evident in autumn and spring with the flush of pasture growth occurs.
In a period of drought, the break will be time when you will have to watch your horse carefully.
Signs of a horse with laminitis are a reluctance to move and stiffness in movement.
It will also have warm to hot feet.
Laminitis is a serious condition and medical treatment should be sort immediately.
Again the earlier you treat the animal the greater the chance of recovery.
In severe cases, the pedal bone or coffin bone rotates or pushes through the sole, resulting in the horse having to be destroyed or its movement and future condition will be seriously impaired. Photosensitization This is caused by sensitisation of un-pigmented skin to sunlight after consuming plants such as clover, medic, St John’s Wort and other plants mentioned in poisonous plants section of this manual.
Chronic liver disease can also lead to photosensitization.
White skin areas are affected, especially the muzzle, back and legs.
The effected skin exudes serum, latter cracking to leave raw bleeding areas.
The areas are often covered by scabs and can be confused with rain scald/ mud fever or greasy heel.
Treat your horse by confining your horse to a dry stable and apply an antibiotic/ corticosteroid cream to the effected areas. Pneumonia Pneumonia is caused by bacterial infections aggravated by dry dusty conditions.
It is more common with foals being fed on dry, dusty feeds in troughs, especially finely hammer milled hay.
Symptoms are nasal discharge, coughing, illthrift and sudden death.
To lower the risk of this condition, avoid feeding dry and dusty feeds.
This may require some damping down of the feed in troughs. Rain scald, mud fever, greasy heel Rain scald is a skin infection caused by bacteria Dermatophilus congolensis.
The disease is characterised by matting of the hair with a formation of a scab under the hair mat, commonly along the midline of the neck and back, the face, muzzle, legs and either side of the rib cage. After the scab falls off the skin underneath is moist and grey to pink in colour.
This condition is also called greasy heel and mud fever.
Large areas of skin may be affected.
The skin infection usually occurs in prolonged wet conditions.
These conditions will be evident at the end of the drought as there is no grass to hold the soil together and mud will prevail.
The distribution of scabs follows the pattern of wetting from rainwater, pasture and mud.
Rain scald spreads rapidly between horses.
In appearances it can resemble sunburn, photosensitization or ring worm.
Mud fever occurs behind the pastern, when horses are standing or walking in wet grass or mud.
It is more common for horses with white legs.
The mud can cause cracking of the skin, which can be painful.
In most cases the disease is self-limiting and will regress after 3-4 weeks.
Any horse that is severely affected should be moved out of the rain and onto dry land or into a dry stable.
The affected area can be bathed in an iodine solution and injectable antibiotics. Respiratory infections An increase of the amount of dust occurring in small containment area such as yards will result in an increase in dust related respiratory diseases.
Once again if you witness a condition in one of your horses, quarantine it and seek advice.
A way of minimising the risk of dust is to water the yards regularly.
A point to watch is rattles.
This effects foals and is a result of a soil borne bacteria.
Dusty yards are a great breeding environment to spread this disease.
If you have had cases of this disease before, the onset of drought may increase the chance of incidence of this disease.
Be extremely watchful for any symptoms in your foals. Ryegrass staggers Horse owners should note that when the break occurs there is a lot of new pasture growth.
A great majority of the new growth could be perennial ryegrass, if it survived the drought.
Ryegrass staggers can occur under these conditions.
The fungus, endophyte emits a toxin called lolitrems which is the cause of ryegrass staggers.
Symptoms include a loss of coordination, standing out stretched, convulsions and in extreme cases, death.
During drought conditions immediately after the break, juvenile perennial ryegrass will be prevalent.
Horses will immediately graze the grass close to the ground.
Endophytes exist in the stem of the grass, so grazing low will increase the chances of infection.
If horses are showing symptoms of staggers, remove them from the pasture immediately and seek veterinary advice.
The best prevention is when renovating pasture is to ensure an endophyte low or free perennial ryegrasses are sown.
Salmonellosis Faecal contamination of feed and water supplied with Salmonella organisms can cause an outbreak in stressed horses.
It is more likely to be a problem when the area becomes wet or muddy following heavy rain or from overflowing water troughs.
Symptoms are fever, scouring and sudden death.
Treatment requires antibiotic treatment and advice should be sought from your veterinarian.
Reduce the risk by feeding in clean bins. Worm infestations and control
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