Enteral Nutrition

Milk provides nutrients, cells, enzymes, hormones, protective and trophic factors, minerals and electrolytes. It is thought that many of these factors contribute to development and maturation of the gastrointestinal tract [1]. Therefore, every attempt should be made to provide colostrum and mare milk to the foal.

I. General Considerations

1. Ill foals should be kept as close to the mare as possible.

1. Maintain bonding - Prevent foal rejection.
2. Stimulate lactation.
3. Severely ill foals in special rooms for care should have intermittent mare visits.

2. Routes of Administration

1. Assisted nursing - If foal has a strong suckle, help the foal to stand next to mare
2. Nasogastric tube

1. Use small size tubes (see Chapter 58)
2. If feeding frequently, place small tube in stomach and feed slowly.
3. A tube can be left in place and the foal can nurse the mare and still be tube-fed to supplement.

3. Bottle

1. Use lamb nipple.
2. Never bottle-feed a foal with a weak suck reflex -aspiration pneumonia and/or inadequate nutrition may develop.

4. Bucket

1. This is easier in healthy orphans than ill foals.

II. Normal Foals without Illness

1. Healthy foal with mare

1. Nurses up to 7 times/hour [2].
2. Consumes 16-28% of BW/day or approximately 155 ml/kg/day [2].
3. Mare's milk production is approximately 15 ml/kg/day.
4. Foal energy metabolism is approximately 5.5 Kcal/hr.
5. Gains 1-3 lbs (approximately 0.5-1.5 kg)/day.

2. Orphan foal

1. Provide adequate colostrum during first 24 hours of life (see Chapter 8 & Chapter 9 ).
2. Bucket feed foal starting day 2 [3].

1. Let foal suck on finger and move bucket up to foal's mouth.
2. Feed 5 equal feedings of up to 25% of body weight/day.
3. Feed 4 equal feedings/day in week 2 and 3 feedings/day in weeks 3-8 [3].
4. Offer creep ration approximately 1 lb/day. At week 2 feed 1 lb/month of age consisting of 16% protein ration.

3. Nurse mare - Has many advantages.

3. Colostrum feeding

1. Feed 1-1.5 liters (32-48 ounces) of good quality colostrum (see Chapter 8).

1. Give 8 oz (240 ml) approximately every hour for the first 8-10 hours of life.
2. Feed by nasogastric tube unless has excellent suck reflex.

2. Check serum IgG in foal.

4. Agalactia Management

1. Most commonly associated with mare consuming fescue infected with Acremonium coenophialum fungus.
2. If exposed to fescue, treat pregnant mare 30 day prior to foaling with domperidone at 0.55 mg/kg per day orally [4]. Treat into lactation period.
   If mare has poor udder development post foaling treat with domperidone at 1.1 mg/kg per day orally to stimulate prolactin for milk production [4].
   Sulpiride, a dopamine (D2) receptor antagonist, increases prolactin levels and therefore milk production. 0.5 mg/kg administered IM. Twice a day has shown to be effective by different studies [1,2].

III. Induction Of Lactation In Non-lactating Mares

Daels et al. [5], were the first to describe induction of lactation in non-foaling mares. The protocol used to induce lactation in 24 "dry" mares was as follows:

1. Mares delivered and nursed at least one foal.
2. Days 1 -7: Placement of a vaginal sponge containing 500 mg altrenogest and 50 mg estradiol benzoate.
3. Days 8 -14: The first sponge was replaced with a second vaginal sponge containing 500 mg altrenogest and 50 mg estradiol benzoate.
4. Day 8: Administer estradiol benzoate (50 mg, IM) and prostaglandin (5 mg dinoprost®, IM).
5. Days 8 -14: Administer sulpiride (1 mg/kg, IM) twice daily.
6. Day 9: Begin milking mares. The mare was milked five times per day using a milking machine designed for goats. Oxytocin (5 IU, IM) administered ≈2 min before milking.
7. A modification of the above system has been described and is available via IVIS on web at no cost.

IV. Milk Replacers

1. The best milk replacer is real mare milk.
2. Mare's milk substitutes.

1. Foal-Lactm (Pet-Ag: www.petag.com)

1. Recently reformulated, easy to mix and better tolerated

2. Mare's Match (Land O Lakes, Webster City, IA) www.lolmilkreplacer.com

1. 15% fat, 22-25% protein.
2. Powder formula in cans, 5 or 20 lb bags.
3. Feed as a 10% solution [3].
4. Foals scour for average of 2-3 days with formula [3].
5. Feed 25% of body weight/day.

3. Acidified cold ad libitum formula (Buckeye Mare's Milk Plus, Buckeye Feeds, Dalton, Ohio; 800/3210412). www.buckeyenutrition.com

1. Designed to be fed free choice via bucket.
2. No antibiotics or preservatives but stays fresh and can change at 12 hr intervals. Considered ideal for orphans and bucket feeding.
3. Well tolerated by foals and palatable [2].
4. Inexpensive.

4. Goat's milk

1. Foals seem to like it.
2. Causes firm stools and may lead to significant impaction.

1. May need 1/2 -1 oz of mineral oil once or twice daily

3. Fresh goat milk is expensive.
4. Report of metabolic acidosis when feeding goat's milk to some foals.
   Editor's Comment - I have seen this in one foal and acidosis was severe and corrected with change to mare's milk replacer. Foals present as lethargic and not eating with tCO2 on panel low (pH 7.0) and often a high serum chloride associated with low serum bicarbonate level. Make your own: 24 oz cow milk, 12 oz saturated lime water, 4 tsp dextrose (not table sugar), 4 oz evaporated milk, 4 oz warm water, 1 tsp white corn syrup. Or simply 8 oz 2% cow's milk, 1 tsp white corn syrup.

V. Feeding Ill And Convalescing Foals

1. Even with knowledge of the nutritional requirements, the feeding regimen for the individual sick or convalescing foal must be tailored to that animal. Prior problems of diarrhea, infections, ileus, etc., must all be taken into account. Two needs must be met 1) hydration and 2) caloric balance. For example, a recumbent, unable to stand 3-day-old foal with sepsis will not often tolerate the amounts of milk to provide the caloric intake a healthy 3-day-old orphan foal will consume.
2. Sick Foals

1. Foals that are ill from a variety of problems often develop an ileus and may bloat, or reflux with tube feeding.
2. Our approach is to start the severely sick foal with small amounts (50 -100 ml) of milk. If well tolerated, we work up to 10% of BW intake by feeding q 1 hr. Can check the tube for residual milk in the stomach by aspirating on tube. If milk is still in the stomach we wait 1 hour and check again. If the foal is bloated or has persistent reflux or profuse nonresponsive diarrhea, consider intravenous nutrition.

3. Convalescent Foals

1. When the foal becomes stabilized and can begin to stand for a few minutes and becomes more alert and hungry, we can begin to approach the 20-30% of BW/day milk intake required for growth and development. Normal and convalescing foals gain 13 lbs/day.
2. Simply diluting the milk in an animal that is not dehydrated will often not soften the stool. Increasing the sugar content of the milk with syrup or giving 1/2 1 oz of mineral oil orally once daily will often solve the problem. Weigh the foal daily to determine how well your feedings are doing. A bathroom scale that weighs you and the foal will work well.

4. Other Recommendations

1. Warm the milk before feeding.
2. Use clean equipment - Bottles, nipples, tubes.
3. Make milk replacer twice daily and keep refrigerated until used.
4. If digestive upsets develop on a particular milk replacer, try another or try goat's milk.
5. Attempt to teach foal bucket feeding.
6. Add good quality roughage and foal pellets, approximately 16% protein beginning at 10-14 days of age.

VI. Treatment of Foal Rejection

1. Recent work suggests that prostaglandin administration may be useful in overcoming rejection of the foal by the mare. Mare must have had a foal at least once and have raised the foal in a satisfactory/normal way. Give mare sulpiride twice a day for 4-8 days and then 3 ml of Estrumate IM about 10 min before introduction of the foal (longer is ok but shorter is not recommended) [6].