Feeding the aging horse

Question 1

What problems are associated with an older horse?

Answer 1

1. difficulty chewing
   - tooth loss, other dental problems
2. weight loss
   - hips, rib bones more visible
   - sway back
3. loss of muscle mass
4. increase in obesity
5. reduced exercise ability/capacity
   - lameness
   - limited mobility
6. greater incidence of certain disorders
   - cushings
   - insulin resistance
   - colic
   - choke
7. Long shaggy hair coat, loss of shine

Question 2

What is chronological age?

Answer 2

how long has the horse been alive

Question 3

What is physiological age?

Answer 3

how well is the horse functioning?

Question 4

Demographic age?

Answer 4

how does the horse compare chronologically to its peers

Question 5

Functional age?

Answer 5

what is the horse being used for

Question 6

Physiological changes with age

Answer 6

• teeth
• nutrient digestibility
• nutrient metabolism

Question 7

Changes with teeth

Answer 7

• crowns of teeth continue to erupt entire life = finite length
• incisors may be longer than cheek teeth
• broken, infected teeth
• tooth loss
• dental difficulties (step mouth = don’t get horizontal grinding; wave mouth = may need teeth pulled –> forage is difficult to grind efficiently & effectively)

Question 8

Changes to nutrient digestibilty

Answer 8

more stuff reaching colon/cecum –> fermented –>methane and CO2 –> increased gas production

Question 9

Nutrient metabolism?

Answer 9

Decreased sensitivity

- but exercise improves tissue sensitivity

Question 10

Implications of dental changes on equine feeding

Answer 10

Dental pain (teeth/gums) may lead to
- decrease in food/water (especially if cold)

Inability to properly grind forage leads to

• quidding = spit balls of semi-chewed food
• difficulty maintaining weight – >increase DE and maybe protein
• appearance of being less healthy
• increased incidence of esophageal choke, colic
• readily digestible, quick moving food = not super high quality, high cellulose –> keep things moving, electrolyes/water

Question 11

Implication of aging for forage digestibility

Answer 11

• forage = critical dietary component (at least 1% DM intake)
• decrease in digestibility (teeth, large intestinal function)

Question 12

Age associated muscle loss

Answer 12

Sarcopenia

Possible causes:

• reduced digestibility (lower DP –> not meeting requirements)
• decreased intake
• reduced level of activity
• increased intestinal use of protein
• chronic, low level inflammation –> stimulatory for protein degradation
• decreased responsiveness of muscle to anabolic stimuli
• produce less sex hormones with age

Question 13

Suggested protein in aging horses

Answer 13

14-16% CP vs. NRC 8% maintenance

Question 14

Is it ok to just give more low quality protein?

Answer 14

No, supply quality not quantity

• excess N –> promotes protein degradation
• processed, complimentary, less imbalanced proteins (oats = good protein/AA)
• AA supplements

Question 15

metabolic disorders in the aging horses

Answer 15

1. obesity
   - mobility concerns
   - predispose to other disorders
2. insulin resistance increases with aging
   - obesity may also be a contributing factor
   - predisposition to laminitis
   - high fat/fibre vs. sugar/starch
3. cushing’s disease
   - symptoms in 70% horses >20
   - altered fat, protein, CHO metabolism

Question 16

Micronutrient requirements in aging horses

Answer 16

P - higher?
Ca - lower?
Vit. C - higher? - role in epithelial tissue health, ROS
electrolytes - higher?
B vitamins - hut health

Question 17

Feeding considerations for the aging horse

Answer 17

1. when to make the change?
   - chronological or physiological
2. feeding behaviour
   - group vs. individual feeding
3. feed frequency
   - smaller, more often
   - beneficial metabolically, especially in horses - small stomachs that constantly secure gastric acid and liver that constantly secretes bile
4. dietary considerations
   - forage = important for continuously growing gut
   - senior complete feeds + concentrates

Question 18

Forage considerations

Answer 18

FORAGE!!!!

• pasture
• quality
• grass vs. legume
• long stem vs. processed (hay cubes, beet pulp)
• supplements to improve digestibility of forage (yeast)

Question 19

Grains and concentrates for seniors

Answer 19

Complete feeds

• can be fed in place of forage
• better maintenance of body condition in old, failing horses than hay/grain?

Physical form of feed

• pellets/extruded vs. texturized
• wet vs. dry - when in doubt wet is always better
• feed composition = high fat/high fibre & low starch/sugar

Question 20

Purpose of adding soybean meal and dehydrated alfalfa?

Answer 20

balanced protein

Question 21

Purpose of adding steam crimped grains (oat/barley)

Answer 21

increased digestibility

Question 22

Purpose of adding flax

Answer 22

omega-3s

- grind right before feeding

Question 23

Purpose of adding whey, casein

Answer 23

super digestible, good bioavailability, rapid absorption, supports muscles

Question 24

Purpose of adding oils

Answer 24

decrease starch, increase fat content

Question 25

Purpose of adding molasses

Answer 25

increase palatability

Question 26

What is important to consider for senior diets?

Answer 26

increased fat (PUFAs), reduced starch, increased palatability and digestibility (processed, yeast)