Nutritional content of grass for stud, yonugstock and performance horses

Question 1

What is fibre broken down into?

Answer 1

Fibre is fermented into VFA in the hindgut. These include

• acetate (75%) - produces 10 ATP
• propionate (15%) - 17 ATP
• butyrate (10%) - 25 ATP

Fibre acts as a fuel for aerobic energy production and can make up to 50-80% of energy needed for maintenance. Muscle glycogen is replenished by high quality forage because it has good levels of CP and WSC.

Question 2

What is the industry perception of feeding a forage only diet?

Answer 2

• it does not provide enough energy required for work (particularly race and performance horses)
• more concentrates are fed instead of hay or forage
• this produces high levels of energy yielded from low levels of feed - the horse is carrying less weight and money is saved (however does increase the risk of ulcers)
• also produces less saliva because there is less chewing
• fibre also holds water that is taken to the hindgut

Question 3

What is the average rate of growth of a foal fed on a grass diet?

Answer 3

A foal fed on grass will grow at about 1kg/day.

Question 4

What are some deficiencies that a horse can get?

Answer 4

1. Selenium deficiency - causes white muscle disease
2. Copper deficiency - causes developmental orthopaedic disorders
3. Calcium deficiency - affects bone development

Question 5

Define WHITE MUSCLE DISEASE

Answer 5

White muscle disease is caused by a selenium deficiency. It is a degenerative disease that affects skeletal and cardiac muscles in foals. The primary signs include recumbency (excessive leaning/lying), fast heart rate, failure to suckle, difficulty swallowing and red/brown urine

Question 6

Define DOD

Answer 6

Developmental orthopaedic disorders are caused by copper deficiency. They range from angular deformities in the limbs to crippling cervical vertebral malfunctions. Symptoms include pain, stiffness, joint effusion (build up of fluid), lameness.

Question 7

What will a calcium deficiency do?

Answer 7

A calcium deficiency will affect bone development and growth. Calcium is therefore key for the full development of a healthy skeleton.

Question 8

What are the energy content levels provided by grass for mares, foals and stallions?

Answer 8

For lactating mares - 132.79 MJ/DE and 1576g of CP

For foals - 80.56 MJ/DE and 797g of CP

For stallions -
During the breeding season - 91.14 MJ/DE and 789g of CP
During the off season - 76 MJ/DE and 720g of CP

Question 9

How can pasture energy be increased?

Answer 9

• change the species of grass e.g. perennial ryegrass, timothy
• increase the sward by using non competing species and introducing hybrids
• cut paddocks to stimulate growth, rotate the paddocks for rest, do a soil sample to find the correct fertiliser and lime in the autumn
• introduce legumes (white and red clover and sainfoin)

Question 10

What are the benefits for the horse of a better pasture?

Answer 10

• more chewing (mastication) - more saliva is produced which helps with lubrication and protecting against ulcers
• better gut health due to higher fibre levels
• more social time (rather than in stable)

Question 11

What are the energy requirements for foals?

Answer 11

At 1 month - 33.52 MJ/DE and 656g of CP
At 6 months - 65.03 MJ/DE and 676g of CP
At 12 months - 78.60 MJ/DE and 846g of CP
At 20 months + (mature) - 70 MJ/DE and 630g of CP

Will also depend on whether the foal is a pony or horse. The microbiome becomes broader if the foal is exposed to a range of plants and therefore becomes healthier and more robust.