#

horse and nutrition

Vitamins

The REVERDY range proposes feeds offerings an optimal coverage of requirements of all these elements, no matter what the age or activity of your horse.

VITAMIN A

Principal functions
Contributes to the synthesis of proteins (with zinc) and intervenes in:

  • production of enzymes, hormones, immunoglobulins,
  • all tissue development, in particular skeletal, thus its action on growth in the young;
  • reproduction, in both the male and the female;
  • the fight against infection, by contributing to healthy epitheliums;
  • sight.

Sources
Green forage is an excellent source of ß-carotenes, precursors of vitamin A. However deficiency in ß-carotenes is frequent at the end of winter because of:

  • deterioration in hay during storage;
  • exhaustion of the hepatic (liver) reserves.

Carrots are also rich in ß-carotenes and can be distributed at the end of the winter without worry of hypervitaminosis.

Recommendations
Reinforced supplementation is indicated if we wish to:

  • improve stallion and broodmare fertility;
  • obtain optimal growth in foals and young horses;

Equally, complementation is recommended at the end of winter for horses not receiving concentrate feeds containing correct levels of this vitamin.
However, excess vitamin A (over 100 times requirements) is both inutile and dangerous.

VITAMIN D

Principal functions
Principally participates in bone mineralisation, because of its role in regulating the phosphocalcic balance.

Sources
Vitamin D is present in sun dried hay. Furthermore it can be synthesised by the skin when exposed to the ultra-violet rays of sunlight. In absence of excellent hay, and exposure to direct sunlight on the horse, including vitamin D in the ration is essential.

Recommendations
Vitamin D must be supplied moderately and conjointly with sufficient and balanced quantities of calcium and phosphorus.
For horses in training, supply must be reinforced because:

  • they are confined to stables for long periods of the day;
  • their skeletal structures are confronted to daily stress.

Overdosing with vitamin D (regular doses of 10 to 100 times daily requirements) is particularly harmful.

VITAMIN E

Principal functions
The major biological anti-oxidant and as such it:

  • ensures the protection of cell membranes rich in polyunsaturated fatty acids. In this way, along with selenium, which is able to play the leading role, vitamin E contributes to muscle integrity;
  • prevents lipid reserves oxidising;
  • intervenes in reproduction:
    • by protecting vitamin A and essential fatty acids;
    • Hoffman and al.(1999) reported an increase blood antibody concentration (IgG) in broodmares who had received supplementation with high doses of vitamin E. After birth, the foals born to these mares also had superior blood antibody levels (IgG).

Sources
Vitamin E is found in young grass and fresh vegetable oils.

Recommendations
Vitamin E requirements increase when the ration is enriched with unsaturated fatty acids (oils) and when work increases. Vitamin E requirements are reduced by the presence of selenium.

VITAMIN K

Principal functions
Vitamin K plays a role in: 

  • blood coagulation ;
  • bone calcification (on a more secondary basis).

Sources
Abundant digestive synthesis by the gut micro-organisms allow sufficient supply, this is coupled with relatively high levels found in forage.

Recommendations
Under normal conditions, deficiency is not a problem. However intensive work may weaken the gut micro-organisms and disrupt the digestive synthesis of vitamin K.

A complementation of 2 - 3mg/ 100kg live weight per day is recommended in horses undertaking heavy intensive work.

Abusive supplementation with vitamin K in the hope of preventing exercise induced pulmonary haemorrhages reveals being ineffective and very dangerous because it can expose the horse to serious kidney damage (acute nephritis).

THE B GROUP VITAMINS

Principal functions
Vitamin B1 (thiamin)
Essential for the metabolism of carbohydrates and important for:

  • sprints: it intervenes in the combustion of carbohydrates in the muscles;
  • healthy functioning of the nervous system and nerve cell communication.

Vitamin B2 (riboflavin)
Activates the catabolism (transformation) of lactic acid (as does zinc) and takes part in the metabolism of carbohydrates and lipids.

Vitamin B3 (PP ou niacin)
Intervenes in energy metabolism.

Vitamin B5 (Pantothenic acid)
Participates in the renewal of epitheliums and integuments. It favours wound healing and hair growth.

Vitamin B6 (pyridoxine)
Intervenes in the metabolism of amino-acids and proteins, and notably, has an anti-anaemic role.

Vitamin B8 (H ou biotin)

  • at doses of 10 to 30mg a day over a period of 6 to 10 months it improves the growth rate and strength of the hoof wall;

  • at lower doses intervenes in the metabolism of carbohydrates.

Vitamin B9 (Folic acid or Znti-anaemic)
Favours regeneration and maturing of red blood cells.

Vitamin B12 (cyanocobalamin)
Participates in the formation of red blood cells, and so, just like vitamins B6 and B9 helps protect against anaemia. Overdosing is inutile.

Sources
The B group vitamins are present in green forage, cereals, and probiotics, they are also synthesised by the gut micro-organisms.

Recommendations
In the adult horse consuming plenty of good quality forage, there is generally a sufficient supply provided by the micro-organisms in the caecum and the colon.
However, taking into consideration the many roles played by the B group vitamins in muscular effort, the requirements of horses in heavy training/work may be increased, even more so as the gut micro-organisms are weakened by the intensity of the work.
Providing too much vitamin B is not a worry, the limit being more an economic one.

VITAMIN C

Principal functions
Vitamin C is a water soluble vitamin which participates in hundreds of processes in the body. Among its’ principal functions, it notably intervenes in :

  • collagen synthesis,
  • formation of red blood cells,
  • maintaining immunity,
  • the healing of wounds.

Vitamin C also increases iron uptake from dietary sources. Finally, as a major anti-oxidant, it plays a very important role in the fight against free radicals by participating in the recycling of vitamin E.

Sources
Vitamin C is naturally synthesised by the bacterial flora.

Recommandations
Unlike man, the horse is able, via his bacterial flora, to synthesise his own vitamin C and cover his maintenance requirements. However, taking into consideration the multiple implications of vitamin C in the metabolism, supplementing horses in intense work and training is recommended, even more so as the requirements related to effort can be accumulated and the flora weakened by work intensity.



The simplest and most common type of vitamin C used is L-ascorbic acid. Unfortunately, this molecule is very fragile and degraded considerably during feed manufacturing and storage processes . For this reason, we have selected a protected, thus very stable form of vitamin C : Phosphorylated L-ascorbic acid.

The active part of this molecule is stabilised (esterified with a phosphate group) and is only reactivated after the vitamin C is absorbed and metabolised within the organism.

The best fulfilment of daily requirements for horses in intensive work is ensured by using this form of protected vitamin C associated with the incorporation of optimum levels into our feeds (500 to 1000 mg/kg).

Recommended daily vitamin requirements (source DSM and BASF)


In mg/100kg LW/day
except for vitamins A and D

GROWING
YOUNGSTERS
LEISURE HORSES RACEHORSES AND
BREEDRING STOCK
Vitamin A
(in UI/100kg LW/day)

10,000 - 12,000 6,000 - 8,000 12,000 - 15,000
Vitamin D
(in UI/100kg LW/day)

1,800 - 2,200 600 - 800 1,200 - 1,500
Vitamin E

100 - 200 90 - 180 200 - 400
Vitamin K

3 - 4 1 - 2 3 - 4
Vitamin B1
(Thiamin)

8 - 10 7 - 10 12 - 20
Vitamin B2
(Riboflavin)

8 - 12 6 - 8 12 - 16
Vitamin B3
(Niacin)

10 - 20 10 - 15 20 - 35
Vitamin B5
(Pantothenic Acid)

8 - 12 8 - 12 9 - 15
Vitamin B6
(Pyridoxine)

6 - 8 4 - 7 7 - 10
Vitamin B8
(Biotin)

0.2 - 0.3 0.2* 0.2 - 0.3*
Vitamin B9
(Folic Acid)

6 - 8 4 - 7 8 - 12
Vitamin B12
(Cyanocobalamin)

0.06 - 0.12 0.06 - 0.12 0.1 - 0.15
Vitamin C
(L-acorbic acid)

200-300 - 200-400


* To improve the quality of the hoof wall, 15 - 20 mg/day for at least 6 months.