Vitamins and Minerals- Disorders on animal health

Proximate analysis ‘Chemistry of Feed’

Dosage for feeding vitamin minerals graph

Feeding nutrients

Feed is a composition of nutrients

The goal is to supply adequate amounts and proportion of these nutrients to meet the animals requirements

Food sources of minerals and vitamins in animal diets

• Forage

• Veggies

• Fruit

• Concentrate

• Mineral blends

Analysis of nutrient compositions

Feeding mineral to animals

Common Macromineral sources for supplementation

True mineral supplementation: when you should

Minerals as antioxidants

• Vitamin E

• Vitamin C

• Selenium

• Iron

• Copper

• Zinc

• Manganese

• Riboflavin- vit B2

Vitamin E & C and selenium are primarily antioxidant function

Iron, copper, zinc and manganese are co- factors for the antioxidant enzymes catalyse and superoxide dismutase

Role of minerals and vitamins in antioxidant systems

Oxidative stress: reactive oxygen species are generated by the induction of exogenous and endogenous sources

Enzymatic antioxidants, non- enzymatic antioxidants, and metal- binding proteins in the body fight against ROS via free radical scavenging and metal chelation mechanisms

When ROS production exceeds antioxidant system, this results in the development of a state called oxidative stress

Specific mineral/ vitamin requirements- cats

Cats require preformed vitamin A and D and niacin

Specific mineral/ vitamin requirements- dogs

Dogs require vitamin D

They can process Vitamin A from B carotene

Specific mineral/ vitamin requirements- zoo animals

Variable digestive system

Omnivores- variety of vegetable and fruits

Obligate carnivores- meat

Insects- mineral blends and supplements

Reason for increased antioxidants?

Increased age or sick animals need more antioxidants

Specific mineral/ vitamin requirement- monogastrics

Sows milk is low in Fe

• high dose of iron intra- muscular

• iron dextrin injections- piglets

Compound feed should meet all nutrients requirements

• laying chickens have high Ca, P requirements

Specific mineral/ vitamin requirement- aqua (fish)

Minerals:

• some absorbed from the aquatic environment

• bioavailability from diet/ supplements

• P and N encourage algal growth

Fish live in a water with a wide range of salinity levels (0-35%) e.g. freshwater, seawater and brackish water

Vitamins: C and B’s: ADEK

• leaching of water- soluble vitamins

• fish cannot synthesise vitamin C

• phosphorylated ascorbic acid

• allowance for manufacturing losses, shelf life ect.

• carotenoids and pigments- astaxanthin, canthaxanthin;

Mineral deficiency symptoms as well as toxicity requires careful balance

Specific mineral/ vitamin requirement- Hind gut fermenters/ ruminants

No cellulase but LI microbial activity

• micro- nutrient req.- ~ monogastrics

• fibre improves gastric evacuation and prevents enteritis

• hoof health in horses- vitamin and mineral supplements

Ruminants:

• rumen microbes synthesise the bulk of B- vitamins

• supplementary B- vitamins for high- producing cows

  - high Ca and others to meet milk production

• Transition cows

  - undergo dynamic change in min and vit requirement

Bioavailability of inorganic micromineral sources

Inorganic, organic, chelated minerals- bioavailability

Minerals are available in inorganic or organic forms

• sulfates, carbonates, chlorides and oxides

Inorganic minerals release free ions; ions are reactive and likely to bind to other dietary components (organic)

Organic mineral sources- provided as a complex with an organic agent e.g. amino acids, proteins, and carboyhyrates

Organic forms are supposed to minimise the interactions and enhance the absorption and bioavailability of minerals

Chelated minerals- minerals that have been chemically bound to an organic molecules, such as amino acid, forming a protective shell around the mineral. The body absorbs amino acids quite effectively and so cheated minerals have a higher bioavailability.

• Bioavailable, more effective, more stable, more tolerated

Examples of inorganic and chelated mineral sources

Why not more inorganics?

Mineral interactions/ antagonists

Lower biological availability/ activity

Environmental concerns

Chelating minerals- improve absorption

Milk fever- what is it?

Calcium deficiency (or failure of calcium homeostasis)

Blood calcium < 8.6 mg/ dL

• clinical cases < 5mg/ dL

Reduces DMI post calving

• predisposes cow to negative energy balance

DMI may be further reduced by:

• retained placenta

• displaced abomassum

• ketosis

Milk fever- cascade 1

Milk fever- cascade 2

Milk fever- calcium homeostasis

Parathyroid hormone (PTH)

• bone resorption

• urinary re- absorption

• stimulates 1,25 (OH)2D

1,25 (OH)- D

• produced in kidneys

• increases calcium uptake from gut

Milk fever- is it just potassium “toxicity”?

High K+ forages increase urinary pH

Lowering K+ pre- calving can improve calcium homeostasis; but not necessarily milk fever

It is through reducing magnesium absorption? No evidence for this direct effect

Low calcium <20 mg/ day

• switch on calcium homeostasis mechanisms

Very high calcium > 1.5% DM

• may overcome passive transport issues

Low DCAD diet- addition of anionic products

Milk fever- how to achieve a low DCAD

Use forage of low potassium status

• non- fertilised “dry cow” pasture/ silage fields

Addition of anionic products

• SoyChlor (approx. -2,616 mEq/ kg)

• BioChlor (aprrox. -3,380 mEq/ kg)

  *Need to add calcium as well

Addition of “All- in- One” mineral packs

• anionic salts PLUS calcium

Anionic salts- NH4Cl; CaCl2; MgSO4

Max 3,000 - 3,500 mEq/ day added to the diet

• danger of acute acidosis

Milk fever- phosphorus

Phosphorus is not as well regulated as calcium

Too much phosphorus can increase the risk of milk fever

• increasing from 0.3%DM to 0.4%DM increased risk by 18%

• practical experience would suggest 60g/ day definitely causes problems

Excessive phosphorus

• reduces the effectiveness of path

• inhibits 1-25 (OH)2D production

Milk fever- magnesium

Magnesium absorbed primarily through rumen epithelium

• at low levels, a K- sensitive pathway is used

• high K reduced the effectiveness of this route

Magnesium is critical for the release of PTH

• low magnesium reduced 1,25(OH)2D production

Increasing magnesium from 0.3% DM to 0.4% DM

• reduces risk of milk fever by 62%

Equates to around 40-50g magnesium / day

• overcomes the K- sensitivity and the K- insensitivity pathway used

Milk fever- vitamin D

Not the lack of vitamin D that causes milk fever it is the refractory receptors

Very high dosage may help

• approx. 20,000 iu/ day

Better effect in Low DCAD rations

Milk fever- summary

Milk fever is a major disease affecting dairy cows

• especially at sub- clinical levels

High potassium forages are a main causative agent

• reduce as much as is practical (lower grass silage peripaturient)

Careful attention is needed to the macro- mineral supply pre- calving

• inter- relationship exist

Phosphorus Cyle

Nutrient supply and availability- phosphorus

Plant based diets contain phytate- an ANF

Most phosphorus in feed can exist in inorganic form, binds to phytate = phytate- phosphorus complex

Low availability of P for digestion and absorption

• significant in fishes, poultry and pigs

Requirement: P to available P

Phytate enzyme is used to bind phytate, release P in the diet

Unavailable P is released with excreta; loss to the environment

P deficiency

Poor appetite and feed intake; poor growth, higher breeder mortality rates, reduced fertility and milk production, bone breakage and bone deformities in severe cases.

Mg: Grass staggers/ hypomagnesaemia

3 danger periods

• spring, shortly after turnout

• summer, if wetter than usual

• autumn, on a flush of grass/ late N application

Reduced Magnesium intake

• grass low in Mg, less supplementary feed used

• spring grass in high moisture, therefore lower intakes of DM

Reduced magnesium absorption

• higher fertiliser use (N)

Increased requirement and stesses

• lactation, growth, age

• cold wet weather, excitement, calving

Copper

Needed in many enzyme systems

Energy metabolism

• fertility, milk yield

Immune function

• mastitis

Pigmentation of hair

• ‘gingering’ of the coat- e.g. horses

Structural functions

• weak legs

Copper poisoning- high accumulation in the liver and kidney causes organ failure

Sheep is highly susceptible to copper toxicity. Texels, Suffolks are sensitive breeds

Mineral interactions and mineral bioavailability

Antagonistic

Iron: interferes with Cu, Zn, Cr

• High Fe in water, silage, soils

• Chain unloaders rust, soil contamination

Cu and Zn compete for absorption sites

High calcium: binds trace minerals-

Sulfur, sulfate: reduce Cu absorption

Molybdenum: reduces Cu absorption

High levels of beta carotene might decrease serum levels of vitamin E

Calcium might form a chelate with riboflavin, decreasing riboflavin absorption

Mineral interaction- synergistic interaction

Vitamin A and E together lead to increased antioxidant capabilities- protection against some cancers, healthier gut.

Sever vitamin A deficiency decreases the uptake of iodine and impacts thyroid metabolism.

Iron is required for converting beta- carotene into vitamin A (retinol)

Zinc is required for vitamin A transport

Selenium

Anti- oxidant functions

• along with vitamin E

Immune functions

• prevent cell breakdown

• white muscle disease

Fertility

• retained cleansing

Growth hormone

• needed for conversion of active T3

Vitamin E

Anti- oxidant functions

• along with selenium

Cell structure

Deficiencies

• weak contractions

• white muscle disease

• high SCC

• mastitis

Iodine

Main role in growth hormone

• Thyroxine (T3)

Heat regulation

Growth and muscle function

Deficiencies:

• Abortion

• Weak calves and lambs

• Goitre- controlled by iodised salts initiative of the WHO

• Hypothyroidism symptoms in dogs, lethargy in horses etc.

Vitamin A

Needed for vision and reproduction

Green forages are rich sources of vitamin A precursors

Conserved feeds are poor sources

Deficiencies:

• blindness

• poor fertility

Vitamin D

Calcium metabolism

No feeds contain vitamin D

Animal ‘manufactures’ vitamin D from sunlight

Must be added minerals

Deficiencies:

• Rickets

• Milk fever

• Displaced abomasum

AHDB decision guide on vitamin and mineral supplementation

Detecting animal’s mineral status

Blood samples are commonly used to monitor the status of most minerals- Macro minerals

Detecting animal’s mineral status

Blood samples are commonly used to monitor the status of most minerals- Micro minerals

Animal feed additives

Additives: products used in animal nutrition for purposes of improving the quality of feed and the quality of food from animal origin, or to improve the animals’ performance and health, e.g. providing enhanced digestibility of the feed materials.

Types of feed additives

• Antibiotics

• Probiotics

• Oligosaccharides

• Antioxidants

• Emulsifiers

• Binders

• Organic acids

• Enzymes

• Phytogenetics

Feed additives in horse nutrition

• Joint supplements

• Digestive supplements/ gut balancers

• Hoof supplements

• Respiratory/ breathing supplements

• Calmers

• Instant calmers

• Hormone supplements for mares

• Performance supplements

• Veteran supplements

• Skin and coat supplements

• Supplements for horses on restricted grazing

• Electrolytes

Joys of Legislation

Ever changing

Still not ratified

Legal maxima changing too

• Cobalt

• Iodine

• Organic selenium

• Zinc

Why it is crucial?

• Legal compliance

• Consumer protection: formulation, composition and declaration requirements

• Animal health and safety: reducing the risk of adverse effects on animal health.

• Quality control

• Traceability

Food Standards Agency (UK) and European Food Safety Authority (EFSA) set guidelines for production, marketing, inclusion and storage of additives

Labelling

Conclusion

Prior to obvious clinical or subclinical signs of over- or under supply of macro or micronutrients, the animal’s immune status offers a quick response which can be used to monitor and prevent morbidity and mortality.

Optimal performance of animals is hinged on, not just the appropriate supply of energy sources and protein in thier diet, but very importantly, the provision of macro- and micro- minerals and vitamins.

Balancing mineral concentration is important because of the antagonistic and synergistic interactions among minerals, and with vitamins. Diet must meet the requirements of the animals for each but also appropriate ratios of some mineral/ vitamin to each other.

Deficiency or toxicity has significant health consequences and can often lead to death.

Other feed additives have potential health- enhancing and performance- enhancing qualities. There is a huge market as innovations are explored to meet consumer, farmer or animal preferences.