Trace elements

Wesley Habershon from GWF Nutrition provides an overview of the importance of trace elements in camelid feed and the function of key minerals.

As any alpaca owner will know, information on camelid nutrition can be limited, especially around vitamin, mineral and trace element intake. Often values are based on ruminant species and indeed many of the feeds sold on the market today have been initially formulated for other species and tweaked to suit the pseudo-ruminant camelid.

The purpose of this article is to look at the camelid's specific requirements and the various differences in organic, inorganic, hydroxy and chelated trace elements. The important trace elements we will focus on are zinc, copper, manganese and selenium.

When speaking about minerals, trace elements and vitamins in both pseudoruminants and ruminants there are two key focuses: the microbial population in the foregut and the camelid itself. The microbial populations found in the foregut of the pseudo-ruminant do need some organic and inorganic minerals but it is the camelid supply which is of particular interest.

Table 1 demonstrates the specific mineral, trace element and vitamin dietary targets for camelids. Practically mineral supplementation should be ground, loose or pelleted to aid intake as camelids cannot protrude their tongue to lick blocks.

How can we measure trace element supply? Forage or blood mineral profiling

Once we know what we are aiming for there are a number of ways we can assess the mineral balance of the herd’s diet:

• forage/hay mineral analysis

• fresh grass mineral analysis

• water mineral analysis

• blood profiling of healthy animals can be helpful in observing your herd, although some mineral imbalances can be masked.

Table 2 demonstrates the typical values of the organic mineral composition of a fresh grass sample and is a helpful starting point. By investigating and combining each herd’s limitations we can build up a picture of deficiencies and antagonisms of the various minerals. It’s worth noting that these need to be applied with dry matter and fibre, and specifically neutral detergent fibre (NDF), intakes.

A vital step for any owner is to take grass samples from across their holding (at least several samples mixed) to understand the lay of the land and any requirements that are potentially not being met.

To put this into context, GWF Nutrition complementary feeds Camelibra and Hembra & Cria have been formulated based on average known values to suit a broader spectrum of requirements given the mineral profile variations across the country. Some alternative formulations may also be available to those with crucial limitations.

Trace element forms Organic minerals

These tend to be the simple forms of minerals found in base raw materials such as hemp meal (see table 3). Organic minerals are easily available to the body. However, they can be vulnerable to binding with each other as with inorganic minerals, but to a lesser extent.

Inorganic minerals

The microbial population of the camelid does have a requirement for simple inorganic minerals but the traditional scattergun approach of feeding these minerals to meet an animal’s requirements in the hope that enough is absorbed is wasteful, potentially harmful and certainly not sustainable.

Inorganic trace element salts dissolve into their ionic forms of cations and anions with the cations being bound to proteins and transported to the liver. However, with each step there are a number of limitations, a significant one being at the lumen where trace element solubility and secondly availability are affected by other forms of ions. For example, if zinc oxide and copper sulphate come into contact the copper and zinc will bind together within the digestive environment and pass out in the excrement unutilised. Diagram 1 depicts how various trace elements and minerals interact.

Table 2

Organic material

• A compound containing carbon.

• Natural plant or animal based bioavailable minerals.

• Seaweed meal, a background feed ingredient (ie. Hemp meal contains 95.7mg/kg organic Zinc).

Hydroxy minerals

• Salt minerals which use paracellular solvent drag to cross the gut lining from an area of high concentration to low concentration.

• Zinc chloride hydroxide monohydrate, Dicopper chloride trihydroxide and Dimanganous chloride trihydroxide.

Inorganic material

• Most basic not bonded with carbon.

• Relatively cheap to produce – not the best for absorption. Common in feedstuffs.

• Zinc Oxide, Manganese Sulfate, Sodium Selenite, Copper Sulfate

• Weak bonds which can easily disassociate.

Chelated minerals

• Seperate releasing ionic form or are metals structurally bound to amino acids and use transcellular transport.

• Zinc/Copper chelate of lysine and glutamic acid, Manganese chelate of amino acids hydrate.

• Zinc-L-Selenomethionine, L-Selenomethionine.

Chelated and hydroxy minerals

There are regulated legal guidelines around feeding trace elements to ensure camelid and product safety. It’s vitally important to make sure what trace elements we do have are used effectively, absorbed and benefit the animal. Chelation (bonding to amino acids) or hydroxy (paracellular solvent drag) are better forms of ensuring more trace elements are absorbed by the small intestines and feed the camelid. The paracellular-hydroxy route enables trace elements to move from an area of high concentration to low. This is an osmosis style absorption process across the gut wall and similar to our ‘Oatinol Delivery System’, which uses a specific oil combination to aid ingredient absorption and safeguard the immune system. It also further helps utilise trace elements.

Chelates either disassociate releasing ionic form or follow a transcellular route by linking to an amino acid. Amino acids are simple forms of proteins all species use within cells from creation. Here we can feed smaller quantities but with much higher bio-availability reaching the desired location and preventing any risk of toxicity and waste when fed correctly.

Camelibra has recently changed its formulation from hydroxy trace elements to chelated Zinpro trace elements (inc. Zinc Chelate of Lysine and Glutamic Acid 3b615). Hembra & Cria, Crialibra and Fibregest will shortly follow.

Key minerals Zinc

Zinc’s specific roles in a camelid include making and breaking proteins, male fertility, immune function, skin defence and fleece fibre growth and integrity.

Soils are particularly variable in zinc supply from 30ppm-300ppm across the country (Ewing & Charlton, 2007) with many being zinc deficient. Alkali soils reduce availability and as grass matures so the zinc content reduces further. To compound this there is a difference between total and available supplies, whilst once in the animal only 15%-60% physical metal may actually be available (Ewing & Charlton, 2007). Good forms of organic zinc are in both linseed and hemp.

Copper

Copper is important for any species although toxicity is a significant risk; high inorganic feed rates have a tendency to accumulate in the liver with potential fatal consequences and so bio-availability is key. Copper is essential for haemoglobin synthesis, pigmentation and keratinisation in fleece amongst other roles. However, in inorganic form it can either interfere with or be bound by calcium, zinc, iron, molybdenum and sulphur. Soils also can vary in their availability of organic forms with clay soils having higher concentrations than sandy soils. Absorption ability also drops as animals age.

Manganese

Manganese is a poorly available trace element in simple form, easily affected by heavy liming or six plus pH soils which are common in the UK. Excess calcium, phosphorus, magnesium, iron and sandy soils can also restrict availability. Body stores of manganese are limited and any liver supply is quickly used in bile secretions. It plays a role in maintaining joints, preventing skeleton abnormalities and the metabolism of feedstuff s, utilising thiamine and vitamin E.

Selenium

Selenium and vitamin E work together to protect the cell from pathogens and resulting oxygen damage. Selenium also aids liver function, stimulates antibody production and protects muscles from degeneration, whilst playing significant roles in fertility from reducing cystic ovaries, metritis and low sperm motility. It can be stored in the liver, kidney and pancreas and there are toxicity risks associated with oversupply. Selenium is stringently regulated so it is common to use selenium enriched yeasts in order to maximise utilisation. There is also a need for some form of inorganic sodium selenite.

There are various other trace element, mineral and vitamin requirements but zinc, copper, manganese and selenium are central to a camelid diet. The key is to ascertain feed, forage and location values of trace elements so you can identify risks and choose the correct method of feeding. At GWF Nutrition we are upgrading our main supply of trace elements to transcellular chelated amino acids to bring the benefits discussed above.