Minerals for Sheep
Minerals are essential to life and seventeen mineral elements are known to required by many animal species. These are divided into two groups: Macro minerals and Micro minerals or micro nutrients.
Like us, animals obtain their minerals from the food and water they consume. If the soil is deficient or imbalances occur due to soil pH etc, the food, or pasture in the case of sheep, may also lead to deficiencies within the body. Deficiencies may be short term or seasonal or long term and need correction by providing a mineral supplement. Supplements may be in block form, loose lick mineral mixes, injection or slow release intra ruminal devices.
At Sugar Gum Farm, our preference is to have blocks out all year round and supplement also with loose lick minerals topped up when necessary. Certain minerals, such as Calcium, will be increased at certain times of the year, including before breeding, during pregnancy and during lactation.
Injectable supplements, particularly the B group vitamins, are kept on hand as a boost for young lambs or any sheep who is unwell.
Macro Minerals
Calcium (Ca)
• 99% of Calcium is stored in bones & teeth.
• Occurs in 2:1 ratio with Phosphorous.
Function - structural in bone, involved in muscle contraction, nerve message transfer & blood coagulation Intake - absorbed in small intestine Excretion – faeces, urine and sweat.
Deficiency
•Young animals – rickets, associated with Vitamin D deficiency which interferes with Calcium metabolism.
•Soft bones, hypocalcaemia, tetany convulsion, sudden death, milk fever, poor blood clotting haemorrhage, tooth loss.
Toxicity
• Abnormalities in bones, kidney stones, inhibits Zinc absorption.
Phosphorous (P)
• 80% of Phosphorus is in the bones.
Function with Calcium is structural, involved in metabolism and cell structure, energy metabolism.
Deficiency
• Rickets in young animals, chewing wood or bone. Abnormal eating (pica).
Toxicity
• Diarrhoea, osteodystrophy, soft bones.
Magnesium (Mg)
• 50% is in the bones, liver, muscles, blood cells and serum
Function – bone constituent, required by mitochondria in heart muscle, enzyme formation for energy.
Deficiency
• Anorexia, reduced weight gain, hypomagnesimia tetany, hypothermia of ears & extremities, muscle twitching, death. Grass tetany occurs on cereal or grass pastures. High levels of Potassium and Protein may inhibit Magnesium.
Toxicity
• Not a problem as kidneys excrete excess.
Potassium, Sodium and Chlorine (K), (Na), (Cl)
• Involved in electrolyte balance and osmotic balance.
Potassium mainly in cells. Sodium and Chlorine mainly in fluids.
Function – Potassium involved in protein synthesis in muscles. Sodium maintains osmotic balance and pH and transfer of nerve impulses. Similarly, Chlorine is involved with osmotic balance.
Deficiency
• Potassium - Abnormal heart function, retarded growth.
• Sodium - reduced growth rate, craving for salt.
• Chlorine – nervous reaction to sudden noise.
Toxicity
• Renal malfunction if water too saline.
Sulphur (S)
• Component of organic compounds especially amino acids, vitamins and mucopolysaccharides. Found in every cell.
Function – Forms in protein, extracellular fluid. Involved in carbohydrate metabolism, blood clotting, collagen and connective tissue metabolism. Component of hormones including oestrogen.
Metabolism – Rumen microbes can use inorganic Sulphur and Nitrogen to form Sulphur containing amino acids.
Deficiency
Protein deficiency signs
• Reduced wool growth.
• Poor weight gain.
• Inadequate microbial subtraction.
​Micro Minerals
Cobalt (Co)
• Vitamin B12 formation by microbes in rumen.
Deficiency
• Loss of appetite.
• Reduced growth.
• Loss of body weight.
• Anaemia.
Toxicity
• Excess Cobalt is lethal.
Iodine (I)
Deficiency
• Leads to goitre, thyroxine deficiency.
• Reduced metabolic rate.
• Cretinism in young lambs.
• Reproductive problems.
Zinc (Zn)
• Found in liver, bone, kidney muscle, pancreas, prostate gland, skin, hair, wool, blood.
Deficiency
•Retarded growth.
• Anorexia.
• Loss of wool.
• Abnormal wool growth.
• Retarded bone formation.
• Reduced semen production.
Toxicity
• Excess Zinc is toxic for rumen microbes.
Iron (Fe)
• 70% of body iron is found in haemoglobin in blood, and myoglobin in muscle. 20% is stored in labile form in the liver and spleen. Iron is involved with oxygen transport, and absorbed in the duodenum. High levels of other trace elements Zinc, Manganese, and Copper can reduce absorption of Iron. Iron is transferred across the placenta to actively concentrate in the foetus. There is very little iron in milk.
Deficiency
• Anaemia, small blood cells with less haemoglobin.
• Similar to induced anaemia and iron deficiency caused by blood sucking parasites.
Toxicity
• Rare under paddock conditions
Copper (Cu)
• Found in liver, brain, kidneys, heart, blood, eye pigment, hair and wool.
• Required for normal red blood cell formation and Iron absorption.
• Required for wool and hair pigmentation and melanin formation.
• Absorbed in the duodenum.
• Excreted in bile.
Deficiency
• Anaemia – reduced red blood cell life.
• Incoordination and ataxia in lambs.
• Sway back associated with high Molybdenum, high Sulphur and low Copper.
• Alopecia, abnormal wool and hair development, loss of wool pigmentation.
• Haemorrhages.
Toxicity
• Sheep are most susceptible.
• Jaundice.
• Growth depression, mild anaemia, liver damage and death.
Sheep feed with copper levels over 25ppm or a Copper:Molybdenum ratio of greater than 10:1 is potentially toxic.
Copper is stored in the body’s lysosomes where it is safe and released at times of stress, which is when problems may occur.
Manganese (Mn)
• Very little required, widespread throughout the body, bone, liver, skin and muscle.
• Involved in bone organic matrix, bone formation in the lamb.
• Required for oestrus and ovulation in the ewe, as well as libido and spermatogenesis in the ram.
• Absorption inhibited by excess Calcium or Phosphorous.
Deficiency
• Skeletal abnormalities.
• Lameness, shortening of bones and enlarged joints.
• Delayed oestrus, poor conception, decreased lambing percentages.
Toxicity
• Interferes with absorption of other nutrients.
• Calcium and Phosphorous utilisation adversely affected by high Manganese.
Selenium (Se)
Selenium exists in two forms: Selenite and Selenate the inorganic forms and selenomethionine and selenocysteine the organic forms. Both are good sources of Selenium.
• Selenium and Vitamin E metabolism are inter-related.
• Present in all cells of the body especially liver, kidney and muscle.
• Involved in maintaining cell membranes and pancreatic function.
• Absorbed from duodenum. And tied to amino acids.
• Transported in blood.
Deficiency
• Muscular Dystrophy and White Muscle Disease.
• Liver necrosis.
• Reduced fertility.
Toxicity
• Blind Staggers.
• Heart Atrophy.
• Paralysis.
• Death.
Chromium (Cr)
• Involved in the synthesis of cholesterol and fatty acids in the liver and glucose utilisation, by being a co-factor in insulin.
Fluorine (F)
• Tooth and bone formation and prevention of tooth decay. 1ppm sufficient in water.
Molybdenum (Mo)
• Involved in growth in lambs.
• Seldom deficient.
• Excess amounts of Molybdenum and Sulphur can cause Copper deficiency.
Vitamins
Vitamins are classed as water soluble or fat soluble. Ruminants receive the B group vitamins from the rumen.
• Vitamin B12 production depends on Cobalt being available in the diet.
• Vitamin C is also produced by the microbes.
• Vitamin E mainly comes from plants, especially the grains.
• Vitamin A comes from Carotene in green and yellow pigments in leaves and grains and may be deficient in droughts in lambs and males.
• Vitamin D is produced in the skin following exposure to the UV light. It may become deficient in lambs kept indoors or dark coloured long fleeced sheep during Winter.