Mineral Deficiencies, Supplementary Feeding and Medicinal Licks

Transcription

1 1 Module # 7 - Component # 1 Mineral Deficiencies, Supplementary Feeding and Medicinal Licks Objectives To obtain the knowledge about the mineral needs of wildlife and the methods to supply the animals with the necessary supplementary feeds and medicines. Expected Outcomes To be able to recognize mineral deficiencies in wildlife and to be able to supply the necessary supplements with the appropriate precautions.

2 2 Supplementary Feeding Introduction The aim of supplementary feeding and mineral licks is to fill the nutrient shortages in natural grazing. The animal is thereby placed in a position to express its genetic potential (making it an attractive mating partner) in terms of maintenance of mass, condition, high reproductivity and mass of calf at weaning. If the animal's feeding status at a given time period is known, a supplementary lick can be formulated and the shortage of a specific mineral or minerals can then be identified. It is accepted that the majority of game yield the same results as in the case of cattle, considering that both are ruminants. There are no commercially registered products that can be used for game. All products are registered for cattle, sheep and goats. Nutritional shortage in natural grazing There is either an over-abundance of low quality grass (sour veld) for grazers, or there is too little rough food of high quality (sweet veld) for browsers. The situation is further worsened by game being tamed by intensive farming and being limited to certain areas by the construction of game fences. Game can no longer move freely over large areas to select the best and most nutritious food. Grazers Natural grasslands in South Africa are only reasonably nutritious for a short period in the year. The veld reaches maturity quickly and crude fibre content rises as a consequence of lignification (grasses becoming older and firmer), the digestibility decreases to about 40% and the crude protein values decrease to as low as 2-3% during the dry season. The percentage of most of the mineral elements also decreases as the grazing season progresses. In certain areas of the country, for example the sweet veld, digestibility is maintained for longer periods and the crude protein content is not lowered so drastically. Crude protein content, however, sometimes decreases for long periods to under 5%, the minimum level associated with the maintenance of mass in cattle. Supplementary feeding is therefore necessary to improve the condition of the animals.

3 3 Browsers In general, the leaves of trees and shrubs seasonally provide a more constant and higher level of protein than the grasses provide. The proteins may be less available if one considers that leaves contain, amongst others, tannins, alkaloids and other compounds that can reduce digestibility. The availability of leaves and browse is sometimes a problem in the sense that quantity and not quality, may be the limiting factor as a result of seasonal loss and change of leaves of trees. The chance that browsers could experience an energy shortage at certain times of the year is therefore greater than in the case of grazers. There are, therefore, shortcomings in natural veld that can be supplemented. Grazers and browsers have different types of nutrient shortages.

4 4 Natural licks Natural mineral licks are mineral-rich reefs in the soil which herbivores utilise by eating the soil (biting or chewing) or by licking it. This practice is called Geophagia and is frequently seen in Kudu and Eland The warmer the climate, the more time the animals will spend on a brack (salt) lick. Natural licks, especially in the drier habitats, occur more abundantly and are also utilised more regularly. This is an indication of nutrient deficiency that can be ascribed to degradation of the environment or an overpopulation of game or both. The appearance of licks can also be ascribed to other factors such as changes in the veld from bushveld to open- or semi-open grassland. There are three problems that occur with the utilisation of natural licks, namely: Soil is removed: Soil is removed by the rolling of animals in or near the licks, the eating and licking of the soil and by the trampling effect of the animals at the licks and in the paths leading to the licks. Vegetation is destroyed: The areas around the licks are usually trampled and over-grazed and have very little plant cover. Disease is spread: As a result of the activities at licks, such as drinking, urinating, grazing, rolling on the ground and defecating disease can spread relatively quickly.

5 5 Mineral Deficiencies (and overdoses) Minerals that are important for the general health of animals can be divided into two main groups, namely: macro- and micro-elements (trace elements). (Refer to Table # 1). Macro-elements Calcium - Ca The calcium content of grasses does not change much from season to season. Calcium is necessary for normal skeleton development. Green plants, for example legumes, are good sources of calcium. Other sources are lime stone powder, bone meal, fish meal and carcass meal. Overdose : Retards the intake of zinc, copper and manganese. Deficiency : Leads to weak bone structure, other deformities and mastitis. Phosphorus - P The whole country, with the exception of the bushveld, can be regarded as lacking in phosphorus. Phosphorus requirements of animals are high during early development of the bone structure of the lamb or calf, late pregnancy or when animals are lactating and in the summer when animals grow. Phosphorus is also necessary for the oxidation of nutrients and the maintenance of micro-organisms in the rumen. Overdose : Leads to kidney stones and a softening of the skeleton. Deficiency : Leads to osteoporosis, gradual weight loss, lameness, dragging hind legs, breaking bones, lowered fertility, weak growth and weak milk production.

6 6 Salt - NaCl Salt can be offered in a lick with good results. Animals can be tested for a shortage of salt by feeding them salt and watching their reactions. Winter licks (all types), on average, must contain 25% salt to meet requirements to make the lick tastier or to limit the intake. Salt is supplemented with sodium chloride or sodium carbonate. Overdose : Has the opposite effect to deficiency and can cause death of the animal. Deficiency : Leads to over-sensitivity to sound and touch, depression, muscle tremors and cramps. Potassium - K Few deficiencies occur but if they do, the consequence is weak nerve development and low fertility. Deficiency can be supplemented with potassium chloride. Sulphur - S Supplementation can be achieved by including 8 10 % blomswael in licks or hypo can be included in drinking water. Overdose : Induces copper or selenium deficiency. Deficiency : Prussic acid poisoning can occur.

7 7 Symptoms Cu Co Ca P Salt Mg S Zn Mn Fe I Mo Se F K Weak appetite Weak nerves Hypersensitivity Spasms Milk fever Osteophagy Brittle teeth Stillborn calf White muscle illness Goitre Diarrhea Abortion Poor blood Itchy skin Geilsiekte Weak pigment Hindquarter Paralysis Grass tetanus Stywesiekte Skin hardening Low milk production Cellulose digestion low Weak growth Bone abnormality Duinetering Low fertility Anemia Loss of weight Table # 1 - Symptoms of Mineral Deficiencies

8 8 Micro-elements (trace elements) Shortage of trace elements cause problems during pregnancy. Small amounts are added to licks or drinking water in areas where shortages occur. Considering that an overdose is very dangerous, certainty over a definite shortage must exist before trace elements can be provided to the animal. In general, it is very difficult to recognise shortages of trace elements, but these may become apparent in times of stress during droughts, cold or at lambing or calving times. When a large variety of secondary causes of deaths are traced, the primary cause is often an apparent trace element deficiency. Copper Copper stimulates the development of healthy connective tissue, hair and hooves and is necessary for the proper growth of bones. Shortages can easily be determined by noticing repeated breaking of bones, especially shin bones, in areas where there is a copper deficiency. Overdose : Causes haemolysis, jaundice and accumulates in the liver and makes the animal anaemic. Deficiency : Gives rise to anaemia, diarrhoea, hair that loses colour and breaks easily, lameness and sometimes acute heart seizure. Change of hair colour occurs especially around the eyes. Weak appetite, low fertility and general low weight of animals are additional symptoms of copper deficiency. Iron Iron is required for, amongst others, the formation of haemoglobin. Deficiencies often occur in sandy soil. Sources of iron are iron oxide, iron carbonate, carcass meal, blood meal and fishmeal. Deficiency : This is observed in ruminants as a type of anaemia. Symptoms of iron deficiency are pale eye and mouth mucous membranes, weak animals, quick and shallow breathing and animals which are highly susceptible to bacterial infection. Overdose : A rare occurrence

9 9 Iodine Iodine stimulates the thyroid gland to produce hormones, which ultimately determines the rate of metabolism (thyroxine). Deficiency can be supplemented with 0.01% potassium iodide. Fishmeal and seaweed also contain high levels of iodine. Overdose : Animals are over-active. Deficiency : Leads to a swollen crop, stillborn lambs and calves and goitre problems. Manganese Shortages occur in lime coastal soils. Required for various reproductive purposes. Deficiency : Lead to weak or stillborn calves, abortion, weak hair pigmentation, bone abnormalities and low fertility. Manganese sulphate is used as a supplement. Cobalt Cobalt is essential in the synthesis of Vitamin B 12 by the rumen microbes. Cobalt is commercially available as a cobalt supplement as well as cobalt sulphate. Deficiency : Shortages of cobalt causes excessive tear formation, anaemia, loss of weight and death follows as a result of starvation. Overdose : A rare occurrence Molybdenum Few deficiencies occur in South Africa, but if they do, it leads to weak digestion of cellulose and weak growth. Zinc South African grazing has a high zinc concentration relative to the requirements of game and cattle. Where animals are fed with very good quality lucerne, or where the soil is poor in zinc, deficiencies can occur. Zinc is an enzyme activator and a necessary part of insulin. Deficiency : Leads to itchy skin and skin keratinisation. An excess of calcium causes zinc not to be absorbed leads to salivary flow, paraceratosis of the rumen and hair loss on the muzzle, neck and flanks. Overdose : A rare occurrence

10 10 Fluorine Some boreholes can have excessive fluorine. Deficiency : Brittle teeth. Overdose : Not problematic, excess fluorine is expelled in the urine. Extreme cases may involve liver complications. Selenium Selenium has a physiological bond with Vitamin E. Overdose : Leads to hair loss at the tip of the tail, ataxia, hooves that fall off and malformed young. Deficiency : Leads to white muscle disease, weak growth and low fertility. Deficiency symptoms differ form animal to animal, but ruminants only show damage to the heart and skeletal muscles.

11 11 Vitamin Deficiencies The absence of one or more vitamins in the diet may lead to a failure in growth or reproduction, or to characteristic disorders known as deficiency diseases. In severe cases, death itself may follow. Although the occasional deficiency symptoms are the most striking result of vitamin deficiencies, it must be emphasised that in practice, mild deficiencies probably cause higher total economic losses than do severe deficiencies. Fat - Soluble Vitamins The fat soluble vitamins include A, D, E, and K. They are soluble in fat and stored in the body in appreciable quantities. Daily intake is not required. Vitamin A Vitamin A promotes growth and stimulates appetite, assists in reproduction and lactation, helps keep the mucous membranes of respiratory and other tracts in healthy condition, and makes for normal vision. A mild deficiency causes lower food consumption and weight gains. A severe deficiency causes night blindness, muscular incoordination, staggering gait, and convulsive seizures. Total and permanent blindness in young animals and other localised paralysis may occur. Other symptoms include Excessive watering of the eyes (rather than xerophthalmia) usually occurs: the corneas of the eyes become keratinized and may upon infection, develop ulceration. Severe and intermittent diarrhoea at advanced stages of deficiency is characteristic. True Vitamin A is a chemically formed compound, which does not occur in plants. Plants are a variable and often unreliable source of carotene. The conversion rate of beta - carotene to vitamin A is different for different species. Stress conditions - such as extremely hot weather, viral infections, and altered thyroid function - have been suggested to cause a reduction in this conversion. Vitamin A deficiency can be detected by carotene and vitamin A analysis of blood and liver tissue.

12 12 Vitamin D Vitamin D aids in assimilation and utilisation of calcium and phosphorus, and is necessary in the normal bone development of animals - including the bones of the foetus. Symptoms of a mild to moderate deficiency include rickets in young calves, the symptoms of which are decreased appetite, lowered growth rate, digestive disturbance, stiffness in gait, laboured breathing, irritability, weakness, and occasionally tetany and convulsions. Prolonged deficiency may be responsible for enlargement of the joints, slight arching of the back, bowing of the legs, and the erosion of the joint surfaces which cause difficult locomotion. Posterior paralysis may follow fracture of vertebrae. Symptoms develop more slowly in older animals. Vitamin D deficiency in pregnant animals may result in dead, weak, or deformed calves at birth. When exposed to enough direct sunlight, game normally acquire their vitamin D needs, for the ultraviolet rays in sunlight penetrate the skin and produce vitamin D from traces of 7 - dehydro - cholesterol in the tissues. Vitamin D helps build strong and sturdy frames. Its primary function is to facilitate absorption of calcium in the intestinal tract as a vitamin component in the production of calcium binding protein. Also, it is involved in the clearance of phosphate in the kidneys and in the intestinal permeability of zinc, iron, cobalt, and magnesium. Vitamin E Vitamin E serves as a physiological antioxidant, facilitating the absorption and storage of vitamin A. Its other biochemical roles in the animal body appear to be related to its antioxidant capability, including the protection of vitamin A. Muscular dystrophy may occur in young animals that suffer a deficiency.

13 13 Vitamin K This vitamin is not associated with specific problems relating to deficiency or overdose Water - Soluble Vitamins The B complex vitamins and vitamin C are classified as water soluble, and are stored by animals for only a brief period of time. For this reason, the large amounts of water that pass through most animals daily tend to carry out, and thereby deplete, the water soluble vitamins of the body. B Vitamins Dietary requirements for the B vitamins (thiamine, biotin, niacin, pyridoxine, pantothenic acid, riboflavin, and vitamin B 12 ) prior to the development of the functioning rumen, are obtained during lactation from the calves mother when the animal is still young. Later, the B vitamins appear to be synthesised in sufficient quantities by rumen bacterial fermentation. However, inadequacy of protein or other nutrients may impair rumen fermentation, with the result that sufficient quantities of the B vitamins will not be synthesised.