Zinc Deficiency in Goats
Zinc Deficiency in Goats
By Daryl Brown
What is zinc and why is it required by goats?
Zinc is a metallic mineral present in trace amounts in the bodies of goats, in the plant material they consume and in the environment in which they live. Zinc is required by goats to maintain a healthy immune system, for keratin production, to maintain metabolic pathways (Harwood, 2006, p138), to ensure the healthy metabolism of feed constituents, for healthy sperm formation (Mackenzie, 1993, p174) and for all round general heath and wellbeing both physically and mentally. A deficiency in this trace element as with any mineral or vitamin can have a significant impact on the health of goats but is usually easily treatable provided the symptoms are recognised.
How is zinc deficiency caused and what are the symptoms?
Zinc intake in goats comes primarily from fresh or dried plant material (Hay) and fortified feed stuffs, as well as mineral supplements in powder form such as Caprivite or block form such as Rumevite Blocks. The correct intake of zinc from these sources is vital in maintaining the level of zinc required in the body for health; Poor quality feed stuffs, no or limited access to pasture and no access to mineral supplements are all contributing factors which can lead to zinc deficiency as well as deficiency or excess of other essential minerals and vitamins. Illness and stress are other causative factors with conditions such as Coccidiosis and the associated profuse scouring and loss of appetite quickly reducing a goat’s mineral and vitamin levels in their body, and when illness coincides with other bodily stress events such as mating, pregnancy and kidding then mineral and vitamin deficiency is possible. Hereditary mal-absorption of the element may also cause deficiency; animals with such genetic defects may present the symptoms of the condition in the face of normal dietary concentrations of zinc and interfering minerals (Smith and Sherman, 1994, p34). Finally excessive dietary calcium can inhibit the absorption of Zinc and lead to deficiency with foods such as Alfalfa being the main culprit.
Despite the ease at which zinc deficiency can come about it is not thought to be a common affliction possibly due to a lack of research but more likely due to the difficulty experienced by veterinarians in diagnosing it, nevertheless it should be something that is considered by goat keepers when presented with any of the following symptoms:
- Hyperemia of the Skin (An increase in the quantity of blood flow to the skin resulting in redness)
- Pruritus of the Skin (Severe itching, often of unbroken skin)
- Alopecia (Loss of hair; baldness)
- Hyperkeratosis (thickening of the skin) particularly on the ears, face, barrel (Middle Body) and on the udders
- Crust formation on the legs, face and ears
- Scale like dandruff across the rest of the body
- Spontaneous skin lesions on any part of the body
- Lack of appetite
- General ill thrift
This list is not all inclusive and all of these symptoms are not required to suspect zinc deficiency, in some cases all of the symptoms will be evident in others perhaps not.
How is zinc deficiency diagnosed?
Diagnosis of zinc deficiency in goats is not straightforward, particularly as the symptoms described could be attributed to a number of other conditions in particular mange, dermatophilosis and Vitamin A deficiency, which pruritus and skin lesions are symptomatic of. Therefore diagnosis should always be carried out by a veterinarian who in an attempt to rule out other potential conditions may conduct a number of tests, these might include skin biopsies (skin scrapes) for demonstration of hyperkeratosis and to rule out mange infestation and culture and identification to rule out a bacterial infection of the epidermis. Provided that mange and skin infection are eliminated then laboratory tests such as trace element blood tests to determine whether abnormal levels of specific vitamins and minerals are present could be conducted and the results compared with recommended levels; however this is not necessarily definitive as cases have been recorded in scientific journals of goats with zinc responsive dermatitis though plasma, liver and dietary levels of zinc appear normal (Reuter et al, 1987, page 351). Smith and Sherman (1994, p34) suggest that diagnosis may be achieved by positive response to treatment, proposing that an arbitrary dose of 1 gram of zinc sulphate be given orally for two weeks. Should no marked improvement occur after two weeks then other diagnoses should be pursued.
It is important that the welfare of an animal potentially suffering from a zinc deficiency is not compromised any further by lengthy and in concise diagnosis, and hoping the condition will remedy itself. The responsibility of diagnosis should always be given to a qualified veterinarian who will have the expertise and facilities to carry out the required tests swiftly to enable expedient treatment. To allow an animal to remain in a state of ill health unnecessarily whether the reason is because of a lack of funds to use veterinary services or in the hope that the condition will improve of its own accord could be regarded as negligence.
How is zinc deficiency treated and how can it be prevented from occurring?
Once a diagnosis has been obtained (perhaps not definitive but based on indicative symptoms and laboratory testing) and consensus reached between the goat keeper and veterinarian then treatment can begin.
Zinc supplementation in the form of zinc sulphate is the most common and most effective method of treatment (although clinical improvements in the skin will take many weeks if not months to manifest). Given orally by mixing it with feed rations or offering it straight have both proved successful ways to administer zinc sulphate easily and with minimum stress as deficient goats will likely consciously consume the amounts they require. The amount of zinc given should be agreed upon with your vet and will vary depending on the severity of the deficiency which is where laboratory test results of zinc serum levels will prove invaluable. In cases of experimentally induced deficiency in goats quantities of zinc sulphate given ranged hugely from 6 grams to 14 grams given daily for 2-6 weeks(Smith and Sherman, 1994, p34), further reinforcing the recommendation that zinc supplementation should be discussed and agreed upon with a veterinarian. Boluses can also be administered, the most appropriate being Zincosel manufactured by Telsol. These are best administered by your vet and have a life of 6 months.
Anyone considering zinc supplementation should be aware that as with all other minerals and vitamins dietary excess can create its own health problems. Various scientific authors have recommended the practical level of dietary zinc in production diets should be between 45-75ppm, with a minimum of 10ppm as recommended by the National Research Council (McDowell et al, 1991, p332). Levels nearing and exceeding 700-750ppm prove toxic and lower but still excessive levels lead to reduced iron function, anaemia, copper deficiency and impaired immunity, once again reinforcing the advice that treatment for zinc deficiency should be discussed and agreed upon with a veterinarian.
Where hereditary mal-absorption is suspected then lifelong supplementation may be required, this is usually indicated by a return of the lesions and alopecia after zinc supplementation ceases.
Topical ointments and Homeopathic medicine have no effect on treating zinc deficiency although soothing ointments have proven beneficial in healing of the skin once zinc levels in the goat’s body are within the recommended range.
To prevent zinc deficiency occurring fortified feed stuffs should be of the best quality and within the best before date; hay should be cut, dried, baled and stored properly to prevent vitamins and minerals being lost at any stage of the hay making process, excessive dietary calcium should be corrected, mineral licks such as Rumevite blocks should be offered consistently and a mineral supplement specially formulated for goats containing Zinc such as Caprivite (Obtained from Goat Nutrition Limited – See Appendix 1 for details) should be added to feed or offered straight. Other methods used in large scale industry to assist in dealing with a zinc deficiency problems include offering feed and drinking water from zinc galvanised troughs or buckets.
In conclusion zinc is an important trace element required by goats to enable proper functioning of a goat’s metabolism, immune system, keratin production and for all round health and wellbeing. Deficiency occurs when feedstuffs or hay contain insufficient quantities of dietary zinc, when access to fresh forage is limited, when illness such as coccidiosis causes excessive output of vitamins and minerals from the body and when illness coincides with events of bodily stress such as mating, pregnancy and kidding. Diagnosis is key in determining whether a suspected case of zinc deficiency is actually a condition with similar symptoms such as mange and so along with treatment it should be the responsibility of a veterinarian. Zinc sulphate supplementation is the most effective method of treatment for this deficiency and once resolved measures should be implemented to ensure sufficient quantities of zinc are ingested by the goat.
For more information contact your vet.
References:
Harwood, D., (2006), Goat Health and Welfare: A Veterinary Guide, (Book) The Crowood Press, Wiltshire, ISBN: 1861268246
Mackenzie, D., (1993), Goat Husbandry, (Book), Fifth Edition, Faber and Faber Limited, London, ISBN: 0571165958
McDowell, L.R., Gordon, B.J., Merkel, R.C., Fadock, V., Wilkinson, N.S. and Kunkle, G.A., (1991), Mineral status comparisons in goats of Florida, with emphasis on zinc deficiency, Small Ruminant Research, Volume 5, September, Pages 327-335.
Reuter, R., Bowden, M., Besier, B and Masters, H., (1987), Zinc responsive alopecia and hyperkeratosis in Angora goats, Australian Veterinary Journal, Volume 64, Part 11, November, Pages 351-352
Smith, M.C. and Sherman, D.M., (1994), Goat Medicine, (Book), Blackwell Publishing, Oxford, ISBN: 0812114787
Appendix 1:
Caprivite Feed Supplement for Goats
The major vitamin/mineral feed supplement designed specifically for goats.
Formulated from the latest worldwide nutritional research, Caprivite provides vitamins, minerals and trace elements essential to optimum health, milk yield and performance.
Caprivite is highly palatable and the unique apple flavouring on a cereal base ensures long-term acceptance.
Available in 2, 4 and 8 kg buckets, each equipped with a handy measuring scoop with 25 kg sacks available for the larger user.
2kg Bucket - £5.44
4kg Bucket - £9.80
8kg Bucket – 16.43
25kg Sack - £42.85
Available from Goat Nutrition Limited:
Units B & C, Smarden Business Estate, Monks Hill, Smarden, Ashford, Kent TN27 8QL England.
01233 770780
Buy Online at http://home.btconnect.com/gnltd/shop/CapriviteFeedSuppl.htm
Appendix 2:
Zincosel Boluses by Telsol
