Mineral deficiencies in goats – An excerpt from Raising Goats Naturally
If goats don’t get enough of any vitamin or mineral, deficiencies will obviously occur. However, some deficiencies are more common than others and will cause more severe problems.
Copper deficiency is far more common than most people realize. It is more common today than in previous years because much of the soil in the United States is deficient in copper, which means plants grown in it are deficient. A prevalent symptom of copper deficiency in my herd is a faded coat, because copper is responsible for pigmentation of hair. My gold goats turn cream, cream goats turn white, and black goats turn rusty red. They also lose hair on their faces. A fishtail or bald tail tip is another common symptom. Severe orthopedic problems, such as bent legs, swaybacks, or spinal injuries, can be caused by copper deficiency. I have not seen deformed legs or swaybacks in my herd, even though I’ve had several goats die from confirmed copper deficiency, so don’t assume that your goats have enough copper simply because they all have straight legs and spines.
Copper is also very important in reproduction, so deficient goats may not come into heat or may have difficulty staying pregnant. In my experience, bucks seem to have more problems with copper deficiency than does, probably because the does are getting a commercial goat ration that is fortified with 40 ppm copper. My bucks are consuming only pasture and hay, which have much lower amounts of copper, so they need to consume enough of the goat minerals as a supplement to get an adequate amount of copper.
Copper deficiency can be primary or secondary. Primary copper deficiency means that the goats are not consuming enough copper. In secondary copper deficiency, the goats are consuming plenty of copper, but antagonists in the diet, such as high molybdenum, sulfur, or iron, interfere with the goat’s ability to absorb and use the copper. For example, alfalfa can have levels of molybdenum that are so high as to induce copper deficiency in goats. Unfortunately, the level of molybdenum varies tremendously from one location to another, making it impossible to say whether or not it is causing a problem in a particular herd unless you have your hay tested. Well water that is high in sulfur or iron can also cause copper deficiency. Excessive iron in the water generally turns white sinks orange, and excessive sulfur makes the water stink like a dirty dishrag or rotten eggs.
Copper deficiency is a challenge to diagnose because hair and blood tests are not very accurate. The most accurate test for copper is a liver biopsy, which is not practical in a live goat. I have learned always to ask for a copper level on a goat’s liver when a necropsy is done. Mineral levels on livers are not performed routinely when doing a necropsy unless something jumps out at as a potential problem when the vet is discussing your feeding practices. I have removed a liver myself and sent it to a lab for copper testing when I suspected the dead goat had been copper deficient based on a faded coat and other symptoms.
Like copper, selenium is an important mineral for the health of the reproductive system of does, and an inability to get pregnant and stay pregnant is sometimes caused by a deficiency of this mineral. A doe with selenium deficiency may have trouble giving birth, is more likely to have a retained placenta, and will have lower milk production than a doe with adequate selenium in her diet. A buck may be less likely to get does pregnant. Kids born to selenium-deficient does are more likely to be stillborn or weak and may suffer from white muscle disease in the first few weeks of life, which can result in death. It is important to understand that the occasional weak kid is probably not selenium deficient. A herd with a selenium deficiency problem will likely see many of these problems in a number of goats.
Soils in North America vary from deficient to toxic in their levels of selenium. In many parts of the United States, soils are deficient in selenium, making it necessary to use fortified feeds as well as free choice minerals that include enough selenium. Although injectable selenium is available by prescription from a vet, some goats have died from toxicity as a result of the injection. It is important that you have evidence of selenium deficiency before using injectable minerals.
When goats die on my farm, I have their livers tested for selenium (as well as other minerals). Years ago they tested at the very low end of the normal range for selenium. Having this knowledge, I gave injectable selenium to my goats prior to breeding season for several years. However, I have switched to a free-choice selenium supplement for a couple of reasons. First, many grass-based cattle producers insist that “cafeteria-style minerals” are the best way to provide minerals for animals. Each individual mineral is available to the animals, and they can take as little or as much as they want. The body absorbs minerals consumed orally better than those injected. When supplements are injected, the majority of the supplement leaves the body in the urine over the subsequent twenty-four hours, suggesting that injection of a routine supplement is not useful in a situation where chronic deficiency is a real problem.
The most obvious symptoms of zinc deficiency are in the hair and skin. A goat with zinc deficiency looks scruffy with flaky dandruff and odd shedding at unusual times of the year. I had a buck that developed bald patches of dry skin in the midst of a winter when temperatures were falling below zero Fahrenheit. Another symptom is excessive salivation, which generally makes a buck look like he is foaming at the mouth.
Zinc deficiency is often caused by excessive calcium in the diet, either from mineral supplements or calcium-rich foods, such as alfalfa. Injectable zinc supplements are available by prescription, but they are formulated with other minerals. The combination of minerals might have the unintended consequence of delivering a toxic dose of a mineral the goat does not need. Zinc is also available as a single mineral supplement, but reducing the amount of calcium in the diet may also correct the problem. Some goats seem to be more prone to zinc deficiency than others.
This is an excerpt from Raising Goats Naturally: A Complete Guide to Milk, Meat, and More, by Deborah Niemann. It will be available from local bookstores and online booksellers starting October 15. It is already available for pre-order from Amazon and other online merchants.