Selenium, cobalt and zinc deficiency in deer

The uneven geographical distribution of trace elements and substandard feeding and management will lead to trace element deficiency diseases. Targeted and appropriate addition of essential trace elements for deer is the most effective way to prevent and treat trace element deficiency diseases of deer.

Trace elements are catalysts for a variety of enzymes and activity regulators for proteins, fats, polysaccharides, nucleic acids, vitamins and hormones in deer. Trace elements cannot be synthesized in deer and must be ingested from feed, but their excretion is continuous; therefore, it is necessary to supplement them according to the actual situation.

The causes of trace element deficiency are as follows: the geographical distribution of ① trace elements in soil is uneven, resulting in the lack of one or more trace elements in feed and drinking water. The content of some trace elements in ② is normal, but the uptake of other elements antagonistic to this element is too high, which affects the absorption and utilization of this trace element. During the pregnancy of female deer or when the growth and development of young deer is vigorous, the demand for some trace elements in ③ deer exceeds the general level, but it can not be obtained in feed. ④ deer suffer from chronic diarrhea or dyspepsia, which affects the absorption of trace elements, resulting in secondary trace element deficiency.

There are many kinds of trace element deficiency. This paper will focus on the deficiency of three elements selenium, cobalt and zinc, which are seriously harmful to deer.

1 selenium deficiency disease

Selenium deficiency can cause a variety of diseases, such as white muscle disease of young deer and mulberry heart disease. The investigation shows that there is a geographical selenium deficiency in a large region of China, which is a strip selenium deficiency zone from Heilongjiang in Northeast China to Yunnan, involving Heilongjiang, Jilin, Liaoning, Inner Mongolia, Shanxi, Hebei, Henan, Hubei, Shaanxi, Gansu, Sichuan, Yunnan, Xizang and other places. In addition, some cities and counties in Shandong, Jiangsu, Zhejiang, Fujian and other provinces are also seriously deficient in selenium. In the areas with serious selenium deficiency, the content of selenium in soil is only 0.06mg/kg. People in these areas are susceptible to Keshan disease and Kaschin-Beck disease. Young deer and other young animals raised in these places are also prone to white muscle disease, so selenium supplementation is very necessary.

However, Enshi in Hubei and Ziyang in Shaanxi are rare selenium-rich areas where there is chronic selenium poisoning in young animals. In the feed, the selenium content of fishmeal is higher, forage grass is the second, cake meal is the second, and cereals are the least, such as corn is only 0.02mg/kg. Antioxidation is the basis of biochemical action of selenium, and selenium and VE have synergistic effect in antioxidation. Selenium supplementation can improve non-specific immune functions such as cellular immunity and humoral immunity. In addition to the regional disease, the deficiency of VE can induce selenium deficiency disease, which is also related to the season. The peak period of the disease is from May to July, which mainly harms young deer and other young animals, because young animals are weak in disease resistance and sensitive to special nutrients.

1.1Clinical symptoms: ① dyskinesia, lying down, difficulty in standing up, stiff limbs; ② cardiac dysfunction, rapid heartbeat, irregular rhythm, sudden death while running; ③ dyspepsia, dyspepsia, loss of appetite; ④ neurological disorder; ⑤ reproductive dysfunction, poor semen of male deer, female deer not easy to conceive or prone to abortion. Postmortem examination of the young deer showed that the obvious symptom was white myopathy, that is, diseased muscle degeneration, light color, gray-white and yellowish markings on the cross section.

1.2Diagnostic methods were combined with epidemiology (history of selenium deficiency), clinical characteristics, feed, tissue selenium content analysis, pathological examination, blood related enzymes-glutamic oxaloacetic transaminase (GOT), lactate dehydrogenase (LDH), plasma peroxidase (GSH-PX) and symptom relief after selenium supplementation.

1.3 after the onset of the disease, 0.1% sodium selenite can be injected subcutaneously or intramuscularly, the young deer 3~5ml/ times, repeated once every 10 days, and supplemented with VE, and the young deer are supplemented with 15mg. It can be effectively prevented by injecting 0.1% sodium selenite, adding selenium in feed, providing lick blocks with selenium salt, placing tumor stomach selenium pills, and subcutaneously embedding sodium selenite. Selenium is a toxic element, it should be used evenly, and the dose should be controlled scientifically. It is best for professional feed enterprises to provide services.

2 cobalt deficiency disease

Cobalt deficiency is a chronic endemic disease characterized by loss of appetite, pica, anemia and progressive wasting caused by a lack of cobalt in soil and feed.

Cobalt is an essential trace element for animals, especially ruminants such as deer. The growth and reproduction of bacteria in the rumen of deer need cobalt, and some of them can use cobalt to synthesize VB12. The synthesized VB12 is a necessary vitamin for ruminants such as deer, which can not only ensure the growth and reproduction of rumen ciliates, but also improve the digestibility of cellulose. If there is a lack of cobalt, insufficient VB12 synthesis will directly affect the growth and reproduction of bacteria and rumen ciliates, and directly affect the digestion of cellulose. Abnormal rumen digestion will directly affect the energy supply of deer, which will lead to weight loss and weakness. Cobalt can accelerate the mobilization of iron in the body and cooperate with the realization of hematopoiesis. In addition, cobalt can improve the absorption of zinc, zinc and taste hormone related, cobalt deficiency can cause loss of appetite, and even pica.

2.1 the clinical symptoms of cobalt deficiency deer were progressive emaciation and anemia, visual mucosa pale, hemoglobin concentration decreased for about 1 year, diarrhea and reproductive function decreased. The autopsy showed that the diseased deer was extremely emaciated, the blood ferritin was precipitated in the liver and spleen, the iron content in the liver and spleen increased and the cobalt content decreased.

2.2.Diagnostic methods can make a preliminary diagnosis according to medical history and clinical symptoms, and the content of cobalt in soil, feed, blood and tissue and other biochemical indexes should be detected: the content of cobalt in soil and feed of ① is lower than that of 3mg/kg and cobalt in feed is lower than 0.07mg/kg, which can be used as an index for the diagnosis of cobalt deficiency. When the content of cobalt in ② blood is 15% lower than the normal level, cobalt deficiency can be considered to have occurred. The amount of cobalt and VB12 in ③ tissue when the content of VB12 in liver is lower than that of 0.1mg/kg and the content of cobalt is lower than 0.07mg/kg, it can be considered that cobalt deficiency has occurred. If the concentration of blood glucose and alkaline phosphatase detected by ④ is lower than the normal value, it can be considered that cobalt deficiency has occurred.

2.3Prophylaxis and treatment of this disease should take oral cobalt salt preparation and supplement VB12 at the same time, the curative effect is obvious, generally there is no cobalt preparation injection. Cobalt oxide, cobalt sulfate and cobalt chloride can be used as sources of oral cobalt supplement. The prevention of this disease can directly add cobalt salt to the feed, or make cobalt salt into additives or lick bricks, which can be licked freely by deer. The addition of cobalt is trace, and the dosage must be well grasped, otherwise cobalt poisoning will occur.

3Zinc deficiency disease

Most provinces in China are poor or lack zinc, such as Hebei, Beijing, Hubei, Jiangxi, Jiangsu, Sichuan, * * and other places have 30% to 50% of the area of zinc deficiency. Plant feed generally contains low zinc or low biological effect, while animal feed such as bone meal and fish meal has high zinc content and is easy to be absorbed. In addition, there are more zinc in wheat bran and bran. Antagonistic factors in feed will also affect the absorption and utilization of zinc. Excessive calcium and phosphorus or excessive copper, iron, manganese, molybdenum and other elements will affect the absorption of zinc.

3.1 the symptoms were hindered growth and development, incomplete or excessive keratosis of the skin, abnormal bone development, such as shortening and thickening of long bones, swelling and stiffness of joints, reproductive dysfunction, dull hair and large area shedding in inappropriate seasons, and the wound was not easy to heal. Combined with the determination of the content of zinc in local soil and feed and the content of zinc in serum of diseased deer, as well as the determination of other elements in feed which are easy to cause zinc deficiency, the diagnosis can be made. The symptoms were relieved about half a month after zinc supplementation.

3.2 the content and proportion of zinc and zinc antagonistic elements in feed should be adjusted according to the actual situation of zinc deficiency. Zinc sulfate, zinc carbonate and zinc oxide can be used as zinc sources for zinc supplement. The prevention of this disease is to ensure the content of zinc in the feed and adjust the ratio of other elements to zinc in the feed so as not to affect the absorption of zinc and cause the deficiency of zinc due to antagonism. Zinc is basically non-toxic and has little risk to use, but it should also be carried out under the guidance of professionals.

In a word, due to the uneven geographical distribution of elements, mistakes in feeding and management and the induction of some other diseases, there is a serious trace element deficiency in the industry in China, which causes huge losses. Some breeders are not aware of it, or do not know how to dispose of it and do not add it; some only know a little about the relevant knowledge to prepare and add trace elements themselves. as a result, the use of trace elements exceeds the standard or the proportion between elements is inappropriate, resulting in man-made lack or poisoning. My suggestion is: after realizing the lack of trace elements, we should ask research institutions or high-tech enterprises with good technical conditions, mature methods and reliable reputation to make a symptomatic diagnosis before adding them properly.