Trace elements in cattle nutrition

Christian Punz Product Manager Nutritional Products Christian Punz Product Manager Nutritional Products

Trace elements in cattle nutrition

The importance of trace elements in livestock nutrition is undisputed. As the name implies, even small amounts of these elements have large and diverse effects on the animal organism. The function of enzymes and hormones is essentially linked to trace elements. This key role in metabolism cannot be replaced by other kinds of nutrients, that’s why we call them „essential“ (irreplaceable) trace elements.

or cattle, copper, zinc, manganese, cobalt, elements are absorbed into the small intestine via the iodine and selenium are among the most amino acid–peptide way. Th e most effi cient absorption important and are usually added to various is when trace elements are bound to single amino ac- supplementary feed. Since iron has a decisive ids. Trace elements bound in chelate form are a mixture infl uence on the interactions between the ele- of all naturally occurring amino acids and are absorbed ments, it will be discussed in later chapters as well. through the diff erent amino acids absorption mecha- FRegarding the bioavailability of trace elements from nisms in the body. the feed, there are signifi cant diff erences due to the bind- Th is article will provide guidance on the basic func- ing form of the elements. In general, two main binding tion of trace elements in ruminants, demonstrate the dif- types can be distinguished: ference in bioavailability of diff erent binding forms and • Inorganic bound trace elements (sulfates, oxides, show practical eff ects in examples from cattle. chlorides, carbonates, …) • Organic bound trace elements (chelates, protein- What are trace elements? ates, glycinates, polysaccharides, fatty acids, methi- Trace elements are defi ned by their extremely low onine-analogues, …) concentrations in the body, such as less than 50 mg of iron per kg of tissue. Based on this, daily animal require- Inorganic bound trace elements are likely to have ments of trace elements are in the milligram range as specifi c interactions and must be bound to transporters well. Needs for trace elements are determined by nutri- to be absorbed in the metabolism. Organic bound trace ent requirement models and nutrient response models.

2 Biological functions of trace elements Iron Manganese Iron is a part of hemoglobin, the pigment of red Manganese is mainly stored in the bone, liver, kidney blood cells and myoglobin, the muscle pigment that and pancreas. It works as an enzyme activator and is is necessary for their formation. In addition, iron is crucial for energy-, protein- and fat metabolism. Fur- responsible for oxygen storage and oxygen transport thermore, it has important enzymatic functions in cell in the body. As an enzyme component iron plays an protection. important role in energy metabolism as well as in the Deficiencies in manganese are reflected in reduced anti-oxidative system (immune system). growth, skeletal deformities, poor fertility and birth Iron deficiency is not common in dairy cows because defects in newborn calves. many feedstuffs (mainly forage) contain iron in suf- ficient amounts. However, it may lead to deficiency Iodine symptoms in calves supplemented with whole milk. Iodine is located in the thyroid glands and is responsi- Deficiency symptoms manifest themselves in the form ble for the formation of thyroid hormones (T3 and T4 of anemia, poor immunity and growth. In fact that hormone). These hormones in turn take over import- iron is much more common than other trace elements, ant control processes in the energy metabolism and are iron excess can lead to poor absorption for copper and thus particularly important for growth, fertility and manganese. milk yield. Iodine deficiency can be detected by an enlarged thy- Copper roid gland and poor milk production. Copper is mainly stored in the liver and is an enzyme component that is part of many essential metabolic Cobalt processes. As an enzyme activator, copper provides Cobalt serves as a central atom of Vitamin B12 (Co- strong bones and joints and is heavily involved in the balamin). If ruminants are adequately supplied with utilization of iron and thus the synthesis of hemoglo- Cobalt, they can synthesize their need for Vitamin bin. In addition, the pigmentation of the hair coat is B12 itself in the rumen. Vitamin B12 is necessary for fundamentally influenced by copper levels. Through a functioning energy- (utilization of propionic acid, the promotion of superoxid dismutase, which deac- gluco neogenesis) and protein metabolism (methi- tivates free oxygen radicals, copper is also involved onine formation) in the liver. in cell protection and thereby in a healthy immune A prolonged deficiency in cobalt leads to a decrease in system. feed intake, limited growth and reduced milk yield. Copper deficiency in dairy cows is often reflected in Selenium reduced fertility and poor immunity. Similarly, dis- turbances in pigmentation (“Copper glasses”), anemia Selenium is an essential component of the enzyme and bone fragility may occur. glutathion peroxidase, which deactivates harmful hy- drogen peroxide radicals and is thus crucial in cell pro- Zinc tection. In addition, it supports the effects of Vitamin Beside iron, zinc is the most common trace element. E and vice versa. A slight lack of one element can be As an activator and a component of more than 300 compensated by a higher supply of the other element enzymes and hormones, zinc plays an important role to a certain extent. Moreover, Selenium also regulates in metabolism. In particular, protein biosynthesis and the thyorid hormone metabolism and thus indirectly the regulation of gene activity can be affected by zinc. affects fertility in dairy cows. Zinc is mainly stored in the liver, pancreas, bone, skin Selenium deficiency causes fertility disorders, muscle and hair. dystrophy and weak calves as well as retained placenta Zinc deficiency causes poor growth, loss of appetite, and mastitis in dairy cows. Also a sufficient selenium and a bad feed conversion rate. Due to its crucial supply is important in dry function in defense enzymes (copper-zinc superoxid cows because still births dismutase), zinc deficiency reduces resistance. In dairy or aborts can otherwise cows, zinc deficiency is visible through bad hoof horn occur. quality, reduced fertility and poor udder health.

Source: Zinpro Figure 1: „Copper glasses“ caused by copper deficiency

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They are responsible for specific functions in the organ- trace elements, macro elements or other food sources. ism for certain metabolic processes and must be regu- For example phytate can build complexes with zinc, larly supplied with feed.. An essential function of trace copper, manganese and iron and negatively impair their elements is that they act as an activator and part of many absorption into the body. Crude fibre can block the ab- enzymes. Furthermore they are present in proteins and sorption of metal ions. carry out several tasks in the hormonal system. There- Ca fore, basic functions such as reproduction of dairy cows Te Co depend a lot on the supply of trace elements. Hg Cu

Regulation of absorption and excretion Al K For a functioning metabolism, trace elements always I W have to be present at a specific concentration in the tar- get tissue. To avoid an over-concentration and thus the Zn risk of poisoning, the trace element metabolism is strict- Se ly controlled by the homeostatic regulation. This means S that the input and outflow are regulated such that the Cd interior of the body always has the same concentration Mn in different target tissues. The processes of acquisition, Mg storage and excretion of trace elements are overlapping Na and always in a dynamic equilibrium. F Mo Pb Fe As P Interactions of trace elements

In the uptake of trace elements, it is always import- Figure 2: Interactions between micro- and ant to consider certain adverse interactions with other macro minerals (Graphic: Punz; Source: Miller, 1979)

Table 1: Trace element content of the most important forages and concentrates in Austria. (ÖAG-Futterwerttabellen für das Grundfutter im Alpenraum, Resch et al. 2006; Daten aus dem Futtermittellabor Rosenau 1998-2008) Feed stuff Trace element content (mg/kg DM) Iron Manganese Zinc Copper Forages Grass silage, 1st cut 696 90 50 7.9 Grass silage, 2nd -5th cut 746 103 46 8.7 Corn silage 125 27 38 3.9 Concentrates Barley 64 19.6 32.9 5.4 Corn 40 8.3 26.0 2.5 Triticale 39 39.9 35.7 6.2 Dried beet pulp 605 67.6 27.4 6.0 Wheat 50 39.8 30.3 5.3 Brewers' grain (dried) 195 57 104.1 14.9 Peas 169 18.1 91 14.9 Rape seed extracted 190 76.2 78.9 7.1 Rape seed cake (8-12% fat) - 63.4 63.1 5.5 DDGS (from bioethanol production) 160 75.2 65.0 10.0 Soy bean full fat 103 30.5 51.5 15.8 Soy bean extracted 301 42.0 56.9 18.6 Soy bean extracted HP 303 50.5 59.0 15.9 Sunflower seed extracted (dehulled) 177 33.5 79.1 28.5 Diets rich in calcium, and drinking water or silages Table 2: Recommendations and legal limits for trace elements high in iron can build hardly soluble complexes with in dairy cows copper or manganese and reduce their availability dra- Recommendations Legal limits matically. In the presence of high levels of molybdenum (mg/kg DM) (mg/kg com- plete feed) and sulfates, copper sulfide can occur which is hardly soluble as well and nearly unusable for ruminants. Jeroch et al. NRC 2001 If the diet contains too much sulfur, the uptake of 2008; GfE Selenium in the body is negatively affected. Calcium and 2001 phosphorus inhibit zinc absorption. Figure 2 shows an Iron 50 13-22 750 overview of the various antagonsims between minerals. Zinc 50 21-73 150 Manganese 50 16-21 150 Trace element concentrations in forages and concentrates Copper 10-15 11-16 35 In principle it should be noted that forages and con- Iodine 0,5 0,4-0,77 5 centrates do not contain enough trace elements to cover Cobalt 0,1-0,2 0,11 2 the needs of high yielding dairy cows. Therefore the total Selenium 0,2-0,25 0,3 0,5 rations have to be supplemented with additional trace elements. One tool to check the efficiency of the trace element Analyses show that corn silage has lower levels of supply is the analysis of blood serum. For this, some trace elements than grass silage. In pastures, the location, representative dairy cows of the herd (including healthy plant population, utilization intensity and fertilization cows, high lactating, low lactating and dry cows) were have a big influence on trace element contents. selected to have their blood samples taken by a veterinar- Energy concentrates are different from protein con- ian. Depending on the results of the analysis, any lack centrates. Protein concentrates are richer in trace ele- can be balanced and oversupply prevented. In some cases ments than energy concentrates. it makes sense to analyse forages for their trace element contents as well. By calculating minerals intake based on Are my cows adequately supplied? the animal’s diet, specific levels can be supplemented to The need for trace elements is mainly determined by meet the animal’s needs. the growth stage, milk or beef usage and performance of cattle. Thus, calves and growing cattle have quanti- Organic bound trace elements tatively different demands than a high yielding dairy To avoid negative interactions between inorganic cow. Trace element recommendations are derived from minerals and trace elements, organic bound trace ele- dose-response studies. In consideration of bioavailability ments are increasingly used in cattle diets successfully. and intermediate interactions, safety margins are con- In particular, amino acid chelates work very efficiently ducted to ensure an adequate trace element supply. On as a binding partner for trace elements. This means that the other hand, there are legal limits on maximum values a trace element ion is bound to an amino acid chelate. for trace elements in cattle. An overview of recommenda- The target is to improve the bioavailability and thus the tions and legal limits can be found in Table 2. intake of trace elements. Thereby the organic binding From a practical point of view, demand for trace el- form uses a separate resorption process in the intestinal ements increase at certain production stages of a cow. tract resulting in higher trace element contents in the In times of high temperatures (heat stress), in stressful blood, tissue, etc. An improved trace element content situations (around calving, disease) and in times of high in the metabolism is the basis for healthy and highly performance we can expect increased trace element re- productive cattle. quirements. Numerous studies have proven that organic bound The meaning of the term bioavailability is fairly am- trace elements are absorbed more effectively. For exam- biguous, but it generally describes mineral absorption by ple Wolfram (1999) documented that different forms and/or retention within the animal. Theoretically, a min- of selenium have different pathways into the body. Fur- eral supplement that is more bioavailable than another thermore Kincaid et al. (1999) reported higher zinc val- will provide a greater proportion of absorbed minerals to ues in the liver of calves after supplementing them with support animal production and health. organic bound zinc. However, the different transport mechanisms of various trace element sources from the feed into the body are not completely known.

Christian Punz Product Manager Nutritional Products

eff ect on a variety of fertility parameters could be sci- entifi cally demonstrated, as shown in Table 3.

Source: Zinpro Figure 3: Molecule structure of a trace element – amino acid chelate bond (Metal Ion= Copper, Zinc or Manganese)

Results from practice In practice, the supply with trace minerals from dairy cows can be measured with certain parameters. Supple- menting trace elements in organic form over a longer Source: Zinpro period results in benefi cial eff ects as described in the pre- Figure 4: Lame cows show poor fertility and low milk vious chapters. Technically it is possible, to supplement production copper, zinc and manganese in organic form. Moreover it is also very common to use selenium in a rumen stable Table 3: Effect of trace element sources on the fertility of form in cattle diets. lactating dairy cows Parameter Trace elements • Lameness a b In a trial, 150 Holstein cows were supplemented either Inorganic Organic with inorganic trace elements (sulfates) or with organ- ic bound trace elements (copper-, zinc- and manga- Days to fi rst insemination 101 97 nese chelates). Th e experimental period lasted 21 days prior to calving until 250 days after calving. Th e use Pregnant cows 150 days 42,7 54,8 after calving, % of organic bound trace elements signifi cantly reduced the incidence of lameness 75 days after calving. At 250 21 day pregnancy rate, % 18,4 27,4 days after calving, it was observed that there were even Insemination index 2,6 2,3 fewer cows with claw disease. Days open 169 147

Influence of different trace element sources on a the incidence of lameness Application of sulfates Application of organic bound trace elements (Zinpro Performance 40 34,1a Minerals®) 30 Ballantine et al., 2002. Professional Animal Scientist 18:211-218 23,6b 17,7 20 Udder health 10 10 In a study with 306 Holstein cows the eff ect of dif-

Cows with claw disorders, % ferent trace element sources on udder health was inves- 0 75 d after calving 250 d after calving Influence of different trace element sources on Inorganic trace elements Zinpro Performance Minerals® the somatic cell count in the milk 200 Mean values with different superscripts are signifi cantly different 183

(P=0,15) 1000/ml , 136 Ballantine et al., 2002. Professional Animal Scientist 18:211-218 150

• Fertility 100 In the same study, the infl uence of organic bound 50

trace elements (copper-, zinc- and manganese chelate) Somatic cell count in the milk Somatic cell count in the milk in comparison to inorganic trace elements (sulfates) Inorganic trace elements Zinpro Performance Minerals® on fertility was investigated. Th rough the supplemen- tation with organic bound trace minerals a positive DeFrain et al., 2009. Professional Animal Scientist 25:709-715 tigated. The experimental period lasted 21 days prior to Conclusion calving until 250 days after calving. The application of It is important to ensure high performing cattle organic bound trace elements resulted in a significant receive an adequate level of trace minerals in their di- decrease in the somatic cell count in the milk. ets. This requires knowledge of the contents in forages, concentrates and mineral feed as well as their specific usage in feeding. The possible negative interactions due to an oversupply of a certain element also have to be considered. Therefore it is crucial that all minerals and trace elements are supplemented completely to meet the animal’s needs. A toxification has to be avoided in any case. Applications of organic bound trace elements have shown clear positive effects in practice, and their usage prevents any negative interactions. Trials demonstrate that bioavailability increased and thus the performance and health status in dairy cows could be improved as well. There is a positive effect on claw and udder health. Furthermore organic bound trace elements support fer- tility in dairy cows. With higher bioavailability of trace elements, it is possible to reduce the levels of trace el- Figure 5: A healthy udder requires an adequate supply of highly ement supplementation. This also ensures a lower dis- available trace elements charge in the manure which benefits the farming envi- ronment. BIOMIN Holding GmbH Industriestrasse 21, A-3130 Herzogenburg, AUSTRIA Tel: +43 2782 803 0, Fax: +43 2782 803 11308, e-Mail: [email protected], www.biomin.net

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