Ostertagia infection and neutrophil function in cobalt-deficient and cobalt-supplemented cattle

Variability of the Ionome of Wild Boar (Sus scrofa) and Red Deer (Cervus elaphus) in a Dutch National Park, with Implications for Biomonitoring

The ionome-an important expression of the physiological state of organisms-is poorly known for mammals. The focus on particular tissues-such as liver, kidney, and bones-in biomonitoring of environmental pollution and potential deficiencies is based on widely held assumptions rather than solid knowledge of full mammalian ionomes. We examined the full ionome of Red deer (Cervus elaphus) and Wild boar (Sus scrofa), two commonly used mammals for biomonitoring, in a Dutch protected nature reserve (Veluwezoom). We used four individuals per species. We dissected 13 tissues and organs from each individuals (eight in total) of each species and measured 22 elemental concentrations in each. We assessed, for each element, how concentrations varied across tissues within and between individuals. Based on existing literature, we put our findings in the context of their function in the mammalian body. We found that the ionome was highly variable between as well as within the two species. For most elements, tissues containing the highest and lowest concentration differed between individuals. No single tissue accurately represented the accumulation of toxic elements or potential deficiencies in the bodies. Our assessment of the element's biological roles revealed a serious lack of reference values. Our findings imply that analyses of commonly used tissues in biomonitoring do not necessarily capture bioaccumulation of toxins or potential deficiencies. We recommend establishing a centralized database of mammalian ionomes to derive reference values in future. To our knowledge, our study is one of the most complete assessments of mammalian ionomes to date.

Relationship between Vitamin B12 and Cobalt Metabolism in Domestic Ruminant: An Update

Cobalt, as a trace element, is essential for rumen microorganisms for the formation of vitamin B12. In the metabolism of mammals, vitamin B12 is an essential part of two enzymatic systems involved in multiple metabolic reactions, such as in the metabolism of carbohydrates, lipids, some amino acids and DNA. Adenosylcobalamin and methylcobalamin are coenzymes of methylmalonyl coenzyme A (CoA) mutase and methionine synthetase and are essential for obtaining energy through ruminal metabolism. Signs of cobalt deficiency range from hyporexia, reduced growth and weight loss to liver steatosis, anemia, impaired immune function, impaired reproductive function and even death. Cobalt status in ruminant animals can be assessed by direct measurement of blood or tissue concentrations of cobalt or vitamin B12, as well as the level of methylmalonic acid, homocysteine or transcobalamin in blood; methylmalonic acid in urine; some variables hematological; food consumption or growth of animals. In general, it is assumed that the requirement for cobalt (Co) is expressed around 0.11 ppm (mg/kg) in the dry matter (DM) diet; current recommendations seem to advise increasing Co supplementation and placing it around 0.20 mg Co/kg DM. Although there is no unanimous criterion about milk production, fattening or reproductive rates in response to increased supplementation with Co, in some investigations, when the total Co of the diet was approximately 1 to 1.3 ppm (mg/kg), maximum responses were observed in the milk production.

Trace elements in the liver of captive and free-ranging European bison (Bison bonasus L.)

European bison is classified as a vulnerable species because of many threats. We analyzed the content of toxic and essential elements (Ag, Al, As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mg, Mn, Na, Ni, Pb, Se, Th, Tl, U, V, and Zn) in the livers of 30 captive and free-ranging European bison from the Bison Breeding Center in Smardzewice and from Białowieża Primeval Forest in Poland. The contents of toxic elements were lower than reported previously in European Bison and were similar to those of wild ungulates from non-polluted areas. Accumulation of Cd and Cr was related to the age of animals. We compared the mineral status between captive and free-ranging European bison to verify whether the maintenance type could affect concentrations of trace elements in the liver. The concentration of Mn and Zn differed between captive and free-ranging group. Our results were compared to the reference values of essential elements for cattle. All animals from this study were Se-deficient and more than 80% of them have Cu deficiency. Deficiency of Mn was present in 20% of captive and 37% of free-ranging animals whereas Zn in 37% and 3% respectively. Statistical analysis confirmed that Mn and Zn deficiencies were related o the maintenance of animals (p<0.05). We revealed that mineral deficiencies could be an additional threat to the Polish population of European bison. Thus, the monitoring of essential minerals is necessary and future work is required to optimize the supplementation and foddering for preventing the occurrence of mineral deficiencies.

BILL E. KUNKLE INTERDISCIPLINARY BEEF SYMPOSIUM: Impact of mineral and vitamin status on beef cattle immune function and health

The importance of optimal mineral and vitamin nutrition on improving immune function and health has been recognized in the preceding decades. In the southeast, beef cattle are raised predominantly on forages that may be limiting in nutrients for optimal health, especially trace minerals such as Cu, Zn, and Se. Clinical deficiencies of these nutrients produce classic symptoms that are common to several nutrient deficiencies (e.g., slow growth and unthrifty appearance); however, subclinical deficiencies are more widespread and more difficult to detect, yet may result in broader economic losses. Dietary mineral concentrations often considered adequate for maximum growth, reproductive performance, or optimal immune function have been found to be insufficient at times of physiological stress (weaning, transport, comingling, etc.), when feed intake is reduced. The impacts of these deficiencies on beef cattle health are not apparent until calves have been subjected to these stressors. Health problems that are exacerbated by mineral or vitamin deficiencies include bovine respiratory disease, footrot, retained placenta, metritis, and mastitis. Many micronutrients have antioxidant properties through being components of enzymes and proteins that benefit animal health. In dairy cattle, high levels of supplemental Zn are generally associated with reduced somatic cell counts and improved foot health, possibly reflecting the importance of Zn in maintaining effective epithelial barriers. Neutrophils isolated from ruminants deficient in Cu or Se have reduced ability to kill ingested bacteria in vitro. Supplemental vitamin E, in its role as an intracellular antioxidant has been shown to decrease morbidity in stressed calves. There is more understanding of the important biological role that these nutrients play in the functioning of the complex and multifaceted immune system. However, there is still much to be learned about determining the micronutrient status of herds (and hence when supplementation will be beneficial), requirements for different genetic and environmental conditions, understanding the bioavailability of these nutrients from feedstuffs and forages, quantifying the bioavailability of different supplemental sources of these nutrients, and identifying the impact of dietary antagonists on these nutrients.

The parasitic phase of Ostertagia ostertagi: quantification of the main life history traits through systematic review and meta-analysis

Predictive models of parasite life cycles increase our understanding of how parasite epidemiology is influenced by global changes and can be used to support decisions for more targeted worm control. Estimates of parasite population dynamics are needed to parameterize such models. The aim of this study was to quantify the main life history traits of Ostertagia ostertagi, economically the most important nematode of cattle in temperate regions. The main parameters determining parasite density during the parasitic phase of O. ostertagi are (i) the larval establishment rate, (ii) hypobiosis rate, (iii) adult mortality and (iv) female fecundity (number of eggs laid per day per female). A systematic review was performed covering studies from 1962 to 2007, in which helminth-naïve calves were artificially infected with O. ostertagi. The database was further extended with results of unpublished trials conducted at the Laboratory for Parasitology of Ghent University, Belgium. Overall inverse variance weighted estimates were computed for each of the traits through random effects models. An average establishment rate (±S.E.) of 0.269±0.022 was calculated based on data of 27 studies (46 experiments). The establishment rate declined when infection dose increased and was lower in younger animals. An average proportion of larvae entering hypobiosis (±S.E.) of 0.041 (±0.009) was calculated based on 27 studies (54 experiments). The proportion of ingested larvae that went into hypobiosis was higher in animals that received concomitant infections with nematode species other than O. ostertagi (mixed infections). An average daily adult mortality (±S.E.) of 0.028 (±0.002) was computed based on data from 28 studies (70 experiments). Adult mortality was positively correlated with infection dose. A daily fecundity (±S.E.) of 284 (±45) eggs per female was found based on nine studies (10 experiments). The average female sex ratio of O. ostertagi based on individual animal data (n=75) from six different studies was estimated to be 0.55. We believe that this systematic review is the first to summarise the available data on the main life history traits of the parasitic phase of O. ostertagi. In conclusion, this meta-analysis provides novel estimates for the parameterization of life cycle-based transmission models, explicitly reports measures of variance around these estimates, gives evidence for density dependence of larval establishment and adult mortality, shows that host age affects larval establishment and, to our knowledge, provides the first evidence for O. ostertagi of a female-biased sex ratio.

How minerals may influence the development and expression of immunity to endoparasites in livestock

This review attempts to explain how dietary mineral intake may affect the immune system, with particular reference to gastrointestinal nematode infestations of livestock, and considers its significance for other gut infections as well as for other species. Of the 56 minerals found in mammalian tissues, 16 are currently considered to be essential, and a further 13 probably essential, for cell and tissue function. To date, eight of these have been shown to affect the function of the mammalian immune system directly. Nine others have roles in physiological pathways such as neurological or endocrine function, or protein or carbohydrate metabolism, which in turn regulate the immune system. The remainder may in the future be shown to have immunologically specific roles. The pathogenesis of mineral effects on immunity involves a number of pathways and molecular mechanisms. Major areas requiring further investigation are the relationship between deficiency of minerals and in vivo immune-mediated protection against disease, in particular diseases of the mucosa, and the mechanisms by which the minerals or their deficiency exert their effect on immunity. Research is also required into the possibility that animals in the process of acquiring gut immunity have higher requirements for minerals.

Differential responses to dietary cobalt in finishing steers fed corn-versus barley-based diets

An experiment was conducted to determine the effects of dietary Co concentration on performance, carcass traits, and plasma, liver, and ruminal metabolites of steers fed corn- or barley-based diets. Sixty steers, initially averaging 316 kg, were stratified by BW and assigned randomly to treatments in a 2 x 3 factorial arrangement, with factors being a corn- or barley-based diet and supplemental Co added at 0, 0.05, or 0.15 mg/kg of DM. Control corn-and barley-based diets analyzed 0.04 and 0.02 mg of Co/kg of DM, respectively. Steers were fed individually using electronic Ca-lan gate feeders. Cobalt supplementation increased (P < 0.05) DMI and ADG over the total study. From d 85 to finish, Co supplementation increased (P < 0.05) ADG by steers fed corn- but not barley-based diets. The G:F was increased (P < 0.05) by Co supplementation during the first 84 d but not over the entire finishing period. Average daily gain and G:F were greater (P < 0.05) for corn- vs. barley-fed steers. Supplemental Co increased vitamin B12 in plasma and liver (P < 0.05), and plasma vitamin B12 was greater (P < 0.05) in steers fed corn-vs. barley-based diets. Cobalt supplementation increased (P < 0.05) ruminal fluid vitamin B12 on d 84 in steers fed corn- but not barley-based diets. Folate was greater in plasma (P < 0.01) and liver (P < 0.05) of steers fed Co-supplemented diets. Increasing supplemental Co from 0.05 to 0.15 mg of Co/kg of DM increased (P < 0.05) liver folate in steers fed barley- but not corn-based diets. Supplemental Co decreased (P < 0.01) plasma methylmalonic acid concentration in steers. Increasing supplemental Co from 0.05 to 0.15 mg/kg of DM decreased plasma and ruminal succinate concentrations, and steers fed barley-based diets had greater (P < 0.05) plasma and ruminal succinate relative to those fed corn-based diets. Addition of supplemental Co to the basal diets increased (P < 0.01) plasma glucose concentrations of steers, and steers fed corn-based diets had greater plasma glucose than those fed barley-based diets. Steers supplemented with Co had greater ruminal propionate (P < 0.01) and lesser (P < 0.05) ruminal acetate and butyrate proportions than controls. Supplemental Co increased dressing percent (P < 0.10) and HCW (P < 0.01) at slaughter. These results indicate that feeding steers corn- or barley-based diets deficient in Co adversely affects performance and vitamin B12 status.

Effect of an injectable microencapsulated Vitamin B12 on serum and liver Vitamin B12 concentrations in calves

AIM

To evaluate the efficacy of a long-acting injectable microencapsulated formulation of Vitamin B12 in dairy calves.

METHOD

Fifty calves, average liveweight 110kg, were randomly allocated to 5 groups of 10 animals and injected subcutaneously in the anterior neck with 0.12, 0.18, 0.24 and 0.3 mg Vitamin B12/kg liveweight using a formulation of microencapsulated Vitamin B12 in a lactide: glycolide copolymer. The untreated calves were injected with the same vehicle, without Vitamin B12. Subsequent changes in serum and liver Vitamin B12 concentrations were followed for 244 days.

RESULTS

The microencapsulated Vitamin B12 significantly increased, then maintained serum and liver Vitamin B12 concentrations higher than those of untreated controls for at least 110 days.

CONCLUSIONS

Injection of the microencapsulated Vitamin B12 at dose rates of 0.12 to 0.24 mg/kg liveweight will increase and maintain the Vitamin B12 status of calves for at least 110 days.

Micronutrients and immune function in cattle

Complex inter-relationships exist between certain micronutrients, immune function and disease resistance in cattle. Several micronutrients have been shown to influence immune responses. The relationship between deficiencies of some micronutrients and disease resistance is less clear. A number of studies have indicated that Cr supplementation may improve cell-mediated and humoral immune response as well as resistance to respiratory infections in stressed cattle. With respiratory-disease challenge models Cr generally does not affect disease resistance. Deficiencies of Cu, Se, vitamin E and Co in cattle reduce the ability of isolated neutrophils to kill yeast and/or bacteria. Cu deficiency reduces antibody production, but cell-mediated immunity is generally not altered. However, Cu deficiency appears to reduce production of interferon and tumour necrosis factor by mononuclear cells. Numerous studies have linked low vitamin E and/or Se status to increased susceptibility of dairy cows to intramammary infections. In contrast to findings in laboratory animals, marginal Zn deficiency does not appear to impair antibody production or lymphocyte responsiveness to mitogen stimulation in ruminants. Co deficiency has been associated with reduced resistance to parasitic infections. It is well documented that vitamin A-deficient animals are more susceptible to various types of infections. beta-Carotene, possibly via its antioxidant properties, may affect immune function and disease resistance independent of its role as a precursor of vitamin A.

Hepatic lipidosis associated with cobalt deficiency in Omani goats

Livers from 36 of 684 (5.3%) apparently healthy goats examined at an abattoir in the greater Muscat area of Oman exhibited gross pathological findings characterized by extremely pale, friable, fatty livers encompassing the entire organ. Histopathologically, diffuse hepatic lipidosis and occasional bile duct proliferation were observed. Periodic acid Schiff-positive, diastase-resistant pigment was observed in the macrophages lining the sinusoids. These histopathological lesions were consistent with those characteristic of ovine white liver disease. Cobalt analysis revealed that normal livers had six times more cobalt and a 3-fold less fat content than those measured in the fatty livers. This is the first report of an association between cobalt deficiency and hepatic lipidosis in Omani goats.

The effect of cobalt supplementation on the immune response in vitamin B12 deficient Texel lambs

The effect of cobalt supplementation on the immune reactivity in vitamin B12 deficient lambs was measured by comparing the humoral and cell-mediated immune responses against bovine herpes virus type 1 and Mycobacterium paratuberculosis. In addition, faecal egg counts were performed after natural infection with gastrointestinal nematodes. The experiments were performed with registered Texel twin lambs of the same sex. One lamb of each twin received three cobalt pellets divided over the grazing period. The non-supplemented lambs had lower serum vitamin B12 levels than their supplemented brother or sister. Our results demonstrate significantly lower lymphoblastic responses against Mycobacterium paratuberculosis in non-supplemented lambs compared with supplemented lambs 4 weeks after paratuberculosis vaccination. Vitamin B12 deficient lambs in this study had significant higher faecal egg counts than their supplemented brother or sister after natural infection with gastrointestinal nematodes. No differences were found in total and differential white blood cell counts, in total protein, albumin, alpha-, beta- and gamma-globulin and in antibody production against bovine herpes virus type 1 and Mycobacterium paratuberculosis.

Pathophysiology of infection with Ostertagia ostertagi in cattle

Infection with the abomasal nematode, Ostertagia ostertagi, is an important cause of impaired productivity in young cattle in temperate parts of the world. Such losses have been associated with marked changes in feed intake, gastrointestinal function, protein, energy and mineral metabolism, and in body composition. The reduction in feed intake is an important factor in the pathogenesis of infection and may account for a large part of the difference in weight gain between ad libitum fed control and infected calves. Despite the obvious importance of inappetance, only recently has an association been made between reduced intake, altered gut motility and elevated levels of certain gastrointestinal hormones, such as gastrin. It has been suggested that the elevated gastrin levels accompanying abomasal parasitism may impair reticulo-ruminal motility and slow down abomasal emptying, leading to a stasis of ingesta and a reduction in feed intake. The rise in blood gastrin levels may also be partly responsible for the marked hyperplasia of the fundic mucosa seen in abomasal infections. Pronounced changes in protein metabolism have also been associated with Ostertagia infection. Radioisotopic studies have demonstrated increased losses of albumin into the gastrointestinal tract which are accompanied by an increase in the rate of synthesis in the liver. Dietary protein breakdown in the abomasum is also likely to be impaired, although there is evidence of a compensatory increase in protein digestion in the lower gut of parasitised calves. Increased losses of albumin are not always accompanied by increases in faecal nitrogen, suggesting that albumin is broken down and recycled as ammonia. Radioisotopic studies in animals with intestinal nematode infections have demonstrated a marked reduction in muscle protein synthesis and an increase in protein synthesis in gastrointestinal tissue. Such changes in the balance of protein synthesis are likely to be brought about by alterations in the balance of certain metabolic hormones. Marked changes in energy metabolism also accompany Ostertagia infection. Parasitised calves exhibit a marked increase in non-esterified fatty acid levels, resulting from the mobilisation of adipose tissue, and a reduction in digestive efficiency of energy, probably associated with the increase in cycling of protein through the gastrointestinal tract and the compensatory increases in protein synthesis. Mineral metabolism may also be affected although relatively little work has been conducted in cattle. Changes in body composition reflect a reduction in deposition of muscle protein and fat, and an increase in bone content and water retention.

Trace element deficiencies in cattle

Deficiency of cobalt, copper, iron, iodine, manganese, selenium, or zinc can cause a reduction in production. Reduced production occurs most commonly when a deficiency corresponds to the phases of growth, reproduction, or lactation. Because of environmental, nutrient, disease, genetic, and drug interactions, deficiencies of single or multiple elements can occur even when the levels recommended by the National Research Council for these nutrients are being fed. Additionally, random supplementation of trace elements above National Research Council recommendations is not justified because of the negative interaction among nutrients and potential toxicosis. Evaluation of trace element status can be difficult because many disease states will alter blood analytes used to evaluate nutrient adequacy. Proper dietary and animal evaluation, as well as response to supplementation, are necessary before diagnosing a trace element deficiency.

The influence of a low cobalt intake on the neutrophil function and severity of Ostertagia infection in cattle

Two trials involving housed cattle examined the effect of Co depletion and supplementation on immune status as assessed by the neutrophil function test which measures the ability of isolated neutrophils to kill the yeast Candida albicans. A third trial investigated the extent to which Co status influenced the severity of Ostertagia ostertagi infection. In the first two trials liveweight gains were unaffected until some 40-60 weeks on the low dietary Co intake despite very low serum vitamin B12 values being recorded after 10 weeks. However, the immune status as measured by the neutrophil function test was reduced within 10 weeks of commencing the low Co diet. On administration of Ostertagia ostertagi larvae, Co-depleted cattle showed a greater weight loss than Co-supplemented cattle but showed no difference in the length of the prepatent period, worm egg production or serum gastrin and pepsinogen concentrations. After anthelmintic treatment both groups showed a similar response. It is postulated that the lowered immune response of Co-depleted cattle resulted in the greater severity of the Ostertagia ostertagi infection.

Ovine white-liver disease (OWLD) in Norway: clinical symptoms and preventive measures

During 6 years, altogether 458 twin lambs of the Dala and Rygia breeds with their dams were put on ovine white-liver disease (OWLD) pastures which were moderately, heavily or not cobalt fertilized, or on control pastures 15 km apart. Groups of lambs were untreated, regularly dosed with Co sulphate or vitamin B12, dosed with Co pellets, copper oxide needles (CuO), selenium pellets or Co-Se-Cu glass boli, or had access to Co enriched salt lick. Clinical symptoms in untreated lambs included varying degree of reduced weight gain or loss of weight appearing after 6-12 weeks on pasture, at an age of 10-15 weeks. Additional symptoms were seen 2-4 weeks later, including inappetence, listlessness, and often serous eye discharge and crusty ears. Of the untreated lambs on OWLD pastures 18% died or were eutanized because of OWLD. The condition was preventable by Co or B12 administration, which yielded an average increase of mid Sept. live weights of between 8 and 17 kg. Co fertilization of pastures, use of Co enriched salt lick, or dosing with Co pellets are recommended under practical circumstances. The lambs grazing control pastures were on average 17 kg heavier by mid Sept. than the OWLD lambs. They showed some weight increase on extra Co supply.