The use of blood analyses to evaluate mineral status in livestock

Probiotic supplementation in sustainable sheep production: impacts on health, performance, and methane mitigation

Probiotics, defined as live microorganisms conferring health benefits, are increasingly recognized for their potential to enhance animal productivity, mitigate environmental impact, and improve overall animal health. Ruminants, including sheep, are significant contributors to greenhouse gas emissions, a key factor in climate change. Literature from 2003 to 2024 was retrieved from PubMed (Medline), Web of Science, and CAB Direct using the keywords: sheep, sustainability, probiotics, methane emission, and greenhouse gas emissions. The inclusion of probiotics in sheep diets demonstrates potential as a methane mitigation strategy through the stimulation of beneficial bacteria and the suppression of methanogenic microbial activity. Probiotics can improve rumen fermentation parameters by increasing volatile fatty acid production, decreasing protozoal numbers, and improving gas production. Additionally, probiotics can sustain intestinal health, boost nutrient digestibility, and strengthen the immune system. Although promising, the variable effectiveness of probiotics underscores the importance of refining formulations and delivery methods, taking into account strain, dose, and administration. Further studies are crucial to understand the underlying mechanisms and maximize their impact on sheep productivity. This review delves into the potential of probiotics to improve growth, health, and environmental sustainability in the sheep industry, drawing on insights from in vitro and in vivo studies.

The Role of Energy-Dispersive X-Ray Fluorescence to Predict Mineral Content in Untreated Bovine Plasma

Minerals and trace elements are vital for numerous physiological processes in mammals. The current reference analysis for mineral determination in biological matrices is inductively coupled plasma mass spectrometry (ICP-MS). This analysis is costly, time-consuming, and destructive. While commercial kits are a viable alternative to ICP-MS due to the lower cost, their limit lies in the ability of determining only one mineral at a time. Energy-dispersive X-ray fluorescence (ED-XRF) has been proposed as a potential alternative for the rapid determination of mineral concentration in biological matrices. This study evaluated the accuracy of ED-XRF as an alternative to commercial diagnostic kits to predict the concentrations of sodium, magnesium, phosphorus, chloride, potassium, calcium, iron, and selenium in cattle plasma without sample pretreatment, potentially reducing the time of analysis compared to commercial kits and costs and labor compared to ICP-MS. Reference mineral concentrations were determined in 277 samples using in vitro diagnostics regulation-certified commercial diagnostic kits. The results indicated a moderate prediction accuracy only for potassium. For the other minerals, the prediction accuracy of ED-XRF was insufficient, which suggests that some degree of sample preparation is necessary to improve the determination of minerals in plasma.

Assessment of Elemental Deficiency of Crossbred Dairy Cows and Mineral Composition in Natural Feed and Nutritional Supplements in the Northern and Northwestern Provinces in Sri Lanka

This study assessed the elemental status of cross-bred dairy cows in small holder farms in Sri Lanka, with the aim to establish the elemental baseline and identify possible deficiencies. For this purpose, 458 milk, hair, serum and whole blood samples were collected from 120 cows in four regions of Northern and Northwestern Sri Lanka, (namely Vavaniya, Mannar, Jaffna and Kurunegala). Farmers also provided a total of 257 samples of feed, which included local fodder as well as 79 supplement materials. The concentrations of As, Ca, Cd, Co, Cr, Cu, Fe, I, K, Mg, Mn, Mo, Na, Ni, Pb, Se, V and Zn were determined by inductively coupled plasma mass spectrometry (ICP-MS). Evaluation of the data revealed that all cows in this study could be considered deficient in I and Co (18.6-78.5 µg L-1 I and 0.06-0.65 µg L-1 Co, in blood serum) when compared with deficiency upper boundary levels of 0.70 µg L-1 Co and 50 µg L-1 I. Poor correlations were found between the composition of milk or blood with hair, which suggests that hair is not a good indicator of mineral status. Most local fodders meet dietary requirements, with Sarana grass offering the greatest nutritional profile. Principal component analysis (PCA) was used to assess differences in the elemental composition of the diverse types of feed, as well as regional variability, revealing clear differences between forage, concentrates and nutritional supplements, with the latter showing higher concentrations of non-essential or even toxic elements, such as Cd and Pb.

Effects of Replacing Inorganic Sources of Copper, Manganese, and Zinc with Different Organic Forms on Mineral Status, Immune Biomarkers, and Lameness of Lactating Cows

(Objectives) The objectives of this study were to evaluate the effect of half-replacement of the supplementary sulfate sources of Cu, Mn, and Zn with methionine-hydroxy-analog-chelated (MHAC) mineral or amino-acid-complexed (AAC) mineral forms in diets on the mineral status, blood immune biomarkers, and lameness of lactating cows. (Methods) Sixty multiparous Holstein cows (158 ± 26 days in milk; body weight: 665 ± 52 kg; milk yield: 32 ± 7 kg/day) were randomly assigned into one of three dietary treatments (n = 20 per group): (1) MHAC: 50% replacement of sulfate minerals with MHAC forms. (2) AAC: 50% replacement of sulfate minerals with AAC forms. (3) S: 100% sulfate minerals (control). Their Cu, Mn, and Zn concentrations, blood immune biomarkers, and lameness were measured monthly. Repeated-measure mixed models were used to evaluate the effects on trace mineral status over time. As the responses with the MHAC and AAC forms were similar, the treatments were also analyzed as organic trace minerals (OTMs, combining the MHAC and AAC groups, n = 40) versus inorganic trace minerals (ITMs, the S group, n = 20). (Results) Cows supplemented with OTMs had higher concentrations of Cu and Mn in their serum (p ≤ 0.05), a higher hoof hardness (p ≤ 0.05), and a lower incidence of lameness compared to those with ITMs on d 90. There were no statistical differences (p > 0.10) in the concentrations of IgA, IgG, or ceruloplasmin, but there were significant differences (p = 0.03) in the concentrations of IgM in the serum as fixed effects of the diet treatments during the whole trial. On d 30 and 90, the serum IgA concentrations of the cows supplemented with OTMs tended to be higher (0.05 < p ≤ 0.10) than those in the cows supplemented with ITMs. (Conclusions) The half-replacement strategy showed that the MHAC and AAC sources of Cu, Mn, and Zn additives had similar effects on the production performance, blood immune biomarkers, and lameness of the lactating cows. The long-term replacement strategy with OTMs led to the enhancement of the trace mineral concentrations in their body fluids, blood immune biomarkers, and hoof health.

Metabolic profile of Charolais young bulls transported over long-distance

Long-distance transport can cause stress to beef cattle impairing health and growth performances. This study aimed to deepen the knowledge of the effects of long-distance transport on young bulls' metabolic profile to identify reliable blood parameters for monitoring their health and welfare. Eighty Charolais young bulls, transported for 12 hours to the final fattening unit, were weighed and blood sampled at three time intervals: before leaving the commingling centre (day -1), upon arrival at the fattening unit (day 0), and 7 days post-arrival (day 7). These bulls were part of a larger study aimed at testing whether the animals have some benefit from the supplementation of live yeast and selenium through slow-release rumen boluses that were administered to half of them before departure from France ('Yeast' vs 'Control' group). The effect of the supplementation on the parameters considered in this study was included in the statistical analysis to account for the structure of the experimental design. Transport affected the initial body weight of the animals, which dropped on day 0 and it was not fully recovered on day 7. Most plasma traits of protein, energy, hepato-muscle, and mineral profiles were affected by transport. Cortisol was also assessed and peaked at day 0. The footprint of the long-distance transport on bulls' metabolic profile indicated a combination of stress, energy deficit, and muscle damage, with a certain degree of dehydration and liver impairment. Plasma traits measured on day -1 highlighted that stressful conditions and physiological responses of the bulls to recover homeostasis already started during the commingling phase before departure. No effect of supplementation was detected, except for higher selenium plasma level in Yeast bulls at day 7. Among blood parameters, non-esterified fatty acids, total protein, cortisol, glucose, and iron were those responsible for most of the variation in metabolic profile of bulls undergoing long journey. Therefore, these traits might be used as major biomarkers to assess stress in transported beef cattle, helping to identify critical situations for which proper mitigating actions should be taken. The outcomes of this study suggested that preventive measures against transport stress in beef cattle should start at the commingling of the animals in the collection centers, thus before departure.

An Investigation of Heavy Metal Concentrations in the Sera of Cattle Grazed in Different Locations in the Kars Province of Türkiye

The aim of this study was to investigate the effects of exposure of cattle to low levels of environmental pollution on trace metal metabolism. The assessment of heavy metal concentrations in blood samples is essential to evaluate the potential effects of pollutants on cattle production and to measure the uptake of pollutants by animals. For this purpose, cattle raised in villages at varying distances to the center of the Kars province were sampled for blood, and heavy metal concentrations were measured in the extracted sera. In total 150 blood samples were collected from 4-to 5-year-old cattle from 15 regions. Sera were extracted from the blood samples from the selected foci and analyzed with an inductively coupled plasma-optical emission spectrometry (ICP-OES) device for essential (Co, Cr, Cu, Fe, Mn, Ni and Zn, Se, V) and non-essential (Pb, Cd and Hg, As, Al, Sn) heavy metals. Heavy metals were detected in the serum samples in the following order: Sn > Fe > Al > Zn > Cu > Pb > Cr > As > V > Ni > Mn > Hg. A confidence interval of 95% was used to evaluate all tests. Differences between the villages were insignificant for the Cu, Pb, Cd, Hg, Se, Al, Co concentrations (p > 0.05), whereas differences between the villages were significant for the Fe, As, Ni, Mn (p < 0.05), Zn, Cr (p < 0.01), V and Sn (p < 0.001) concentrations. The results of this study show that heavy metals detected in bovine sera from the sampling area do not exceed the maximum permissible limits, suggesting limited exposure to heavy metals and no associated health risk to animals in the region.

Trace Mineral Nutrition of Sheep

Trace mineral nutrition of sheep often focuses on their greater susceptibility to copper toxicosis due to a lesser biliary excretion ability compared with other ruminants. Our understanding of sheep trace mineral requirements has improved for most elements allowing for a factorial approach to determining daily requirement instead of a dietary concentration. Forage trace mineral content is influenced by many factors making issues of trace mineral supplementation geographic-dependent. Oral delivery of trace elements is a preferred supplementation method, and this can be achieved through free choice trace mineralized salt or direct dietary incorporation.

Trace Mineral Metabolism: The Maternal-Fetal Bond

Trace minerals are essential nutrients that have many biologic functions, many of which are related to metabolic activities, immune function, and antioxidant capacity. The pregnant dam provides essential nutrients to support fetal development, including trace minerals. Milk is known to be an insufficient source of many trace minerals during the early nursing neonatal period. The fetal liver is capable of concentrating minerals to generate a reserve for use during postnatal life; however, the sufficiency of this reserve is dependent upon maternal mineral status. Appropriate mineral supplementation in the gestational diet is critical to supporting fetal development, maintaining adequate antioxidant capacity to survive the birthing process, and sustain immune function and growth of the newborn animal.

Trace Mineral Supplementation for Beef Cows: Dry Range Environment

Range mineral supplementation is based on providing trace minerals not adequately provided from grazed forage in meeting beef cattle needs throughout life cycle stages. Supplementation programs should be developed with consideration of ranch production goals, economics, and practicality for implementation. Factors such as season of grazing, forage analysis, water analysis including antagonistic elements, and measured animal responses are used in mineral supplement formulation for range cattle. Mineral intake is a critical factor to a supplement program's success. Salt-based mineral products are most used under range conditions, yet there is much individual intake variation.

Investigations on the Effects of Different Calcium Supply Exceeding the Requirements on Mineral Serum Concentrations and Bone Metabolism in Young Warmblood Stallions

Simple Summary

In horse husbandry, it is a common practice to supplement roughages with mineral or complementary feeds, which contain, among others, macro elements. However, roughages usually fulfil the requirements for macro minerals but not of trace elements of horses at maintenance. Therefore, in the present feeding trial mineral feeds with different calcium levels moderately exceeding the requirements vs. 2-fold higher levels were tested in young stallions (2–3 years old) for five months under practical conditions. Blood samples of the stallions were analysed to prove whether the feeding regimes influence mineral status or bone metabolism. The results suggest that reduced calcium intake favours phosphorus levels in the blood, but does not affect serum levels of trace elements and bone metabolism in young, still growing stallions.

Abstract

Since mineral supplements for horses commonly contain macro minerals, although the requirement for such is usually covered by roughage-based diets, the aim of this study was to investigate the effects of different dietary calcium levels on mineral serum concentrations and bone metabolism. The trial was conducted in 30 young warmblood stallions (2–3 years) that were divided into two groups for a five-month feeding trial. The groups were fed a hay- and oat-based diet and were either supplied with high (Ca-High) or moderate (Ca-Moderate) calcium excess. While in Ca-High calcium supply was about 2–2.5-fold of the requirement, in Ca-Moderate calcium requirements were slightly surpassed (1.5–1.6-fold). In order to monitor the effects of the different calcium supply, blood samples were taken during the trial and analysed for levels of macro and trace elements as well as concentrations of two bone markers. In Ca-Moderate a trend towards higher phosphorus serum levels compared to Ca-High was observed which was significant at the end of the trial (p = 0.0002). Furthermore, results showed no influence of the diet on bone markers. Results support the idea that forage-based rations for horses do not necessarily have to be supplemented with macro minerals but with trace elements.

Vitamin E and Selenium Decreased Cortisol in Cattle

Twenty dairy cows with left abomasal displacement were used to investigate the effects of vitamin E and selenium treatment on blood cortisol in dairy cows stressed by omentopexy. The cows were randomly divided into two groups. Ten hours before surgery 6 g of DL-α-tocopheryl acetate (6 mg.kg−1) and 67 mg of natrium selenite (0.1 mg.kg−1) in a volume of 40 ml were administered subcutaneously to 10 cows; the control animals (n = 10) received an equivalent volume of injectable water (40 ml). The injection of vitamin E and selenium produced a rapid rise (P < 0.05) in blood α-tocopherol and selenium concentrations. The serum vitamin E increased several times ten hours after vitamin E and Se injection and raised continuously to the highest average concentration of 21.6 mg.l−1 at hour 24 after the surgery. The highest selenium concentration was seen ten hours after selenium administration with holding the increased concentrations in comparison to initial ones during the whole study. Serum cortisol increased in both groups after surgery. The highest cortisol concentrations were reached at one hour after surgery in the experimental and control group (56.7 ± 28.8 and 65.3 ± 26.1 μg.l−1, respectively). A return to the levels similar to the initial ones was recognized 24 hours after the surgery. The ANOVA revealed a significant effect of vitamin E and selenium injection on serum cortisol (P < 0.05). In conclusion, we have demonstrated that abdominal surgery resulted in typical stress changes with a weaker cortisol response to the abdominal surgery in animals treated with vitamin E and selenium.

An investigation of micronutrient supplementation in weaner lambs to improve growth rates in southeast Australia

OBJECTIVE

A producer survey by questionnaire assessed supplements used in sheep and reasons for use. This was followed by field trials on eight sheep properties in SE NSW to determine the effect of commonly used commercially available supplements on growth rates of Merino and crossbred lambs.

DESIGN

On each property, 450 lambs were selected at weaning and randomly allocated to nine groups of 50 sheep (eight treatment and a control group). Supplements were applied as per manufacturer's recommendation every 6-12 weeks. At each application, all sheep were weighed and data on general flock health and management were collected.

RESULTS

All but one of the survey respondents (n = 77) had used supplements in their sheep at some stage. The reasons for use were most commonly for general health and production benefits (n = 21; 26.9%) and to prevent or treat specific diseases/deficiencies (n = 7; 9.0%). The average daily weight gains (ADWG) of the lambs over the trial period varied from 0.074 kg to 0.213 kg/head/day. Statistical analysis showed that overall there was not a significant difference (P = 0.587) between ADWG among lambs that received supplements and lambs that did not.

CONCLUSION

Results of this study show that application of supplements were not linked to improved growth rates in clinically normal crossbred and Merino lambs under the trial farm conditions between weaning and 15 months of age. Effects of supplements on health and production in adult sheep and how supplement response can be best measured in sheep flocks (especially in relation to health and welfare) and linked to productivity requires further investigation.

Potential bio-indicators for assessment of mineral status in elephants

The aim of this study was two-fold: (1) identify suitable bio-indicators to assess elemental status in elephants using captive elephant samples, and (2) understand how geochemistry influences mineral intake. Tail hair, toenail, faeces, plasma and urine were collected quarterly from 21 elephants at five UK zoos. All elephant food, soil from enclosure(s), and drinking water were also sampled. Elemental analysis was conducted on all samples, using inductively coupled plasma mass spectrometry, focusing on biologically functional minerals (Ca, Cu, Fe, K, Mg, Mn, Na, P, Se and Zn) and trace metals (As, Cd, Pb, U and V). Linear mixed modelling was used to identify how keeper-fed diet, water and soil were reflected in sample bio-indicators. No sample matrix reflected the status of all assessed elements. Toenail was the best bio-indicator of intake for the most elements reviewed in this study, with keeper-fed diet being the strongest predictor. Calcium status was reflected in faeces, (p 0.019, R² between elephant within zoo - 0.608). In this study urine was of no value in determining mineral status here and plasma was of limited value. Results aimed to define the most suitable bio-indicators to assess captive animal health and encourage onward application to wildlife management.

Blood metabolic profile tests at dairy cattle farms as useful tools for animal health management

Blood metabolic profile tests are simple cost-effective biochemical tests which are mostly used to identi-fy nutritional and/or management challenges in dairy cattle herds, but they also can be simply used to find animals which are clinically healthy, but really have some hidden problems like low production performance, reproductive diseases and/or long calving intervals and other sub-clinical diseases. Rou-tine metabolic profile tests commonly consist of blood glucose, urea, albumin, cholesterol, beta-hydroxybutyric acid and non-esterified fatty acids values, as well as sodium, potassium, chloride, calci-um, magnesium and inorganic phosphate levels. Briefly, the current review discusses blood metabolic profile tests, their importance, introduces an easy method for it, emphasises on the relation between blood metabolic profile parameters and many important sub-clinical diseases including ketosis, milk fever, mastitis, cystic ovaries, displaced abomasum and etc., and indicates that because of its simplicity, low cost and easy for analysis results, it can be considered as a good method for diagnosis of important diseases at dairy cattle farms.

Effects of Vitamin E and Selenium on Growth Performance, Antioxidant Capacity, and Metabolic Parameters in Growing Furring Blue Foxes (Alopex lagopus)

The objective of this study was to determine whether different dietary vitamin E (VE) and selenium (Se) levels affect the nutrient digestibility, production performance, and antioxidant abilities of growing furring blue foxes. A 4 × 2 factorial arrangement that included 4 levels of VE (0, 100, 200, or 400 mg/kg diet from α-tocopherol acetate) and 2 levels of Se (0 or 0.2 mg/kg diet from glycine selenium) was performed from mid-September to pelting. A metabolism study was conducted for four days starting at the 30th day of the trial. Serum samples were collected at the last day of the study. The results showed that supplementation of growing furring blue fox diets with VE and Se significantly affected the average daily gain (ADG), average daily feed intake, and feed conversion ratio (F:G) (P < 0.05). Dietary Se supplementation enhanced protein and fat digestibility of male blue foxes. There were significant effects of different VE and Se levels in diets on serum antioxidant parameters and metabolic parameters of blue foxes (P < 0.05). In conclusion, this research indicated that dietary supplementation with VE improved ADG and F:G of blue foxes. Addition of VE and Se to blue fox diets increased the antioxidant capacity of blue foxes. The diet with high VE and Se supplementation reduced glucose and triglycerides concentrations in serum. The present study found that growing furring blue foxes had increased growth performance and antioxidant abilities when fed diets with 200 mg VE/kg and nearly 0.1 mg Se/kg.

Dietary supplementation with glucogenic precusors and fatty acids improves performance and health of periparturient dairy cows

This experiment aimed to make a comparison between the effect of a mix of two energy preparations (a glucogenic preparation (G) and a free fatty acid preparation (F)), administered in the diet during the transition period over different periods of time (5 or 8 weeks), on the animal condition, feed intake, yield and composition of milk, and blood and urine parameters. The experimental additive was a mixture (1:1) of two energy preparations, namely, a loose mixture of propylene glycol and sodium propionate and a free fatty acid preparation in the form of rumen-undegradable pellets. The study included 50 Polish Black-and-White Holstein–Friesian dairy cows, allocated into five treatment groups, including one control (C) and four experimental ones (G1F1, G2F2, G2F1 and G1F2). The preparations were mixed at a 1:1 weight ratio (500 g per head, comprising 250G and 250F) and they were administered to all experimental groups of cows daily as a component of the experimental concentrate for 5 weeks (from the 2nd week before the expected calving and until the 3rd week of lactation). From the 4th until the 6th week of lactation, the supplementation in the experimental groups changed and animals received either no additive (G1F1), or were continuously supplemented with the G–F mix (G2F2), or received only G (G2F1) or only F (G1F2). The preparations used in the study had a long-term influence on the increase in the milk yield of cows, on the improvement of their health condition, and on the reduction of weight loss. The study results confirmed that prolongation of the supplementation until the 6th week of lactation may cause favourable changes in animal performance and milk quality. Due to different modes of action, the simultaneous supplementation of G and F reduced the negative energy balance in the cow and improved milk production and composition. The best results were obtained after administration of the mixture (1:1) of the G and F at the dose of 500 g/cow.day over the 8-week periparturient period.

Commercial human kits' applicability for the determination of biochemical parameters in sheep plasma

Currently, several commercially available biochemical kits are validated for their use in human but not in animals. The purpose of this work is to demonstrate the applicability of human kits for alanine-aminotransferase, aspartato-aminotransferase, albumin, total protein, total cholesterol, and triglycerides in ovine plasma. Assays were validated according to international guidelines and stability was explored. Accuracy values were between 67 and 100%, and intra and interday precisions (%RSD) were <15% for all studied parameters. These results confirm the suitability of the studied human kits for their use in ovine plasma and they were used in plasma collected from pregnant ewes.

[Management of the dry and transition periods of dairy cattle in free stall housing systems in Lower Saxony. Part 1: Farm management. Teil 1: Betriebsmanagement]

OBJECTIVE

Describing husbandry and management of dairy cows during the dry and transition periods on farms of different sizes in Lower Saxony, Germany.

MATERIAL AND METHODS

A total of 51 dairy farms were visited and asked via questionnaire about the husbandry and management in the following categories: general operating data, stable and husbandry of milking cows, dry cows, transition cows and the youngstock, pasture management, feeding, health data and prophylactic treatments. In addition, during a farm inspection, data on cow comfort were collected.

RESULTS

German Holstein was the predominant breed on the dairy farms. Most cattle were kept in three-rowed free-stall housing systems (74%) with straw bedding (47%) without division in productivity groups (59%). The dry cows were most frequently separated in two groups (68%) in free-stall housing systems (68%). The heifers were similarly mainly kept in free-stall housing systems (67%) and were mostly separated according to their reproductive status (74%). On 29% of the farms, pasture grazing was not practiced at any time. On 80% of the farms, cows were fed a mixed ration with computerized concentrate supplementation and on 68% of the farms biphasic dry cow diets were used. The most frequently stated health problems were of the limb and claw (61%). Prophylaxis of ketosis was practiced on 21% of the farms and milk-fever prophylaxis on 12% of the farms, both for each individual cow around calving.

CONCLUSION AND CLINICAL RELEVANCE

Husbandry and management on farms differ widely and are still in need of optimization with respect to barn concepts, implementation of production groups and feeding, as well as veterinary consultation with respect to health problems and prophylactic measures.

Effects of selenium biofortification of hayfields on measures of selenium status in cows and calves consuming these forages

Two experiments were conducted to evaluate the Se status of weaned calves (Exp. 1) and pregnant cows and newborn calves (Exp. 2) consuming bermudagrass [ (L.) Pers.] fertilized with Se. Sodium selenate was dissolved into water (8.8 g/L) and sprayed onto hayfields. Selenium-fertilized forage had greater ( ≤ 0.001) Se concentration compared with the control forage without Se fertilization (7.7 ± 1.81 vs. 0.1 ± 0.04 mg Se/kg DM and 10.8 vs. 0.1 mg Se/kg DM for Exp. 1 and Exp. 2, respectively). In Exp. 1, beef calves ( = 32; 176 ± 8.7 kg initial BW) were stratified by BW and randomly assigned to pens (16 pens; 2 calves/pen). Treatments were randomly assigned to pens, including control (no supplemental Se), Se hay, or sodium selenite ( = 2, 7, and 7 pens, respectively). A 42-d pair-feeding design was used, wherein each pen receiving Se hay was paired to a pen receiving sodium selenite. Blood and liver samples were collected on d 0, 21, and 42. Liver Se concentrations were greatest ( ≤ 0.005) on d 42 for calves provided Se hay compared with calves provided sodium selenite or control. This difference was attributed only to paired-feeding groups consuming <3 mg Se daily. In Exp. 2, mature, late-pregnancy cows were randomly assigned to 3 treatments: Se hay ( = 12), sodium selenite ( = 9), or control (no supplemental Se; = 6). Cows assigned to the sodium selenite and Se hay treatments were provided 2.5 mg of supplemental Se daily. Upon enrollment, cows were moved into individual feeding areas at an estimated 30 d prior to calving. Following calving, cotyledon and colostrum samples were collected from cows. Four days later, liver and blood samples were collected from both cows and calves. Selenium-supplemented cows had greater ( ≤ 0.001) liver, cotyledon, plasma, and whole blood Se concentrations compared with cows not receiving supplemental Se. Furthermore, cows provided Se hay tended ( = 0.11) to have greater liver Se concentrations compared with cows provided sodium selenite. Calves born to Se-supplemented cows had greater ( = 0.001) plasma Se concentrations than calves born to cows receiving no supplemental Se. Furthermore, calves born to cows provided Se hay tended ( = 0.06) to have greater plasma Se concentrations compared with calves born to cows provided sodium selenite. These data imply that Se biofortification of hayfields is an effective method to increase Se concentration of forage. Consumption of these forages result in increased Se status of weaned calves, periparturient cows, and their calves.

Reference values for biochemical analytes in Mexican dairy farms: interactions and adjustments between production groups

ABSTRACT Blood samples of 189 healthy Holstein cows classified as high-producers, low-producers, or dry cows, were collected with the purpose of establishing reference values for several biochemical analytes in Mexican dairy farms. Mean values were calculated for: 1) Energy profile: glucose, cholesterol, triglycerides, β-hydroxybutyrate, and non-esterified fatty acids, 2) Protein profile: urea, albumin, globulin, and total protein, 3) Mineral profile: calcium, phosphorus, sodium, potassium, magnesium, chlorine, carbon dioxide, bicarbonate, and anion gap, and 4) Hepatic enzyme: γ-glutamyl transpeptidase. The resulting data set was analyzed using Gaussian distribution and descriptive statistics. Confidence intervals of 95% were established. The linear relationships between the biochemical analytes were quantified, and an analysis of variance was performed to compare the mean values between the three production groups. The overall concentrations of the described analytes are consistent with values reported by international literature. However, lower values were found for urea, calcium, and sodium; higher values were found for cholesterol, and γ-glutamyl transpeptidase. Negative correlations were found between β-hydroxybutyrate and glucose or urea, γ-glutamyl transpeptidase and urea, and bicarbonate and urea or phosphorus or anion gap. Positive correlations were found between β-hydroxybutyrate and cholesterol or anion gap, non-esterified fatty acids and anion gap, cholesterol and globulin, different analytes of mineral profile and anion gap or urea or glucose, and between sodium and calcium. Differences among the three production groups were observed for β-hydroxybutyrate and cholesterol concentrations. The γ-glutamyl transpeptidase concentration was similar in high and low-producing cows but was higher in comparison to serum levels of dry cows. Calcium showed differences between high-producing cows and the other two groups, and sodium showed the highest concentration in dry cows. The outcomes of this work improve the accuracy of the metabolic profiles as a tool for assessing the nutritional and health status of dairy cows.

Comparison of Various Indices of Energy Metabolism in Recumbent and Healthy Dairy Cows

Background

Downer cow syndrome (DCS) is often diagnosed in dairy cattle during the early post-partum period. The etiology of this condition is not completely understood, as it can be related to the energetic or electrolyte metabolism, as well as to infectious diseases or to trauma.

Hypothesis/Objectives

The aim of this study is to compare energy metabolism and insulin sensitivity indices and various biochemical parameters between recumbent and healthy dairy cows.

Animals

A prospective study has been undertaken on 361 recumbent and 80 healthy Holstein cows.

Methods

Plasmatic glucose, insulin, non-esterified fatty acid (NEFA) and β-hydroxybutyrate (BHB) were assayed in all cows in order to calculate the insulin sensitivity indices but also minerals (Calcium, Phosphorous and Magnesium), thyroxin and creatine kinase. Body Condition Scores (BCS) was assessed.

Results

Significant differences in NEFA, and the glucose and insulin sensitivity indices (“Homeostasis Model Assessment” HOMA, “Revised Quantitative Insulin Sensitivity Check Index” RQUICKI, RQUICKI-BHB) were observed between healthy and recumbent cows in the early post-parturient period indicating disturbances of glucose and insulin homeostasis in the recumbent cows. In the same manner, mineral concentrations were significantly different between healthy and recumbent cows. Glucose, insulin NEFA, and HOMA, were different between early post-partum downer cows and the DCS-affected cows later in lactation.

Conclusion and clinical importance

Results indicate disturbances in energy homeostasis in DCS-affected dairy cows. Further research should determine a prognostic value of the indices in cows suffering from recumbency of metabolic origin.

Assessment of Serum Trace Elements in Diarrheic Yaks (Bos grunniens) in Hongyuan, China

Diarrhea is one of the main causes of animal deaths especially in neonatal calves. The objective of this study was to investigate the blood serum for cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), Molybdenum (Mo), selenium (Se), and zinc (Zn) concentrations in yak serum samples by inductively coupled plasma mass spectrometry (ICP-MS) from 35 yaks consisting of 10 healthy and 25 diarrheic ones. Our observations indicated that the concentrations of Mn, Zn, and Fe in yak affected with diarrhea had statistically significant reduced levels as compared to the control group (P < 0.05). The mean concentration of Cu in blood serum of diarrheic yaks was found significantly higher than the normal ones (P < 0.05). The Mn and Zn in the serum of diarrheic groups were observed significantly different (P < 0.05) with different ages. These findings can provide for some valuable information for the investigation on relationship between trace elements in the serum of normal and diarrheic yaks.

Selenium in Cattle: A Review

This review article examines the role of selenium (Se) and the effects of Se supplementation especially in the bovine species. Selenium is an important trace element in cattle. Some of its roles include the participation in the antioxidant defense the cattle farms. The nutritional requirements of Se in cattle are estimated at 100 μg/kg DM (dry matter) for beef cattle and at 300 μg/kg DM for dairy cows. The rations high in fermentable carbohydrates, nitrates, sulfates, calcium or hydrogen cyanide negatively influence the organism's use of the selenium contained in the diet. The Se supplementation may reduce the incidence of metritis and ovarian cysts during the postpartum period. The increase in fertility when adding Se is attributed to the reduction of the embryonic death during the first month of gestation. A use of organic Se in feed would provide a better transfer of Se in calves relative to mineral Se supplementation. The addition of Se yeasts in the foodstuffs of cows significantly increases the Se content and the percentage of polyunsaturated fatty acids (PUFA) in milk compared to the addition of sodium selenite. The enzyme 5-iodothyronine deiodinase is a seleno-dependent selenoprotein. It is one of the last proteins to be affected in the event of Se deficiency. This delay in response could explain the fact that several studies did not show the effect of Se supplementation on growth and weight gain of calves. Enrichment of Se in the diet did not significantly affect the slaughter weight and carcass yield of bulls. The impact and results of Se supplementation in cattle depend on physiological stage, Se status of animals, type and content of Se and types of Se administration. Further studies in Se supplementation should investigate the speciation of Se in food and yeasts, as well as understanding their metabolism and absorption. This constitute a path to exploit in order to explain certain different effects of Se.

A comparative study of the metabolic profile, insulin sensitivity and inflammatory response between organically and conventionally managed dairy cattle during the periparturient period

The number of organically managed cattle (OMC) within the European Union has increased tremendously in the last decade. However, there are still some concerns about animals under this farming system meeting their dietary requirements for milk production. The aim of this study was to compare the metabolic adaptations to the onset of lactation in three different herds, one conventional and two organic ones. Twenty-two conventionally managed cattle (CMC) and 20 from each organic farm were sampled throughout the periparturient period. These samplings were grouped into four different stages: (i) far-off dry, (ii) close-up dry, (iii) fresh and (iv) peak of lactation and compared among them. In addition, the results of periparturient animals were also compared within each management type with a control group (animals between the 4th and 5th months of pregnancy). Metabolic profiles were used to assess the health status of the herds, along with the quantification of the acute phase proteins haptoglobin and serum amyloid A, insulin and the calculation of different surrogate indices of insulin sensitivity. Generalised linear mixed models with repeated measurements were used to study the effect of the stage, management type or their interaction on the serum variables studied. The prevalence of subclinical ketosis was higher in OMC, although they showed better insulin sensitivity, a lower degree of inflammation and less liver injury, without a higher risk of macromineral deficiencies. Therefore, attention should be paid on organic farms to the nutritional management of cows around the time of calving in order to prevent the harmful consequences of excessive negative energy balance. Moreover, it must be taken into account that most of the common practices used to treat this condition in CMC are not allowed on a systematic basis in OMC.

Epidemiology of trace elements deficiencies in Belgian beef and dairy cattle herds

Selenium (Se), iodine (I), zinc (Zn) and copper (Cu) deficiencies in cattle have been reported in Europe. These deficiencies are often associated with diseases. The aim of the study was to assess trace element status in Belgian cattle herds showing pathologies and to compare them to healthy cattle herds. Eighty-two beef herds with pathologies, 11 healthy beef herds, 65 dairy herds with pathologies and 20 healthy dairy herds were studied during barn period. Blood and/or milk samples were taken in healthy animals. Plasma Zn, Cu, inorganic I (PII) and activity of glutathione peroxidase in erythrocytes (GPX) were assayed. In milk, I concentration was measured. Data about pathologies and nutrition in the herds were collected. According to defined thresholds, it appeared that a large proportion of deficient herds belonged to "sick" group of herds. This conclusion was supported by the mean value of trace elements and by the fact that a majority of individual values of trace elements was below the threshold. Dairy herds had mean values of trace elements higher than beef herds. More concentrates and minerals were used in healthy herds versus "sick" herds. These feed supplements were also used more often in dairy herds, compared to beef herds. Trace elements deficiencies are present in cattle herds in Belgium and are linked to diseases. Nutrition plays a major role in the trace elements status.

Selenium and vitamin E

Deficiency of selenium and vitamin E has recently been identified as a major health concern of sheep producers in certain regions of the United States, and familiarity with published data on these nutrients seems to be of value to small ruminant practitioners. This article begins with a description of the biochemical roles and metabolism of selenium and vitamin E. A literature review follows in which the influence of these nutrients on the musculoskeletal, reproductive, and immune systems, as well as on flock productivity, is discussed. Methods for detection of deficiency and supplementation strategies are also described.