Effect of dietary copper and breed on gene products involved in copper acquisition, distribution, and use in Angus and Simmental cows and fetuses

Impacts of trace mineral source and ancillary drench on steer performance during a 60-day backgrounding phase

Nutritional approaches to optimize cattle health and performance during the receiving period are warranted. This experiment evaluated the impacts of supplementing organic complexed Cu, Co, Mn, and Zn on productive and health responses of high-risk beef cattle during a 60-day backgrounding phase. Crossbred steers (120) were purchased at auction and transported to the experimental facility, where BW was recorded (day-1; initial shrunk BW = 227.7 ± 1.3 kg). On day 0, steers were ranked by BW and allocated to one of eight groups and housed in drylot pens equipped with GrowSafe automated feeding systems (Model 8000; two bunks/pen). Groups were randomly assigned to receive a total mixed ration containing: (1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 40); (2) organic complexed sources of the same minerals (AAC; Zinpro Availa 4 based on a metal:amino acid complex ratio of 1:1 for Zn, Cu, and Mn in addition to cobalt glucoheptonate; Zinpro Corp., Eden Prairie, MN; n = 40); or (3) AAC and an organic complexed trace mineral drench (APF; 30 mL/hd; Zinpro ProFusion, Zinpro Corp.) on day 0 and with morbidity treatment (n = 40). Diets provided the same daily amount of all nutrients and minerals based on 7 g/steer daily of Zinpro Availa 4. Steers were assessed for bovine respiratory disease (BRD) signs daily. Liver biopsies were performed on days 0, 28 and 60. Blood samples were collected on days 0, 2, 6, 10, 13, 21, 28 and 45. No treatment differences were detected (P ≥ 0.23) for feed intake, final BW, average daily gain, or BRD incidence. Mean liver Co concentrations were greater (P = 0.02) in AAC and APF compared to INR steers. Mean liver Cu was greater (P = 0.02) in APF compared to AAC steers. Liver Zn tended to be greater (P = 0.10) on day 28 but less (P = 0.05) on day 60 for INR compared to AAC and APF steers. Plasma cortisol was lowest (P = 0.05) for AAC steers on day 6, whereas AAC steers tended to have greater (P = 0.09) plasma cortisol on day 13 compared with APF. Plasma haptoglobin tended to be greater (P ≤ 0.10) for INR steers on days 28 and 45 compared to AAC and APF. While supplementing cattle with AAC or INR results in similar animal performance and clinical disease, AAC and APF reduce stress and acute phase protein responses.

Trace Mineral Supplementation of Beef Cattle in Pasture Environments

The United States Department of Agriculture defines pastureland as "A land cover/use category of land managed primarily for the production of introduced forage plants for livestock grazing." The purpose of this article is to review trace mineral supplementation for beef cattle in this environment. Supplementation of trace minerals in these environments is accomplished with the use of a trace mineralized salt or a complete mineral-vitamin product that contains macrominerals, trace minerals, and vitamins. The form of the supplement may influence uptake and utilization. Supplementation may be augmented with pulse dosing with injectables or oral products.

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.

Effects of copper, zinc, and manganese source and inclusion during late gestation on beef cow-calf performance, mineral transfer, and metabolism

To determine effects of Cu, Zn, and Mn source and inclusion during late gestation, multiparous beef cows [n = 48; 649 ± 80 kg body weight (BW); 5.3 ± 0.5 body condition score (BCS)] were individually-fed hay and supplement to meet or exceed all nutrient recommendations except Cu, Zn, and Mn. From 91.2 ± 6.2 d pre-calving to 11.0 ± 3.2 d post-calving, cows received: no additional Cu, Zn, or Mn (control, CON), sulfate-based Cu, Zn, and Mn (inorganic, ITM) or metal methionine hydroxy analogue chelates (MMHAC) of Cu, Zn, and Mn at 133% recommendations, or a combination of inorganic and chelated Cu, Zn, and Mn (reduce and replace, RR) to meet 100% of recommendations. Data were analyzed with treatment and breeding group (and calf sex if P < 0.25 for offspring measures) as fixed effects, animal as experimental unit, and sampling time as a repeated effect for serum, plasma, and milk measures over time. Post-calving cow liver Cu was greater (P ≤ 0.07) in MMHAC compared with all other treatments. Calves born to RR had greater (P ≤ 0.05) liver Cu than ITM and CON, and MMHAC had greater (P = 0.06) liver Cu than CON. Liver Mn was less (P ≤ 0.08) for RR calves than all other treatments. Calf plasma Zn was maintained (P ≥ 0.15) from 0 to 48 h of age in ITM and MMHAC but decreased (P ≤ 0.03) in CON and RR. Gestational cow BW, BCS, and metabolites were not affected (P ≥ 0.13) by treatment, but gestational serum thiobarbituric acid reactive substances (TBARS) were greater (P = 0.01) for CON than MMHAC. Treatment did not affect (P ≥ 0.13) calf birth size, vigor, placental size and minerals, or transfer of passive immunity. Neonatal calf serum Ca was greater (P ≤ 0.05) for MMHAC than all other treatments; other calf serum chemistry and plasma cortisol were not affected (P ≥ 0.12). Pre-suckling colostrum yield, and lactose concentration and content, were greater (P ≤ 0.06) for MMHAC compared with ITM and RR. Colostral triglyceride and protein concentrations were greater (P ≤ 0.08) for RR than MMHAC and CON. Cow lactational BW and BCS, milk yield and composition, and pre-weaning calf BW and metabolism were not affected (P ≥ 0.13) by treatment. Lactational serum TBARS were greater (P = 0.04) for RR than CON at day 35 and greater (P ≤ 0.09) for MMHAC at day 60 than all other treatments. Source and inclusion of Cu, Zn, and Mn altered maternal and neonatal calf mineral status, but calf size and vigor at birth, passive transfer, and pre-weaning growth were not affected in this study.

Copper chaperone antioxidant 1: multiple roles and a potential therapeutic target

Copper (Cu) was recently demonstrated to play a critical role in cellular physiological and biochemical processes, including energy production and maintenance, antioxidation and enzymatic activity, and signal transduction. Antioxidant 1 (ATOX1), a chaperone of Cu previously named human ATX1 homologue (HAH1), has been found to play an indispensable role in maintaining cellular Cu homeostasis, antioxidative stress, and transcriptional regulation. In the past decade, it has also been found to be involved in a variety of diseases, including numerous neurodegenerative diseases, cancers, and metabolic diseases. Recently, increasing evidence has revealed that ATOX1 is involved in the regulation of cell migration, proliferation, autophagy, DNA damage repair (DDR), and death, as well as in organism development and reproduction. This review summarizes recent advances in the research on the diverse physiological and cytological functions of ATOX1 and the underlying mechanisms of its action in human health and diseases. The potential of ATOX1 as a therapeutic target is also discussed. This review aims to pose unanswered questions related to ATOX1 biology and explore the potential use of ATOX1 as a therapeutic target.

Effects of feeding a vitamin and mineral supplement to cow-calf pairs grazing native range

Our objectives were to evaluate the impacts of providing vitamin and mineral (VTM) supplements to cow-calf pairs during the summer grazing period on cow and calf performance and liver concentrations of minerals. During a two-year period, 727 crossbred cows and their calves (initial cow BW = 601.7 ± 48.1 kg; calf BW = 87.8 ± 5.0 kg; n = 381 in year 1, n = 346 in year 2) from the Central Grasslands Research Extension Center (Streeter, N.D.) were blocked by parity (young [parity 1 to 3], and old [parity 4+]) and randomly assigned to pastures at the beginning of the grazing season (16 in year 1 and 14 in year 2). Pastures were assigned to receive a free-choice VTM supplement (SUPP) or no VTM supplement (CON) from pasture turnout to pasture removal (158 and 156 days in year 1 and 2, respectively). Consecutive day weights were taken from cows and calves at pasture turnout and removal and liver biopsies were collected from a subset of cows at both timepoints and from calves at weaning. Cows were bred via AI 37 to 41 d after pasture turnout and by natural service cleanup bulls for a 70 to 80 d breeding season. Calving and weaning data were collected from the calf conceived and gestated during treatments. Data were analyzed for the effect of VTM treatment (SUPP vs. CON), block of parity, and their interaction using the GLM procedure of SAS with pasture as the experimental unit. Year was considered a random effect in the final analysis. Cow pregnancy success was evaluated using the GLIMMIX procedure in SAS with model terms of VTM treatment, parity, and their interaction with year as a random effect. In year 2, cows in differing days postpartum (DPP) groups at pasture turnout (66.1, 48.8, and 34.5 ± 1.04 DPP for EARLY, MID, and LATE groups, respectively) were selected for liver biopsies with cow as the experimental unit. Cow and calf BW and BW change were not impacted (P ≥ 0.20) by VTM access. Pregnancy rate to AI, overall pregnancy rate, gestating calf birth BW and calving distribution were not affected (P ≥ 0.11) by treatment. Liver concentrations of Se, Cu, and Co were greater (P ≤ 0.002) at pasture removal and weaning for cows and suckling calves that had access to VTM. Cows considered EARLY calving had greater (P = 0.05) concentrations of liver Se compared with LATE calving cows. Although VTM supplementation enhanced concentrations of key minerals in the liver of cow-calf pairs, reproductive and growth performance was not affected.

Relative Bioavailability of Trace Minerals in Production Animal Nutrition: A Review

The importance of dietary supplementation of animal feeds with trace minerals is irrefutable, with various forms of both organic and inorganic products commercially available. With advances in research techniques, and data obtained from both in-vitro and in-vivo studies in recent years, differences between inorganic and organic trace minerals have become more apparent. Furthermore, differences between specific organic mineral types can now be identified. Adhering to PRISMA guidelines for systematic reviews, we carried out an extensive literature search on previously published studies detailing performance responses to trace minerals, in addition to their corresponding relative bioavailability values. This review covers four of the main trace minerals included in feed: copper, iron, manganese and zinc, and encompasses the different types of organic and inorganic products commercially available. Their impact from environmental, economic, and nutritional perspectives are discussed, along with the biological availability of various mineral forms in production animals. Species-specific sections cover ruminants, poultry, and swine. Extensive relative bioavailability tables cover values for all trace mineral products commercially available, including those not previously reviewed in earlier studies, thereby providing a comprehensive industry reference guide. Additionally, we examine reasons for variance in reported relative bioavailability values, with an emphasis on accounting for data misinterpretation.

Broiler responses to copper levels and sources: growth, tissue mineral content, antioxidant status and mRNA expression of genes involved in lipid and protein metabolism

BACKGROUND

Five hundred 8-d old male broilers Cobb500 were randomly allotted into 10 treatments in factorial arrangement with 5 Cu levels (0, 4, 8, 12, and 16 mg/kg), and 2 sources (Cu proteinate, CuPro and Cu sulphate, CuSO4.5H2O) for a 10-d-experiment.

RESULTS

Feed conversion ratio (FCR) was better (P < 0.05) in CuPro fed chicks compared with CuSO4.5H2O group. Average daily feed intake (ADFI) decreased linearly (P < 0.05) as dietary Cu increased. A quadratic response (P < 0.05) to Cu levels was found for FCR, being optimized at 9.87 and 8.84 mg Cu/kg in CuPro and CuSO4.5H2O diets, respectively. Copper supplementation linearly increased liver Cu content (P < 0.05) and tended to linearly increase (P = 0.07) phosphorus (P) and copper in tibia. Manganese and zinc were higher (P < 0.05) in tibia of CuPro fed birds. Broilers fed CuPro exhibited lower liver iron (P < 0.05) content, lower activities of Cu, Zn superoxide dismutase (CuZnSOD) in breast muscle and liver, and glutathione peroxidase in liver. Glutathione peroxidase reduced linearly (P < 0.05) with CuPro levels and increased linearly (P < 0.05) with CuSO4.5H2O levels and were lower (P < 0.05) in all CuPro levels in breast muscle. Breast muscle malondialdehyde concentration tended to be higher (P = 0.08) in broilers fed CuSO4.5H2O. Copper levels linearly increased (P < 0.05) metallothionein (MT) and malate dehydrogenase (MDH) expression in liver, and six-transmembrane epithelial antigen of the prostate-1 (STEAP-1) in the intestine. Copper elicited a quadratic response (P < 0.050) in AKT-1 and mammalian target of rapamycin (mTOR) in breast muscle, CuZnSOD in liver and antioxidant 1 copper chaperone (ATOX 1) in intestine. Broilers fed CuPro exhibited higher mRNA expression of mTOR in muscle breast and lower CuZnSOD in liver and ATOX 1 in intestine. Interaction (P < 0.05) between levels and sources was found in mRNA expression for GSK-3β, MT, and CuZnSOD in breast muscle, FAS and LPL in liver and MT and CTR1 in intestine.

CONCLUSIONS

CuPro showed beneficial effects on feed conversion and bone mineralization. Organic and inorganic Cu requirements are 9.87 and 8.84 mg Cu/kg, respectively.

Impact of Cell Culture and Copper Dose on Gene Expression in Bovine Liver

The objectives of these experiments were to investigate (1) the relative abundance of transcripts for Cu-responsive genes in whole bovine liver vs. cultured hepatocytes and (2) the influence of Cu dose on the relative abundance of transcripts for Cu-responsive genes in cultured bovine hepatocytes. Experiment 1: Liver samples were obtained immediately post-mortem from one healthy Angus steer. Half of the tissue samples were placed in RNAlater solution; the remaining half was used to isolate hepatocytes. Experiment 2: A subset of cultured hepatocytes was incubated in media containing: 0 mg/L, 0.10 mg/L, 1.0 mg/L, 10.0 mg/L, and 100 mg/L Cu for 1 h. Transcripts analyzed were aldehyde dehydrogenase (ALDH2), apolipoprotein A-1 (APOA1), antioxidant 1 (ATOX1), ATPase copper transporting alpha (ATP7A), ATPase copper transporting beta (ATP7B), betaine homocysteine methyltransferase (BHMT), flavin reductase (BLVRB), carbonic anhydrase II (CA2), copper chaperone for superoxide dismutase (CCS), cytochrome c oxidase copper chaperone (COX17), Cu transporter 1 (CTR1), glutamate dehydrogenase (GLUD1), glutathione synthetase (GSS), protein disulfide isomerase A3 (PDIA3), and superoxide dismutase (Cu-Zn) (SOD1). Β-Actin (ACTB) was selected as the endogenous control in both experiments. Experiment 1: Whole liver had greater (P < 0.01) relative abundance of mRNA for APOA1, ATOX1, ATP7A, ATP7B, COX17, CTR1, ALDH2, BHMT, BLVRB, CA2, GLUD1, and GSS when compared with cultured hepatocytes. Experiment 2: Copper dose impacted all identified transcripts. These results indicate that the relative abundance of Cu-responsive transcripts is different in whole vs. cultured hepatocytes and that the relative abundance of Cu-responsive genes is dependent on Cu dose in cultured hepatocytes.

Evaluation of the solubility of a range of copper sources and the effects of iron & sulphur on copper solubility under rumen simulated conditions

BACKGROUND

Antagonisms exist in vivo which inhibit copper bioavailability in ruminants. Although the antagonism between iron, sulphur and copper has been well observed in vivo in practice the mechanism by which it acts has not yet been elucidated, nor the compound it creates identified. This results in problems when trying to optimise supplementation to prevent the interaction from occurring or provide a copper source which is able to negate its effects. This work aims to establish if the antagonism between sulphur, iron and copper could be elicited under in vitro rumen replicated conditions and using a range of copper sources to investigate any differences in their participation in the interaction.

METHODS

Rumen simulated conditions were used to test solubility as a proxy for bioavailability of different copper sources. Sources from ionic, hydroxy and organic compounds were tested in de-ionised water and warmed, strained rumen fluid which mimicked duration, agitation, temperature and pH of the rumen.

RESULTS

All copper sources were less soluble in rumen fluid than in de-ionised water. The addition of sulphide, alone or as part of a sulphur mix with sulphate produced a pronounced reduction in solubility on each of the copper sources. The most soluble were the greatest affected.

CONCLUSION

There was no indication that an in insoluble compound containing copper and iron was formed under these conditions. The intricacy of the in vivo rumen is required to elicit the reaction between copper, iron and sulphur.

Effect of bis-glycinate bound zinc or zinc sulfate on zinc metabolism in growing lambs

To assess the efficacy of bis-glycinate bound Zn, 36 crossbred wethers (34 ± 2 kg) were sorted by body weight into three groups and stagger started on a Zn-deficient diet (18 mg Zn/kg dry matter [DM]; 22.5% neutral detergent fiber [NDF]) for 45 d prior to a 15-d metabolism period (10 d adaptation and 5 d collection). On day 46, lambs were randomly assigned to dietary treatments (four lambs treatment⁻¹group⁻¹): no supplemental Zn (CON) or 15 mg supplemental Zn/kg DM (ZINC) as Zn sulfate (ZS) or bis-glycinate (GLY; Plexomin Zn, Phytobiotics). Blood was collected from all lambs on days 1, 44, 56, and 61. Liver, jejunum, and longissimus dorsi samples were collected after euthanasia on day 61. Gene expression was determined via quantitative real-time polymerase chain reaction. Data were analyzed using ProcMixed of SAS (experimental unit = lamb; fixed effects = treatment, group, and breed) and contrast statements assessed the effects of supplemental Zn concentration (ZINC vs. CON) and source (GLY vs. ZS). After 15 d of Zn supplementation, plasma Zn concentrations were greater for ZINC vs. CON and GLY vs. ZS (P ≤ 0.01); tissue Zn concentrations were unaffected (P ≥ 0.27). Liver Cu concentrations were lesser for ZINC vs. CON (P = 0.03). Longissimus dorsi Mn concentrations were greater for ZINC vs. CON (P = 0.05) and tended to be lesser for GLY vs. ZS (P = 0.09). Digestibility of DM, organic matter (OM), and NDF was lesser for ZINC vs. CON (P ≤ 0.05); acid detergent fiber digestibility tended to be greater for GLY vs. ZS (P = 0.06). Nitrogen retention (g/d) tended to be greater for GLY vs. ZS (P = 0.10), and N apparent absorption was lesser for ZINC vs. CON (P = 0.02). Zinc intake, fecal output, retention, and apparent absorption were greater for ZINC vs. CON (P ≤ 0.01). Apparent absorption of Zn was −5.1%, 12.8%, and 15.0% for CON, ZS, and GLY, respectively. Nitrogen and Zn retention and apparent absorption were not correlated for CON (P ≥ 0.14) but were positively correlated for ZINC (retention: P = 0.02, r = 0.52; apparent absorption: P < 0.01, r = 0.73). Intestinal expression of Zn transporter ZIP4 was lesser for ZINC vs. CON (P = 0.02). Liver expression of metallothionein-1 (MT1) tended to be greater for GLY vs. ZS (P = 0.07). Although Zn apparent absorption did not differ between sources (P = 0.71), differences in post-absorptive metabolism may be responsible for greater plasma Zn concentrations and liver MT1 expression for GLY-supplemented lambs, suggesting improved bioavailability of GLY relative to ZS.

Expression of cardiac copper chaperone encoding genes and their correlation with cardiac function parameters in goats

Copper deficiency (CuD) is a common cause of oxidative cardiac tissue damage in ruminants. The expression of copper chaperone (Cu-Ch) encoding genes enables an in-depth understanding of copper-associated disorders, but no previous studies have been undertaken to highlight Cu-Ch disturbances in heart tissue in ruminants due to CuD. The current study aimed to investigate the Cu-Ch mRNA expression in the heart of goats after experimental CuD and highlight their relationship with the cardiac measurements. Eleven male goats were enrolled in this study and divided into the control group (n = 4) and CuD group (n = 7), which received copper-reducing dietary regimes for 7 months. Heart function was evaluated by electrocardiography and echocardiography, and at the end of the experiment, all animals were sacrificed and the cardiac tissues were collected for histopathology and quantitative mRNA expression by real-time PCR. In the treatment group, cardiac measurements revealed increased preload and the existence of cardiac dilatation, and significant cardiac tissue damage by histopathology. Also, the relative mRNA expression of Cu-Ch encoding genes; ATP7A, CTr1, LOX, COX17, as well as ceruloplasmin (CP), troponin I3 (TNNI3), glutathione peroxidase (GPX1), and matrix metalloprotease inhibitor (MMPI1) genes were significantly down-regulated in CuD group. There was a significant correlation between investigated genes and some cardiac function measurements; meanwhile, a significant inverse correlation was observed between histopathological score and ATP7B, CTr1, LOX, and COX17. In conclusion, this study revealed that CuD induces cardiac dilatation and alters the mRNA expression of Cu-Ch genes, in addition to TNNI3, GPX1, and MMPI1 that are considered key factors in clinically undetectable CuD-induced cardiac damage in goats which necessitate further studies for feasibility as biomarkers.

Supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn to beef cows during gestation: physiological and productive response of cows and their offspring until weaning

One hundred and ninety non-lactating, pregnant beef cows (three-fourth Bos taurus and one-fourth Bos indicus; 138 multiparous and 52 primiparous) were assigned to this experiment at 117 ± 2.2 d of gestation (day 0). Cows were ranked by parity, pregnancy type (artificial insemination = 102 and natural service = 88), body weight (BW), and body condition score (BCS) and assigned to receive a supplement containing: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or 2) an organic-complexed source of Cu, Mn, Co, and Zn (AAC; Availa 4; Zinpro Corporation, Eden Prairie, MN; n = 95). The INR and AAC provided the same daily amount of Cu, Co, Mn, and Zn, based on 7 g of the AAC source. From day 0 to calving, cows were maintained in a single pasture and were segregated three times weekly into 1 of the 24 individual feeding pens to receive treatments. Cow BW and BCS were recorded on days -30, 97, upon calving, and at weaning (day 367). Milk production was estimated at 42 ± 0.5 d postpartum via weigh-suckle-weigh (WSW) method. Liver biopsies were performed in 30 cows per treatment on days -30, 97, upon calving, and the day after WSW. Calf BW was recorded at birth and weaning. Liver and longissimus muscle (LM) biopsies were performed in 30 calves per treatment upon calving and 24 h later, the day after WSW, and at weaning. No treatment effects were detected (P ≥ 0.49) for cow BCS during gestation, despite AAC cows having greater (P = 0.04) BW on day 97. Liver Co concentrations were greater (P < 0.01) for AAC compared with INR cows, and liver concentrations of Cu were greater (P = 0.02) for INR compared with AAC cows on day 97. Upon calving, INR cows had greater (P ≤ 0.01) liver Cu and Zn concentrations compared with AAC cows. No other treatment differences were noted (P ≥ 0.17) for cow and calf liver trace mineral concentrations. Cows receiving AAC had greater (P = 0.04) hepatic mRNA expression of metallothionein 1A at calving, and their calves had greater (P = 0.04) hepatic mRNA expression of superoxide dismutase at weaning. Milk production did not differ between AAC and INR cows (P = 0.70). No treatment effects were detected (P ≥ 0.29) for mRNA expression of LM genes associated with adipogenic or muscle development activities in calves at birth and weaning. Calf birth and weaning BW also did not differ (P ≥ 0.19) between treatments. In summary, supplementing AAC or INR to beef cows during the last 5 mo of gestation yielded similar cow-calf productive responses until weaning.

Differences in copper and selenium metabolism between Angus (Bos taurus) and Brahman (Bos indicus) cattle

A 2-yr study was conducted at the Range Cattle Research and Education Center, University of Florida - Institute of Food and Agricultural Sciences (IFAS) (Ona, FL), to evaluate differences in the metabolism of Cu and Se of Angus (Bos taurus) and Brahman (Bos indicus) cattle. Thirty-two pregnant beef cows (n = 8 Brahman and 8 Angus/yr) were enrolled in the study in the first trimester of gestation. This study consisted of three phases: 1) restriction (day 0 to 90), 2) supplementation (day 91 to 150), and 3) calving. During all three phases, cows were individually fed and housed in partially covered drylot pens. During the restriction and supplementation phases, cows were provided a 1.5 kg/d of a grain-based concentrate supplement, which was fortified with flowers of S (50 g of supplemental S/cow daily; restriction phase) or Cu and Se (100 and 3 mg/d of Cu and Se, respectively; supplementation phase). Blood and liver samples were collected from all cows at 30 d intervals and from both cows and calves within 24 h of calving. Colostrum and milk samples were collected at calving and 7 d after birth. All data were analyzed using the MIXED procedure of SAS, where cow and calf were the experimental unit. During the restriction phase, a breed × day effect (P = 0.03) was observed where Brahman had greater liver Cu concentration than Angus cows in all sampling days. For liver Se concentration, a tendency (P = 0.07) for a breed effect was observed where Angus cows tended to have greater liver Se concentration than Brahman. During the supplementation phase, breed (P < 0.001) and day (P < 0.01) effects were observed, where Brahman cows had greater liver Cu concentration than Angus. For liver Se concentration, a day effect (P < 0.001) was observed, where liver Se concentration increased (P < 0.001) from day 90 to 120 and remained unchanged (P = 0.86) until day 150. At calving, no effects of breed (P = 0.34) were observed for liver Cu concentration of cows; however, Brahman calves tended (P = 0.09) to have greater liver Cu concentration than Angus calves. For Se liver concentration at calving, Angus cows tended (P = 0.07) to have greater liver Se concentration than Brahman cows; however, no breed differences (P = 0.70) were observed for liver Se concentration of calves at birth. In summary, substantial differences in multiple indicators of Cu and Se status were observed between Angus and Brahman cattle, implying that Angus and Brahman cattle possibly have different mechanisms to maintain adequate Cu and Se status.

Impacts of Bovine Trace Mineral Supplementation on Maternal and Offspring Production and Health

Nutritional status can have major implications for animal health and production. Energy balance is easily determined using a body condition scoring system. This allows producers to readily adjust diets to meet an animal's needs. Far less obvious is an animal's trace mineral status, which is typically not assessed until an animal's performance falls below expectation or illness is detected. Trace mineral toxicities and deficiencies can manifest as reduced thriftiness and/or poor reproductive performance, resulting in economic consequences for producers. Maternal mineral status not only impacts dam heath, but also the health of subsequent offspring. Both the oocyte and embryo are susceptible to changes in maternal mineral status. This susceptibility is maintained throughout fetal development via placental control of nutrient transfer to the fetal system. Furthermore, maternal mineral status continues to impact offspring health via colostrum and milk quality. Herein we discuss the roles of trace minerals in bovine reproductive performance, maternal health, colostrum and milk quality, and offspring health.

Copper Supplementation, A Challenge in Cattle

Ensuring adequate copper supplementation in ruminants is a challenging task due to the complexity of copper metabolism in these animals. The three-way interaction between copper, molybdenum and sulphur (Cu-Mo-S) in the rumen makes ruminants, particularly cattle, very susceptible to suffering from secondary copper deficiency. Paradoxically, excessive copper storage in the liver to prevent deficiency becomes a hazard when ruminants are fed copper-supplemented diets even slightly above requirements. While cattle were traditionally thought to be relatively tolerant of copper accumulation, and reports of copper poisoning were until recently somewhat rare, in recent years an increased number of episodes/outbreaks of copper toxicity in cattle, particularly in dairy cattle, have been reported worldwide. The growing number of lethal cases reported seems to indicate that copper intoxication is spreading silently in dairy herds, urging the development of strategies to monitor herd copper status and improve farmers' awareness of copper toxicity. In fact, monitoring studies carried out on numerous samples collected from culled animals in slaughterhouses and/or diagnostic laboratories have demonstrated that large numbers of animals have hepatic copper concentrations well above adequate levels in many different countries. These trends are undoubtedly due to copper supplementation aimed at preventing copper deficiency, as dietary copper intake from pasture alone is unlikely to cause such high levels of accumulation in liver tissue. The reasons behind the copper overfeeding in cattle are related both to a poor understanding of copper metabolism and the theory of "if adding a little produces a response, then adding a lot will produce a better response". Contrary to most trace elements, copper in ruminants has narrow margins of safety, which must also be formulated considering the concentrations of copper antagonists in the diet. This review paper aims to provide nutritionists/veterinary practitioners with the key points about copper metabolism in cattle to guarantee an adequate copper supply while preventing excessive hepatic copper loading, which requires à la carte copper supplementation for each herd.

The influence of dietary energy and zinc source and concentration on performance, trace mineral status, and gene expression of beef steers

The objective of this study was to determine the effects of increased supplemental Zn from differing sources on growth performance of steers fed diets differing in net energy. Angus steers (n = 72, 324 ± 2.1 kg) with Genemax gain scores of 3, 4, or 5 were blocked by BW and stratified by Genemax gain score into 12 pens of 6 steers each for 158 d. Pens were randomly assigned to 1 of 3 Zn treatments (ZNTRT): 1) control (no supplemental Zn, analyzed 33 mg Zn/kg DM; CON); 2) inorganic Zn (CON + 120 mg supplemental Zn/kg DM as ZnSO₄ for entire trial; INZN); or 3) 120 mg supplemental Zn/kg DM as Zn-amino acid complex (Availa-Zn; Zinpro, Eden Prairie, MN) for first 60 d, then a blend of ZnSO₄ and Zn-AA complex (CON + 60 mg supplemental Zn/kg DM as ZnSO₄ + 60 mg supplemental Zn/kg DM as Zn-amino acid complex) for the remainder of the trial (ZNBLD). Two dietary energy strategies (ENERGY) were formulated to reach ADG rates of 1) 1.6 kg/d (LE) or 2) 2.0 kg/d (HE) utilizing a 3 × 2 factorial arrangement (12 steers/treatment). All steers were fed LE for a 60 d growing period, then pens were randomly assigned to ENERGY treatments fed the remaining 91 d. Day 60 BW tended to be greater (P = 0.07) in steers receiving supplemental Zn vs. CON. Liver Cu was decreased in Zn supplemented steers vs. CON (P = 0.02). Liver Zn concentrations on d 56 did not differ for Zn vs. CON (P = 0.22) nor were there differences due to Zn source (P = 0.98). There were or tended to be ZNTRT × ENERGY effects for d 67-90 ADG and G:F (P ≤ 0.01), and d 122 BW and d 90-122 G:F (P ≤ 0.10) driven by improved performance for ZNBLD-HE over ZNBLD-LE, while ENERGY within CON and INZN did not differ. Day 90-122 ADG, overall ADG and overall G:F was greater (P ≤ 0.02) and d 67-90 G:F tended to be greater (P = 0.10) for HE vs. LE. No ZNTRT × ENERGY or ZNTRT effects were detected for HCW, REA, BF, KPH, MS, or YG (P ≥ 0.37) while HE increased HCW, BF, MS, and YG compared with LE (P ≤ 0.05). In the liver, ZNTRT affected d 97 MT1A expression (P = 0.03) where INZN was greater than ZNBLD or CON (P ≤ 0.02), while ZIP14 was unaffected due to ZNTRT, ENERGY, or the interaction (P ≥ 0.39). Supplying supplemental Zn as ZNBLD during the transition period appeared to improve performance measures, but no final performance advantages were noted due to increased supplemental Zn, regardless of source. Additionally, differences in liver MT1A expression may indicate differing post-absorptive metabolism between Zn sources.

Copper physiology in ruminants: trafficking of systemic copper, adaptations to variation in nutritional supply and thiomolybdate challenge

Ruminants are recognised to suffer from Cu-responsive disorders. Present understanding of Cu transport and metabolism is limited and inconsistent across vets and veterinary professionals. There has been much progress from the studies of the 1980s and early 1990s in cellular Cu transport and liver metabolism which has not been translated into agricultural practice. Cu metabolism operates in regulated pathways of Cu trafficking rather than in pools of Cu lability. Cu in the cell is chaperoned to enzyme production, retention within metallothionein or excretion via the Golgi into the blood. The hepatocyte differs in that Cu-containing caeruloplasmin can be synthesised to provide systemic Cu supply and excess Cu is excreted via bile. The aim of the present review is to improve understanding and highlight the relevant progress in relation to ruminants through the translation of newer findings from medicine and non-ruminant animal models into ruminants.

Microelements in seminal and serum plasma are associated with fresh semen quality in Yorkshire boars

This study aimed to explore associations between semen quality and trace element level in serum and seminal plasma in Yorkshire boars. Semen quality of 112 Yorkshire boars was assessed for 13 weeks to calculate semen utilization rate, which was then divided into three categories: low utilization rate group (LG, < 60% utilization rate), medium utilization rate group (MG, 60-80%), and high utilization rate group (HG, > 80%). After grouping, serum and seminal plasma samples of selected boars were collected to determine concentrations of 10 elements including Ca, Mg, Cu, Fe, Zn, Mn, Se, Cr, Pb and Cd using inductively coupled plasma mass spectrometry. Results showed the increase of semen utilization rate was accompanied by the increase of sperm motility and the decrease of abnormal sperm rate among three groups (P < 0.01). Serum Fe concentration in LG boars was lower than that in HG boars (P < 0.05). Regression analysis revealed serum Fe concentration was positively correlated with sperm motility (r = 0.251; P < 0.05), while negatively correlated with abnormal sperm rate (r = -0.207; P < 0.05). However, MG and HG boars had lower serum Se concentration than LG boars (P < 0.05), and serum Se concentration contribution to sperm motility varied in a quadratic manner (Sperm motility = -0.0004 Se_(serum)² +0.136 Se+74.06; r = 0.300; P < 0.01). Semen utilization rate tended to decrease with the increase of seminal plasma Pb concentration (P = 0.09). Regression analysis exhibited seminal plasma Pb negatively related to sperm motility (r = -0.237; P < 0.05), while positively correlated with abnormal sperm rate (r = 0.237; P < 0.05). Furthermore, seminal plasma Pb was the most influential factor among trace element in serum and seminal plasma on sperm motility basing on the generalized linear model analysis (P < 0.05). Sperm motility decreased by approximately 3.47% when seminal plasma Pb concentration increased from 0 μg/L to 11.16 μg/L. In conclusion, deficiency of serum Fe reduces semen utilization rate by impairing sperm motility and morphology, whereas excessive serum Se decreases sperm motility. More importantly, the mere existence of seminal plasma Pb has more impact on semen quality than other trace elements in serum and seminal plasma in Yorkshire boars.

Pyrosequencing reveals diverse fecal microbiota in Simmental calves during early development

From birth to the time after weaning the gastrointestinal microbiota of calves must develop into a stable, autochthonous community accompanied by pivotal changes of anatomy and physiology of the gastrointestinal tract. The aim of this pilot study was to examine the fecal microbiota of six Simmental dairy calves to investigate time-dependent dynamics of the microbial community. Calves were followed up from birth until after weaning according to characteristic timepoints during physiological development of the gastrointestinal tract. Pyrosequencing of 16S rRNA gene amplicons from 35 samples yielded 253,528 reads clustering into 5410 operational taxonomic units based on 0.03 16S rRNA distance. Operational taxonomic units were assigned to 296 genera and 17 phyla with Bacteroidetes, Firmicutes, and Proteobacteria being most abundant. An age-dependent increasing diversity and species richness was observed. Highest similarities between fecal microbial communities were found around weaning compared with timepoints from birth to the middle of the milk feeding period. Principal coordinate analysis revealed a high variance particularly in samples taken at the middle of the milk feeding period (at the age of approximately 40 days) compared to earlier timepoints, confirming a unique individual development of the fecal microbiota of each calf. This study provides first deep insights into the composition of the fecal microbiota of Simmental dairy calves and might be a basis for future more detailed studies.

Evaluation of bioaccumulation and toxic effects of copper on hepatocellular structure in mice

The present study was to evaluate the hepatotoxicity effects in mice exposed to copper (Cu) used as dietary supplements for 95 days. Cu-treated mice showed increased body weight, and no toxic symptoms were observed at the beginning, but the tendency gradually changed with progress of experiment. In the liver, beneficial metals [Cu, iron (Fe), zinc (Zn), manganese (Mn), and molybdenum (Mo)] were analyzed by flame atomic absorption spectrometry. The content of Cu maintained at the same level during the experiments, but not resulting in the imbalance of Fe, Zn, Mn, and Mo being distributed. The activities of alkaline phosphatase (AKP) and super oxidation dismutase (SOD) showed significantly improvement during the first 30 days in Cu-supplemented group (P<0.01) but declined rapidly from 30th to 60th days, and later, they stabilized and were not statistically significant compared with control (P>0.05). No statistically significant correlation of ceruloplasmin (CPL) activity was appreciated during the experiment. The histopathological and ultrastructural abnormalities changes were observed in the liver of mice including vacuolar degeneration, necrosis, karyorrhexis, and endolysis. Many hepatocytes showed increased collagenic fibers, appearance of triglyceride droplets, and swollen mitochondria due to oral route of copper, which may lead to lipid peroxidation and free radicals. In conclusion, our study showed that exposure to copper influenced behavioral pattern and body weight, affected several enzymatic activities, and led to the physiological and considerable structural changes in the liver of mice. The public should pay more attention to avoid being exposed to copper.

In-feed use of heavy metal micronutrients in U.S. swine production systems and its role in persistence of multidrug-resistant salmonellae

The study aimed to characterize the role of heavy metal micronutrients in swine feed in emergence of heavy-metal-tolerant and multidrug-resistant Salmonella organisms. We conducted a longitudinal study in 36 swine barns over a 2-year period. The feed and fecal levels of Cu(2+) and Zn(2+) were measured. Salmonella was isolated at early and late finishing. MICs of copper sulfate and zinc chloride were measured using agar dilution. Antimicrobial susceptibility was tested using the Kirby-Bauer method, and 283 isolates were serotyped. We amplified pcoA and czcD genes that encode Cu(2+) and Zn(2+) tolerance, respectively. Of the 283 isolates, 113 (48%) showed Cu(2+) tolerance at 24 mM and 164 (58%) showed Zn(2+) tolerance at 8 mM. In multivariate analysis, serotype and source of isolates were significantly associated with Cu(2+) tolerance (P < 0.001). Fecal isolates were more likely to be Cu(2+) tolerant than those of feed origin (odds ratio [OR], 27.0; 95% confidence interval [CI], 2.8 to 250; P = 0.0042) or environmental origin (OR, 5.8), implying the significance of gastrointestinal selective pressure. Salmonella enterica serotypes Typhimurium and Heidelberg, highly significant for public health, had higher odds of having >20 mM MICs of Cu(2+) than did "other" serotypes. More than 60% of Salmonella isolates with resistance type (R-type) AmStTeKm (32 of 53) carried pcoA; only 5% with R-type AmClStSuTe carried this gene. czcD gene carriage was significantly associated with a higher Zn(2+) MIC (P < 0.05). The odds of having a high Zn(2+) MIC (≥8 mM) were 14.66 times higher in isolates with R-type AmClStSuTe than in those with R-type AmStTeKm (P < 0.05). The findings demonstrate strong association between heavy metal tolerance and antimicrobial resistance, particularly among Salmonella serotypes important in public health.

NutriPhysioGenomics applications to identify adaptations of cattle to consumption of ergot alkaloids and inorganic versus organic forms of selenium: altered nutritional, physiological and health states?

NutriPhysioGenomics (NPG) seeks to measure nutrition-responsive genome expression during specific physiological states, thus defining how a given challenge alters the ‘basal’ transcriptome. Application of NGS regimens (transcriptome and bioinformatics analyses) in combination with targeted-gene approaches has revealed cellular mechanisms putatively responsible for complex, whole-animal, metabolic syndromes such as heat stress and subacute ruminal acidosis. Using similar approaches, our laboratory sought to understand how the basal physiology of developing cattle adapted to two prevalent health challenges of forage-based beef cattle production in south-eastern USA: fescue toxicosis and selenium (Se) deficiency. In Model 1, pituitary and hepatic genomic expression profiles of growing beef steers grazing high (E+, n = 9) versus low (E–, n = 10) endophyte-infected tall fescue pastures for 85 days, and consuming sodium selenite (ISe) as a free-choice Se supplement, were compared by a combination of microarray, bioinformatic, and targeted-gene/protein (real-time reverse transcription–PCR, Nanostring, immunoblot) analyses. In Model 2, hepatic genomic expression profiles of growing beef heifers (0.5 kg gain/day) fed a cotton seed hull-based diet and different sources (n = 9) of dietary Se (3 mg/day) supplements (no supplement, Control; inorganic Se, sodium selenite, ISe; organic Se, Sel-Plex; OSe), or a 1.5 mg : 1.5 mg blend of ISe and OSe, MIX) were compared after 168 days of supplementation, as described for Model 1. The results for Model 1 showed, that in the pituitary of E+ steers, expression of genes for prolactin signalling; redox capacity; regulation of lactotroph, gonadotroph, and thyrotroph proliferation; gonadotropin-releasing hormone-mediated signalling; and Se-based metabolism was impaired. Concomitantly, the livers of E+ steers had an increased level of expression of genes encoding proteins responsible for shunting of amino acid carbons into pyruvate and ATP synthesis capacity (oxidative phosphorylation pathway, mitochondrial mass), increased serine and proline biosynthesis, and reduced selenoprotein-mediated metabolism. Result for Model 2 showed that, overall, there were clear differences in the profiles of differentially expressed genes (DEG) among the four Se treatment groups, with the form of Se administered being more reflective of DEG profiles than the total amount of Se assimilated. Moreover, hepatic transcriptomes profiles of MIX heifers revealed an increased potential for selenoprotein synthesis and selenoprotein-mediated metabolism. In addition, several genes involved with increased redox capacity were upregulated in MIX versus ISe heifers. Taken together, our NGS approach characterised adaptation to physiological challenges and, serendipitously, identified suppression of several metabolic pathways by consumption of ergot alkaloid consumption that have the potential to be increased with supplementation of the MIX form of Se.