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The present study compared the net intestinal absorption of zinc (Zn) and copper (Cu) after meals containing different dietary ratios among these trace elements. Ten 46-kg pigs were used in a cross-over design to assess the 10-h net portal-drained viscera (PDV) flux of serum Cu and Zn after ingestion of boluses containing ZnSO4 and CuSO4 in different Zn:Cu ratios (mg:mg): 120:20; 200:20; 120:8; and 200:8. Arterial Zn concentrations peaked within the first hour post-meal and responses were greater with 200 (0.9 to 1.8 mg/L) than with 120 mg (0.9 to 1.6 mg/L) of dietary Zn (dietary Zn × time, P = 0.05). Net PDV flux of Zn was greater (P = 0.02) with 200 than with 120 mg of dietary Zn and tended to be greater (P = 0.10) with 20 than with 8 mg of dietary Cu. The cumulative PDV appearance of Zn (% of dietary intake) was greater with 120 than 200 mg of dietary Zn from 8 h post-meal (P ≤ 0.04) and with 20 than 8 mg of dietary Cu from 7 h post-meal (P ≤ 0.05). At the end of the postprandial period (10 h), estimated PDV appearance of Zn was 16.0%, 18.4%, 12.0%, and 15.3% of Zn intake for 120:8, 120:20, 200:8, and 200:20 ratios, respectively. For Cu, irrespective of treatment, arterial values varied (P < 0.01) by less than 5% across postmeal times. Net PDV flux was not affected by treatments (P ≥ 0.12), but the value for ratio 120:20 was different from zero (P = 0.03). There was an interaction dietary Zn × dietary Cu on cumulative PDV appearance of Cu (% of dietary intake) at 30 min post-meal (P = 0.04) and thereafter at 3 h post-meal (P = 0.04). For the whole postprandial period (10 h), estimated PDV appearance of Cu was 61.9%, 42.1%, −17.1%, and 23.6% of Cu intake for 120:8, 120:20, 200:8, and 200:20 ratios, respectively. In conclusion, the present dietary amounts and ratios of Zn and Cu can affect the metabolic availability of both trace minerals for pigs. Ratios with 120 mg of dietary Zn maximized the postintestinal availability of both Zn and Cu.

A total of 2,430 pigs (PIC 337 × 1050; Hendersonville, TN; initially 30.1 kg) were used in a 113-d growth trial to determine the effects of increasing dietary Zn on growth performance and carcass characteristics of finishing pigs raised under commercial conditions. Pens of pigs were assigned to be fed one of five dietary treatments in a randomized complete block design. Treatments consisted of 50, 87.5, 125, 162.5, or 200 mg/kg added Zn from Zn hydroxychloride (IntelliBond Z, Micronutrients, Indianapolis, IN). Two identical barns were used for a total of 18 pens per treatment with 27 pigs per pen. Experimental diets were fed in five phases and contained a vitamin-trace mineral premix without added Zn. Pens of pigs were weighed approximately every 2 wk to calculate average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F). At the end of the experimental period, pigs were tattooed with a pen identification number and transported to a packing plant to measure hot carcass weight (HCW), backfat, loin depth, and calculated lean percentage. Data were analyzed block nested within barn as a random effect and pen as the experimental unit. From days 0 to 42, pigs fed diets with increasing added Zn had lower (linear, P = 0.043) ADFI and a tendency (P = 0.092) for lower ADG. From days 42 to 113, increasing added Zn resulted in a quadratic response (P = 0.042) for ADFI and a tendency (linear, P = 0.056) for improved G:F. Overall (days 0 to 113), there were tendencies for quadratic responses for ADFI (P = 0.073) and G:F (P = 0.059), with the greatest G:F observed when 125 mg/kg of Zn was fed. Increasing added Zn resulted in a linear increase (P < 0.001) in daily Zn intake. There were no differences (P > 0.10) in overall ADG, final body weight, HCW, backfat, loin depth, lean percentage, mortality, and removal rate. In conclusion, there were no improvements in ADG when feeding beyond 50 mg/kg added Zn; however, providing 125 mg/kg added Zn resulted in the greatest G:F.

This study evaluated the effects of lipopolysaccharide (LPS) injection on the immune response over a 24-h period in nursery pigs. Pigs consumed corn-soybean meal-based diets with added pharmacological levels of ZnO (d 0–14) and CuSO4 (d 14–23). On d 23, thirty pigs were randomly blocked based on BW and sex to one of five-time points (h 0 baseline, 3, 6, 12, and 24 post-challenge) and injected with a single i.m. LPS (O55:B5) at 12 μg/kg BW. At each time point, BW, rectal temperature (RT), and blood samples (n = 30, 24, 18, 12, and 6 per time point, respectively) were collected before one block (n = 6) was euthanized for liver and duodenum collection. Tissue samples were quantified for interleukin-6 (IL-6), zinc transporters (duodenal Zip4 and hepatic Zip14), and metallothionein-1 (MT-1) mRNA expression. Data were analyzed using PROC GLIMMIX of SAS with pig as the experimental unit. Following LPS, RT increased from h 0 to 6 (P < 0.05), and serum TNF-α increased from h 0 to 3 (P < 0.0001). Serum zinc and copper decreased (P < 0.01) from h 0 to 6, and h 0 to 12, respectively. Serum C-reactive protein tended to increase linearly following LPS (P = 0.10). LPS upregulated duodenal Zip4 and MT-1 (P < 0.05) at h 12 and 24, respectively, while all hepatic genes increased (P < 0.01) at h 3 post-challenge. Duodenal IL-6 did not change over time (P > 0.05). Quantification of mRNA expression displayed a positive correlation (P < 0.01) among hepatic IL-6, Zip14, and MT-1 in pairwise comparisons. In summary, LPS challenge induces fever and hepatic inflammation with consequent increases in hepatic and duodenal zinc importers, and their metal-binding protein, along with decreases in serum zinc and copper concentrations. However, our data indicate that pigs recover within 24-hour post-challenge.

The objectives of the current research are to quantify the effects that increased dietary Zn during late gestation and early lactation has on ewe and progeny body weights, serum and milk minerals, and somatic cell count. Within Rambouillet (WF) and Hampshire (BF) breeds, ewes were ranked by BW and randomly assigned down the rank into 1 of 2 treatment groups: Control (n = 34, 37 mg Zn/kg DM, ≈1×NRC) and Zn treatment (n = 37, 113 mg Zn/kg DM, ≈3×NRC). Treatments were delivered via a ZnSO4-fortified alfalfa pellet fed at a rate of 0.45 kg/d DM from a RFID-activated automated feeder from d 108 ± 10 of gestation to d 30 post-lambing. Ewe BW were recorded at d 0, 29, lambing, 30 post-lambing, and weaning. Lamb BW was recorded at lambing, d 15, 30, and weaning. Serum samples were taken from ewes and lambs at 18 ± 4 h post-lambing and analyzed for mineral concentrations. Maternal trace mineral transfer efficiency were calculated by dividing lamb serum values by their respective dam’s serum value and expressed as a percentage. Ewe milk was collected twice weekly. Milk was analyzed for mineral content (d 0, 10, and 30 of lactation) and SCC (d 3–5, 6–9, 10–12, 13–16, 17–19, 20–23, 24–26, 27–29, or 30–32). Ewe and lamb BW was not influenced by Zn treatment (P > 0.19). Ewe serum Zn and maternal transfer efficiency did not differ between control and Zn treatment ewes (P ≥ 0.47). There was a treatment × breed type interaction for lamb serum LogZn (P = 0.04), where BF lambs within Zn treatment had greater serum LogZn (0.63 ± 0.32) than WF lambs (-0.37 ± 0.27; P = 0.04), but breeds did not differ within lambs in the Control treatment group. Milk Ni and Zn was greater for Zn treated ewes than control ewes (P < 0.01), but Mg and P concentrations were greater for control ewes (P ≤ 0.02). Control and Zn treated ewes did not differ in LogSCC through the first 30 d of lactation (P = 0.68) nor did they differ at weaning (P = 0.48). White face and BF ewes LogSCC did not differ at weaning (P = 0.09), but for the first 30 d of lactation BF (5.79 ± 0.06) had greater LogSCC than WF ewes (5.54 ± 0.06; P < 0.01). Day of lactation impacted ewe SCC (P < 0.01), with peak SCC between d 6 and 9 which began to decline as lactation progressed. Current Zn recommendations appear to be adequate for ewe and lamb growth during late gestation and early lactation, but results suggest litter size and breed nuances. Milk Zn is also increased with dietary Zn above NRC recommendations, while further interactions with milk Ni, Mg, and P occur. Additionally, longitudinal values of SCC throughout lactation may inform preventative intervention strategies for cases of sub-clinical mastitis since peak SCC is within the first 9 d post-lambing.

This study evaluated the impact of supranutritional levels of dietary zinc oxide (ZnO) on zinc (Zn), copper (Cu), and iron (Fe) homeostasis in post-weaned pigs. One hundred twenty piglets were selected at d14 of age (5.65 ± 0.68 kg). At weaning (d21), they were fed a basal post-weaning diet (without antibiotics) supplemented (n = 40/treatment) with 100 mg/kg (low; LZn), 1000 mg/kg (medium; MZn) or 3000 mg/kg (high; HZn) of ZnO until d42. Dietary levels of Cu (130 mg/kg) and Fe (260 mg/kg) remained constant throughout the experimental period. Piglets were sacrificed at d21, d23, d35, and d42 of age (n = 10/treatment/d) for samples collection. Serum concentrations and total liver content of Zn and Cu were not different among treatments on d21 and d23 (P ≥ 0.10). For Zn, treatment effects were detected at d35 and d42 (P < 0.01) on both serum concentration and total Zn content in liver. For both parameters, values were greatest for HZn, intermediary for MZn, and lowest for LZn irrespective of ages in the two periods. For Cu, treatment effects were detected at d35 and d42 (P < 0.01) on both serum concentration and total Cu content in liver. For both parameters, values were greatest for LZn and MZn and lowest for HZn irrespective of ages. For Fe, no treatment effect was detected either on whole blood Fe concentrations (P = 0.81) or hemoglobin levels (P = 0.76). However, for total Fe content in liver, treatment effects were detected (P < 0.01). Values were greatest for LZn and lowest for HZn at d35 and d42 whereas for MZn they were intermediary at d35 and similar to LZn at d42 (P ≤ 0.01). In conclusion, supranutritional levels of dietary ZnO fed to piglets during 3 weeks post-weaning significantly impacted Zn, Cu, and Fe homeostasis. These results emphasise the potential risk of Cu deficiency as well as impairment in building body Fe reserves under long-term supranutritional supplementation of ZnO.

A total of 320 finishing pigs (PIC 327 × 1050; initially 98 kg) were used to determine the effects of adding Zn to diets containing ractopamine HCl (RAC) on muscle fiber type distribution, fresh chop color, and cooked meat characteristics. Dietary treatments were fed for approximately 35 d and consisted of a corn-soybean meal-based negative control (CON), a positive control diet with 10 mg/kg of RAC (RAC+), and the RAC+ diet plus 75, 150, or 225 mg/kg added Zn from either ZnO or Availa-Zn. Loins randomly selected from each treatment (n = 20) were evaluated using contrasts: CON vs. RAC+, interaction of Zn level × source, Zn level linear and quadratic polynomials, and Zn source. There were no Zn source effects or Zn source × level interactions throughout the study (P > 0.10). Pigs fed RAC+ had increased (P 0.07). In conclusion, RAC+ diets produced chops that were lighter and less red but maintained a greater percentage of surface oxymyoglobin throughout a 5-d simulated retail display. Ractopamine reduced MRA at the end of the display period, but supplementing Zn to RAC diets restored MRA to near CON treatment levels at the end of the display period.

Zinc is a trace element known to be an essential nutrient for life. It functions as a cofactor for numerous enzymes, including those involved in DNA and RNA replication and protein synthesis. Soldiers represent a unique population faced with intense metabolic and mental demands, as well as exposure to various immune challenges. Some of these factors may affect their dietary zinc requirements. Although severe zinc deficiency is unlikely to occur, some soldiers may experience less than optimal zinc status because of diminished intake coupled with increased requirements. For those soldiers, supplemental dietary zinc may serve a protective function in numerous disease states affecting modern warfighters. This review highlights the importance of adequate zinc nutriture to soldiers and discusses the potential benefits of supplemental zinc in a number of diseases currently affecting soldiers, including diarrhea, respiratory diseases, malaria, and leishmaniasis.

Two 28-d randomized complete block design experiments were conducted to evaluate the effects of concentrations and sources of Zn on growth performance of nursery pigs. Seven stations participated in Exp. 1, which evaluated the efficacy of replacing 2,500 ppm of Zn from ZnO with 125, 250, or 500 ppm of Zn from Zn methionine. A control diet with 125 ppm of supplemental Zn was included at all stations. A total of 615 pigs were used in 26 replicates. Average weaning age was 20.6 d and the average initial BW was 6.3 kg. There were no differences in any growth response among the three supplemental Zn methionine levels fed in Exp. 1. Zinc supplementation from Zn methionine improved ADG compared with the control during all phases (P < 0.05), due primarily to an increase in ADFI. Pigs fed 2,500 ppm of Zn from ZnO gained faster (P < 0.01) than those fed the control diet during all phases, and faster (P < 0.05) than those fed supplemental Zn from Zn methionine for the 28-d experiment. Differences in gain were again due mainly to differences in feed intake. A second experiment compared five sources of supplemental organic Zn (500 ppm of Zn) with 500 and 2,000 ppm supplemental Zn from ZnO and a control (140 ppm total Zn). Six stations used a total of 624 pigs, with an average weaning age of 20.4 d and averaging 6.2 kg BW in 15 replicates. Pigs fed 2,000 ppm of Zn from ZnO gained faster (P < 0.05) than pigs fed the control or any of the 500 ppm of Zn treatments (ZnO or organic Zn). Pigs fed the 2,000 ppm of Zn from ZnO also consumed more feed than those receiving 500 ppm of Zn from ZnO or from any of the organic Zn sources (P < 0.05). Organic sources of Zn did not improve gain, feed intake, or feed efficiency beyond that achieved with the control diet. Supplemental Zn at a concentration of 500 ppm, whether in the form of the oxide or in an organic form, was not as efficacious for improved ADG as 2,000 to 2,500 ppm of Zn from ZnO.

The main objective of this study was to describe Holstein neonatal growth and development as influenced by dietary zinc supplementation and the CD18 genotype, both of which may affect immune com- petence. Holstein calves (n = 421), after being fed colos- trum, were brought to a calf facility, randomly assigned to one of four zinc supplementation groups (control at 40 mg Zn/kg DM or the control diet supplemented with an additional 60 mg Zn/kg DM provided as either zinc sulfate, zinc lysine, or zinc methionine), weighed, and measured for morphometric growth parameters. Mea- surements were repeated at 30, 60, and 90 d. Calves were also genotyped for the presence of the mutant D128G CD18 allele, which, if present in two copies

Citation: Jordan, K. E., Gourley, K. M., Tokach, M. D., Goodband, R. D., Dritz, S. S., DeRouchey, J. M., . . . Usry, J. L. (2016). Effects of dietary zinc source and level on nursery pig performance. Journal of Animal Science, 94, 139-139. doi:10.2527/msasas2016-297

Two 8-wk experiments were conducted with Sprague-Dawley weanling rats to determine whether interactions occurring between Zn and Si, or a nutritional deficiency of either Cu or Zn, affect silica urolith formation. In Exp. 1, concentrations of 0, 540, and 2,700 mg of Si/kg of diet from tetraethylorthosilicate were used with dietary Zn concentrations of 4, 12, and 500 mg/kg of diet in a 3 x 3 factorial arrangement. In Exp. 2, copper at 1 or 5 mg/kg of diet and Zn at 4, 12, and 500 mg/kg of diet were used in a 2 x 3 factorial arrangement. All diets in Exp. 2 contained 2,700 mg of Si/kg. Silica uroliths occurred in all treatments providing, 2,700 mg of Si/kg of diet. There was a trend (P = .17) toward a reduction of silica urolith incidence with increasing concentrations of dietary Zn in Exp. 1. In Exp. 2, a deficiency of Zn, and a Cu deficiency exacerbated by 500 mg of Zn/kg of diet, increased (P < .05) silica urolith formation. An antagonism between Si and Zn, as demonstrated previously in the rat, may not be of a sufficient magnitude to be applicable to the prevention of silica urolithiasis. The data further demonstrate that Zn deficiency and, to a lesser extent, Cu deficiency contributed to silica urolith formation in rats fed diets having a high content of absorbable Si. However, 540 mg of Si/kg of diet may potentiate the metabolic activity of Zn, as indicated by a 23% Si-mediated weight gain response in Zn-deficient rats.

Three experiments were conducted to determine whether concentrations of minerals in hair and other tissues of rats and goats are affected by level of dietary Zn or Cd. In the first experiment, rats were fed diets that contained 10.3, 20.5, 33.7, 41.3 or 52.9 micrograms Zn/g for 57 d. Rats fed the diet that contained 10.3 micrograms Zn/g suffered from mild Zn deficiency, as indicated by depressed feed intakes and slower growth rates than rats fed diets containing higher amounts of Zn. Zinc concentrations in hair (P less than .01), liver (P less than .01) and kidney (P less than .01) increased as dietary Zn increased. Confidence intervals for dietary Zn concentration predicted from Zn analysis of hair were large. In the second experiment, rats were fed diets that contained .1, 4.0, 7.6, 10.1 or 15.9 micrograms Cd/g for 57 d. Total growth, feed intake, feed efficiency and liver, kidney and testes weights were not affected (P greater than .05) by dietary Cd concentration. Cadmium increased linearly in liver (P less than .01) and kidney (P less than .01) and quadratically in testes (P less than .01) as Cd intake increased, but Cd in hair was not affected by dietary level of Cd. High correlations between Cd concentrations in liver (R2 = .88) and kidney (R2 = .90) and dietary Cd concentration indicate that Cd intakes of rats may be accurately predicted from Cd analyses of these tissues. In the third experiment, goats were fed diets containing 0, 10.4, 18.0 or 28.5 micrograms Cd/g for 125 d. Growth, feed intake, feed efficiency and liver and kidney weights were not affected by dietary Cd intake. Cadmium in hair samples was not affected by level of dietary Cd; however, cadmium in liver (P less than .01), kidney (P less than .01) and proximal duodenum (P less than .01) increased as dietary Cd increased. Cadmium in liver, kidney, lungs and proximal duodenum was highly correlated (R2 = .67, .89, .57, .49, respectively) with dietary Cd concentration.

Effects on the tissue mineral concentrations of pigs from sows fed four dietary Zn levels were studied. A male and a female from first- and second-parity litters were killed at 1 and 21 d of age. The dams were fed a corn-soybean meal basal diet supplemented with 0, 50, 500 or 5,000 ppm Zn from 30 kg body weight until completion of the second lactation. Pigs from sows fed 5,000 ppm additional zinc had heavier liver, heart, thyroid and adrenal weights relative to their body weight than did pigs from sows on the other treatments. First- and second-parity pigs from sows on the highest Zn supplementation level had higher Fe stores in the liver, higher Zn concentrations in the liver, kidney and pancrease, and higher Cu levels in the kidney compared with pigs from sows on the other treatments. However, Cu concentrations in the liver, heart, pancreas, esophagus, aorta and testes were reduced in pigs from sows on the 5,000 ppm Zn treatment. In first-parity pigs, Ca in the liver was higher for pigs whose dams received 5,000 ppm Zn compared with pigs from sows on all other treatments, and the Mn level was higher compared with pigs from sows receiving 50 or 500 ppm additional zinc. Pigs at 1 d of age from sows on the 0, 50 or 500 ppm treatment had lower hepatic P and Zn concentrations than pigs from sows on the same treatment at 21 d of age. The reverse was true for pigs whose dams received 5,000 ppm Zn.

The effect of dietary Zn levels on the growth and development of gilts was studied. Sixty crossbred and purebred Yorkshire gilts weighing about 30 kg were allotted by sire into four treatment groups and blocked by the date they were farrowed into three blocks. The dietary treatments, which were the amounts of Zn from Zn0 added to the diet, were 0, 50, 500 and 5,000 ppm. Thus, the treatments were less than NRC nutrient requirement, equal to the NRC requirement, 10 times requirement and 100 times requirement for Zn added to a basal corn-soybean meal diet. Weight gain and feed efficiency were not affected by dietary treatment, although there was a trend for gilts receiving 5,000 ppm added Zn to weigh less after 20 wk. After 4 wk on the experimental diets, gilts receiving 5,000 ppm supplemental Zn had elevated serum alkaline phosphatase (SAP) activity and serum Zn levels. The activity of SAP tended to decline with age for animals receiving the other dietary treatments. Gilts receiving no supplementary Zn or 50 ppm additional Zn tended to have lower serum Zn concentrations at 4, 12 and 20 wk on the study than initially. Copper concentrations in the serum were reduced when gilts were fed 5,000 ppm additional Zn. These results suggest that gilts tolerate 5,000 ppm supplemental Zn from Zn0 during growth and development, but mineral profiles are altered.

The activity in serum of zinc-dependent angiotensin converting enzyme (ACE), is measured to aid in diagnosis and monitor treatment of certain diseases. This report shows the effect of dietary zinc deprivation on ACE activity in the serum of rats. The mean (and SE) of the zinc concentration (mumol/L) in serum was 3.5 (0.3) in rats deprived of dietary zinc for four days, 16.3 (0.2) in control rats, and 19.8 (0.9) in rats deprived of zinc for four days, then repleted with zinc for 12 h. The respective mean (and SE) of ACE activities (nmol/mL per min) in serum were 390 (15), 543 (13), and 545 (20). Serum ACE activity was restored also by adding zinc to the assay mixture in vitro. The Vmax for ACE was 1.4 times greater when serum was diluted 40-fold as compared with twofold dilution. There was a small effect on the Km for the substrate, but the Km for zinc was decreased by 22-fold when serum was diluted 40-fold. The Vmax under these conditions was decreased by only 9%.