The effect of copper-amended fertiliser and copper oxide wire particles on the copper status of farmed red deer (Cervus elaphus) and their progeny

AIM: To determine changes in serum and liver copper concentrations in postnatal, weaner, yearling, and mature deer after grazing pasture topdressed with copper (Cu) at two rates of application of copper sulphate (CuSO4(.)5H2O), and following oral administration of copper oxide (CuO) wire particles to some of the deer. METHODS: In mid-March 2000 (Year 1), 1.1-ha paddocks (two/treatment) of ryegrass/white clover pasture received either 0 (Control), 6 (Low) or 12 (High) kg CuSO4(.)5H2O /ha applied with 250 kg potash superphosphate/ha. They were grazed by 4-month-old red deer hinds (n=11/treatment) from mid-April 2000 until early March 2001. In mid-March 2001 (Year 2), the pastures were topdressed again as for Year 1, and the original hinds, now yearlings which had grazed as a single group between studies, were returned to their respective treatments in mid-April 2001 and remained on the trial until mid-March 2002. They were mated during April/May. The pastures were also grazed by pregnant mature hinds (n=8/treatment) from mid-May 2001. As the Cu status (i.e. liver Cu concentration) of the yearling hinds on the pasture treated with 6 kg CuSO4(.)5H2O/ha was not significantly different from the untreated animals, in late July 2001 the yearling and mature deer on this treatment were treated orally with 10 g CuO wire particles. The mature hinds calved in November and the yearling hinds in December. Pasture samples were collected at about monthly intervals to determine concentrations of Cu and other minerals. In Year 1, liver biopsies and blood samples were collected at 4-6-weekly intervals for determination of Cu concentrations. In Year 2, samples were collected similarly at 6-12-weekly intervals. Liver biopsies and blood were also collected from progeny, along with milk from their dams. Liveweights were determined at 3-7-monthly intervals, as well as data on calving/mortality rates. RESULTS: Pasture Cu concentrations before the application of CuSO4(.)5H2O were 6-9 mg Cu/kg dry matter (DM) and remained at this level in the untreated Control paddocks throughout the study. In Year 1, 28 days after treatment, pasture Cu concentration was 25 and 35 mg Cu/kg DM for the Low and High treatments, respectively; while at the same time for the same treatments in Year 2 it was 20 and 60 mg/kg DM, respectively. A second 60 mg Cu/kg DM peak also occurred on Day 85 in Year 2 with the High treatment. The pasture Cu concentration returned to 6-9 mg/kg DM, and there were no differences between treatments at Days 80 and 150 in Years 1 and 2, respectively. In Years 1 and 2, the Low treatment had no significant effect on the Cu status of the weaner and yearling hinds, respectively, when compared with that of animals grazing the untreated Control pastures. Weaner (Year 1) and yearling (Year 2) deer on the High treatment had significantly higher mean serum and liver Cu concentrations in the late winter and spring period when compared with those on untreated Control pastures. CuO wire particles increased the mean serum Cu concentration at Days 60 and 180, and liver Cu concentration at Day 60, in yearling hinds. A similar effect was observed in mature hinds. Regardless of Cu treatment, the liver Cu concentration of the 1-4-week-old progeny was markedly greater (p<0.001) than that of their dams, and then decreased significantly until weaning in March. In progeny of treated yearling hinds, but not mature hinds, serum and liver Cu concentrations were significantly higher (p=0.013) than progeny of untreated dams. CONCLUSION: Topdressing pastures with CuSO4(.)5H2O at a rate of 12 kg/ha, but not 6 kg/ha, in mid-March was effective in increasing the Cu status of weanling hinds; while pastures topdressed with 12 kg CuSO4(.)5H2O /ha in mid-March and dosing hinds with 10 g CuO in late July were effective in increasing the Cu status of pregnant hinds, and in the case of the yearling hinds, significantly improved the Cu status of their progeny from birth to weaning.     

Effect of ostertagiasis on copper status in sheep: a study involving use of copper oxide wire particles

Lambs infected with Ostertagia circumcincta larvae and uninfected controls were either doses with 5 g copper oxide wire particles (COWP) or remained undosed. The change in abomasal pH was monitored from duodenal digesta and that in liver copper concentration from initial liver biopsy samples and liver obtained at necropsy after 22 days. Infection increased the pH of digesta from 2.5 to 4.5. The change in liver copper content in sheep not treated with COWP was +6.1 mg (12.6 per cent) and -6.8 mg (13.8 per cent) in control and infected sheep, respectively. Significantly greater amounts of COWP were recovered from the abomasa of infected than from control animals (3.6 +/- 0.23 and 1.6 +/- 0.55 g, respectively) and hepatic uptake of copper from COWP was 0.7 and 1.8 per cent of the dose, respectively. There were significant relationships between the pH of duodenal contents and COWP retained, soluble copper concentration in duodenal digesta and hepatic uptake of copper. It was concluded that, through causing an increase in pH in abomasal and duodenal digesta, gastrointestinal nematodes interfere with copper metabolism.     

Interaction between copper oxide wire particles and Duddingtonia flagrans in lambs

An experiment was completed to determine if copper oxide wire particles (COWP) had any effect on the activity of the nematode-trapping fungus Duddingtonia flagrans in growing lambs. COWP has been used recently as a dewormer in small ruminants because of nematode resistance to anthelmintics. D. flagrans has been used to control free-living stages of parasitic nematodes in livestock. Katahdin and Dorper lambs, 4 months of age, were administered no or 4 g COWP (n=24/dose) in early October 2003. Haemonchus contortus was the predominant gastrointestinal parasite during the trial, which was acquired naturally from pasture. Half the lambs from each COWP group were supplemented with corn/soybean meal with or without D. flagrans for 35 days. Fecal egg counts (FEC) and packed cell volume (PCV) were determined weekly between days 0 (day of COWP administration) and 35. Feces from lambs in each treatment group were pooled and three replicates per group were cultured for 14 days at room temperature. Larvae (L3) were identified and counted per gram of feces cultured. Treatment with COWP was effective in decreasing FEC, which remained low compared with FEC from lambs not treated with COWP. This led to an increase in PCV in these lambs (COWP x day, P<0.001). Number of larvae was decreased in feces from lambs treated with COWP and D. flagrans between days 14 and 35 compared to the other groups of lambs (COWP x D. flagrans x day, P<0.003). Percentage of larvae identified as H. contortus decreased in feces collected from lambs treated with COWP and D. flagrans between days 14 and 28 compared with other treatments (COWP x D. flagrans x day, P<0.05). Other trichostrongyles were present and remained less than 7% in feces collected from control lambs. There was no adverse effect of COWP on the ability of D. flagrans to trap residual larvae after COWP treatment. With fewer eggs being excreted due to the effect of copper on H. contortus, and the additional larval reducing effect exerted by the nematode destroying fungus D. flagrans, the expected result would be a much lower larval challenge on pasture when these two tools are used together in a sustainable control strategy.     

Efficacy, distribution and faecal excretion of copper oxide wire particles in a novel bolus in red deer (Cervus elaphus)

AIM: To determine the efficacy of a novel copper oxide wire particle (COWP) formulation in elevating concentrations of copper (Cu) in the liver and serum of red deer (Cervus elaphus), and to investigate the distribution of particles in the gastrointestinal tract and the rate of their excretion in faeces. METHODS: Mixed-age red deer hinds were allocated to three groups (n=10 per group) on the basis of pre-treatment liver Cu concentrations. Groups 1 and 2 were treated orally with a 10-g COWP bolus on Days 0 and 30, respectively, while the remaining group served as an untreated control. Animals were slaughtered on Day 60, when blood and liver samples were collected for determination of Cu concentrations. An additional group of 18-month-old red deer hinds (n=20) were treated orally with a 10-g COWP bolus, and four were slaughtered on each of Days 1, 5, 15, 30 and 60 after treatment. The gastrointestinal tract was secured between compartments below the oesophagus and contents rinsed until sedimentation of particles was complete. The sediment was oven-dried and COWP were separated and weighed. Faeces were collected continuously from four additional animals held in metabolism cages for 4 days after treatment, sub-sampled daily, and COWP recovered. RESULTS: Mean liver Cu concentrations at slaughter were 80, 597 and 447 micromol/kg for controls and hinds treated 30, and 60 days previously, respectively. Corresponding mean serum Cu concentrations were 7.7, 12.9 and 11.9 micromol/L, respectively. Liver and serum Cu concentrations were higher in both treatment groups than in untreated control animals (p<0.001). COWP were found in all compartments of the gastrointestinal tract measured, for at least 15 days, and in the rumen/reticulum and abomasum for at least 60 days post-administration. The highest rate of recovery overall was from the rumen/reticulum. Mean weight of COWP recovered from faeces was 0.09 g during the first 24 h and 0.94 g over the first 4 days following administration. CONCLUSION: The COWP bolus tested resulted in elevated mean liver Cu concentrations for at least 60 days compared with control animals. The majority of COWP were found in the rumen/ reticulum, where recovery was possible for at least 60 days. About 10% of particle weight was excreted in the faeces within 4 days of administration. CLINICAL SIGNIFICANCE: The test bolus was efficacious in deer, elevating mean liver and serum Cu concentrations 30 and 60 days after treatment. Variation in faecal excretion may explain between-animal differences in efficacy.     

The effect of oral oxidised copper wire on liver copper in farmed red deer

Twenty-two weaner red deer stags grazed on a marginally copper-deficient property were used to evaluate the effect on liver copper levels of log oxidised copper wire particles given orally. The deer were assigned to two groups on the basis of pre-trial liver copper levels, and grazed together for the duration of the trial from March to October. Liver biopsies were collected from treated and control deer on six occasions at monthly intervals and were analyzed for copper content.

Mean liver copper in the treated group rose from pre-treatment levels of 101.8μmol/kg to a peak of 849.6μmol/kg two months after copper administration. Thereafter, levels fell steadily until six months after administration when they averaged 84.8μmol/kg. The mean liver copper content of untreated deer rose from 102.7μmol/kg at the commencement of the trial, peaked at 255.3μmol/kg after two months, fell to 103μmol/kg one month later and remained low thereafter. The liver copper content in treated deer was significantly higher than for control deer for the duration of the study (p<0.0l for months 1–4 and 6, p <0.05 for month 5).

It is concluded that log oxidised copper wire particles acted to provide adequate liver copper stores for up to five months in deer grazed on a marginally copper-deficient property.     

Persistence of the efficacy of copper oxide wire particles against Haemonchus contortus in sheep

The aim was to determine the persistent efficacy of copper oxide wire particles (COWP) against Haemonchus contortus in sheep, using the harmonization guidelines protocol. Thirty-six male lambs (2 months old) reared free of gastrointestinal nematodes were used (average body weight of 10.8±3.8kg). Before and for the duration of the study, lambs were kept in raised cages with slatted floors and were offered ad libitum a complete mixed diet. Animals were divided into six groups (n=6): one non-treated control group (G0) and five groups treated with one COWP capsule (1.7g of copper oxide; Copinox(?)). Animals in each group were treated on pre-defined dates before the artificial infection was applied: days -35 (G1), -28 (G2), -21 (G3), -14 (G4) and -7 (G5). On day 0 animals were infected with 3700 H. contortus infective larvae per animal. Animals were humanely slaughtered between days 22 and 23 post-infection. The abomasums were individually washed to obtain the contents. These organs were subjected to separate artificial digestions. Adult parasites were counted from the abomasum contents and the larvae from the digested material. Worm burden geometric means were calculated for each group. A significant worm burden reduction in either of the treated groups (G1, G2, G3, G4, and G5) compared to the control (G0) was considered as persistence of the anthelmintic effect. Copper levels were determined from individual liver samples of each animal. The geometric mean worm burden of the control group (G0) was 1959. Compared to the control, worm burdens geometric means were significantly reduced in groups G1 (1108), G4 (528) and G5 (1063) (P<0.03). Efficacies in G1, G4 and G5 were 43.4%, 73.0% and 45.7% respectively. No significant reduction was found for G2 (1342) and G3 (1430). A larger quantity of Cu was found in the livers of treated animals compared to the control group (P<0.05) except for G3 (P=0.06). A negative association between Cu liver content and worm burdens was found (r=-0.42, P<0.05). Live weight gain was similar in all groups and no clinical or post-mortem manifestations of Cu toxicity were recorded in treated animals.     

Effect of copper oxide wire particles dosage and feed supplement level on Haemonchus contortus infection in lambs

The objective of the experiment was to determine the optimal dose of copper oxide wire particles (COWPs) to reduce infection of Haemonchus contortus in male lambs. Five to six-month-old hair breed lambs were housed on concrete and fed 450 (L; n = 25) or 675 g (H; n = 25) corn/soybean meal supplement and bermudagrass hay. In July, lambs were inoculated with 10,000 L(3) larvae (97% H. contortus; Day 0). Lambs were administered 0, 2, 4, or 6 g COWP on Day 28. Concentrations of copper in the liver were determined. There were no effects of supplement level on concentrations of copper in the liver and a linear relationship existed between COWP treatment and concentrations of copper in liver (P < 0.001). Least squares means of the 0, 2, 4, 6 g COWP treatments were 62.2, 135.7, 161.1, and 208.4 ppm (P < 0.001). Between Days 0 and 28, PCV declined and by Day 42, PCV of all COWP-treated lambs was markedly higher than control lambs and remained higher (COWP x day, P < 0.05). By Day 21, PCV was greater in the H compared with the L group of lambs (P < 0.001). Within 14 days of COWP treatment FEC declined from more than 8000 eggs/g (epg) to less than 250 epg in all COWP-treated lambs (COWP x day, P < 0.001). The numbers of H. contortus in the abomasum were greatly reduced in all COWP-treated groups of lambs and remaining nematodes were predominantly males. FEC were greater in L versus H supplemented lambs and values decreased to a greater extent in H lambs when treated with COWP (supplement x COWP; P < 0.02). The 2 g COWP was effective in alleviating H. contortus infection and reducing number of egg-laying nematodes in the abomasum with the lowest concentration of copper in the liver of the COWP treatment groups. PCV values were more favorable for lambs fed the higher level of supplement, especially when FEC were greater than 8000 epg.     

Osteochondrosis associated with copper deficiency in young farmed red deer and wapiti x red deer hybrids

Osteochondrosis is reported in association with copper deficiency in young red deer and wapiti x red deer hybrids on eight deer farms throughout New Zealand. On two farms, more than 30% of fawns were affected. Affected animals were lame, often had one or more swollen joints, and in some cases had an abnormal “bunny-hopping” gait or “cow-hocked” stance. Lesions were most common in the carpal, tarsal, stifle and hip joints, and were usually bilateral. Defects in articular cartilage ranged from loose flaps to complete separation with exposure of subchondral bone and the presence of cartilage fragments within the joint space. In advanced cases, the joints had features of degenerative arthropathy. Bilateral epiphyseolysis of the femoral head was observed in some severely lame deer. All deer with osteochondrosis had low serum and/or liver copper concentrations.     

Osteochondrosis associated with copper deficiency in young farmed red deer and wapiti x red deer hybrids

Osteochondrosis is reported in association with copper deficiency in young red deer and wapiti X red deer hybrids on eight deer farms throughout New Zealand. On two farms, more than 30% of fawns were affected. Affected animals were lame, often had one or more swollen joints, and in some cases had an abnormal "bunny-hopping" gait or "cow-hocked" stance. Lesions were most common in the carpal, tarsal, stifle and hip joints, and were usually bilateral. Defects in articular cartilage ranged from loose flaps to complete separation with exposure of subchondral bone and the presence of cartilage fragments within the joint space. In advanced cases, the joints had features of degenerative arthropathy. Bilateral epiphyseolysis of the femoral head was observed in some severely lame deer. All deer with osteochondrosis had low serum and/or liver copper concentrations.     

Effects of copper oxide bolus administration or high-level copper supplementation on forage utilization and copper status in beef cattle

Two experiments were conducted to study effects of high-level Cu supplementation on measures of Cu status and forage utilization in beef cattle. In Exp. 1, eight steers randomly received an intraruminal bolus containing 12.5 g of CuO needles (n = 4) or no bolus (n = 4). Steers were individually offered free-choice ground limpograss (Hemarthria altissima) hay. On d 12 (Period 1) and d 33 (Period 2) steers were placed in metabolism crates, and total forage refused and feces produced were collected for 7 d. Daily samples of forage offered and refused and of feces excreted for each steer within period were analyzed for DM, ash, NDF, ADF, and CP. Liver biopsies were collected on d 0, 12, and 33. Copper oxide bolus administration resulted in greater (P < 0.03) liver Cu (DM basis) accumulation in Period 1 (556 vs. 296 mg/kg) and Period 2 (640 vs. 327 ppm). Apparent digestibilities of NDF and CP were greater (P < 0.04) for steers receiving no bolus in Period 2 (62.2 vs. 57.1% and 50.2 vs. 43.4% for NDF and CP digestibility, respectively). In Exp. 2, 24 crossbred heifers were assigned to individual pens and received a molasses-cottonseed meal supplement fortified with 0, 15, 60, or 120 ppm of supplemental Cu (Cu sulfate; six pens per treatment). All heifers were offered free-choice access to ground stargrass (Cynodon spp.) hay. Heifer BW and liver biopsies were collected on d 0, 42, and 84. Forage refusal was determined daily, and diet DM digestibility was estimated over a 21-d period beginning on d 42. Heifers consuming 120 ppm of supplemental Cu gained less (P < 0.05; 0.04 kg/d) than heifers consuming 15 (0.19 kg/d) and 60 ppm of Cu (0.22 kg/d), but their ADG did not differ from that by heifers consuming no supplemental Cu (0.14 kg/d; pooled SEM = 0.07). Heifers supplemented with 15 ppm of Cu had greater (P < 0.05) liver Cu concentrations on d 84 than those on the 0-ppm treatment and the high-Cu treatments (60 and 120 ppm). Forage intake was less (P = 0.07) by heifers receiving no supplemental Cu than by heifers on all other treatments (6.6 vs. 5.8 +/- 0.37 kg/d). Apparent forage digestibility was not affected by Cu treatment. These data suggest that high rates of Cu supplementation (Cu sulfate; > 60 ppm of total Cu) resulted in less liver Cu accumulation by beef heifers compared with heifers consuming diets supplemented with moderate dietary Cu concentrations (i.e., 15 ppm). As well, the administration of CuO boluses might depress the digestibility of forage nutrient fractions in steers.     

The effectiveness of copper oxide wire particles as an anthelmintic in pregnant ewes and safety to offspring

The objective of the experiment was to determine the effectiveness of copper oxide wire particles (COWP) in pregnant ewes and safety to lambs. COWP have been used recently as an anthelmintic in small ruminants to overcome problems associated with nematode resistance to chemical dewormers. Doses of COWP (相似文献   

Control of gastrointestinal nematodes with copper oxide wire particles in a flock of lactating Polypay ewes and offspring in Iowa, USA

Copper oxide wire particles (COWP) have been used to reduce infection of Haemonchus contortus in hair breed lambs in southeastern USA without signs of copper toxicity. However, copper sensitivity among breeds and regions varies. The objective was to determine the effectiveness and safety of COWP in lactating Polypay ewes and their offspring grazing alfalfa/bluegrass pasture in a rotational grazing system. Mature Polypay ewes were administered 0, 0.5, 1, or 2 g (n=8 or 9/dose) COWP approximately 60 days after lambing in mid-July 2005. Their offspring were administered 0 (n=6), 0.5 or 0.75 g (n=9), 1 or 2 g (n=6) COWP 2 weeks later in late July. The primary gastrointestinal nematode was H. contortus (70%). Between Days 7 and 35, FEC were greater in 0 and 0.5 g COWP groups compared with ewes administered 2 g COWP (COWP x day, P<0.004). PCV decreased in all groups of ewes between Days 0 and 21 (day, P<0.001). Aspartate aminotransferase (AST) activity, a measure of liver copper levels, and body weight was similar among groups of ewes. FEC decreased within 7 days in COWP-treated compared with untreated lambs and remained low throughout experiment (COWP x day, P<0.05). PCV increased in COWP-treated lambs between Days 7 and 35 and decreased in untreated lambs between Days 0 and 21 (COWP x day, P<0.009). AST activity was similar among groups of lambs. Administration of 2 g COWP to ewes prevented a rise in FEC, but a dose of 0.5 g was ineffective as an anthelmintic. Administration of all doses of COWP to lambs decreased FEC and increased PCV compared to untreated lambs. There were no signs of copper toxicity in ewes or lambs. Alternative suppression of H. contortus infections may be necessary in ewes, but COWP was effective in H. contortus management for lambs.     

Failure of copper or vitamin D supplements to affect the dental condition of young sheep on two Wairarapa farms

Regular injections of copper or vitamin D had no overall effect on growth rate, fleece weight, or the amount of wear of the central incisor teeth of sheep on two Wairarapa farms over 26 months. The greatest amount of tooth wear occurred during the period when soil ingestion (measured by acid-insoluble residue, titanium or aluminium in the faeces) was also greatest. Various indicators of copper, calcium or nutritional status were measured in the blood of control sheep and those receiving vitamin D or copper. At no sampling time was there a significant difference for any of these between groups on either farm. Pasture samples were analysed regularly for calcium, cobalt, copper, magnesium, manganese, molybdenum, phosphorus, sulphur, zinc and percentage ash. At most times values were, on the basis of existing criteria, considered normal. Although the pasture calcium/phosphorus ratio fell below one on several occasions this did not result in a change in plasma calcium or phosphorus levels. On the basis of criteria established for pen-fed sheep, dietary available copper levels on both farms were considered low for much of the time. However, liver and blood copper values were adequate at alI times.     

Interaction between copper and zinc in sheep parenterally treated with zinc oxide

Changes in copper and zinc concentrations in the blood serum of sheep were studied in clinical conditions for sixty days in relation to the intramuscular application of zinc oxide at a dose of 10 mg Zn per kg liveweight; zinc oxide was administered in a developmental preparation. Serum concentrations of zinc started increasing significantly the eighth day after administration (p less than 0.01), the maximum values were found out on the twelfth day (21.19 +/- 3.89 mumol X l-1). Significantly higher concentrations of zinc in the blood serum of test sheep were observed as soon as on the eighth day (p less than 0.01), in comparison with the untreated group, and they persisted till the end of investigation (p less than 0.01). Simultaneously with the changes in serum zinc concentrations, copper metabolism was influenced when the statistically higher values of copper concentrations in the blood serum of the test group were recorded the eighth and twelfth days (p less than 0.01), in comparison with the control animals. In the remaining period, serum copper concentrations did not show any mathematical dependence and the equalization to the original values in the treated group occurred at the end of the experiment. The above-mentioned results from the sheep treated with zinc oxide refer to a possibility of influencing mutually the copper and zinc metabolism also parenterally; this could be utilized during the treatment of secondary deficiencies, or toxicosis.     

Use of copper oxide wire particles (Copinox) for the prevention of congenital copper deficiency in a herd of German Improved Fawn breed of goat

In a herd of German Improved Fawn breed of goat in the year 2000 neonatal kid losses due to congenital copper deficiencies were observed. To clarify the problems and to prevent losses in the next breeding season serum copper levels of 10 dams and four control Boer goats were investigated at four time points during one year. Additionally ten kids of the following year were sampled and the serum copper levels were studied. Immediatly after parturition and 8 weeks later the dams showed low serum copper levels (10.4 +/- 11.1 micromol/l, 5.7 +/- 2.9 micromol/l resp.). At the end of the pasture season an increase of serum copper could be measured (19.3 +/- 16.0 micromol/l). To prevent enzootic ataxia due to congenital copper deficiency, the dams were treated with copper oxide wire particles in the next late gestation. At this time point serum copper concentrations started to decrease (18.5 +/- 8.4 micromol/l). The re-examination 3 month later demonstrated an increase of the serum mean copper concentrations up to 23.4 micromol/l in the dams and to 16.2 micromol/l in the kids. The serum copper levels were significantly higher compared to the levels the year before. Big variation of the serum copper levels in the control Boer goats occurred during the year, but no clinical symptoms of copper deficiency could be observed. The copper levels in the grass and soil samples were 6.8 mg/kg and 0.2 mg/kg dry substance, respectively. A secondary copper deficiency based on cadmium could be excluded through the low levels of soil samples. The contents of sulphur and molybdenum were not determined. The results indicate that the German Improved Fawn breed of goats suffered from a primary copper deficiency due to the inefficient mineral supplementation. The administration of Copinox in the last third of the gestation leads to a continious raising of the copper concentrations in the serum and is suited to prevent ataxia due to congential copper deficiency in neonatal kids.     

Effect of copper oxide wire particle treatment on establishment of major gastrointestinal nematodes in lambs

Eighty-four 10-week-old lambs were used to investigate the effect of copper oxide wire particle treatment on the establishment of major gastrointestinal nematodes. They were maintained on pasture previously treated to minimise larval contamination. Five grams of uniform sized copper oxide wire particles were given orally five days before infection with either 20,000 Trichostrongylus colubriformis larvae, 20,000 Ostertagia circumcincta larvae or 3000 Haemonchus contortus larvae given as three doses at three-day intervals. The animals were slaughtered 21 or 22 days after the last infective dose. Parasite burdens in the lambs treated with copper oxide wire particles were reduced by 96 per cent in the case of H contortus and by 56 per cent in the case of O circumcincta compared to burdens in controls. There was no significant effect of copper particles on the establishment of T colubriformis.     

Weight gain in steer and heifer calves treated with zeranol or oestradiol 17 beta

Male and female Hereford and Hereford cross beef calves between 2.5 and 4.5 months of age were implanted with 36 mg zeranol, 24 mg oestradiol 17 beta or left untreated, and then weighed every 4 to 5 weeks. Calves treated with zeranol or oestradiol 17 beta gained 9.6 kg (8.2%) and 12.9 kg (11.0%) more weight respectively than untreated calves. Steer calves gained more weight than heifer calves. There was no response to either growth promotant in heifers or in zeranol-treated steers beyond 35 days after implantation, and the only significant further gains in the next 31 days were made by steers treated with oestradiol 17 beta. After this time growth of treated and control calves was similar. The lack of a continued response to the growth promotants was not associated with significantly lower growth rates in any weighing interval.     

蛋氨酸铜对绵羊增重及体内代谢的影响

26只晋中绵羊随机分为试验组(添加蛋氨酸铜)和对照组(添加硫酸铜),供试日粮及营养水平完全相同,试验时间60d。结果表明,试验组比对照组绵羊平均日增重提高34.22%(P<0.05);平均日粮干物质采食量、肝脏铜和血浆铜含量明显提高(P<0.05)。     

Safety and effectiveness of cupric oxide particles for increasing liver copper stores in sheep

Five groups of four, housed Cheviot ewes (mean live-weight 50 kg) were given single doses of 0, 2.5, 5, 10 or 20 g cupric oxide particles in gelatin capsules while receiving a diet of marginal copper content based on pelleted oats. After 65 days liver copper concentrations had increased curvilinearly in relation to dose and all ewes given 10 or 20 g cupric oxide particles showed increases of at least 13.4 mmol kg-1 dry matter (850 ppm). Liver copper concentrations had generally declined after 85 days but biochemical and histological evidence of copper toxicity was recorded in one ewe which had received 20 g cupric oxide particles. Despite marked variations between individual sheep a dose of 0.1 g kg-1 liveweight (5 g) was considered to be safe and did not induce clinical copper toxicity in five sheep of the susceptible North Ronaldsay breed given the same basal diet.     

Safety and effectiveness of cupric oxide particles for increasing liver copper stores in cattle

Five groups of three or four crossbred steers, mean initial liveweight 220 kg, were given a diet of barley and hay ad libitum. Each animal received a single oral dose of 0, 5, 10, 20 or 40 g cupric oxide particles. A dose of 5 g cupric oxide particles increased liver copper stores for about 240 days and higher doses increased liver stores for longer but 40 g was no more effective than 20 g (85 mg kg-1 liveweight). Variation among individuals was marked but the highest liver copper concentration recorded (7.59 mmol kg-1 dry matter) produced no biochemical evidence of copper toxicity. Earlier, cupric oxide particles were separated into three fractions, clumps, short rods and long rods and 5 mg kg-1 liveweight of each fraction given to steers of 173 kg mean liveweight. The form of the particles did not affect either their retention in the alimentary tract or the accumulation of copper in the liver.