An assessment of the copper status of dairy herds in the Waikato, Taranaki and Northland in spring and the effects of daily supplementation with copper sulphate

The copper status of dairy herds in the Waikato, Taranaki and Northland regions between 1 August and 30 September was assessed by copper determinations made on composite sera from ten cows in each herd. Comparisons were made between two major groups categorised as as received and supplemented. In the latter, the cows received 2.0-6.0 g/day of copper sulphate orally from late gestation to the end of lactation. Mean copper values were determined from pastures in Taranaki and Northland and from pastures from three soil types in the Waikato. The lowest were in Northland (134.3 micromol/kg) and the highest in Taranaki (173.3 micromol/kg). Calculated dietary available copper levels showed the lowest were from pastures grown on organic soils in the Waikato. These soils also had high molybdenum levels. Serum copper values as received were lowest in Northland (7.30 micromol/l), and were marginal for both Taranaki (9.91 micromol/l) and the Waikato (9.93 micromol/l). The levels in supplemented herds were considerably higher, i.e. from the Waikato 11.7 micromol/l and from Taranaki 11.5 micromol/l. When liver and serum copper levels from paired samples were compared there was a reasonable correlation (r = 0.64) but the standard deviation approximated the mean liver copper level, i.e. 155 +/- 141 micromol/l.     

规模化奶牛场产奶牛和育成牛粪中污染因子的四季动态监测研究

本研究对规模化奶牛场产奶牛和育成牛粪中污染因子进行了四季监测,结果表明,鲜粪中含水率两类牛群夏季最高、春季最低;风干粪样中,除产奶牛夏季全氮和全磷外,产奶牛和育成牛5项检测指标及其年均值的季节变化规律均保持一致,即有机质＞全氮＞全磷＞锌＞铜;两类牛群全磷含量夏季最高、秋季最低,有机质含量春季最高、夏季最低,铜和锌含量夏季均最低;产奶牛全氮含量夏季最低、春季最高,铜含量春季最高,锌含量冬季最高;育成牛全氮含量夏季最高、秋季最低,铜含量秋季最高,锌含量春季最高.     

Bulk milk urea concentrations and their relationship with cow fertility in grazing dairy herds in southern Chile

Milk urea determination is being used as a broad indicator of protein/energy imbalance in dairy herds. The main purpose of this study was to compare blood and bulk milk urea values in grazing herds, to evaluate their seasonal variation under South Chilean conditions, and to examine their potential relationships with herd fertility. The association between herd blood urea concentration (mean of seven lactating cows) and bulk milk urea concentration (tank containing milk from the previous 24 h) was determined in 21 diary herds. Reference values, seasonal and herd variance, and the frequency of herds with values outside a range of 2.5 to 7.3 mmol/l were determined in bulk milk samples obtained monthly for a period of one year from 82 suppliers at two creameries located in southern Chile. Finally, bulk milk urea was measured every two weeks in samples from 24 herds, and the first service conception rate (FSCR) from 2153 dairy cows was determined. Mean bulk urea concentration was highly correlated with mean herd blood urea concentration (r = 0.95; p < 0.01). Mean urea concentration in the bulk milk samples obtained during one year from 82 herds was 4.9 +/- 1.2 mmol/l, with a range of 1.5 to 11.6 mmol/l. The highest values were found during spring and the lowest values during the summer. There was a high seasonal variation (CV = 13-47%) and between-herd variation (CV = 20-31%). Out of a total of 984 samples, 5.4% had urea values > 7.3 mmol/l and 3.8% had values < 2.5 mmol/l. Of the 82 herds, 27% had values outside the reference interval (2.5-7.3 mmol/l) on two or more occasions. FSCR was lower in herds when the bulk milk urea was > 7.3 mmol/l (50.7%) than in cows, where the urea concentration was < 5.0 mmol/l (73.8%) at the time of insemination. The study concluded that bulk milk urea concentrations provided information similar to herd blood urea concentrations in local grazing dairy herds. There was a high frequency of herds with abnormal values, with large variations between herds and between seasons. Increased milk urea concentrations during spring were associated with lower conception rates.     

Haematological and clinicochemical blood profiles in slaughter pigs.

In a cohort study, 40 pig finishing herds were selected: twenty pig herds with a low and twenty pig herds with a high prevalence of several pathological lesions recorded at slaughter in a six-month period before the start of the study. Blood samples were taken from 20 pigs per herd at the end of the finishing period to investigate haematological and clinicochemical profiles. There was only a significant difference in serum albumin concentration between the low and high lesion prevalence groups. There were distinct differences in blood profiles between pig herds, but also between batches of pigs within a herd, housed in different compartments. Differences between castrated males and gilts were also demonstrated with respect to mean values of the blood variables haemoglobin, iron, copper, beta-globulin, eosinophils and segmented neutrophils. However, the differences were not of a biologically important magnitude. The mean values of the blood variables pepsinogen and lymphocytes differed significantly between pig herds from the two participating integration groups. Pigs with a higher albumin concentration, a lower gamma-globulin concentration, a higher copper concentration and a higher creatine kinase activity in serum showed a higher daily weight gain.     

Serum copper concentrations in beef cows and heifers

OBJECTIVE: To characterize serum copper status of cows and heifers in beef cow-calf herds throughout the United States and to evaluate use of copper supplements in those herds. DESIGN: Cross-sectional survey. ANIMALS: 2,007 cows and heifers from 256 herds in 18 states. PROCEDURES: Producers participating in a health and management survey conducted as part of the National Animal Health Monitoring System voluntarily allowed serum samples to be obtained from cows and heifers for determination of copper concentration. Results were categorized as deficient, marginally deficient, or adequate. The proportion of cattle and herds (on the basis of mean value of the tested cattle) in each category was determined. Copper concentrations were compared between herds that reportedly used copper supplements and those that did not. RESULTS: Overall, 34 of 2,007 (1.7%) cows and heifers were deficient in copper, and 781 (38.9%) were marginally deficient. In each region, at least a third of the cattle were deficient or marginally deficient. For herds, 92 of 256 (35.9%) were marginally deficient, and 22 (0.8%) were deficient. Approximately half of the producers reported use of copper supplements, but a sizeable proportion of those producers' cattle and herds were classified as marginally deficient or deficient. CONCLUSIONS AND CLINICAL RELEVANCE: Copper deficiency is not restricted to a single geographic region of the United States. Copper deficiency can persist despite reported use of supplements by producers. Veterinarians dealing with beef cow-calf herds that have problems consistent with copper deficiency should not rule out copper deficiency solely on the basis of geographic region or reported use of copper supplements for the herd.     

Serological Observations on Chlamydia Psittaci Infection in Finnish Dairy Herds

Chlamydial complement fixing antibodies were followed in 5 small Finnish dairy herds. All 53 animals in the herds were bled. In herds A, B, C and D the blood samples were collected in May and in the following autumn after the pasturing period and in herd E over a period of 2 years at about 1 ½-month intervals. The frequencies of positive reactions among the adults and the calves younger than 1 year did not differ significantly from each other, but there were considerable seasonal variations in the frequencies. The highest frequency was found during springtime and early summer and the lowest in autumn.     

Nationwide survey of antibodies to bovine coronavirus in bulk milk from Swedish dairy herds.

Bulk milk samples from 2236 dairy herds randomly selected throughout Sweden in proportion to region and herd size were analysed for antibodies to bovine coronavirus (BCV) in an ELISA. The results were expressed as optical density (OD) values and an OD > 0.04 was considered positive. Eighty-nine per cent of the samples were antibody-positive and 52 per cent had high levels of antibodies to BCV (an OD > 0.70). There were significantly higher OD values (P < 0.001) and fewer antibody-negative samples (P < 0.001) from larger herds than from smaller herds. There were also significantly higher OD values and fewer antibody-negative samples from herds in southern Sweden than from herds in northern Sweden (P < 0.001 and P < 0.001, respectively). These results indicate a higher frequency of BCV infections in larger herds and in herds in southern Sweden.     

Relationships between the concentrations of trichloroacetic acid-soluble copper and caeruloplasmin in the serum of cattle from areas with different soil concentrations of molybdenum

The concentrations of trichloroacetic acid (tca)-soluble copper and caeruloplasmin were determined in 345 serum samples taken from cattle in March 1998 by eight Scottish Agricultural College veterinary disease surveillance centres serving areas with soils ranging from being 'high' in molybdenum (Thurso) to 'low' (Perth and St Boswells). The mean concentrations varied significantly between the centres, with Thurso having the lowest values for both variables. There were strong linear regressions (r>0.8) between caeruloplasmin and tca-soluble copper for each centre but no significant differences in slope or intercept between the areas with the highest and lowest soil molybdenum, and the pooled regression accounted for 88 per cent of the variation. The distribution of the ratios of caeruloplasmin to tca-soluble copper, unlike those of the individual variables, was not normal, and 70 per cent of the values fell within 10 per cent of the mean ratio of 20.3 mg/micromol and close to the 22 mg/micromol copper expected in pure caeruloplasmin. Low ratios were generally associated with low tca-soluble copper. Ratios above 24 were found in 8 per cent of the samples and were probably attributable to acute-phase reactions and the non-specificity of the assay for caeruloplasmin.     

The cell count in milk of goats]

Weekly milk samples were taken from mammary halves from 30 goats from 8 different herds each with from 2 to 5 experimental animals throughout their lactation periods. The physiological variations in the cell counts of goats milk during lactation were investigated by a projection microscope. Only small variations were found in the average cell counts in milk samples from goats in the same herd, but big variations from one herd to another (Table I and Fig. 3.). The curves of the average cell counts in milk samples of 5 herds showed a rise at the beginning of the season at pasture (Fig. 1 and Fig. 2). Also in the housed periods the cell count showed transitory rises. The herd with the lowest average cell count (220,000/ml) was milked by an ordinary bucket milking system, while the herd with the highest average cell count (1,490,000/ml) was milked by a pipeline milking system. Five herds milked by machine had an average cell count of 720,000/ml and three herds milked by hand 540,000/ml. All the herds in the material had an average cell count of 680,000/ml.     

Occurrence of anti-Neospora caninum antibodies in Brazilian cervids kept in captivity

Neospora caninum is a coccidian parasite that causes disease in captive and domesticated animals and has been found in wild animals such as cervids. Sera from 150 cervids of the genus Mazama, were collected from 31 captive herds and 16 zoos from different Brazilian regions and analyzed by indirect fluorescent antibody test for anti-N. caninum antibodies. Positive reactions were found in 42% (63) of the samples and the titers varied from 50 to 51,200. Of the 86 cervids from the captive herds, 38 (44.2%) had anti N. caninum antibodies and of the 64 samples from the zoo, 25 (39.1%) were positive. No significant difference (p>0.05) was found for the occurrence values observed between the animals from captive herds and zoos as well as within the values documented for each one of the species analyzed. Therefore, the results indicate that the agent is prevalent from cervids in captivity in Brazil.     

Copper toxicity in a New Zealand dairy herd

Chronic copper toxicity was diagnosed in a Jersey herd in the Waikato region of New Zealand following an investigation into the deaths of six cattle from a herd of 250 dry cows. Clinical signs and post-mortem examination results were consistent with a hepatopathy, and high concentrations of copper in liver and blood samples of clinically affected animals confirmed copper toxicity. Liver copper concentrations and serum gamma-glutamyl transferase activities were both raised in a group of healthy animals sampled at random from the affected herd, indicating an ongoing risk to the remaining cattle; these animals all had serum copper concentrations within normal limits. Serum samples and liver biopsies were also collected and assayed for copper from animals within two other dairy herds on the same farm; combined results from all three herds showed poor correlation between serum and liver copper concentrations.To reduce liver copper concentrations the affected herd was drenched with 0.5 g ammonium molybdate and 1 g sodium sulphate per cow for five days, and the herd was given no supplementary feed or mineral supplements. Liver biopsies were repeated 44 days after the initial biopsies (approximately 1 month after the end of the drenching program); these showed a significant 37.3% decrease in liver copper concentrations (P <0.02). Also there were no further deaths after the start of the drenching program. Since there was no control group it is impossible to quantify the effect of the drenching program in this case, and dietary changes were also made that would have depleted liver copper stores.Historical analysis of the diet was difficult due to poor record keeping, but multiple sources of copper contributed to a long term copper over supplementation of the herd; the biggest source of copper was a mineral supplement. The farmer perceived this herd to have problems with copper deficiency prior to the diagnosis of copper toxicity, so this case demonstrates the importance of monitoring herd copper status regularly. Also the poor correlation between liver and serum copper concentrations in the three herds sampled demonstrates the importance of using liver copper concentration to assess herd copper status.     

Prevalence of Treponema hyodysenteriae in healthy pigs.

The prevalence of Treponema hyodysenteriae in faecal samples from healthy pigs of various ages in different farrowing units was investigated.Samples from herds designated as Category I were processed within 2 hrs. of sampling. Samples from herds designated as Category II were transported 2 to 3 days before cultivation procedures started. T. hyodysenteriae was demonstrated in 53.7 % to 93 % of the samples collected from Category I herds. No marked difference in the frequency of positive samples from the various age groups of pigs was found. In Category II herds, the organism was demonstrated in 10 % of the samples.The degree of beta-haemolysis shown by isolated strains was grouped into 3 groups: weak, moderate and strong. Strongly betahaemolytic strains, supposedly enteropathogenic, were demonstrated in all Category I herds. Such strains were found in 4.6 % to 25 % of the positive samples in these herds. In Category II herds, 2 out of 17 positive samples harboured strongly beta-haemolytic strains of T. hyodysenteriae.The amount of growth of T. hyodysenteriae on primary plates inoculated with sample material originating from the 2 categories of herds was mostly moderate or abundant. Strongly beta-haemolytic isolates originating from Category I herds produced abundant growth on primary plates in approx. 60 % of samples harbouring such strains. In samples from Category I herds with strains producing weak or moderate beta-haemolysis sparse and moderate amount of growth of the organism was predominant.     

Ostertagia ostertagi antibodies in milk samples: Relationships with herd management and milk production parameters in two Mediterranean production systems of Spain

The present study analyzed Ostertagia ostertagi antibodies by indirect ELISA in milk samples in two cattle systems in Mediterranean Spain to indirectly monitor gastrointestinal nematode (GI) parasitism effects on production. Individual samples from 10 animals and the corresponding milk herd samples were collected from 133 herds in Girona (intensive management) and 123 herds in Minorca (extensive management). Both locations showed high and significant positive relationships between average optical density ratios (ODR) of individual animals and ODR in their milk tank. Although antibodies levels were low, there were significantly higher in Minorca. Negative correlations between ODR values and milk production were found in both systems. Importantly, in Minorca, average herd milk production was higher in the herds that treated their animals against GI nematodes compared to those that did not treat. The ELISA technique was valuable to indirectly assess differences in the level of GI nematode infection even in cattle production systems with low levels of infection.     

Prevalence of selected enteropathogenic bacteria in Hungarian finishing pigs

The aim of this study was to obtain prevalence estimates about the most important enteropathogenic bacteria: Lawsonia intracellularis, Brachyspira hyodysenteriae, Brachyspira pilosicoli, Salmonella enterica and Clostridium perfringens A and C in Hungarian farrow-to-finish pig herds. A total of 31 herds were selected, from where six pooled faecal samples, each containing three individual rectal faecal samples were collected from fattening pigs of 5-6 months of age. All 186 samples were examined by polymerase chain reaction (PCR) for the presence of the pathogens mentioned above. Lawsonia intracellularis was found in 29 herds (93.55%) and in 108 samples (58.06%); B. hyodysenteriae in 14 herds (45.16%) and in 23 samples (12.37%); B. pilosicoli in 19 herds (61.29%) and in 53 samples (28.49%); S. enterica in 17 herds (54.83%) and in 40 samples (21.50%). We detected the presence of C. perfringens A in 19 herds (61.29%) and in 46 samples (24.73%), while C. perfringens C was found in 8 herds (25.81%) and in 11 samples (5.91%). All examined herds were infected with one or more of these agents. Herds with diarrhoea in the mid- to late finishing phase had almost 10 times higher prevalence of B. hyodysenteriae than herds without such a history.     

Ostertagia ostertagi antibodies in milk samples: Relationships with herd management and milk production parameters in two Mediterranean production systems of Spain

The present study analyzed Ostertagia ostertagi antibodies by indirect ELISA in milk samples in two cattle systems in Mediterranean Spain to indirectly monitor gastrointestinal nematode (GI) parasitism effects on production. Individual samples from 10 animals and the corresponding milk herd samples were collected from 133 herds in Girona (intensive management) and 123 herds in Minorca (extensive management). Both locations showed high and significant positive relationships between average optical density ratios (ODR) of individual animals and ODR in their milk tank. Although antibodies levels were low, there were significantly higher in Minorca. Negative correlations between ODR values and milk production were found in both systems. Importantly, in Minorca, average herd milk production was higher in the herds that treated their animals against GI nematodes compared to those that did not treat. The ELISA technique was valuable to indirectly assess differences in the level of GI nematode infection even in cattle production systems with low levels of infection.     

Corynebacterium pseudotuberculosis infection in goats. II. The prevalence of caseous lymphadenitis in 36 goat herds in Northern Norway

The precalen-ce of caseous lymphadenitis was surveyed in 36 goat herds in Northern Norway. In each herd, information concerning the occurrence of the disease was obtained from the farmer. Adult animals (1 year of age or older) in 35 herds were examined for superficial swellings, and serum samples were collected from most animals in the herds. The sera were examined for antibodies to Corynebacterium pseudotuber-culosis using the bacterial agglutination test (BAT) and the hemolysis inhibition test (HIT).Gaseous lymphadenitis was diagnosed with certainty in 19 herds. Information from the farmers indicated that the disease indeed oc-curred in these herds, and that the majority had been infected with the disease for many years. The herds had apparently become infected through contact with animals from infected herds. Clinical examina-tions were carried out in 18 of these herds and superficial swellings were found in 26 % of the examined animals. The prevalence of ani-mals with lesions varied from 11 to 40 % among the herds. Of the animals in these herds, 81 % were positive in BAT and 84 % in HIT. The prevalence of positive animals varied from 26 to 99 % in BAT and 28 to 99 % in HIT. The prevalence of seropositive animals was lowest in a herd in which animals were kept separately in stalls.Caseous lymphadenitis could not be diagnosed in 16 herds. In-formation from the farmers indicated that the disease indeed seemed to be absent in 14 of these herds. These 14 herds had no history of contact with animals from herds considered to be infected. However, in the remaining 2 herds, the farmers were somewhat uncertain about the occurrence of the disease. One of these 2 herds had a history of contact with infected herds through participation in a goat “breeding circle”. Only a few of the animals were, however, seropositive and all these had low antibody titres.In 1 newly established herd, a single animal showed a high posi-tive titre in BAT only. All the other animals were negative in both tests. This particular herd consisted of animals obtained both from herds with caseous lymphadenitis and from herds in which the disease was not considered to occur.     

Herd-level factors associated with longevity in Swedish dairy cattle

The aim of this study was to find herd-related factors associated with average longevity in Swedish dairy herds. Herds with short or long (bottom or top quartile) total life (from birth, TL, 841 and 839 herds) or productive life (from first calving, PL, 799 and 821 herds) were chosen. A logistic regression model was used to estimate associations between herd type and herd-related factors. Large herds and herds increasing in size by more than 50% were less likely to have long PL. High average milk yield was not a risk factor for short PL, but herds with the lowest yield were more likely to be long PL herds. These herds had lower estimated breeding values for milk, most likely due to a slower herd turnover rate. A high proportion of cows culled early in first lactation had a large effect on the probability of being a short PL herd.     

Bovine viral diarrhoea (BVD) infections--control and eradication programme in breeding herds in Slovenia

A Slovenian BVD control and eradication programme was initiated in 1994, and the results from testing of bovine herds for antigen and antibodies in 1996 are presented. Samples originating from breeding herds, breeding herds for young bulls, and insemination stations were tested by antigen or antibody ELISA, or by PCR. Out of 7968 samples from 354 herds we found 18% of the animals antibody-positive. In one region situated in the north-east of Slovenia we found the herds to be almost nearly free of BVDV infections (5% prevalence). No positive antigen ELISA findings were done in 374 blood samples from recruitment herds for young bulls, whereas two out of 206 sera were investigated by PCR-reacted positive. The differences in seroprevalence found between regions is thought to be caused by differences in summer pasturing and husbandry practices.     

Prevalence of antibody to caprine arthritis-encephalitis virus in goats in the United States.

Goats from 28 states were tested for antibodies to caprine arthritis-encephalitis virus. Of 3,790 goats, 1,175 (31%) tested positive, and of 196 herds tested, 143 (73%) had 1 or more seropositive members. This prevalence, based on serum samples from all goats in the participating herds, was lower than most rates reported in other studies. Such studies were based on fewer samples, incomplete sampling of herds, or smaller geographic base. Prevalence was highest in western Pacific and northern plains regions, increased with age to 3 years, was highest among goats on family-owned farms, and was lowest in the Angora breed. Differences in prevalence was not related to gender or size of herd.