Occurrence of antibodies to group specific chlamydia antigen in Finnish sheep, cattle and horse sera

A serological survey on the occurrence of group-specific chlamydial antibodies in random sera of Finnish sheep, cattle and horses was performed. The whole material consisted of 1347 serum samples, including 432 ovine, 454 bovine and 461 equine sera. The sera were sent to the laboratory for various serological tests during 1968–1972. Of the ovine sera 9.5%, bovine 12.8 % and equine 7.1 % showed a titer ≥ 1:16 in the complement fixation test.No definite geographic differences could be found in the distribution of the herds which showed positive results. The ubiquity of chlamydial infections in domestic mammals and their role as a cause of clinical diseases is discussed.     

Occurrence of antibodies to group specific chlamydia antigen in cattle in various areas of Finland.

The occurrence of group specific complement fixing antibodies was studied in 361 cattle sera from 36 herds in 6 areas in Finland. Sixty-two (17.2%) were positive. The antibody frequency increased significantly from the south to the north and the frequency was significantly higher in forest than in field pastures. The reasons for the differences are discussed. The tick, Ixodes ricinus, perhaps has no significant epidemiological role in chlamydial epidemiology in Finland.     

Calf Diseases and Mortality in Swedish Dairy Herds

Olsson, S.-O., S. Viring, U. Emanuelson and S.-O. Jacobsson: Calf diseases and mortality in Swedish dairy herds. Acta vet. Scand. 1993,34, 263-269.– A survey of the mortality and morbidity affecting calves during the first 3 months of life was carried out. Results are reported from 131 herds with altogether 5,050 calvings. These herds kept individual calf cards for all calves born. The incidences of abortions and stillborn calves were 0.6% and 3.6%, respectively. During the period 0-90 days the mortality and morbidity were 2.6% and 11.0%, respectively. The frequencies of enteritis and pneumonia in calves were 7.2% and 0.8%. Mortality and morbidity were influenced by breed, season, age of the dam and time of first colostrum. The frequencies of abortions, stillborn calves, mortality and morbidity varied considerably between herds. Herd factors influencing mortality and morbidity during different periods of time were: herd size, yield, zero-grazing, whether the calf was allowed to feed by suckling, the design of the calf pens, and previous incidence of infectious enteritis in the herd. On average, both mortality and morbidity in calves were low, though in certain herds, temporarily high frequencies were registered.     

Urea concentration in bulk milk as an indicator of the protein supply at the herd level

Levels of urea in bulk milk from 80 herds were analysed twice monthly during 1 year to study herd variations and effect of season (Experiment 1). The overall (mean ± s) was 4.7 ± 1.3 mmol/1 ranging from 1.4 to 10.0 mmol/1. Generally, the urea levels were high in summer and early autumn and during this period there were 3 peaks, the first one at the beginning of June, the second one in the middle of July and the third one at the end of September. The peaks reflected feed changes and use of fertilizers commonly practized in the area.In another study samples of bulk milk were obtained from 49 herds using single forage diets with fresh grass silage and standardized concentrate mixtures (Experiment 2). In these herds all feed components given on the day of urea sampling were weighed as accurately as possible and a sample of the silage was taken for chemical analyses and determination of in vitro digestibility. Mean level of crude protein (CP) in silage dry matter was 15.6 ± 2.2 % and average dietary digestible crude protein (DCP) per feed unit (FU) was 146 ± 16 g. In all herds the protein levels in the total daily ration were equal to or above recommended standards. Urea concentration in bulk milk was significantly affected by the GP content in silage, level of dietary DGP and amount of DCP/FU. In energy deficient herds relatively high urea values were obtained without any great surplus of protein. Yield did not significantly affect the urea concentration in bulk milk.     

Specific Pathogen‐Free Pig Herds also Free from Campylobacter?

As Specific Pathogen‐Free (SPF) pig herds are designed and managed to prevent specific pig diseases, it might be feasible to expand the list of micro‐organisms also including zoonotic pathogens such as Campylobacter coli as this agent has its origin in pigs. In a previous survey, 15 of 16 of SPF herds were found free from human pathogenic Yersinia enterocolitica. Accordingly, three nucleus and seven multiplying herds were surveyed for Campylobacter to investigate whether the Norwegian SPF pig pyramid also might be free from this agent. In conclusion, the intervention of Campylobacter at the herd level might be possible as four of 10 SPF herds tested negative in two sets of samples from both autumn 2008 and summer/early autumn 2010. The four negative herds were all located in remote areas several kilometres away from conventional pig farming while the positive SPF farms were all situated in neighbourhoods with conventional pig production. It seems more difficult to control Campylobacter than some specific animal disease agents and another significant zoonotic agent, Y. enterocolitica, in pig herds.     

Transmission of intestinal helminths in Danish sow herds.

Faecal samples from sows and their litters, all untreated with anthelmintics, were examined in eight sow herds, ranging from very intensive to very traditional management. Four helminth genera were recorded, namely Oesophagostomum sp., Ascaris suum, Trichuris suis and Strongyloides ransomi. The herds with the most intensive management were only infected with A. suum, while the more traditionally managed herds were infected with three or four species. In one herd, the sows showed a small relative increase in the excretion of Oesophagostomum eggs during lactation, but in general there was no consistently observable peri-parturient increase in faecal egg output. Furthermore, faecal examination of 5-12-week-old pigs indicated that sow-to-piglet transmission was important in the traditionally managed herds, while it was negligible in the intensive herds. A seasonal variation in the excretion of Oesophagostomum sp. and A. suum eggs was observed in the youngest pigs in the traditional herds, with the highest faecal egg counts occurring in the summer and autumn. However, this pattern became indistinct during the fattening period and did not exist in the sows, except for A. suum infections in the heavily infected traditional herds. The helminths egg excretion in the intensive herds did not show any seasonal variation.     

The effect of season on reproduction in dairy cattle

A survey was carried out in North West Tasmania to compare the breeding performance of 2,068 cows in 27 dairy herds--15 herds calving in spring and 12 in autumn. The percentage of cows submitted to artificial insemination for the first time in the first 24 days of the mating period was 87% for the spring calving group and 75% for the autumn calving group. Figures for non-return-to-service rate over the subsequent 21 days were 72% and 55%, respectively. The difference in breeding performance associated with time of calving was not attributable to age, calving to mating interval or on cow condition or daily milk fat yield at 3 weeks (+/- 1 week) after the start of mating.     

Frequencies of Alleles of the B-Blood Group System in Red Danish Dairy Cattle

The frequencies of B-alleles in RDM were analysed in samples of 637 bulls born in 1963–64–65, 794 bulls born in 1960–61–62 and 1226 cows from common herds.Among the 46 distinct alleles for which frequencies were estimated only about 10 alleles have frequencies above 1 %. The frequency of some alleles shows consistent variations during the last 10–15 years.The degree of homozygosity at the B-locus has remained almost constant among bulls during the last 10–15 years, while the homozygosity among cows from common herds shows a decreasing tendency.     

Influence of feeding management, concentrate intake and energy intake on the risk of hyperketonæmia in Swedish dairy herds

The risk of hyperketonaemia (clinical and subclinical ketosis) and how it is influenced by feeding and management routines was analyzed in 291–354 dairy herds over a 3 year period. The overall frequencies of cows with milk acetone ≥ 0.40 mM ranged between 4.2 and 6.2% in Parity 1 and 12.7 and 13.8% in Parity 2+. The incidence was probably underestimated, as samples were taken once per 30 day period. The risk of hyperketonæmia was higher at low than at high feeding frequencies; most odds ratios (OR) were in the range of 1.0–2.7 for two versus four meals per day. The effect of feeding frequency was most evident on high concentrate rations. A larger amount of concentrate in early lactation was deemed to increase the risk of hyperketonæmia, but not consistently so; OR ranged between 0.4 and 2.7, with highest risks for the Swedish Red and White breed. Feeding forage before concentrate and feeding the cows a meal close to milking time reduced the risk of hyperketonæmia, but the results were inconsistent. Hyperketonæmia occurred more often in herds with feeding barriers than in short stall without feeding barrier. Our findings suggest that a high feeding frequency and a cautious feeding strategy of concentrate early in lactation are important factors in the prevention of subclinical or clinical ketosis.     

Cow-calf herds in eastern Germany: status quo of some parasite species and a comparison of chemoprophylaxis and pasture management in the control of gastrointestinal nematodes.

Infections with gastrointestinal parasites (Eimeria spp., Cryptosporidium spp., Buxtonella sulcata, Fasciola hepatica, Moniezia spp. and trichostrongyles) and lungworms were monitored in five cow-calf herds in the north German lowlands. Estimated prevalences of infections with Eimeria spp. (predominantly Eimeria bovis) ranged between approximately 2 and 48%. The highest prevalences were found during late summer and autumn. On one farm Cryptosporidium spp. were detected in July and August (prevalence: 8.5 +/- 2.7% and 6.7 < 2.0%). The latter finding coincided with diarrhoea in many calves. Buxtonella sulcata was found during the entire study period in highly variable estimated prevalences ranging between zero and 73%, but without any obvious association with clinical disease. Fasciola hepatica was detected on four out of five farms at estimated prevalences of approximately 1-20%. Lungworm infections played a minor role in at least three of five study herds. The estimated prevalence of trichostrongyle infections rose from August until November whereas the intensity of infection did not change significantly. No difference in the intensity of infection could be detected between one farm on which infections with gastrointestinal nematodes were controlled only by moving the animals to an uninfected pasture in July, and three other herds on which strategic anthelmintic control was in place.     

Pyrrolizidine alkaloidosis of cattle associated with Senecio lautu

Summary Serious incidents of pyrrolizidine alkaloidosis of cattle in 10 herds exposed to the Australian native plant, Senecio lautus (Asteraceae), were seen in central Queensland during 1988–1992. The deaths of 226 cattle were recorded. A mean of 8% of cattle died in affected groups (range 2 to 58%). Sickness and deaths usually occurred some months after access to S lautus. Typically, affected cattle lost body condition to the point of emaciation before dying and had persistent diarrhoea. Some animals developed abnormal behaviour and died after a shorter illness. Liver specimens from affected cattle in all herds contained lesions consistent with pyrrolizidine alkaloidosis. Thin layer chromatography of extracts of blood and liver samples from cattle from 5 herds detected pyrrolic metabolites. The identity of these was confirmed by mass spectroscopy on samples from one herd. Unseasonal autumn and winter rain after a dry summer appeared to favour growth of S lautus at the expense of other pasture species. A subsequent dry period promoted consumption of S lautus and was followed by a cluster of poisoning incidents.     

Cow–Calf Herds in Eastern Germany: Status Quo of Some Parasite Species and a Comparison of Chemoprophylaxis and Pasture Management in the Control of Gastrointestinal Nematodes

Infections with gastrointestinal parasites (Eimeria spp., Cryptosporidium spp., Buxtonella sulcata, Fasciola hepatica, Moniezia spp. and trichostrongyles) and lungworms were monitored in five cow–calf herds in the north German lowlands. Estimated prevalences of infections with Eimeria spp. (predominantly Eimeria bovis) ranged between approximately 2 and 48 %. The highest prevalences were found during late summer and autumn. On one farm Cryptosporidium spp. were detected in July and August (prevalence: 8.5 ± 2.7 % and 6.7 < 2.0 %). The latter finding coincided with diarrhoea in many calves. Buxtonella sulcata was found during the entire study period in highly variable estimated prevalences ranging between zero and 73 %, but without any obvious association with clinical disease. Fasciola hepatica was detected on four out of five farms at estimated prevalences of approximately 1–20 %. Lungworm infections played a minor role in at least three of five study herds. The estimated prevalence of trichostrongyle infections rose from August until November whereas the intensity of infection did not change significantly. No difference in the intensity of infection could be detected between one farm on which infections with gastrointestinal nematodes were controlled only by moving the animals to an uninfected pasture in July, and three other herds on which strategic anthelmintic control was in place.     

The influence of different factors on selenium levels in dairy cow herds in the central-eastern region of Poland

Selenium has been recognised as a basic bioelement that determines normal development and health of animals and humans alike. Studies of many authors revealed the influence of selenium deficiency on immunity, health, reproduction and production of dairy cows. Selenium deficiency have been reported in a number of countries, for example in different regions of Poland. The aim of the study was to determine the Se levels in blood serum of dairy cows in the Lublin region. In the periods: autumn 2003, winter 2003 and autumn 2004 selenium concentrations were investigated in serum samples from 180 dairy cows. The samples were obtained from 11 farms. The selenium concentrations were estimated with the ASA method. The monitoring studies have found that Se serum levels are dependent on season of the year, physiological period, maintenance systems and methods of feeding. Mean selenium serum levels observed in the study were between 0.21-0.92 micromol/l, especially (micromol/l): lactation 0.74 +/- 0.13, drying-off period 0.67 +/- 0.15, autumn 2003 0.38 +/- 0.17, winter 2003 0.48 +/- 0.16, autumn 2004 0.69 +/- 0.18. These results suggest that selenium should be supplemented, especially in high-producing dairy cow herds.     

Prevalence of Leptospira interrogans serovar hardjo antibodies in milk in Belgian dairy herds

Pooled milk samples were collected from 2000 Belgian dairy herds in the autumn of 1989. Antibodies against Leptospira interrogans serovar hardjo were detected in 9.2% of the herds, with the incidence being higher in the southern part of the country.     

A survey to determine relationships between bulk tank milk antibodies against Ostertagia ostertagi and milk production parameters

In temperate climate regions, gastrointestinal nematodes are still widespread in adult dairy cows, but until now there exists no reliable diagnostic tool that can identify herds where the infection interferes with productivity. The objective of this study was to investigate the relationships between levels of antibodies against Ostertagia ostertagi in bulk tank milk and milk production. Bulk tank milk samples of 2553 dairy herds were obtained in spring and 2104 of these herds were sampled a second time in autumn. The antibody levels against O. ostertagi were determined with a milk ELISA and test results were expressed as an optical density ratio (ODR). The effect of bulk tank milk ODR on three different production parameters, kg milk, % and kg fat, % and kg protein was assessed by a multivariable linear regression model on the herds for which production data were available (n = 1063 and 867 in spring and autumn, respectively). The mean and standard deviation for ODRautumn (0.972+/-0.238) were higher than for ODRspring (0.825+/-0.201). Significant negative relationships were found between ODR and milk yield. An increase in ODRspring and ODRautumn from the 25th to the 75th percentile of the available ODR data was associated with a drop in the annual milk yield of 1.1 kg/cow/day, respectively 0.9 kg/cow/day. When a herd's ODR increased between spring and autumn with 0.142, it produced on average 0.4 kg/cow/day less in September than in April, in comparison with herds where the ODR did not increase. A significant negative association was found between ODRautumn and % protein averaged over the period of a year. No significant associations were found between ODR and % fat averaged over the year. When protein and fat production of September were expressed in kg an increase in ODRautumn from the 25th to the 75th percentile was associated with a decrease of 0.037 kg protein/cow/day and 0.042 kg fat/cow/day.     

Natural history of influenza in swine in Hawaii: swine influenza virus (Hsw1N1) in herds not infected with lungworms

To obtain more information on mechanisms by which influenza virus is perpetuated in swine, retrospective and prospective seroepizootiologic observations were made in swine herds in Hawaii, beginning in 1974. An epizootic of swine influenza (Hsw1N1) virus was observed in November and December 1976, involving 31 of 41 herds. Features of the epizootic included (1) infection of all herds within one geographic location, during a short period; (2) no obvious introduction of virus from the outside in most herds; (3) epizootics mainly in herds with serologic history of infection; (4) no evidence that lungworms were involved; and (5) little clinical disease associated with infection. There was evidence of viral activity in some herds before the epizootic period and afterward in two of three herds monitored. Evidence of viral transmission by feral animals was not obtained. Data indicated that swine influenza virus persists through latently or chronically infected swine, with epizootics occurring when herd immunity reaches a critically low degree.     

Seasonal variations in egg passage of Fasciola hepatica in dairy cows in Quebec

Seasonal changes in Fasciola hepatica egg passage were documented in 17 dairy herds in Portneuf County, Quebec (Canada). Egg passage was low or absent in spring and summer but rose in autumn to reach a peak in winter, then subsequently returned to low levels. This study suggests that there are two periods of transmission to the bovine host during the grazing season: a minor period in the spring, due to overwintered snails, and a major period in August and September due to snails that acquired the infection in May or June.     

Epidemiological and genetical studies in Norwegian pig herds. I. Design of a disease recording system

The study was based on 70 pig herds in the south-eastern part of Norway during the period from 1984 to 1986. The purpose was to design a health card system based on individual disease records covering diseases in sows, piglets and slaughter pigs. It is concluded that individual health records on a herd basis may well be suited for use in epidemiological and genetical studies of disease frequencies and disease resistance. Feedback of results to farmers and veterinarians seems to be important for satisfactory follow-up in the herds.     

Type and frequency of contacts between Belgian pig herds

Knowledge of the frequency of direct and indirect contacts between pig herds is a requirement for understanding the potential between-herd transmission of pathogens. Our aim was to investigate the different contacts between Belgian pig herds. We obtained data by conducting a postal survey on 421 pig herds in August 2005 and by analysis of available information on livestock movements in the national identification-and-registration database (18-months period in 2004-2006). Direct contacts included transports of pigs by onto-farm, off-farm and between-farm movements. Indirect contacts included vehicles entering the herd and visitors entering the stables. The median number of direct contacts per herd made by onto-farm movements was 0.2/month (Q1: 0; Q3: 0.5). About 1.2% of herds had > or = 3 onto-farm movements/month. We used a zero-inflated negative-binomial regression model to describe differences in the number of onto-farm movements according to herd size and herd type. Piglet multipliers followed by finishing herds were predicted to have the most onto-farm movements. Farrow-to-finishing herds made less movements compared to breeding herds. A median of 3997 between-farm movements/month was made in Belgium; these mainly concerned piglets. The median number of origin herds during an 8-month period for between-farm movements was 4 (Q1: 2; Q3: 8). For a typical 1-month period, we constructed directed graphs of between-farm piglet and replacement stock movements, illustrating potential receivers and distributors of infection. Of these between-farm movements, many were made over a short distance (median straight-line distance 19 km (Q1: 8; Q3: 36)). The median number of vehicles entering a herd and visitors entering the stables was 8/month (Q1: 6; Q3: 13) and 3/month (Q1: 2; Q3: 6) respectively. The number of indirect contacts by vehicles and persons were associated with herd size (Spearman's r: 0.7 and 0.2), herd type and other factors. Skewness of both direct and indirect contacts, illustrated that there was a wide variety in contact structure between pig herds in Belgium. Infection control might benefit by accounting for this variation in contacts and by targeting 'high-risk' herds in case of animal-disease emergencies.     

Seasonal variations in serum progesterone levels in pregnant sows

In the autumn and winter of 1979 and the spring and summer of 1980 serum samples were taken from approximately 20 sows at between 40 and 90 days of gestation in each of seven commercial herds. In most of these herds progesterone concentrations were significantly lower in the autumn than in the other three seasons. Between June 1980 and June 1981 every pregnant sow in a further herd of 250 sows was sampled at 25 to 30 days and at 70 to 91 days of gestation. Seasonal differences in progesterone concentrations were again evident, with the concentrations rising from their lowest in August, September and October to a peak in March. Comparisons between the early and late pregnancy progesterone levels from sows sampled in this herd at different times of the year suggested that corpora lutea which were formed in the summer and early autumn were fully competent and responsive, but that their lower hormone production was possibly the result of reduced luteotrophic stimulation. These findings are pertinent to the pathophysiology of the autumn abortion syndrome and other seasonal reproductive problems in sows.