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1.  Isolation of Ureaplasma from bovine granular vulvitis. 
Cultures for mycoplasmatales, viruses and bacteria were made from bovine vulvar swabs to determine whether ureaplasma was associated with a clinical granular vulvitis observed in 16 Ontario dairy herds. Ureaplasma was isolated from 23.5% of 34 clinically normal cows, 74% of 27 cows with mild to moderate vulvar hyperemia but no discharge and 100% of 20 cows with acute vulvar hyperemia accompanied by purulent discharge. There were statistically significant differences in rates of isolation among clinical groups. Mycoplasma bovigenitalium was isolated from 7.7% and 20% of cows with moderate or acute vulvitis respectively but not from normal cows. Haemophilus somnus was isolated from 25% of cows with acute vulvitis. There were no significant differences in isolations of Escherichia coli, Corynebacterium pyogenes and alpha-hemolytic streptococcus between normal and clinically affected animals. Cultures of 135 repeat samples from 33 cows revealed that ureaplasma persisted in some animals for at least three months. No viruses were isolated from any of the animals in this study.
PMCID: PMC1277608  PMID: 352491
2.  Experimental bovine genital ureaplasmosis. I. Granular vulvitis following vulvar inoculation. 
Granular vulvitis was reproduced in ten virgin heifers following vulvar inoculation with strains of ureaplasma previously isolated from natural cases. The disease appeared one to three days postinoculation and was characterized by vulvar swabs but not from the upper mucopurulent discharge. At necropsy 13 to 41 days later, ureaplasmas were recovered consistently from vulvar swabs but not from the upper reproductive tract. It was concluded that some strains of ureaplasma are pathogenic and should be viewed as a cause of bovine granular vulvitis.
PMCID: PMC1320070  PMID: 7427772
3.  Experimental Bovine Genital Ureaplasmosis II. Granular Vulvitis, Endometritis and Salpingitis Following Uterine Inoculation 
Twenty-three virgin Holstein heifers received uterine inoculations with ureaplasma and were necropsied one to thirteen days later. Three heifers inoculated intracervically were necropsied on days 3, 5 and 11.
Granular vulvitis was produced on average by 3.6 days in fourteen of sixteen uterine inoculated heifers monitored for four or more days. Two cervically inoculated heifers monitored for over four days also developed granular vulvitis by the fourth day.
At necropsy, ureaplasma was recovered from 94% of uterine horn cultures for the first four days postinoculation and 50% during days 5 to 7. Thereafter all uterine cultures were negative. The percentage of positive ureaplasma recoveries from uterine tube flushings was lower than for uterine horns but remained positive for a longer period. By day 7, three of four uterine tube flushings were still positive. No bacterial pathogens were isolated from the uterine horns or uterine tube flushings.
On histopathology 50% of uterine inoculated heifers had endometritis up to six days postinoculation and a slightly higher percentage (58%) had salpingitis. Endometritis was not found in any heifers after day 6. Residual salpingitis was present in one heifer on day 7. Endometritis was present in cervically inoculated heifers necropsied on days 3 and 5 but not on day 11. Salpingitis was not found in any of the three cervically inoculated animals.
The study concluded that some strains of ureaplasma are pathogenic for the upper reproductive tract of the cow and should be considered significant when isolated from cases of granular vulvitis, endometritis or salpingitis.
PMCID: PMC1320071  PMID: 7427773
4.  Housing system and herd size interactions in Norwegian dairy herds; associations with performance and disease incidence 
According to the Norwegian animal welfare regulations, it has been forbidden to build new tie-stall barns since the end of 2004. Previous studies have shown that cow performance and health differ between housing systems. The interaction between housing system and herd size with respect to performance and disease incidence has not been evaluated.
Cow performance and health in 620 herds housed in free-stall barns were compared with in 192 herds housed in tie-stall barns based on a mail survey and data from the Norwegian Dairy Herd Recording and Cattle Health Systems. The housing systems herds were comparable with respect to herd size (15-55 cows). Associations between performance/disease incidence and housing system, herd size and year of building the cow barn were tested in general linear models, and values for fixed herd size of 20 and 50 cows were calculated. On the individual cow level mixed models were run to test the effect of among others housing system and herd size on test-day milk yield, and to evaluate lactation curves in different parities. All cows were of the Norwegian Red Breed.
Average milk production per cow-year was 134 kg lower in free-stall herd than in tie-stall herds, but in the range 27-45 cows there was no significant difference in yields between the herd categories. In herds with less than 27 cows there were increasingly lower yields in free-stalls, particularly in first parity, whereas the yields were increasingly higher in free-stalls with more than 45 cows.
In free-stalls fertility was better, calving interval shorter, and the incidence rate of teat injuries, ketosis, indigestions, anoestrus and cystic ovaries was lower than in tie-stalls. All of these factors were more favourable in estimated 50-cow herds as compared to 20-cow herds. In the larger herd category, bulk milk somatic cell counts were higher, and the incidence rate of mastitis (all cases) and all diseases was lower.
This study has shown that there is an interaction between housing system and herd size, and that performance and health is not universally better in small free-stalls than in tie-stalls.
PMCID: PMC2833153  PMID: 20158884
5.  Temporal trends in reproductive performance in Irish dairy herds and associated risk factors 
Irish Veterinary Journal  2004;57(3):158-166.
Irish dairy herd fertility has been declining since the 1980s. The extent, nature and causes of this decline in fertility and the current status of Irish dairy herd fertility were described. An increase in calving interval of approximately one day per year has been recorded. The principal components of this trend have been an increased incidence of postpartum endocrinopathies, reduced expression of oestrus and a fall in conception rate. Both submission rate and calving-to-service interval have increased slightly over time. Significant risk factors associated with these trends have been strain substitution within the Holstein-Friesian breed and single trait selection for milk production. Critically, these changes have been reflected in loss of body condition. Contributory factors included increased herd size and possibly increased use of DIYAI. The most recent Irish study showed that 48% of cows conceived to first service and 14% of cows were not pregnant at the end of the industry-average 15-week spring breeding season. However, the top quartile of herds achieved a first-service conception rate of 59%, illustrating the wide variation between herds. These phenotypic trends were attributed to both genetic and environmental factors and their interactions. Recent Irish dairy herd fertility performance falls short of the targets set for seasonal compact calving.
PMCID: PMC3113820  PMID: 21851656
Cattle; Fertility; Genetics; Nutrition; Management
6.  Interrelationships between ambient temperature, age at calving, postpartum reproductive events and reproductive performance in dairy cows: a path analysis. 
Path analysis was used to determine the interrelationships between ambient temperature, age at calving, postpartum reproductive events and reproductive performance in dairy cows. The data used in the analysis were collected on 226 Holstein-Friesian cows calving in a commercial dairy herd during a 17 month period (May 1, 1981 to October 1, 1982). The data were obtained from a double blind study evaluating the effects of gonadotrophin releasing hormone and cloprostenol in postpartum cows. Rectal palpation to assess uterine involution and ovarian activity was performed on each cow on days 15, 24 and 28 postpartum. At the same time, blood samples were collected for subsequent progesterone assay. Data were recorded on the occurrence of reproductive diseases and events from the time of parturition until the diagnosis of pregnancy or until the cow left the herd in the case of culled cows. There was an increase in the incidence of retained placenta, in the percentage of cows with abnormal vaginal discharge in the early postpartum period as well as a delay in uterine involution during the winter months. In addition, cows calving during the winter had prolonged intervals to first estrus, first service and conception compared to cows calving during the summer. (Cows calving during the warmest months, on average, were seen in estrus 24 days sooner, received first service 42 days sooner and conceived 27 days sooner than cows calving during the coldest months of the year).(ABSTRACT TRUNCATED AT 250 WORDS)
PMCID: PMC1236166  PMID: 4041971
7.  Characterisation of the Repeat Breeding Syndrome in Swedish Dairy Cattle 
Acta Veterinaria Scandinavica  2002;43(2):115-125.
Repeat breeding (RB), defined as cows failure to conceive from 3 or more regularly spaced services in the absence of detectable abnormalities, is a costly problem for the dairy producer. To elucidate the occurrence of RB in Swedish dairy herds and to identify risk factors of the syndrome totally 57,616 dairy cows in 1,541 herds were investigated based on data from the official Swedish production-, AI- and disease- recording schemes. The characteristics of the RB syndrome were studied on both herd and individual cow level. The effects of risk factors on the herd frequency of RB were studied by logistic regression. A generalised linear mixed model with logit link, and accounting for herd-level variation by including a random effect of herd, was used to study the individual animal risk for RB.
The total percentage of RB animals was 10.1% and the median proportion of RB animals in the herds studied was 7.5%. The proportion of RB cows in herds increased with decreased herd sizes with decreased average days from calving to first AI, with increased herd incidence of clinical mastitis, with decreased reproductive disorders, and increased other diseases treated by a veterinarian. On animal level, the risk factors were milk yield, lactation number, difficult calving or dystocia, season at first service, days in milk at first service and veterinary treatment for reproductive disorders before the first service. Cows being an RB animal in the previous lactation had a higher risk of becoming an RB animal also in the present lactation. In conclusion our results show that the repeat breeding syndrome is a multifactorial problem involving a number of extrinsic factors as well as intrinsic factors coupled to the individual animal.
PMCID: PMC1764189  PMID: 12173501
fertility; repeat breeder; dairy cow
8.  Can pre-collected register data be used to identify dairy herds with good cattle welfare? 
Acta Veterinaria Scandinavica  2011;53(Suppl 1):S8.
Pre-recorded register data from dairy herds are available in almost all Nordic countries. These databases can be used for research purposes, and one of the research areas is animal welfare. The aim of this study was to investigate if pre-recorded register data could be used to identify herds with good welfare, and to investigate if a combination of register data sets could be used to be able to more correctly distinguish between herds with good welfare and herds with welfare deficiencies.
As a first step, nine animal-based measurements on calves, young stock and cows in 55 randomly selected herds were performed on-farm as the basis for a classification of welfare at the herd level. The definition for being a case herd with “good welfare” was no score lying among the 10% worst in any of the nine welfare measurements. Twenty-eight of the 55 herds were cases according to this definition. As a second step, 65 potential welfare indicators, based on register data in a national dairy database, were identified by expert opinion. In the final step, the extent to which the suggested welfare indicators predicted farms’ as having good welfare according to the stated definition was assessed. Moreover, the effect of combining in sequence a previously developed model that identified herds with poor welfare with the present model identifying herds with good welfare was investigated.
The final set of welfare indicators used to identify herds with good animal welfare included two fertility measures, cow mortality, stillbirth rate, mastitis incidence and incidence of feed-related diseases (including gastrointestinal disturbances but excluding paralyses and cramps). This set had a test sensitivity of correctly classifying herds with no score lying among the 10% worst of the nine welfare measurements of 96 %. However, the specificity of the test was only 56% indicating difficulties for the test to correctly classifying herds with one or more scores lying among the 10% worst. Combining the previously developed model with the present model, improved the welfare classification.
This study shows that pre-collected register data may be used to give approval to dairy farms with “good welfare” and that combining different sets of register data can improve the classification of herd welfare.
PMCID: PMC3194127  PMID: 21999569
9.  Paratuberculosis sero-status and milk production, SCC and calving interval in Irish dairy herds 
Irish Veterinary Journal  2009;62(Suppl 4):265-271.
The objective of this study was to investigate the impact of paratuberculosis sero-status on milk yield, fat, protein, somatic cell count and calving interval in Irish dairy herds. Serum from all animals over 12 months of age (n = 2,602) in 34 dairy herds was tested for antibodies to Mycobacterium avium subsp. paratuberculosis using an ELISA. Herds were categorised by sero-status into positive, non-negative and negative, where a positive herd contained two or more positive cows, a non-negative herd contained only one positive cow and a negative herd contained no positive cows. Data at animal, parity and herd-level were analysed by multiple regression using general linear models. Positive herds (mean herd size = 129 cows) and non-negative herds (81 cows) were larger than negative herds (72 cows) (P < 0.01). Negative herds had the highest economic breeding index (EBI), while positive herds had the highest estimated breeding value (EBV) for milk yield. There was no significant effect of paratuberculosis sero-status at animal, parity or herd-level on milk yield, milk fat or protein production, somatic cell count score (SCCS) or calving interval. Negative herds tended to have a lower SCCS than positive and nonnegative herds (P = 0.087). This study only examined the effects of paratuberculosis sero-status but did not examine the clinical effects of Johne's disease at the farm or dairy industry levels.
PMCID: PMC3339344  PMID: 21851733
calving interval; dairy cows; ELISA; milk yield; paratuberculosis; SCC
10.  Quantifying the Association between Bovine and Human Trypanosomiasis in Newly Affected Sleeping Sickness Areas of Uganda 
Uganda has active foci of both chronic and acute HAT with the acute zoonotic form of disease classically considered to be restricted to southeast Uganda, while the focus of the chronic form of HAT was confined to the northwest of the country. Acute HAT has however been migrating from its traditional disease focus, spreading rapidly to new districts, a spread linked to movement of infected cattle following restocking. Cattle act as long-term reservoirs of human infective T. b. rhodesiense showing few signs of morbidity, yet posing a significant risk to human health. It is important to understand the relationship between infected cattle and infected individuals so that an appropriate response can be made to the risk posed to the community from animals infected with human pathogens in a village setting.
Methodology/Principal Findings
This paper examines the relationship between human T. b. rhodesiense infection and human infective and non-human T. brucei s.l. circulating in cattle at village level in Kaberamaido and Dokolo Districts, Uganda. The study was undertaken in villages that had reported a case of sleeping sickness in the six months prior to sample collection and those villages that had never reported a case of sleeping sickness.
Conclusions and Significance
The sleeping sickness status of the villages had a significant effect with higher odds of infection in cattle from case than from non-case villages for T. brucei s.l. (OR: 2.94, 95%CI: 1.38–6.24). Cattle age had a significant effect (p<0.001) on the likelihood of T. brucei s.l. infection within cattle: cattle between 18–36 months (OR: 3.51, 95%CI: 1.63–7.51) and cattle over 36 months (OR: 4.20, 95%CI: 2.08–8.67) had significantly higher odds of T. brucei s. l. infection than cattle under 18 months of age. Furthermore, village human sleeping sickness status had a significant effect (p<0.05) on the detection of T. b. rhodesiense in the village cattle herd, with significantly higher likelihood of T. b. rhodesiense in the village cattle of case villages (OR: 25, 95%CI: 1.2–520.71). Overall a higher than average T. brucei s.l. prevalence (>16.3%) in a village herd over was associated with significantly higher likelihood of T. b. rhodesiense being detected in a herd (OR: 25, 95%CI: 1.2–520.71).
Author Summary
Human African trypanosomiasis (HAT) is a fatal parasitic disease of humans. Domestic cattle act as reservoirs for T.b. rhodesiense HAT. In a survey of cattle in Ugandan villages; six that had a reported HAT case in the previous six months, and six which did not, an association was detected between presence of HAT in a village and infection of village cattle with human infective parasites. Village HAT status was significant (p<0.05) for detection of T.b. rhodesiense in the village herd, with significantly greater likelihood of T.b. rhodesiense in herds from case villages (OR:25,95%CI:1.2–520.71). T. brucei s.l. prevalence of over 16.3% in cattle was associated with significantly greater likelihood of T.b. rhodesiense infection within the herd (OR:25, 95%CI:1.2–520.71). Cattle age had a significant effect (p<0.001) on the likelihood of a T. brucei s.l. infection: cattle between 18–36 months (OR:3.51,95%CI:1.63–7.51) and over 36 months (OR:4.20,95%CI:2.08–8.67) had significantly higher rates of T. brucei s.l. than animals under 18 months of age. Cattle are long-term reservoirs of T.b. rhodesiense that will outlive control strategies that do not directly eliminate parasite infection. T.b. rhodesiense and/or elevated T. brucei s.l. prevalence in village herds can serve as an indicator for HAT risk.
PMCID: PMC4046956  PMID: 24901845
11.  Bovine Herpesvirus Type 1 in the Sperm of a Bull From a Herd With Fertility Problems 
The Canadian Veterinary Journal  1980;21(12):336-339.
A herd of 125 Holstein cows manifested fertility problems for two years. The number of services per pregnancy was 2.97, conception rate was 33% after the first service, and the average number of open days was 127. Abortions occurred in four cows over the last 12 months. The herd was not vaccinated against any disease. Natural service by a bull and artificial insemination were used for breeding the cows. Bovine herpesvirus type 1 was demonstrated in sperm heads from the bull by direct and indirect fluorescent antibody techniques, and the virus was isolated on cell cultures. The virus was also isolated from the uterine secretions of some cows and from two aborted fetuses.
PMCID: PMC1789830  PMID: 6266630
12.  Isolation of Ureaplasma diversum and mycoplasmas from genital tracts of beef and dairy cattle in Saskatchewan 
We report herein a survey in which cultures of bovine reproductive tracts for Ureaplasma diversum and mycoplasmas were carried out in order to better understand the role of these organisms in granular vulvitis (GV). Samples cultured were vulvar swabs from clinically normal cows or ones with GV, preputial swabs or raw semen from bulls, and abomasal contents of aborted fetuses.
Ureaplasma diversum was isolated from 104 (43.3%) of 240 dairy cows, 32 (27.1%) of 118 beef cows, 43 (47.2%) of 91 beef heifers, 23 (67.6%) of 34 beef bulls, and three (60%) of five dairy bulls. Mycoplasmas were isolated from 18 (7.5%) dairy cows, two (1.6%) beef cows, three (8.8%) beef bulls, and one dairy bull. No isolation was made from 97 aborted fetuses. For 65 dairy cows and 30 beef heifers with vulvar lesions, the isolation rates for ureaplasmas of 62.5% and 69.7%, respectively, were significantly higher (X2) than those for normal animals (37.5% and 30.3%). On immunofluorescent serotyping of 137 of the 205 isolates, there were 66 in serogroup C (strain T44), 18 in serogroup B (strain D48), eight in serogroup A (strain A417 or strain 2312), 14 cross-reacting, and 31 that were not identified. It was concluded that U. diversum is commonly present in the lower reproductive tract of beef/dairy cattle in Saskatchewan and is associated with granular vulvitis.
PMCID: PMC1481172  PMID: 17423929
13.  Suboptimal Herd Performance Amplifies the Spread of Infectious Disease in the Cattle Industry 
PLoS ONE  2014;9(3):e93410.
Farms that purchase replacement breeding cattle are at increased risk of introducing many economically important diseases. The objectives of this analysis were to determine whether the total number of replacement breeding cattle purchased by individual farms could be reduced by improving herd performance and to quantify the effects of such reductions on the industry-level transmission dynamics of infectious cattle diseases. Detailed information on the performance and contact patterns of British cattle herds was extracted from the national cattle movement database as a case example. Approximately 69% of beef herds and 59% of dairy herds with an average of at least 20 recorded calvings per year purchased at least one replacement breeding animal. Results from zero-inflated negative binomial regression models revealed that herds with high average ages at first calving, prolonged calving intervals, abnormally high or low culling rates, and high calf mortality rates were generally more likely to be open herds and to purchase greater numbers of replacement breeding cattle. If all herds achieved the same level of performance as the top 20% of herds, the total number of replacement beef and dairy cattle purchased could be reduced by an estimated 34% and 51%, respectively. Although these purchases accounted for only 13% of between-herd contacts in the industry trade network, they were found to have a disproportionately strong influence on disease transmission dynamics. These findings suggest that targeting extension services at herds with suboptimal performance may be an effective strategy for controlling endemic cattle diseases while simultaneously improving industry productivity.
PMCID: PMC3966883  PMID: 24671129
14.  A field study on the usefulness of milk progesterone determination to confirm estrus and pregnancy of dairy cows in the Fraser Valley area of British Columbia 
The Canadian Veterinary Journal  1993;34(6):349-352.
A field study was conducted to determine the usefulness of milk progesterone determination at the time of breeding to confirm estrus and at 21 days postbreeding to detect open cows. Twenty-seven dairy farmers collaborated in this study by providing milk samples on the day of breeding and 21 days later, together with pregnancy diagnosis data and information on herd reproductive management. Herd size ranged from 15 to 175 cows, the average being 65 milking cows. Six hundred and sixty-seven breeding-day samples and 472, 21-day samples were provided by the farmers. Analysis of milk samples for progesterone by a solid phase radioimmunoassay showed that only 32 (4.8%) of the services were performed when the cow was not in estrus (progesterone > 1 ng/mL). Of the 472, 21-day samples, 337 (71%) showed progesterone levels of > 1 ng/mL, while 135 (29%) showed progesterone levels of < 1 ng/mL. Subsequently, 243 (72%) of the cows with progesterone > 1 ng/mL and eight (6%) of the cows with progesterone < 1 ng/mL were diagnosed pregnant by transrectal palpation, giving a pregnancy rate of 53%. Progesterone concentration on the day of breeding was not associated with season or herd size. However, progesterone concentration at 21 days and pregnancy rate were associated with herd size. These results indicate that fertillzation failure and/or early embryonic mortality, rather than inaccurate detection of estrus, are the major reproductive problems encountered by the dairy farmers in British Columbia. Furthermore, progesterone values at 21 days were closely related to reproductive status and indicate the usefulness of milk progesterone assay for the early detection of open cows.
PMCID: PMC1686551  PMID: 17424239
15.  Bovine viral diarrhoea virus seroprevalence and vaccination usage in dairy and beef herds in the Republic of Ireland 
Irish Veterinary Journal  2012;65(1):16.
Bovine viral diarrhoea (BVD) is an infectious disease of cattle with a worldwide distribution. Herd-level prevalence varies among European Union (EU) member states, and prevalence information facilitates decision-making and monitoring of progress in control and eradication programmes. The primary objective of the present study was to address significant knowledge gaps regarding herd BVD seroprevalence (based on pooled sera) and control on Irish farms, including vaccine usage.
Preliminary validation of an indirect BVD antibody ELISA test (Svanova, Biotech AB, Uppsala, Sweden) using pooled sera was a novel and important aspect of the present study. Serum pools were constructed from serum samples of known seropositivity and pools were analysed using the same test in laboratory replicates. The output from this indirect ELISA was expressed as a percentage positivity (PP) value. Results were used to guide selection of a proposed cut-off (PCO) PP. This indirect ELISA was applied to randomly constructed within-herd serum pools, in a cross-sectional study of a stratified random sample of 1,171 Irish dairy and beef cow herds in 2009, for which vaccination status was determined by telephone survey. The herd-level prevalence of BVD in Ireland (percentage positive herds) was estimated in non-vaccinating herds, where herds were classified positive when herd pool result exceeded PCO PP. Vaccinated herds were excluded because of the potential impact of vaccination on herd classification status. Comparison of herd-level classification was conducted in a subset of 111 non-vaccinating dairy herds using the same ELISA on bulk milk tank (BMT) samples. Associations between possible risk factors (herd size (quartiles)) and herd-level prevalence were determined using chi-squared analysis.
Receiver Operating Characteristics Analysis of replicate results in the preliminary validation study yielded an optimal cut-off PP (Proposed Cut-off percentage positivity - PCO PP) of 7.58%. This PCO PP gave a relative sensitivity (Se) and specificity (Sp) of 98.57% and 100% respectively, relative to the use of the ELISA on individual sera, and was chosen as the optimal cut-off since it resulted in maximization of the prevalence independent Youden’s Index.
The herd-level BVD prevalence in non-vaccinating herds was 98.7% (95% CI - 98.3-99.5%) in the cross-sectional study with no significant difference between dairy and beef herds (98.3% vs 98.8%, respectively, p = 0.595).
An agreement of 95.4% was found on Kappa analysis of herd serological classification when bulk milk and serum pool results were compared in non-vaccinating herds. 19.2 percent of farmers used BVDV vaccine; 81% of vaccinated herds were dairy. A significant association was found between seroprevalence (quartiles) and herd size (quartiles) (p < 0.01), though no association was found between herd size (quartiles) and herd-level classification based on PCO (p = 0.548).
The results from this study indicate that the true herd-level seroprevalence to Bovine Virus Diarrhoea (BVD) virus in Ireland is approaching 100%. The results of the present study will assist with national policy development, particularly with respect to the national BVD eradication programme which commenced recently.
PMCID: PMC3443026  PMID: 22849554
16.  The selenium status of dairy herds in Prince Edward Island 
The Canadian Veterinary Journal  2004;45(2):124-132.
Bulk tank milk selenium (Se) concentration was compared with mean serum Se concentration in 15 herds and was found to be an accurate reflection of the herd Se status. The Se status of 109 Prince Edward Island (PEI) dairy herds was monitored for 1 year using bulk tank milk Se concentration. Fifty-nine percent of the herds surveyed were, at some point, found to be marginal or deficient in Se, putting them at risk of disease and suboptimal production. The periods of greatest risk of deficiency were fall and winter, at which time 5% and 4%, respectively, of herds sampled fell in the range considered truly deficient in Se. Herds in which Se supplementation was provided in the form of a commercial dairy concentrate were over 4 times more likely to be Se-adequate than herds not using this method, and adjusted average daily milk yield was 7.6% greater in herds determined to be Se-adequate when compared with Se-marginal herds. We conclude that many dairy producers in PEI are providing insufficient supplementary Se in the ration to meet the recommended Se intake for lactating cows.
PMCID: PMC548601  PMID: 15025148
17.  The Effect of Clinical Outbreaks of Salmonellosis on the Prevalence of Fecal Salmonella Shedding Among Dairy Cattle in New York 
Foodborne Pathogens and Disease  2010;7(7):815-823.
The objective of this study was to determine if the within-herd prevalence of fecal Salmonella shedding is higher in dairy herds with clinical outbreaks of disease, as compared to herds with subclinical infections only. Data were collected prospectively from dairy herds throughout New York that had at least 150 lactating cows and that received clinical service from participating veterinarians. After enrollment, Salmonella surveillance consisted of both environmental screening and disease monitoring within the herd. Herds positive by either environmental or fecal culture were sampled during three visits to estimate the within-herd prevalence of Salmonella. We characterized isolates by serovar and antimicrobial resistance pattern. Among 57 enrolled herds, 44 (77%) yielded Salmonella-positive samples during the study period; 27 (61%) of the positive herds had Salmonella isolated from environmental samples only, and 17 (39%) had one or more laboratory-confirmed clinical cases. The within-herd prevalence of fecal Salmonella shedding ranged from 0 to 53%. Salmonella Cerro was the predominant serovar, accounting for 56% of all isolates. Antimicrobial resistance ranged from zero to nine drugs, and 14 (32%) of the positive farms generated multidrug-resistant isolates. Herds with laboratory-confirmed clinical cases had a higher prevalence of fecal Salmonella shedding than herds that only generated positive environmental samples, as estimated by a Poisson regression model (prevalence ratio, 2.7; p = 0.01). An association between dairy herd outbreaks of salmonellosis and a higher prevalence of asymptomatic shedding should help guide strategies for reducing the public health threat of Salmonella, as the ability to recognize high-risk herds by clinical laboratory submissions presents an obvious opportunity to maximize food safety at the preharvest level. This is in contrast with other foodborne zoonotic pathogens, such as Campylobacter jejuni and Escherichia coli O157:H7, which occur widely in adult cattle without accompanying clinical disease.
PMCID: PMC3132070  PMID: 20353290
18.  Bovine mastitis in Ontario due to Mycoplasma agalactiae subsp. bovis. 
Bovine mastitis caused by Mycoplasma agalactiae subsp. bovis was first diagnosed in 16 of 55 cows in an Ontario herd in Feburary 1972. A total of 182 of 598 (30.4%) cows from 33 of 64 (51.5%) farms in widely separated areas of the province were culturally positive. Herd incidence varied from 15 to 40% with one closed herd having an incidence of 61%. Four herds were investigated culturally and serologically by the growth inhibition test for 15 months. In the acute phase the organism was present in the milk in extremely high numbers and could still be isolated from a few cows after eight to 12 months. The sera from 89.5% of the animals with clinical mycoplasma mastitis produced a zone of surface "film" and/or colony inhibition and some cows remained positive for six to 12 months. The disease was experimentally reproduced with a pure culture of the organism isolated from the milk of a cow from one of the herds.
PMCID: PMC1277538  PMID: 1000385
19.  Leptospirosa pomona Abortion Storm in a Cattle Herd in Saskatchewan 
The Canadian Veterinary Journal  1986;27(11):440-442.
Abortions occurred in 18% of 131 beef cows and heifers during two months, on a farm in southern Saskatchewan. The losses began two weeks after acute febrile illness and agalactia in a dairy cow to which the beef herd had been exposed. A diagnosis of Leptospira interrogans serovar pomona infection was made on the basis of serology in cows and the finding of leptospires in fetal tissues by fluorescent antibody test. Tentative diagnosis of infectious bovine rhinotracheitis delayed treatment and prophylaxis until infection attained high intensity in the herd and severe losses to the farmer occurred. Abortions ceased after vaccination against pomona and oxytetracycline treatment of pregnant cows, although chronic debility followed the acute phase of the disease in some cows. Recrudescence of infection was suspected four months later, when acute agalactia occurred in one cow and debility in calves and cows was recurring. Pomona infection was not proven, but dihydrostreptomycin treatment and revaccination were applied to the whole herd. Seroconversion and IgM antibody continued to indicate a persistent source of infection and susceptibility in a minority of the population one year after onset. The source of the original infection is believed to have been a carrier beef cow, or a dairy cow which was leptospiruric at the time of contact with the beef herd. With the exception of one aborted calf, no evidence of pomona infection was found outside the farm, in cattle or wild mammals tested serologically within a radius of 30 km, during one year following the outbreak.
PMCID: PMC1680310  PMID: 17422717
Abortion; bovine; pomona; leptospirosis
20.  Veterinary dairy herd fertility service provision in seasonal and non-seasonal dairy industries - a comparison 
Irish Veterinary Journal  2010;63(4):230-235.
The decline in dairy herd fertility internationally has highlighted the limited impact of traditional veterinary approaches to bovine fertility management. Three questionnaire surveys were conducted at buiatrics conferences attended by veterinary practitioners on veterinary dairy herd fertility services (HFS) in countries with a seasonal (Ireland, 47 respondents) and non-seasonal breeding model (The Netherlands, 44 respondents and Portugal, 31 respondents). Of the 122 respondents, 73 (60%) provided a HFS and 49 (40%) did not. The majority (76%) of all practitioners who responded stated that bovine fertility had declined in their practice clients' herds with inadequate cow management, inadequate nutrition and increased milk yield as the most important putative causes. The type of clients who adopted a herd fertility service were deemed more educated than average (70% of respondents), and/or had fertility problems (58%) and/or large herds (53%). The main components of this service were routine postpartum examinations (95% of respondents), fertility records analysis (75%) and ultrasound pregnancy examinations (69%). The number of planned visits per annum varied between an average of four in Ireland, where breeding is seasonal, and 23 in Portugal, where breeding is year-round. The benefits to both the practitioner and their clients from running a HFS were cited as better fertility, financial rewards and job satisfaction. For practitioners who did not run a HFS the main reasons given were no client demand (55%) and lack of fertility records (33%). Better economic evidence to convince clients of the cost-benefit of such a service was seen as a major constraint to adoption of this service by 67% of practitioners.
PMCID: PMC3113840  PMID: 21851745
Reproductive management; questionnaire survey; veterinary services
21.  Relationship between herd-level incidence rate of energy-related postpartum diseases, general risk factors and claw lesions in individual dairy cows recorded at maintenance claw trimming 
Laminitis and energy-related postpartum diseases share several risk factors, indicating a common etiology. Thus, a herd’s incidence rate of energy-related postpartum diseases, such as displaced abomasum and clinical ketosis, might reflect the likelihood of cows to suffer from laminitis-related claw lesions. The aim of this study was to investigate the association between herd-level incidence rate of displaced abomasum and clinical ketosis, general risk factors, and claw lesions in individual cows recorded at maintenance claw trimming.
The dataset consisted of 6773 trimmings, performed between 2004 and 2006 by professional trimmers, from 3607 Swedish Red and Swedish Holstein cows in 26 herds. The herds were classified as having a high, inconsistent-high or low incidence rate of energy-related postpartum diseases, based on the number of recorded cases of veterinary-diagnosed displaced abomasum and clinical ketosis in the Swedish national animal disease recording system during 2002 to 2006, and observations and interviews in connections with herd visits. Generalized linear mixed models were used to investigate the association between herd-level incidence rate of energy-related postpartum diseases and laminitis-related lesions including sole ulcer and sole hemorrhage; and hygiene-related lesions including interdigital dermatitis, digital dermatitis, heel-horn erosion, verrucose dermatitis, and interdigital hyperplasia; and absence of any claw lesion. Systematic effects, including first-order interactions, with P < 0.05 were included in the models. Herd classification was forced into the models, and a random effect of herd was included.
In comparison to herds with a high incidence rate of energy-related postpartum diseases, low-incidence herds showed a lower odds ratio (OR; 0.2) for laminitis-related lesions in cows trimmed during the summer months. Low-incidence herds also showed numerically lower OR estimates for laminitis-related lesions in all parity classes and a numerically lower OR for hygiene-related lesions. In addition, low-incidence herds showed tendencies towards a numerically higher OR for absence of any lesion, irrespective of trimming season or parity.
Only a few statistically significant associations were found, but several tendencies pointed towards better claw health in herds with low as compared with high incidence rate of energy-related postpartum diseases.
PMCID: PMC3737044  PMID: 23880035
Dairy cow; Energy-related metabolic diseases; Claw trimming; Claw lesions; Risk factors
22.  Vulvitis plasmacellularis: two new cases. 
Genitourinary Medicine  1995;71(5):311-313.
Vulvitis chronica plasmacellularis or Zoon's vulvitis is a rare benign circumscribed inflammation of the vulvar mucosa. It is found in women ranging in age from 26 to 70 years. Shiny, macular erythematous lesions, which are irregular in shape and sharply marginated are usually observed. The histologic findings show chronic subepithelial dense inflammation composed largely of plasma cells. We here report two cases of vulvitis plasmacellularis with typical clinical manifestations, courses and histopathologic findings.
PMCID: PMC1195548  PMID: 7490049
23.  A polymorphism in the insulin-like growth factor 1 gene is associated with postpartum resumption of ovarian cyclicity in Holstein-Friesian cows under grazing conditions 
Insulin-like growth factor 1 (IGF-1) gene is considered as a promising candidate for the identification of polymorphisms affecting cattle performance. The objectives of the current study were to determine the association of the single nucleotide polymorphism (SNP) IGF-1/SnaBI with fertility, milk production and body condition traits in Holstein-Friesian dairy cows under grazing conditions.
Seventy multiparous cows from a commercial herd were genotyped for the SNP IGF-1/SnaBI. Fertility measures evaluated were: interval to commencement of luteal activity (CLA), calving to first service (CFS) and calving to conception (CC) intervals. Milk production and body condition score were also evaluated. The study period extended from 3 wk before calving to the fourth month of lactation.
Results and discussion
Frequencies of the SNP IGF-1/SnaBI alleles A and B were 0.59 and 0.41, respectively. Genotype frequencies were 0.31, 0.54 and 0.14 for AA, AB and BB, respectively. Cows with the AA genotype presented an early CLA and were more likely to resume ovarian cyclicity in the early postpartum than AB and BB ones. No effect of the SNP IGF-1/SnaBI genotype was evidenced on body condition change over the experimental period, suggesting that energy balance is not responsible for the outcome of postpartum ovarian resumption in this study. Traditional fertility measures were not affected by the SNP IGF-1/SnaBI.
To our knowledge this is the first report describing an association of the SNP IGF-1/SnaBI with an endocrine fertility measure like CLA in cattle. Results herein remark the important role of the IGF-1gene in the fertility of dairy cows on early lactation and make the SNP IGF-1/SnaBI an interesting candidate marker for genetic improvement of fertility in dairy cattle.
PMCID: PMC3599257  PMID: 23409757
IGF-1; Polymorphism; Commencement of luteal activity; Cattle
24.  The genital Mycoplasma and Ureaplasma flora of healthy and diseased dogs. 
The genital mycoplasma and ureaplasma flora was compared in 136 dogs with varied reproductive histories. Mycoplasmas were recovered from 88% of vulvovaginal swabs, 85% preputial swabs and 72% semen samples. Isolation rates were slightly higher from dogs that were infertile or had evidence of genital disease but the differences from those that were fertile or clinically normal were statistically significant only in the male. Ureaplasmas were recovered from half the females sampled. Higher, but not statistically significant isolation rates (75%) were made from infertile females with purulent vulvar discharge versus those that were clinically normal and fertile (40%). In the male dog there was a significantly higher incidence of ureaplasmas in the prepuce of infertile animals (69%) than those that were fertile (0%) (p less than or equal to 0.05). Semen isolations although not significantly higher in infertile males, were all made from ejaculates, with subnormal motility, low sperm counts and/or a high percentage of midpiece and tail abnormalities (bent or tightly coiled).
PMCID: PMC1320213  PMID: 7340908
25.  Salmonella enterica Serotype Cerro Among Dairy Cattle in New York: An Emerging Pathogen? 
Foodborne Pathogens and Disease  2010;7(6):659-665.
The focus of this study was Salmonella enterica serotype Cerro, a potentially emerging pathogen of cattle. Our objectives were to document the within-herd prevalence of Salmonella Cerro among a sample of New York dairy herds, to describe the antimicrobial resistance patterns and pulsed-field gel electrophoresis types of the isolates, and to elucidate the status of this serotype as a bovine pathogen. Data were collected prospectively from dairy herds throughout New York that had at least 150 lactating cows and that received clinical service from participating veterinarians. Following enrollment, Salmonella surveillance consisted of both environmental screening and disease monitoring within the herd. Herds positive by either environmental or fecal culture were sampled during three visits to estimate the within-herd prevalence of Salmonella. Among 57 enrolled herds, 44 (77%) yielded Salmonella-positive samples during the study period. Of these, 20 herds (46%) were positive for Salmonella Cerro. Upon follow-up sampling for estimation of prevalence, Cerro was identified in 10 of the 20 herds; the median within-herd Cerro prevalence was 17%, with a maximum of 53%. Antimicrobial resistance ranged from zero to nine drugs, and eight (40%) of the Cerro-positive farms generated drug-resistant isolates. Eight XbaI pulsed-field gel electrophoresis types were represented among 116 isolates tested, although 89% of these isolates shared the predominant type. Among herds with clinical cases, cattle that had signs consistent with salmonellosis were more likely to test positive for Cerro than apparently healthy cattle, as estimated by a logistic regression model that controlled for herd as a random effect (odds ratio: 3.9). There is little in the literature concerning Salmonella Cerro, and published reports suggest an absence of disease association in cattle. However, in our region there has been an apparent increase in the prevalence of this serotype among cattle with salmonellosis. Other Salmonella serotypes important to bovine health have emerged to become leading causes of human foodborne disease, and close monitoring of Cerro is warranted.
PMCID: PMC3132111  PMID: 20187753

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