Adult Dairy Cattle Research Articles

Defining ruminal and total-tract starch degradation for adult dairy cattle using in vivo data

Literature was searched for studies performed in adult dairy cattle that simultaneously measured starch degradability in the rumen (RSDeg) and starch digestion in the total tract to compute postruminal starch digestion (PRSDig). Forty-one studies with 161 dietary treatments were used to form the data set. Of these diets, the major starch source was corn for 83 diets, small grain for 58 diets, and sorghum for 8 diets. Corn RSDeg was more variable than other sources. As measured in vivo across all starch sources, the percent RSDeg was influenced only by the amount of starch consumed, with the amount of degradation being approximately 75% at low starch intakes and decreasing to about 60% when 4kg or more of starch were consumed. Small grain starch had greater RSDeg than corn or sorghum starch, which were approximately equal. The PRSDig of corn and small grain starches were approximately equal, but sorghum was about 15% less. Across all diets, models derived from the Cornell Net Carbohydrate Protein System predicted percentage of total-tract digestibility of starch very accurately, but overpredicted RSDeg and, as a result, underpredicted percent PRSDig. Calculation of RSDeg using a French model predicted the mean RSDeg with greater accuracy but less precisely. The relative differences in RSDeg percent among starch sources was correctly predicted by these models. A model using a revised rate of digestion as a way of combining effects of starch type and processing was developed, which predicted corn starch RSDeg and PRSDig with greater accuracy than nutrition models but only slightly better than using the mean observed degradation or the French calculation. Inaccuracies in prediction of RSDeg may be due mainly to processing effects and particle sizes, but these were not well reported in literature studies and were difficult to estimate. More accurate assessment of RSDeg and PRSDig will require better and more consistent reporting of grain processing. Based on this study, the French calculation is the most accurate of the models examined, although adjustments will be required to improve accuracy.

Immunization of adult dairy cattle with a new heat-killed vaccine is associated with longer productive life prior to cows being sent to slaughter with suspected paratuberculosis

The objective of this study was to evaluate the efficacy of a new heat-killed Mycobacterium avium ssp. paratuberculosis (MAP) vaccine for control of premature culling in tuberculosis-free dairy cattle. Feces and gastrointestinal tissues were collected from 50 vaccinated cows and 38 nonvaccinated cows at slaughter and analyzed by bacteriological culture and histopathology. Vaccination was associated with a significant reduction of the frequency of vaccinated animals with MAP in feces and gut tissues compared with the nonvaccinated animals. In addition, the frequency of vaccinated animals with heavy bacterial load in gut tissues was 40% lower than the frequency of the nonvaccinated animals with the same MAP load. The peak age of paratuberculosis-associated culling was from 4.5 to 5 yr old (21%) in the vaccinated animals and from 3 to 4.5 yr old (60%) in the nonvaccinated animals. The vaccinated and nonvaccinated animals with suspected paratuberculosis were culled at an average age of 4.7 and 3.7 yr old, respectively. Therefore, a significant increase in the productive life of the vaccinated animals sent to slaughter with suspected paratuberculosis was observed. In addition, our analysis revealed a positive effect of the vaccine on the carcass weights of the animals with severe histopathological lesions at slaughter compared with the nonvaccinated animals. In summary, our findings suggest a therapeutic effect of the vaccine and a significant attenuation of pre-existing infection in cows naturally infected with paratuberculosis that were adults at the time of vaccination.

Evaluation of the humoral immune response in adult dairy cattle three years after vaccination with a bluetongue serotype 8 inactivated vaccine

Despite the widespread use of bluetongue serotype 8 (BTV-8) inactivated vaccines across Europe from 2008 to 2011, two very practical questions remain unanswered about the length of persistence of group-specific antibodies in milk and serum post-vaccination and the duration of protection beyond one year post-vaccination. This study has firstly revealed that group-specific antibodies persist at high levels in milk and serum in the majority of cattle for at least 3 years post-vaccination, thus removing the option of using these animals in ELISA-based surveillance programmes. Secondly neutralising antibodies have been shown to persist in the majority of cattle for at least 3 years post-vaccination, indicating that the cattle are likely to be protected for this time period. This extended duration of protection may have contributed towards the rapid and efficient eradication of BTV-8 from many European countries, despite reducing levels of vaccine coverage.

Anthropogenic and meteorological factors influence vector abundance and prevalence of bluetongue virus infection of dairy cattle in California

Bluetongue is an economically important arboviral disease of ruminants that is transmitted by hematophagous Culicoides midges. In light of dramatic recent changes in the global distribution of bluetongue virus (BTV), the goals of this study were to re-evaluate the prevalence of BTV infection of cattle and abundance of Culicoides midges on individual dairy farms in California. A serosurvey of adult dairy cattle confirmed that BTV infection is prevalent throughout much of the state, although the coastal northwestern region remains free of infection and prevalence varies markedly among farms in the remainder of the state. Intensive sampling for one year of 4 farms in the northern Central Valley of California showed that the abundance of Culicoides midges was markedly different and coincided with the prevalence of BTV infection of sentinel cattle on each farm. Mean maximum and minimum temperatures and other meteorological parameters were similar on all 4 farms, thus we speculate that particular management practices were responsible for both the increased midge abundance and prevalence of BTV infection of cattle at individual farms. Specifically, it is concluded that variation in vector abundance at individual farms most likely is the result of waste-water lagoon and irrigation management practices, leading to higher BTV infection rates among livestock held on farms with more waste-water lagoons and greater acreage of land for waste-water irrigation.

Cryptosporidium andersoni is the predominant species in post-weaned and adult dairy cattle in China

Dairy industry plays an important role in the agricultural economy of China. To estimate the prevalence and public health significance of cryptosporidiosis in post-weaned and adult dairy cattle in China, during four consecutive years (from 2006 to 2009), a total of 1315 fecal samples from 22 dairy cattle farms in ten prefectures in Henan Province were examined for the presence of Cryptosporidium oocysts. The overall prevalence of Cryptosporidium was 7.9%, with the highest infection rate (11.3%) in 3 to 11-month-old calves and the lowest infection rate (1.0%) in >2-year-old cows (p<0.01). Cryptosporidium-positive samples (n=104) were analyzed by PCR-restriction fragment length polymorphism (RFLP) analysis of the small subunit (SSU) rRNA gene, and 25 representative samples were further analyzed by DNA sequencing of the PCR products. Cryptosporidium bovis and Cryptosporidium andersoni were identified. C. andersoni (84/104) was the predominant species and was found in all age groups, whereas C. bovis (20/104) was only detected in 3 to 11-month-old calves. Thus, C. andersoni appears to be the dominant species in weaned dairy calves and heifers in China, in contrast with its common occurrence in adult cattle in other parts of the world.

HEMORRHAGIC BOWEL SYNDROME IN DAIRY CATTLE IN IRAN: A CASE REPORT

Summary Hemorrhagic bowel syndrome is a highly fatal intestinal disease of adult dairy cattle with uncertain cause. In a dairy herd in Khorasan Razavi province, Northeast of Iran, two cows showed depression, anorexia, decrease in milk production, ruminal hypomotility, bruxism and dehydration. At necropsy, massive hemorrhage and clot formation was observed within the jejunum and bacterial culture of the intestinal ingesta and lesions showed the presence of a large number of Clostridium perfringens. Subacute ruminal acidosis was detected in fresh and mid-lactation cows. This report shows the possibility of diagnosis of other hemorrhagic bowel syndrome cases in dairy cows in Iran.

Gastrointestinal nematode infections in adult dairy cattle: Impact on production, diagnosis and control

Due to the intensification of dairy herds and the recognition of subclinical infections with a negative impact on production as disease, control of gastrointestinal (GI) nematodes in adult cows is becoming established in an increasing number of dairy herds. The objectives of this paper are to review the aspects related to the impact on production, diagnosis and control of GI nematodes in adult dairy cattle. During the last decade substantial evidence has been generated that GI nematodes can have a negative impact on the performance of adult animals. The milk-yield response to anthelmintic treatment in recent studies in pastured dairy herds was observed to be around 1 kg/cow per day, whereas effects on reproductive performance remain equivocal. GI-nematode infections can be monitored based on Ostertagia ostertagi-specific antibody measurement, which provides information on the level of larval exposure and an indication of the associated production losses. Other diagnostic parameters are considered of limited use in adult cattle. Control relies on anthelmintic treatment and grazing management, which can be used complementary to each other. There are three critical points that need to be considered when developing anthelmintic control recommendations in adult cows: the unpredictability of the treatment response, the timing of treatment and the risk for developing anthelmintic resistance. As a consequence, monitoring of GI-nematode infections is desirable in order to focus anthelmintic treatments on those herds with a high larval challenge and associated production losses. For the future, more studies are needed to evaluate the effects of different control approaches in terms of financial benefits for the farmer and sustainability on the long term.

Seroprevalence estimation and management factors associated with high herd seropositivity for Babesia bovis in commercial dairy farms of Puerto Rico

A cross-sectional study was conducted to determine individual cow seroprevalence of Babesia bovis in adult lactating dairy cattle of Puerto Rico (PR), to assess the associations of farm management factors on herd seroprevalence, and to document the species of ticks infesting cattle within these farms. Antibody activity against B. bovis was determined using an indirect fluorescent antibody test (IFAT). Serum samples were obtained from 2,414 adult lactating dairy cattle from 76 randomly selected commercial dairy farms. Herd seroprevalence ranged from 0 to 51% with an overall individual cow seroprevalence for B. bovis of 26%. Ticks were collected from animals on 7 (9%) of the 76 participating commercial dairy farms. All collected ticks (n = 87) were Rhipicephalus (Boophilus) microplus. Factors associated with high herd seropositivity were dairy farms with calf but not heifer raising facilities (OR = 16, 95% CI = 3.0-86), having more than 4 neighbors with cattle (OR = 17, 95% CI = 1.6-178), same producer owning more than one farm (OR = 7.2, 95% CI = 1.6-32), and use of government services to apply amitraz on cattle (OR = 5.5, 95% CI = 1.5-20).

Seroprevalence estimation and management factors associated with high herd seropositivity for Anaplasma marginale in commercial dairy farms of Puerto Rico

A cross-sectional study was conducted to determine individual cow seroprevalence of Anaplasma marginale in adult lactating dairy cattle of Puerto Rico (PR) and to assess the associations of farm management factors on herd seroprevalence. Antibody activity against A. marginale was determined using the MSP-5 competitive enzyme-linked immunosorbent assay. Serum samples were obtained from 2,414 adult lactating dairy cattle from 76 randomly selected commercial dairy farms. Herd seroprevalence ranged from 3 to 100% with an overall individual cow seroprevalence for A. marginale of 27.4%. Factors associated with high herd seropositivity were pasture grazing as the main feed source (OR = 6.5, 95% CI = 1.2-34), observed monkeys on the premises (OR = 13, 95% CI = 1.2-138), use of 11% permethrin (OR = 17, 95% CI = 2.2-129), farmers who attended an acaricide certification program (OR = 0.18, 95% CI = 0.04-0.74), and lack of a fly control program (OR = 5.6, 95% CI = 1.3-24).

The first detection of Cryptosporidium deer-like genotype in cattle in Japan

The general perception is that cattle are major reservoirs for Cryptosporidium parvum infections in humans and that C. parvum is a major cause of diarrhea and production loss in cattle. Adult cattle may play an important role as cryptic carrier of the infection. Cryptosporidium spp. in asymptomatic adult dairy cattle from some farms around Osaki area, Miyagi prefecture, Japan, was examined on a field visit during August, 2007, by polymerase chain reaction techniques for detection, genotyping, and subtyping. Cryptosporidium oocysts were detected in the feces of five out of 50 animals. Of the five Cryptosporidium-positive specimens available for molecular analysis, C. parvum was identified in three specimens, Cryptosporidium deer-like genotype in one, and Cryptosporidium andersoni in one specimen. Amplification of Cpgp60 from C. andersoni and Cryptosporidium deer-like genotype samples revealed that these samples have light concurrent C. parvum infection. Sequence analysis of the 60-kDa glycoprotein gene indicated that all C. parvum samples are IIa subtype. Detection of Cryptosporidium deer-like genotype is geographically unique in Japan. The genetic diversity of Cryptosporidium in dairy cattle in Japan may be much greater than that reported before.

Study on diagnostic values of haptoglobin and serum amyloid A concentration in bovine heart diseases

Two hundred dairy breed cattle of different ages [42 were between 3 and 6 months (20 males and 22 females), 55 cases were heifers (16–24 months old) and the rest were adult dairy cattle] from four dairy farms were examined by auscultation. Seventy-seven cases out of 200 cattle had various types of functional (n = 50) and pathological (n = 10) murmurs, pericarditis (n = 10), and endocarditis (n = 7). Twenty normal cattle without any sign of heart disease and cardiac murmurs were also taken as a control group. Blood samples were taken from all cattle having cardiac disorders and control group for determination of haptoglobin (Hp), serum amyloid A (SAA), and complete blood count. White blood cell (WBC) of cases with endocarditis was significantly higher than other groups. Cases with pericarditis and endocarditis had the highest Hp and SAA levels, respectively. The optimal cutoff point was set, by the receiver operating characteristics method, to >4.74 μg/ml for SAA and >0.14 g/l for Hp with corresponding 58.44% sensitivity and 80.00% specificity for SAA and 22.08% sensitivity and 100% specificity for Hp. Our study showed that for differentiation of four types of cardiac disorders mentioned (functional murmurs, pathologic murmurs, endocarditis, and pericarditis), SAA determination is more suitable than Hp and WBC count.

An outbreak of dictyocaulosis in lactating cows on a dairy farm

The owner of a herd of 74 Holstein-Friesian cattle reported decreased milk production, weight loss, and coughing among lactating cows. Owner-initiated antimicrobial treatment was unsuccessful; 1 lactating cow died, and 50% of the lactating cows had clinical signs of respiratory distress, such as tachypnea and coughing. On the basis of history, physical examination findings, and fecal examination results, affected animals were determined to have Dictyocaulus viviparus (lungworm) infestation. The disease history suggested that the herd contained cows with subclinical patent lungworm infestations; after introduction of susceptible heifers, the pastures had become heavily infested with D viviparus and clinical problems subsequently developed in both newly introduced and resident cows. Affected and unaffected heifers and adult cows were treated with a pour-on formulation of eprinomectin (0.5 mg/kg [0.23 mg/lb]). One animal died, but 2 weeks after treatment, clinical signs among affected cattle were markedly improved. Ten weeks after treatment, milk production improved from 23 kg/cow/d (51 lb/cow/d) to 28 kg/cow/d (62 lb/cow/d). The outbreak provides additional evidence that dictyocaulosis is becoming more common among adult dairy cattle, rather than almost exclusively affecting young stock. This may be attributable to anthelmintic use and management practices on dairy farms. Combined with anecdotal reports of an increase in the incidence of dictyocaulosis among adult cattle in North America, D viviparus infestation should be included as a differential diagnosis for decreased milk production, weight loss, and coughing among adult dairy cattle.

Microbiological differences between cull cattle slaughtered at an abattoir and cull cattle slaughtered on farms

Tissue samples from 27 casualty adult dairy cattle slaughtered on farms and 32 ‘normal’ cull dairy cattle were analysed microbiologically for total viable counts (tvc), Enterobacteriaceae, Escherichia coli o157, Salmonella...

Methods and normal values for echocardiography in adult dairy cattle

Objective The objective of the study was to report normal ultrasonographic appearance and intra-cardiac dimensions in two dairy breeds and to calculate cardiac output (CO) using echocardiography. Background Intra-cardiac dimensions, time indices and CO estimation have not previously been reported in adult cattle. Animals, materials and methods Echocardiograms were obtained from healthy adult dairy cows (10 Jersey (J) and 12 Holstein Friesians (HF)) in the body weight range of 400 to 700 kg. Standard echocardiographic images were obtained from the left and right hemithoraces. Velocity time integrals were obtained in order to calculate CO using pulsed wave Doppler of aortic flow in the J cows. Measurements obtained included pulmonary artery and aortic diameters, left and right ventricular diameters (and calculated fractional shortening and left ventricular ejection fraction), left atrial size and time indices assessing valve function. Results HF cows had significantly ( p < 0.05) larger pulmonary artery and aortic diameters, larger left atrial diameters and left ventricular internal diameters during diastole, but these were not different when corrected for body weight. Left and right ventricular dimensions, adjusted for body weight, were significantly larger ( p = 0.02 and p = 0.035 respectively) in J cows when compared to HF cows. No differences were noted in the time indices between the two groups. No significant differences were noted in intra-operator variability and the only significant difference in inter-operator variability was in measurement of the pulmonary artery ( p = 0.03; ICC = 0.63). Conclusions It is possible to obtain repeatable, reliable echocardiograms in order that meaningful intra-cardiac dimensions can be obtained in adult dairy cattle.

Effect of hyperimmunization with an Escherichia coli J5 bacterin in adult lactating dairy cows

To determine the effect of hyperimmunization with an Escherichia coli J5 bacterin on serum IgG2 concentration, incidence of clinical mastitis, and rate of survival to the end of the lactation period (ie, day 305) in adult lactating dairy cattle. Randomized controlled trial. 1,012 Holstein cows in their second lactation and greater. All cows were given 3 doses of the J5 bacterin; cows in the hyperimmunization group were given an additional 3 doses during the first 3 months of lactation. Blood was collected from a small sample of cows to determine anti-J5 IgG2 concentrations. Cows in the hyperimmunization group had higher mean serum anti-J5 IgG2 concentrations than did control cows 28 days after administration of the fourth, fifth, and sixth doses of the J5 bacterin. However, mean serum anti-J5 concentrations during the subsequent lactation were not significantly different between groups. The proportions of cows that developed clinical mastitis were not significantly different between groups. However, control cows were more likely to have severe clinical mastitis than were cows in the hyperimmunization group. The percentage of control cows that remained in the herd to day 305 was significantly lower than the percentage of cows in the hyperimmunization group that did. Results suggested that hyperimmunization of mature lactating dairy cattle was associated with increased serum anti-J5 IgG2 concentrations and decreased incidence of severe clinical mastitis, but did not alter survival rate of cows that developed severe clinical mastitis.

Field testing of an enhanced direct-fecal polymerase chain reaction procedure, bacterial culture of feces, and a serum enzyme-linked immunosorbent assay for detecting Mycobacterium avium subsp paratuberculosis infection in adult dairy cattle

To estimate the sensitivity (Se) and specificity (Sp) for an enhanced direct-fecal PCR procedure, bacterial culture of feces (BCF), and a serum ELISA for detecting Mycobacterium avium subsp paratuberculosis (MAP) infection in adult dairy cattle. Fecal and serum samples were collected from 669 adult cattle randomly selected from a 4,000-cow dairy herd known to contain animals infected with MAP. Serum samples were evaluated for MAP-specific antibodies via ELISA. Fecal samples were evaluated by BCF and enhanced PCR methods (both gel-based [GB]-PCR and quantitative real-time [qRT]-PCR assays). Fecal samples also were pooled (5:1) and then subjected to GB-PCR assay. Bayesian statistical methods were used to estimate Se and Sp for each diagnostic test without knowledge concerning true MAP infection status. Adjusting for Se conditional dependence between serum ELISA and BCR, overall Se and Sp were estimated at 33.7% and 95.9%, 51.3% and 99.0%, and 32.2% and 100% for serum ELISA, qRT-PCR, and BCF, respectively.The GB-PCR assay yielded positive results for 38.3% of the pools known to contain feces from at least 1 cow that had positive GBPCR results. Estimated Se values for the serum ELISA and BCF were slightly lower than those reported elsewhere. The enhanced qRT-PCR method offered relative improvements in Se of 52% and 59% over serum ELISA and microbial culture, respectively. Pooling of fecal samples and testing with the GB-PCR assay are not recommended. Additional studies with qRT-PCR and fecal pools are required.

Clinical and Surgical Findings and Outcome Following Rumenotomy in Adult Dairy Cattle Affected with Recurrent Rumen Tympany Associated with Non-Metallic Foreign Bodies

Medical records of 31 adult dairy cows suffering from recurrent rumen tympany for at least 1 month duration that underwent exploratory laparotomy and rumenotomy were reviewed and information was obtained on signalment, history, physical examination findings, laboratory findings and surgical findings. Cases were categorized according to surgical findings into 3 groups. Group 1 (n = 10) included cattle with reticuloruminal, metallic foreign bodies and perireticular adhesions/inflammation, group 2 (n = 14) included cattle with reticuloruminal, non-metallic foreign bodies and no perireticular adhesions/inflammation and group 3 (n = 7) included cattle with no reticuloruminal foreign bodies and no perireticular adhesions/inflammation. Anorexia and decreased milk production were the most common clinical signs in all groups. Reluctant to move and arched back were prominent in group 1. In 45% of cases, frothy bloat was associated with the presence of large amounts of reticuloruminal, non-metallic foreign bodies. Collectively, factors that significantly had negative impact on outcome were: presence of perireticular adhesions, feeding finely-ground grain and plasma fibrinogen levels above 600mg dL -1 . However, the amount of grain fed per day and type of bloat (free-gas or frothy gas) had no significant effect on the outcome. Results of this study suggest that similar to metallic foreign bodies, non-metallic foreign bodies in the reticulorumen of adult dairy cattle are equally important in causing recurrent rumen tympany.

Short Communication: Patterns of Fecal Shedding of Klebsiella by Dairy Cows

Patterns and persistency of fecal shedding of Klebsiella spp. by healthy adult dairy cattle were explored with probabilistic, statistical, and molecular methods. Fecal shedding was monitored longitudinally in 92 animals in 1 herd for 5 mo. Shedding patterns followed a random binomial distribution, and associations with host factors were not detected. For 12 animals from 4 herds, strain-typing of multiple fecal Klebsiella isolates was performed by means of random-amplified polymorphic DNA typing. For 2 animals, additional typing was performed on isolates from samples collected on several consecutive days. A large variety of Klebsiella strains was detected within samples (on average, 3.1 strains per 4 isolates) and between samples (18 of 20 strains were detected only once in feces from cows that were sampled for 5 d consecutively). Results from each method suggest that fecal shedding of Klebsiella is associated with transient rather than persistent presence of the organism in the gastrointestinal tract.

Genetic and Phenotypic Variability among Salmonella enterica Serovar Typhimurium Isolates from California Dairy Cattle and Humans

Fifty-six human and 24 adult dairy cattle isolates of Salmonella enterica serovar Typhimurium from a single county in California were compared using ribotyping, insertion sequence typing (IS200), pulsed-field gel electrophoresis, plasmid typing, phage typing, and antimicrobial resistance testing. The majority of the isolates fell into one of two groups which were phage types DT104 and DT193. Combining the information from all typing methods, a total of 45 different "clusters" were defined, with 35 of those including only a single isolate. The library of isolates had a high degree of variability, but antibiotic resistance and plasmid typing each defined single clusters in which human or bovine isolates predominated (chi2, P < 0.05).

Descriptive Epidemiology of Adult Dairy Cow Mortalities on a Modern Colorado Dairy

Studies have reported that mortality rates for adult dairy cows have been increasing over the past couple of decades and are now between 4 and 12% at the state level. None of these studies looked closely at the causes or specific risk factors associated with death. The objectives of this study were 1) to determine the causes of death of adult dairy cattle on a modern dairy farm and 2) to identify a classification scheme that facilitates directed management changes to reduce mortality.