Efficacy of oral administration of specific immunoglobulins in preventing neonatal calf diarrhoea in dairy herds.

BACKGROUND: The aim of this study was to evaluate the efficacy of bovine concentrated lactoserum (BCL) containing specific immunoglobulin G against Escherichia coli, rotavirus and coronavirus in preventing neonatal calf diarrhoea (NCD). METHODS: A total of 489 newborn calves from 35 herds were orally given either BCL or a placebo before the first feeding of colostrum and clinically supervised by the farmers for the first 14 days of life. The diarrhoea score was defined according to the following criteria: 0 = no diarrhoea; 1 = light diarrhoea without medical treatment; 2 = diarrhoea requiring oral treatment (rehydration and/or antibiotic therapy); and 3 = severe diarrhoea requiring parenteral rehydration or resulting in death. RESULTS: A total of 138 calves suffered from diarrhoea (28%), and 65 (13%) showed signs of diarrhoea requiring treatment. The odds of getting NCD were reduced (odds ratio = 0.326; p < 0.001) in the BCL group. There was a tendency towards a reduction in the duration of NCD in the BCL group (2.25 (±1.7) days vs. 2.88 (±2.7) days in the placebo group) (p = 0.052). Furthermore, no calves died in the BCL group, whereas four calves died in the placebo group. LIMITATIONS: Because of the design of the study using animals in practice, the mechanisms explaining the clinical findings remain as hypotheses. Diarrhoea scoring performed by farmers has to be analysed and interpreted with caution. CONCLUSIONS: This study demonstrates that BCL as a single preventive treatment is effective in reducing the incidence of NCD even in a region with good general management of dairy calves and overall good colostrum quality.

Modelling the burden of disease for cattle-A case of ticks and tick-borne diseases in cattle in a rural set-up in South Africa.

BACKGROUND: The study aimed to estimate the burden of ticks and tick-borne diseases (TBDs) among rural cattle-keeping households of the Eastern Cape province of South Africa using Productivity Adjusted Life Years (PALYs). We modified Disability Adjusted Life Year (DALY) equations for humans to PALYs to estimate the societal burden of tick-borne animal diseases. Whilst the World Health Organization has indicated the adaptability of DALYs to assess burden of animal diseases, nothing has been done in this regard. This could be due to several reasons including that the assessment of animal disease burden is often less of a priority compared to human diseases, particularly in low- and middle-income countries where resources may be limited. As a result, less funding and attention may be given to developing and implementing PALYs for animal diseases. Furthermore, technical and conceptual challenges may be associated with applying DALYs equations to animal diseases, such as determining appropriate measures of productivity loss for different types and categories of animals and diseases. This motivated our study, which is focused on modelling the burden of ticks and TBDs in cattle (cows, oxen and bulls) reared in resource-poor settings. METHOD: We formulated a PALYs approach for cattle populations by adapting the DALYs approach to assess the burden of ticks and TBDs for cattle populations in 20 villages in the Eastern Cape province of South Africa. PALYs is a measurement used to assess the burden of disease in cattle populations, quantifying the years of life lost due to premature mortality and disability. It encompasses years of life lost due to premature mortality (YLL) and years lost due to disability (YLD) caused by health conditions. PALYs provide a comprehensive perspective on the effective number of years lost due to disability and premature death in cattle populations. The PALYs model involves several parameters that are examined to understand their impact on the model's behavior. To illustrate this, we used a structured questionnaire to collect data on parameters that feed into PALY equations. We coded and entered data from questionnaires directly into Statistical Package of Social Sciences (IBM SPSS Version 20) and entered the estimated values of PALY parameters to calculate PALYs equations, which were to estimate the societal disease burden of ticks and TBDs in cattle. PALYs calculations were done in three categories; PALYs without discounting and age weighting, PALYs with only discounting, and PALYs with discounting and age weighting in a practical example to study how these parameters influence the outcomes of the PALYs model. RESULTS: Our results revealed that the years of productivity lost by a cow, bull, and ox that suffered from ticks and TBDs could be estimated at various disability weights. Approximately 26%, 23% and 35% of the productivity years of a cow, ox and bull, respectively, reared by resource-poor livestock owners are lost due to the burden of ticks and TBDs in the Eastern Cape province of South Africa. However, introducing tick control measures reduces the loss to approximately 3%, 2% and 3% of their lifespan productivity, an indication that tick control will save approximately 23%, 21% and 32% of years of the productive life of cows, oxen and bulls, respectively. Therefore, it is evident that using ticks and TBD prevention measures at an early age of cattle will improve cattle productivity and hence the socioeconomic welfare of resource-poor rural farming communities in the Eastern Cape province of South Africa. CONCLUSION: The findings generated from the PALYs approach are helpful in projections for the future burden of any livestock disease. They may be used as a basis in policy formulation and decision-making by various stakeholders, and hence a priority in animal health economics. We recommend that a classification of livestock diseases of national economic importance should consider both the societal burden (non-monetary) and economic impact instead of the common practice of only considering the economic (monetary) impact. Adding a societal burden measure to existing economic measures provides a holistic understanding of the impact of a disease on society especially in resource-limited settings where the livestock value goes beyond monetary value.

A participatory approach to understand the attitudes and perceptions towards priority endemic cattle diseases among dairy farmers and animal health experts in Henan province, China.

The dairy industry is threatened by a variety of endemic diseases and emerging diseases, and various control programs have been initiated in China. The increased application of evidence to policymaking can help improve the efficiency of disease control programs; however, the relevant research literature is currently lacking. The objective of this study was to gain an in-depth understanding of the attitudes and perceptions towards priority endemic diseases among dairy farmers and animal health experts by taking Henan province of China as the example and using semi-structured interviews and focus group discussions, respectively. This study involved 24 farmers and 27 animal health experts from December 2019 to January 2021. The diseases considered by farmers to be of significance to their animals are different from those considered priorities by the participating experts and the government list. From the perspective of the individual farmers, the effects of zoonotic disease risks such as bovine brucellosis and tuberculosis appear to be less pronounced than "visible" losses at the farm level, contrary to the opinion of experts. Participating experts believed that poor on-farm biosecurity measures posed challenges to the control and eradication of priority endemic diseases; however, there are gaps in farmers' understanding of biosecurity principles, and low motivations to take such disease prevention measures. Several other challenges to the control and eradication of priority endemic diseases also emerged in the data, including the lack of diagnostic tools applicable in the field as well as differential diagnostic tools to differentiate natural infection from vaccination, lack of effective and commercially available vaccines against single or multiple pathogen(s) or new genotypes/serotypes, weak early warning and information networks and insufficient economic compensation. A holistic understanding of people's perceptions of disease control would facilitate the implementation of inclusive and engaging disease control strategies, thereby increasing the efficiency of disease control.

A randomized field trial assessing the timing of postpartum calcium bolus administration on milk yield of multiparous Holstein cows.

Recent studies have shown that cows with subclinical hypocalcemia (SCH) at 4 d in milk (DIM), regardless of their blood Ca concentration before that time point, suffer from an increased early-lactation disease risk and reduced milk yield, whereas cows experiencing a transient reduction in blood Ca that regain normocalcemia by 4 DIM are at a reduced risk of disease and have greater milk yields. With a goal of improving outcomes for dyscalcemic cows with SCH at 4 DIM, our primary objective was to assess the effect of a herd-level oral Ca bolus strategy that delayed supplementation to 24 and 48 h postpartum on productive performance of multiparous Holstein cows. Our secondary objectives were to assess the effects of delayed Ca bolus supplementation on blood Ca concentration, disease incidence within 30 DIM, and pregnancy risk to first service. At calving, multiparous cows on a single commercial dairy farm in Iran were randomly assigned to 1 of 3 treatment groups: (1) control, no Ca bolus administration (CON; n = 95); (2) traditional bolus, one Ca bolus administered immediately following calving and a second Ca bolus administered 24 h after calving (TRD, n = 102); or (3) experimental bolus, one Ca bolus administered 24 h after calving with a second Ca bolus administered 48 h after calving (EXP, n = 99). Blood samples were collected at 0, 24, 48, 72, and 96 h, and 7 d after parturition, with sampling occurring before bolus administration for the TRD (0 and 24 h) and EXP (24 and 48 h) groups. A general linear mixed model was created to analyze the change milk yield over the first 4 monthly tests and serum Ca concentrations over 7 DIM. Given the lack of disease events diagnosed within 30 DIM, no statistical analysis was conducted for this outcome. The effect of treatment group on risk of pregnancy to first service was assessed using Poisson regression. The incidence of dyscalcemia within CON cows was 72%. We found no difference in mean monthly milk yield among treatment groups across the first 4 tests, with an average monthly production of 51.8 ± 8.8 kg/d for CON cows, 52.5 ± 8.7 kg/d for TRD cows, and 51.8 ± 8.7 kg/d for EXP cows. Mean blood Ca concentration also did not differ across 7 DIM among treatment groups and was 2.04 mmol/L [95% confidence interval (CI) = 2.00 to 2.07 mmol/L] for CON cows, 2.06 mmol/L (95% CI = 2.03 to 2.09 mmol/L) for TRD cows, and 2.09 mmol/L (95% CI = 2.05 to 2.12 mmol/L) for EXP cows. The risk of pregnancy to first service was numerically greater for CON than TRD and EXP cows but not statistically different; however, our study was underpowered for this outcome. Under the conditions of our study, our findings suggest that delaying oral Ca bolus supplementation to 24 and 48 h postpartum has no effect on milk production across the first 4 monthly tests.

SARS coronavirus 2-reactive antibodies in bovine colostrum.

Objective: To determine if bovine colostrum and sera have antibodies that react with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Animals: Dairy and beef cattle from North America and Europe, sampled before and after the SARS-CoV-2 pandemic. Procedures: Indirect ELISAs using whole bovine coronavirus (BCoV) and SARS-CoV-2; whole SARS-CoV-2 Spike 1, Spike 2, and nucleocapsid proteins; and SARS-CoV-2-specific nucleocapsid peptide as antigens. Virus neutralization assay for BCoV. Surrogate virus neutralization assay for SARS-CoV-2. Results: Antibodies reactive to BCoV were highly prevalent in samples collected from cattle before and after the SARS-CoV-2 pandemic. Antibodies reactive with SARS-CoV-2 were present in the same samples, and apparently increased in prevalence after the SARS-CoV-2 pandemic. These antibodies had variable reactivity with the spike and nucleocapsid proteins of SARS-CoV-2 but were apparently not specific for SARS-CoV-2. Conclusions: Bovine coronavirus continues to be endemic in cattle populations, as indicated by the high prevalence of antibodies to the virus in colostrum and serum samples. Also, the prevalent antibodies to SARS-CoV-2 in bovine samples, before and after the pandemic, are likely the result of responses to epitopes on the spike and nucleocapsid proteins that are shared between the 2 betacoronaviruses. Cross-reactive antibodies in bovine colostrum could be examined for prophylactic or therapeutic effects on SARS-CoV-2 infections in humans.

Anticorps réactifs au coronavirus du SRAS 2 dans le colostrum bovin. Objectif: Déterminer si le colostrum et des échantillons de sérum bovins contiennent des anticorps qui réagissent avec le coronavirus 2 du syndrome respiratoire aigu sévère (SRAS-CoV-2). Animaux: Bovins laitiers et bovins de boucherie d'Amérique du Nord et d'Europe, échantillonnés avant et après la pandémie de SARS-CoV-2. Procédures: Épreuves ELISA indirectes utilisant le coronavirus bovin entier (BCoV) et le SARS-CoV-2; ensemble des protéines SARS-CoV-2 Spicule 1, Spicule 2 et nucléocapside; et le peptide de nucléocapside spécifique du SARS-CoV-2 comme antigènes. Test de neutralisation du virus pour le BCoV. Virus de substitution pour le test de neutralisation du SRAS-CoV-2. Résultats: Les anticorps réactifs au BCoV étaient très répandus dans les échantillons prélevés sur les bovins avant et après la pandémie de SRAS-CoV-2. Des anticorps réactifs au SRAS-CoV-2 étaient présents dans les mêmes échantillons et leur prévalence a apparemment augmenté après la pandémie de SRAS-CoV-2. Ces anticorps avaient une réactivité variable avec les protéines de spicule et de nucléocapside du SARS-CoV-2 mais n'étaient apparemment pas spécifiques du SARS-CoV-2. Conclusion: Le coronavirus bovin continue d'être endémique dans les populations bovines, comme l'indique la forte prévalence d'anticorps dirigés contre le virus dans les échantillons de colostrum et de sérum. De plus, les anticorps prévalents contre le SRAS-CoV-2 dans les échantillons de bovins, avant et après la pandémie, sont probablement le résultat de réponses à des épitopes sur les protéines de spicule et de nucléocapside qui sont partagées entre les 2 bêtacoronavirus. Les anticorps à réaction croisée dans le colostrum bovin pourraient être examinés pour leurs effets prophylactiques ou thérapeutiques sur les infections par le SRAS-CoV-2 chez l'humain.(Traduit par Dr Serge Messier).

Cost of lameness in dairy herds: An integrated bioeconomic modeling approach.

Foot disorders are costly health disorders in dairy farms, and their prevalence is related to several factors such as breed, nutrition, and farmer's management strategy. Very few modeling approaches have considered the dynamics of foot disorders and their interaction with farm management strategies within a holistic farm simulation model. The aim of this study was to estimate the cost of foot disorders in dairy herds by simulating strategies for managing lameness. A dynamic and stochastic simulation model (DairyHealthSim) was used to simulate the herd dynamics, reproduction management, and health events. A specific module was built for lameness and related herd-level management strategies. Foot disorder occurrences were simulated with a base risk for each etiology [digital dermatitis (DD), interdigital dermatitis, interdigital phlegmon, sole ulcer (SU), white line disease (WLD)]. Two state machines were implemented in the model: the first was related to the disease-induced lameness score (from 1 to 5), and the second concerned DD-state transitions. A total of 880 simulations were run to represent the combination of the following 5 scenarios: (1) housing (concrete vs. textured), (2) hygiene (2 different scraping frequencies), (3) the existence of preventive trimming, (4) different thresholds of DD prevalence detected and from which a collective footbath is applied to treat DD, and (5) farmer's ability to detect lameness (detection rate). Housing, hygiene, and trimming scenarios were associated with risk factors applied for each foot disorder etiologies. The footbath and lameness detection scenarios both determined the treatment setup and the policy of herd observance. The economic evaluation outcome was the gross margin per year. A linear regression model was run to estimate the cost per lame cow (lameness score ≥3), per case of DD and per week of a cow's medium lameness duration. The bioeconomic model reproduced a lameness prevalence varying from 26 to 98% depending on the management scenario, demonstrating a high capacity of the model to represent the diversity of the field situations. Digital dermatitis represented half of the total lameness cases, followed by interdigital dermatitis (28%), SU (19%), WLD (13%), and interdigital phlegmon (4%). The housing scenarios dramatically influenced the prevalence of SU and WLD, whereas scraping frequency and threshold for footbath application mainly determined the presence of DD. Interestingly, the results showed that preventive trimming allowed a better reduction in lameness prevalence than spending time on early detection. Scraping frequency was highly associated with DD occurrence, especially with a textured floor. The regression showed that costs were homogeneous (i.e., did not change with lameness prevalence; marginal cost equals average cost). A lame cow and a DD-affected cow cost €307.50 ± 8.40 (SD) and €391.80 ± 10.0 per year on average, respectively. The results also showed a cost of €12.10 ± 0.36 per week-cow lameness. The present estimation is the first to account for interactions between etiologies and for the complex DD dynamics with all the M-stage transitions, bringing a high level of accuracy to the results.

Investigation of the outbreaks of abortions and orchitis in livestock in Namibia during 2016-2018.

This study investigated outbreaks of seemingly related abortions and orchitis which occurred in the Khomas, Omaheke and Otjozondjupa regions of Namibia from 2016 to 2018, affecting cattle, sheep and goats. Fifty-nine questionnaires were administered, and 48 were completed giving an 81.4% return. The outbreaks were limited to Namibia's east and central regions, mainly on farms rearing cattle, sheep and goats and on farms with a mixture of these species. There was no significant difference between Khomas and other regions on abortion reporting at the farm level [X2 (1, N = 48) = 0.0002, p = 0.987851]. However, there was a significant difference in the abortions at the animal level among the three regions [X2 (2, N = 6246) = 239.8339, p = .00001]. In addition, the proportions of abortions calculated at the animal level at each farm were significantly different when the Khomas region was compared to the other regions. Seventeen cattle sera, 35 sheep sera, 52 caprine sera, 18 bovine liver samples, one caprine liver, five aborted cattle foetuses, two cattle placentas, 18 testes (one bull, eight bucks and nine rams) and ten bull sheath scrapings were collected and tested. Histopathology, microbiology, serology, immunohistochemistry, real-time PCR and mineral analytical techniques were used to establish the aetiology of the abortion and orchitis outbreaks. The gross and histopathological findings on the 18 testicles were characteristic of chronic orchitis. In aborted foetuses, significant histopathological findings included meconium aspiration, funisitis and cardiomyopathy. Placentitis and endometritis were the primary pathologies observed in cows. The bacteria isolated from microbiological samples included Enterococcus spp. (65.5% [19/29]), Enterobacter spp. (6.9% [2/29]) and Streptococcus spp. (10.3% [3/29]), Trueperella pyogenes (3.4% [1/29]), Stenotrophomonas maltophilia (3.4% [1/29]), Staphylococcus epidermidis (3.4% [1/29]), Providencia rettgeri (3.4% [1/29]) and Acinetobacter lwoffii (3.4% [1/29]), mostly opportunistic bacteria. On mineral analysis, 28%, 33%, 83%, 33% and 17% (n = 18) of cattle livers were low in copper, zinc, manganese, selenium and iron, respectively. Twenty-three percent (12/52) of the caprine sera were positive for Brucella melitensis on the Rose Bengal and complement fixation tests. Thirty-five ovine sera were tested for B. melitensis, B. ovis and Coxiella burnetii, and the prevalence for each was 2.9% (1/35). PCR tests on foetuses were all negative for Brucella spp., Coxiella burnetii, Chlamydia spp., Listeria monocytogenes, Salmonella spp., Campylobacter fetus spp., Leptospira pathogenic strains, bovine viral diarrhoea virus, Rift Valley fever virus, Anaplasma phagocytophilum and bovine herpes virus 4 Campylobacter fetus spp. and Trichomonas foetus spp. The authors concluded that Brucella spp., Enterococcus spp., Escherichia coli, Streptococcus spp., Trueperella pyogenes and Coxiella burnetii could have contributed to this outbreak. Micronutrient imbalances and pathogenic abiotic nanoparticles were also identified as possible contributors to the abortion outbreaks.

The effect of pre-calving injection of trace mineral supplements on periparturient disease incidence in pasture based dairy cows.

Trace minerals, have a role in immune function and a trace mineral supplement (TMS) can improve animal health in dairy herds. This prospective randomised clinical study assessed whether subcutaneous injection of 5.5 mL of TMS (40 mg zinc, 10 mg manganese, 5 mg selenium, 15 mg copper per mL), 14-28 days before planned start of calving (PSC) reduced clinical mastitis (CM), subclinical mastitis (SCM) and purulent vaginal discharge (PVD). From four farms, half of 1700 cows stratified on somatic cell count, age and breed were randomly allocated to treatment or no treatment. Occurrence of CM from - 7 to PSC + 100 days, SCM at PSC + 60 days and PVD at PSC + 24 days was analysed using survival analysis and Bayesian generalised mixed multivariable models. From -7 to PSC +30 days, TMS reduced the adjusted hazard ratio (HR) for CM at quarter and cow level (P < 0.001), with no evidence for an effect beyond 30 days. The adjusted OR (and 95% highest density interval, HDI) for the effect of TMS on CM from -7 to PSC +30 days was 0.40 (95% HDI, 0.26-0.63) at quarter level, 0.51 (95% HDI, 0.38-0.69) at cow level and for SCM, 0.72 (95% HDI, 0.54-0.95). The difference in CM incidence from TMS at the cow level was -2.0% (95% HDI, -3.4 to -1.1%) and -1.2% (95% HDI, -3.2 to - 0.6%) at quarter level. No clear effect was identified of TMS on cumulative incidence of PVD.

Metabolic profiling in periparturient dairy cows and its relation with metabolic diseases.

OBJECTIVE: Periparturient period is associated with multiple changes including serum concentration of macro minerals and drop in feed intake. Therefore, it is essential to know the actual concentrations of major macro minerals, glucose and ketone bodies in blood during the periparturient period. The objectives of the study were to study the dynamics of calcium, magnesium, phosphorus, and glucose in serum and ketone bodies in the urine of periparturient cows and to estimate the incidence of subclinical metabolic diseases. RESULTS: Results showed that all the urine samples were negative for ketone bodies. Incidence of subclinical form of hypocalcaemia, hypomagnesaemia, hypophosphatemia, and hypoglycemia in periparturient cows was 31.03%, 48.28%, 17.24% and 55.17%, respectively. Older cows with high BCS and milk yield were mostly affected with a subclinical form of hypocalcaemia and hypoglycemia. No significant differences were observed in serum level of macro minerals and glucose at different time points of periparturient period of cows fed with a balanced ration, and between two groups of cows those were given IV injection of calcium and magnesium on the day of parturition and those were not given. Age, parity, and milk yield had no significant effect on the concentration of calcium, magnesium, phosphorus, and glucose.

Mycobacterium paratuberculosis zoonosis is a One Health emergency.

A singular pathogen has been killing animals, contaminating food and causing an array of human diseases. Mycobacterium avium subspecies paratuberculosis (MAP) is the cause of a fatal enteric infectious disease called Johne's (Yo'-nees), a disorder mostly studied in ruminant animals. MAP is globally impacting animal health and imparting significant economic burden to animal agriculture. Confounding the management of Johne's disease is that animals are typically infected as calves and while commonly not manifesting clinical disease for years, they shed MAP in their milk and feces in the interval. This has resulted in a "don't test, don't tell" scenario for the industry resulting in greater prevalence of Johne's disease; furthermore, because MAP survives pasteurization, the contaminated food supply provides a source of exposure to humans. Indeed, greater than 90% of dairy herds in the US have MAP-infected animals within the herd. The same bacterium, MAP, is the putative cause of Crohn's disease in humans. Countries historically isolated from importing/exporting ruminant animals and free of Johne's disease subsequently acquired the disease as a consequence of opening trade with what proved to be infected animals. Crohn's disease in those populations became a lagging indicator of MAP infection. Moreover, MAP is associated with an increasingly long list of human diseases. Despite MAP scientists entreating regulatory agencies to designate MAP a "zoonotic agent," it has not been forthcoming. One Health is a global endeavor applying an integrative health initiative that includes the environment, animals and humans; One Health asserts that stressors affecting one affects all three. Recognizing the impact MAP has on animal and human health as well as on the environment, it is time for One Health, as well as other global regulatory agencies, to recognize that MAP is causing an insidious slow-motion tsunami of zoonosis and implement public health mitigation.

Gastrointestinal nematodes and mineral deficiencies in yearling cattle in Santiago del Estero, northern Argentina.

The aims were to study the epidemiology and the effect of gastrointestinal nematodes (GINs) on yearling cattle in a semiarid region in Argentina and to evaluate the mineral serum levels. Ten- to twelve-month-old calves were monitored between November and April 2019. Animals were divided into three groups: untreated control (CONG; n = 20); group treated with moxidectin (MXD, 200 µg/kg) every 30-40 days (MXDG; n = 20); group equally MXD treated and mineral supplementation administered in November and January (MMG; n = 20). Individual GIN egg counts (epg) and fecal cultures were made every 30-40 days. Animal live weight gain was determined. On 7-11-18, 25-1-19, and 3-4-19, serum levels of Se, Cu, Zn, Mg, and Ca were determined by atom absorption spectrophotometry. At the start of the trial, epg values were low (x̄ = 5.5), which increased only in CONG towards the end of the assay (x̄ = 229). In both GMXD and MMG, epg remained very low (x̄ = 4.1). Cooperia spp. (81%) prevailed over Haemonchus spp. (9%) and Oesophagostomum spp. (9%). Deficiency of Se ranged between marginal and important, except for MMG, although mean values were always below normal. Cu was marginally deficient in CONG and MXDG on the first two sampling dates, whereas MMG had normal values after treatment. Mg had low values in the three groups (x̄ = 1.5 mg/dl), whereas Ca and Zn exhibited normal values. Live weight gain (LWG) was higher in MMG than in MXDG, with significant differences (p < 0.05) by mid-January and then, when epg increased, dewormed groups showed higher LWG (p < 0.034) than CONG. A negative effect of GINs on LWG was observed, as well as low to marginal levels of Se, Cu, and Mg.

A systematic approach to analyse the impact of farm-profiles on bovine health.

In this study we present systematic framework to analyse the impact of farm profiles as combinations of environmental conditions and management practices on common diseases in dairy cattle. The data used for this secondary data analysis includes observational data from 166 farms with a total of 5828 dairy cows. Each farm is characterised by features from five categories: husbandry, feeding, environmental conditions, housing, and milking systems. We combine dimension reduction with clustering techniques to identify groups of similar farm attributes, which we refer to as farm profiles. A statistical analysis of the farm profiles and their related disease risks is carried out to study the associations between disease risk, farm membership to a specific cluster as well as variables that characterise a given cluster by means of a multivariate regression model. The disease risks of five different farm profiles arise as the result of complex interactions between environmental conditions and farm management practices. We confirm previously documented relationships between diseases, feeding and husbandry. Furthermore, novel associations between housing and milking systems and specific disorders like lameness and ketosis have been discovered. Our approach contributes to paving a way towards a more holistic and data-driven understanding of bovine health and its risk factors.

Spatial variation in direct and indirect contact rates at the wildlife-livestock interface for informing disease management.

Little is known about disease transmission relevant contact rates at the wildlife-livestock interface and the factors shaping them. Indirect contact via shared resources is thought to be important but remains unquantified in most systems, making it challenging to evaluate the impact of livestock management practices on contact networks. Free-ranging wild pigs (Sus scrofa) in North America are an invasive, socially-structured species with an expanding distribution that pose a threat to livestock health given their potential to transmit numerous livestock diseases, such as pseudorabies, brucellosis, trichinellosis, and echinococcosis, among many others. Our objective in this study was to quantify the spatial variations in direct and indirect contact rates among wild pigs and cattle on a commercial cow-calf operation in Florida, USA. Using GPS data from 20 wild pigs and 11 cattle and a continuous-time movement model, we extracted three types of spatial contacts between wild pigs and cattle, including direct contact, indirect contact in the pastoral environment (unknown naturally occurring resources), and indirect contact via anthropogenic cattle resources (feed supplements and water supply troughs). We examined the effects of sex, spatial proximity, and cattle supplement availability on contact rates at the species level and characterized wild pig usage of cattle supplements. Our results suggested daily pig-cattle direct contacts occurred only occasionally, while a significant number of pig-cattle indirect contacts occurred via natural resources distributed heterogeneously across the landscape. At cattle supplements, more indirect contacts occurred at liquid molasses than water troughs or molasses-mineral block tubs due to higher visitation rates by wild pigs. Our results can be directly used for parameterizing epidemiological models to inform risk assessment and optimal control strategies for controlling transmission of shared diseases.

Osteomalacia as a result of phosphorus deficiency in beef cattle grazing subtropical native pastures in Uruguay.

We investigated 2 outbreaks of osteomalacia as a result of phosphorus (P) deficiency in herds of lactating beef cows grazing subtropical native pastures in Uruguay. Cows exhibited pica, difficulty to stand and walk, rib fractures, and body weight loss even with adequate forage availability. Osteopenia and severe osteomalacia were observed on gross and histologic examination. The concentrations of bicarbonate-extractable P in soil (4.0, 4.1 mg P/kg), total P in pasture (0.9, 1.1 g P/kg), inorganic P in serum (1.0, 0.71 mmol P/L), and P in bone (73 mg P/mL) were all low. Although injectable and mineral salt supplements provided additional P in both outbreaks, these supplementary amounts were insufficient to prevent P deficiency. The P ingested by the cows from the pasture and supplements would have provided 20-55% of their daily P requirements of ~21 g P/d. Osteomalacia occurred in cattle at the 2 ranches as a result of severe P deficiency in the soil and forage, and inadequate P supplementation. Following diagnosis, control of P deficiency in beef cattle requires estimation of the amount of pasture P ingested and provision of sufficient additional supplementary P to meet the animals' requirements.

Red propolis effect analysis of dairy calves health based on Weibull regression model with long-term survivors.

Diarrhea is the most common cause of mortality and morbidity in dairy calves during the first weeks of life. It is responsible for the majority of costs related to animal death and treatments, as well as lower productivity due to reduced weight gain. Therefore, studies that focus on strategies to reduce diarrhea incidence and to improve animal welfare are very important for the dairy industry. For that reason, the beneficial effects of red propolis on the health status of preweaned dairy calves was studied. Animal disease data usually present incomplete observations of interest time, so-called censored observations and one of the statistical techniques for this modeling type is the survival analysis, hence it is a set of methods for analyzing data where the response variable is the time until the occurrence of an event of interest. We propose among some methods of survival data analysis, the long-term models. The motivation to study these models is the fact that part of the population is not susceptible to the event of interest during the period of the study, considered as immune or cured. In this paper, we studied the Weibull distribution in a structure of long-term model, including the covariates in the proportion of cured through the logistic link function. Besides, we used the residual analysis to check the assumptions of the model. The reason for the choice of the Weibull distribution was that this model is very flexibility to model a variety of data sets, among them animal science and long-term survival data. We illustrate its application with a case study from an animal experiment, which examined the time till the occurrence of diarrhea in Holstein calves, where a proportion of the animals were not susceptible to this health condition. This experiment aimed to verify the efficiency of red propolis in disease prevention and the influence of that on the proportion of animals that are not susceptible to diarrhea.

Gastro-intestinal parasitism and control practices in dairy cattle in North-west Cameroon (Central Africa).

PURPOSE: The main objective of this study was to assess the gastrointestinal parasitism in relation with the worm control practices (WCP) in dairy cattle in areas of major importance for dairy/milk production of Cameroon. METHODS: Fresh fecal samples were randomly collected from 402 cattle from August to October 2016 in North West Cameroon, and analyze using the McMaster technique. Data on WCP were collected using a questionnaire. RESULTS: A total of 11 parasites species were identified: Trichostrongylus sp. (5.97%); Oesophagostomum sp. (5.47%); Haemonchus sp. (2.48%); Bonostomum sp. (1.74); Cooperia sp. (1.49%). Toxocara sp (0.24%); Ostertagia sp. (0.50%); Nematodirus sp. (0.74%); Trichuris sp. (0.50%); Moniezia sp. (0.50%); Eimeria sp. (0.50%). The mean individual parasite load for helminthes and protozoa ranged from 100 to 400 eggs per gram of feces (epg) and 333-400 oocysts per gram of feces (opg), respectively. Most farmers (95.12%) used conventional drugs (Albendazole, Doramectin, Fenbendazole, Ivermectin.) to deworm animals as compared with traditional phytotherapy (e.g., Carica papaya leaves) (4.88%). The mean epg/opg in animals treated with conventional drugs was significantly higher (p < 0.05) than in those receiving traditional treatment. Animals treated less than four times a year with conventional drugs had the highest (p < 0.05) mean epg/opg compared with animals treated four to six times a year. CONCLUSION: This study suggests that treating at least four times a year with conventional drugs, and at least two times a year with traditional approaches could help reducing GIP burden in dairy cattle in North West Cameroon. Since the majority of farmers use conventional drugs, it is imperative for them to appropriately use these conventional drugs for a better control of GIP on their farms.

Effect of trehalose supplementation in milk replacer on the incidence of diarrhea and fecal microbiota in preweaned calves.

Trehalose, a nonreducing disaccharide consisting of d-glucose with α,α-1,1 linkage, was evaluated as a functional material to improve the gut environment in preweaned calves. In experiment 1, 173 calves were divided into two groups; the trehalose group was fed trehalose at 30 g/animal/d with milk replacer during the suckling period, and the control group was fed nonsupplemented milk replacer. Medication frequency was lower in the trehalose group (P < 0.05). In experiment 2, calves (n = 20) were divided into two groups (control group [n = 10] and trehalose group [n = 10]) based on their body weight and reared under the same feeding regimens as in experiment 1. Fresh feces were collected from individual animals at the beginning of the trial (average age 11 d), 3 wk after trehalose feeding (experimental day 22), and 1 d before weaning, and the fecal score was recorded daily. Fecal samples were analyzed for fermentation parameters and microbiota. The fecal score was significantly lower in the trehalose group than in the control group in the early stage (at an age of 14 to 18 d; P < 0.05) of the suckling period. Calves fed trehalose tended to have a higher proportion of fecal butyrate on day 22 than calves in the control group (P = 0.08). Population sizes of Clostridium spp. were significantly lower (P = 0.036), whereas those of Dialister spp. and Eubacterium spp. tended to be higher in the feces of calves in the trehalose group on day 22 (P = 0.060 and P = 0.083). These observations indicate that trehalose feeding modulated the gut environment and partially contributed to the reduction in medication frequency observed in experiment 1.

Influence of individual or group housing of newborn calves on rotavirus and coronavirus infection during the first 2 months of life.

Bovine rotavirus A (RVA) and bovine coronavirus (CoV) are the two main viral enteropathogens associated with neonatal calf diarrhea. The aim of the present work was to study the impact of group and individual housing systems in the epidemiology of RVA and CoV infection. Eleven calves reared in individual housing (FA) and nine calves in group housing (FB) were monitored during the first 7 weeks of life. Stool and serum samples were screened for RVA and CoV antigens by ELISA. IgG1 antibodies (Ab) to both antigens were also measured. From the 160 fecal samples collected, the proportion of positive samples to RVA and CoV was significantly higher in FB (23.6%) than in FA (9%) (p = 0.03). The geometric mean of colostral IgG1 Ab titers to CoV and RVA in FA (IgG1 anti-CoV 1024 and anti-RVA 1782.9) was lower than in FB (IgG1 anti-CoV 10,321.2 and anti-RVA 4096) at birth. Calves less than 2 weeks of life from FB had a higher risk of being infected by RVA (OR = 4.9; p = 0.01) and CoV (OR = 17.15; p = 0.01) than calves from FA. The obtained results showed that there was higher RVA and CoV shedding in group-housed calves than in individual-housed animals.

Current status of prevalence and risk factors associated with liver fluke Fasciola hepatica in cattle raised in different altitudinal regions of Colombia.

Fasciola hepatica is a trematode parasite with a worldwide distribution that affects mammals, including humans, and is considered a major food safety and public health problem. A research was conducted in three hundred eighty-five livestock farms located in different altitudinal regions of Colombia between February 2017 and March 2018 with the aim to determine the coprological prevalence, seroprevalence (SP) and risk factors associated with liver fluke F. hepatica. A total of 5620 fecal sample were collected from cattle and processed using sedimentation technique. Additionally, 597 blood samples were collected and processed by an ELISA test. The coprological prevalence of F. hepatica in animals and herds was 6.4% and 38.4%, respectively. Regarding the prevalence by municipalities, there was statistical association (P < .05), indicating that the prevalence was higher in those municipalities above 2000 masl (meters above sea level). Regarding risk factors, cattle raised in municipalities at 2000 to 3000 masl showed about 4 (OR = 3.96 [CI95% 3.1-5]; P < .05) times higher probability for infection than those raised at lower altitude. Cattle from 2 to 3 year of age, showed almost 4 times (OR = 3.7[CI95% 2.5-5.4]; P < .05), increased infection risk. Females and dairy breeds showed almost 2 (OR = 1.9 [CI95% 1.3-2.6]; P < .05) and 10 times (OR = 10 [CI95% 7.8-12.8]; P < .05), respectively, increased infection risk. The presence of antibodies anti- F. hepatica (SP = 37.8%; [CI95% 35.8-39.7]; P < .05) in cattle of the region under study is confirmed, which suggests an endemic behavior of this parasitosis. The present study provides current information on the prevalence of F. hepatica in different altitudinal regions of Colombia, and these findings could be useful for designing new holistic control measures for the liver fluke F. hepatica infection.