Lameness is a detrimental health and welfare concern of dairy cattle with high prevalence in North American herds. As a practical and farm-specific approach toward its mitigation in Alberta, Canada, ...a score-based lameness risk assessment questionnaire (RAQ) was developed for veterinarians to conduct with their clients; however, its accuracy in identifying risk for lameness and hoof lesions has not been evaluated. Our objectives were to (1) provide an update on prevalence of lameness and hoof lesions in Alberta freestall herds, (2) validate the RAQ by determining the association between RAQ scores and the prevalence of herd lameness and herd lesions, and (3) determine the association between presence of common hoof lesions and lameness. For the first 2 objectives, 65 Alberta dairy farms were visited between March and October 2018 to collect a completed RAQ, hoof trimming records from their hoof trimmer, and video footage of the entire lactating herd. For the third objective, 10 participant herds were visited twice between November 2013 and June 2014 to take video footage of the entire lactating herd and collect hoof trimming records from their hoof trimmer within 48 h after video footage collection. Median herd-level lameness prevalence was 20% (range = 2–56%), infectious lesion prevalence was 10% (range = 0–49%), and noninfectious lesion prevalence was 15% (range = 2–39%). Of cows that were lame, 93% had a lesion, whereas 21% of cows with a lesion were lame. Cows with an infectious and noninfectious lesion were, respectively, 1.5 and 3.1 times more likely to be lame than cows with no lesion. Total RAQ score and herd lameness prevalence were correlated (r = 0.26) and noninfectious RAQ score and noninfectious lesion prevalence were correlated (r = 0.45), whereas infectious RAQ score and infectious lesion prevalence were not. Cow-level mixed logistic regression models indicated no associations between any of the RAQ scores and presence of lameness or a hoof lesion. Lameness prevalence in Alberta remains high, indicative of a low adoption rate of mitigation strategies by producers. Improvement of the RAQ could allow for better reflection of lameness and lesions on farm and can be achieved through further risk factor analysis within the RAQ, which may result in removal or addition of questions as well as the adjustment of scores based on risk factors' strength of association with lameness and lesions.
Dairy cows suffer blood Ca losses as lactation begins and might be affected by hypocalcemia in its clinical (total serum Ca concentration <1.50 mM) or subclinical form (total serum Ca concentration ...≤2.14 mM). Several studies have suggested that hypocalcemia is associated with different health problems of the cow but results from different studies are not consistent. The objective of this study was to assess potential associations between subclinical hypocalcemia (SCHC) and displaced abomasum, intramammary infections, metritis, retained placenta, and ketosis. Also, the associations between SCHC and milk yield and reproductive function were evaluated. After discarding cows (32) with clinical hypocalcemia, a total of 764 cows from 6 different commercial farms were enrolled in this study. Blood samples were collected at 24 to 48 h postcalving and analyzed for total Ca concentration. Odds ratios of the different afflictions potentially associated with SCHC were calculated. Seventy-eight percent of the analyzed cows incurred SCHC. The occurrence of displaced abomasum, ketosis, retained placenta, and metritis was 3.7, 5.5, 3.4, and 4.3 times more likely, respectively, in cows that had SCHC than in cows with normocalcemia. Furthermore, the risk of incurring retained placenta or metritis increased in multiparous cows as serum Ca concentrations decreased compared with that in primiparous cows. Normocalcemic cows, independent of parity, were more likely to show their first estrus sooner after calving than SCHC cows, but no correlation was found between SCHC and other reproductive parameters. Different serum Ca concentration cutoffs were identified for several postpartum afflictions (≤1.93, ≤2.05, ≤2.05, and ≤2.10 mM for ketosis, retained placenta, metritis, and displaced abomasum, respectively). In conclusion, SCHC, defined as serum Ca ≤2.14 mM, is a frequent illness affecting the majority of the dairy cows with important repercussions on health. However, if SCHC were to be used to predict postpartum disease, different serum Ca cutoff points are likely to be needed because best predictive cutoff values varied among postpartum ketosis, displaced abomasum, retained placenta, and metritis.
The relationship between biosecurity and digital dermatitis (DD) was evaluated in 8,269 cows from a convenience sample of 39 freestall dairy herds. The hypothesis was that poor implementation of ...biosecurity was associated with higher within-herd prevalence of DD. All lactating cows were scored as negative or positive for DD at the hind legs during milking in the milking parlor. Information about biosecurity was obtained through questionnaires addressed to farmers, on-farm observations, and information from the Danish Cattle Database (www.seges.dk). These assessment tools covered potential infection sources of DD pathogens to susceptible cows (e.g., via animals, humans, manure, vehicles, equipment, and facilities). External and internal biosecurity measures were explanatory variables in 2 separate logistic regression models, whereas within-herd DD prevalence was the outcome. Overall DD prevalence among cows and herds were 24 and 97%, respectively; the within-herd DD prevalence ranged from 0 to 56%. Poor external biosecurity measures associated with higher prevalence of DD were recent animal purchase, access to pasture, lack of boots available for visitors, farm staff working at other dairy farms as well, hoof trimming without a professional attending, and animal transporters having access to cattle area. For internal biosecurity, higher DD prevalence were associated with infrequent hoof bathing, manure scraping less than 8 times a day, manure removal direction from cows to heifers, animal pens' exit without water hoses, manure-handling vehicle used in other activities, and water troughs contaminated with manure. These findings showed that improvements on biosecurity may be beneficial for controlling DD in dairy herds. The study is relevant for farmers facing problems with DD, as well as hoof trimmers, advisors, and veterinarians, who can use the results for optimized recommendations regarding biosecurity in relation to DD. Furthermore, our results might be considered by future studies investigating DD pathogen reservoirs and transmission routes.
The average productive lifespan is approximately 3 to 4 years in countries with high-producing dairy cows. This is much shorter than the natural life expectancy of dairy cattle. Dairy farmers ...continue to cull cows primarily for reasons related to poor health, failure to conceive or conformation problems prior to culling. These reasons may indicate reduced welfare leading up to culling. Improvements in health care, housing and nutrition will reduce forced culling related to these welfare reasons. However, productive lifespan has remained similar in decades, despite large improvements in cow comfort and genetic selection for the ability to avoid culling. On the other hand, genetic progress for economically important traits is accelerating within the last decade, which should slightly shorten the average economically optimal productive lifespan. A major driver of productive lifespan is the availability of replacement heifers that force cows out when they calve. The average productive lifespan could be extended by reducing the supply of dairy heifers, which would also have benefits for environmental sustainability. Improvements in culling decision support tools would strengthen economically optimal replacement decisions. In conclusion, major factors of the relatively short productive lifespan of dairy cows are welfare-related, but other economic factors like supply of heifers, genetic progress and non-optimal decision-making also play important roles.
•Overall mean treatment incidence in Swiss veal calves was 21 days/calf/year.•Health check and quarantine were associated with reduced treatment incidence.•Shared air space among groups was ...associated with increased treatment incidence.•Vaccination, beef breed, and small homogeneous groups reduced the mortality risk.•The principles of prudent use of antimicrobials were insufficiently applied.
Ninety-one Swiss veal farms producing under a label with improved welfare standards were visited between August and December 2014 to investigate risk factors related to antimicrobial drug use and mortality. All herds consisted of own and purchased calves, with a median of 77.4% of purchased calves. The calves’ mean age was 29±15days at purchasing and the fattening period lasted at average 120±28 days. The mean carcass weight was 125±12kg. A mean of 58±33 calves were fattened per farm and year, and purchased calves were bought from a mean of 20±17 farms of origin. Antimicrobial drug treatment incidence was calculated with the defined daily dose methodology. The mean treatment incidence (TIADD) was 21±15 daily doses per calf and year. The mean mortality risk was 4.1%, calves died at a mean age of 94±50 days, and the main causes of death were bovine respiratory disease (BRD, 50%) and gastro-intestinal disease (33%). Two multivariable models were constructed, for antimicrobial drug treatment incidence (53 farms) and mortality (91 farms). No quarantine, shared air space for several groups of calves, and no clinical examination upon arrival at the farm were associated with increased antimicrobial treatment incidence. Maximum group size and weight differences >100kg within a group were associated with increased mortality risk, while vaccination and beef breed were associated with decreased mortality risk. The majority of antimicrobial treatments (84.6%) were given as group treatments with oral powder fed through an automatic milk feeding system. Combination products containing chlortetracycline with tylosin and sulfadimidine or with spiramycin were used for 54.9%, and amoxicillin for 43.7% of the oral group treatments. The main indication for individual treatment was BRD (73%). The mean age at the time of treatment was 51 days, corresponding to an estimated weight of 80–100kg. Individual treatments were mainly applied through injections (88.5%), and included administration of fluoroquinolones in 38.3%, penicillines (amoxicillin or benzylpenicillin) in 25.6%, macrolides in 13.1%, tetracyclines in 12.0%, 3th and 4th generation cephalosporines in 4.7%, and florfenicol in 3.9% of the cases.
The present study allowed for identifying risk factors for increased antimicrobial drug treatment and mortality. This is an important basis for future studies aiming at reducing treatment incidence and mortality in veal farms. Our results indicate that improvement is needed in the selection of drugs for the treatment of veal calves according to the principles of prudent use of antibiotics.
•First large survey on management factors related to Anaplasma infections in beef cattle in California.•Anaplasma marginale infection status may be underestimated in beef herds in California.•The ...Central Coast region in California reports highest Anaplasma infections.•Management differences between regions and herd sizes are described.•Changing of needles between cattle and testing of herd additions are rare.
Bovine anaplasmosis is a tick-borne disease caused by Anaplasma marginale in the United States. The objective of this study was to use a survey tool to generate information for beef operations in California on anaplasmosis prevention and control management, including to what extent management activities were informed by perceived herd-level exposure to A. marginale infection or occurrence of clinical anaplasmosis cases. We mailed 2,621 questionnaires with questions on Anaplasma status, herd demographics, anaplasmosis control and prevention measures, and environmental factors to beef ranchers in California in October 2020. Survey-weighted chi-square tests were used to compare management differences according to perceived Anaplasma infection status. Generalized estimating equations (GEEs) were used to analyze whether region of California, management practices, or environmental factors were associated with reported clinical cases of anaplasmosis in the previous five years. A total of 466 questionnaires describing 749 herds were obtained and used in this study. Use of management measures, including deliberate exposure of calves to ticks, vaccination for Anaplasma, infection control through antibiotics in feed, maintaining a completely closed herd, blood testing for Anaplasma on all herd additions, and taking no anaplasmosis control and prevention measures, were significantly different between herds with or without perceived A. marginale infection based on producers’ self-declared status. The overall perceived prevalence for Anaplasma infection and reported clinical cases of anaplasmosis at the herd level was 26.0 % (95 % CI: 24.3–27.7 %) and 17.1 % (95 % CI: 15.6–18.6 %) respectively, with the highest perceived infection and case numbers reported in the Central Coast region. In the GEE model, higher odds of reporting clinical cases of anaplasmosis in the previous five years were observed in cattle located in the Central Coast region, cattle within a large herd, cattle that are treated with tick/fly control, cattle in a completely closed herd, and cattle receiving Anaplasma vaccine. Anaplasma infection and bovine anaplasmosis status may be underestimated in beef herds in California based on previous study results. Changing needles between cattle after injections and conducting blood testing for Anaplasma on herd additions are important Anaplasma management measures that are infrequently implemented in beef herds in California. The results show a need for producer education to improve producers’ awareness of bovine anaplasmosis and implement proper measures for disease control and prevention.
No immunogen to date has reliably elicited broadly neutralizing antibodies to HIV in humans or animal models. Advances in the design of immunogens that antigenically mimic the HIV envelope ...glycoprotein (Env), such as the soluble cleaved trimer BG505 SOSIP, have improved the elicitation of potent isolate-specific antibody responses in rabbits and macaques, but so far failed to induce broadly neutralizing antibodies. One possible reason for this failure is that the relevant antibody repertoires are poorly suited to target the conserved epitope regions on Env, which are somewhat occluded relative to the exposed variable epitopes. Here, to test this hypothesis, we immunized four cows with BG505 SOSIP. The antibody repertoire of cows contains long third heavy chain complementary determining regions (HCDR3) with an ultralong subset that can reach more than 70 amino acids in length. Remarkably, BG505 SOSIP immunization resulted in rapid elicitation of broad and potent serum antibody responses in all four cows. Longitudinal serum analysis for one cow showed the development of neutralization breadth (20%, n = 117 cross-clade isolates) in 42 days and 96% breadth (n = 117) at 381 days. A monoclonal antibody isolated from this cow harboured an ultralong HCDR3 of 60 amino acids and neutralized 72% of cross-clade isolates (n = 117) with a potent median IC
of 0.028 μg ml
. Breadth was elicited with a single trimer immunogen and did not require additional envelope diversity. Immunization of cows may provide an avenue to rapidly generate antibody prophylactics and therapeutics to address disease agents that have evolved to avoid human antibody responses.
Temperament traits are of high importance across species. In humans, temperament or personality traits correlate with psychological traits and psychiatric disorders. In cattle, they impact animal ...welfare, product quality and human safety, and are therefore of direct commercial importance. We hypothesized that genetic factors that contribute to variation in temperament among individuals within a species will be shared between humans and cattle. Using imputed whole-genome sequence data from 9223 beef cattle from three cohorts, a series of genome-wide association studies was undertaken on cattle flight time, a temperament phenotype measured as the time taken for an animal to cover a short-fixed distance after release from an enclosure. We also investigated the association of cattle temperament with polymorphisms in bovine orthologs of risk genes for neuroticism, schizophrenia, autism spectrum disorders (ASD), and developmental delay disorders in humans.
Variants with the strongest associations were located in the bovine orthologous region that is involved in several behavioural and cognitive disorders in humans. These variants were also partially validated in independent cattle cohorts. Genes in these regions (BARHL2, NDN, SNRPN, MAGEL2, ABCA12, KIFAP3, TOPAZ1, FZD3, UBE3A, and GABRA5) were enriched for the GO term neuron migration and were differentially expressed in brain and pituitary tissues in humans. Moreover, variants within 100 kb of ASD susceptibility genes were associated with cattle temperament and explained 6.5% of the total additive genetic variance in the largest cattle cohort. The ASD genes with the most significant associations were GABRB3 and CUL3. Using the same 100 kb window, a weak association was found with polymorphisms in schizophrenia risk genes and no association with polymorphisms in neuroticism and developmental delay disorders risk genes.
Our analysis showed that genes identified in a meta-analysis of cattle temperament contribute to neuron development functions and are differentially expressed in human brain tissues. Furthermore, some ASD susceptibility genes are associated with cattle temperament. These findings provide evidence that genetic control of temperament might be shared between humans and cattle and highlight the potential for future analyses to leverage results between species.
In this research it was evaluated the influence of different forage allowances and combinations of forage allowances along the year on the pasture accumulation dynamic and animal performance. The ...experiment was conducted in a natural pasture area with yearling beef heifers maintained in continuous grazing with variable stocking rate. The treatments utilized with fixed forage allowances during the year were 4; 8; 12 e 16kg 100kg.sup.-1 of live weight; and the treatments of forage allowance combinations were 8 on Spring and 12 on Autumn-Winter-Summer (8-12%); 12 on Spring and 8 on Autumn-Winter-Summer (12-8%); 16 on Spring and 12 on Autumn-Winter-Summer (16-12%), constituting a experimental design in randomized blocks with two replicates of area. The primary and secondary productions were evaluated on the accumulation period of 2007-2008. The results proved that in situations of very low forage allowances, e.g. 4%, the individual performance of animals and per area were prejudiced. Management of forage allowance combination of 8-12% promoted increase of 35% on the individual performance of animals (0,345kg animal.sup.-1), and of 20% on the production per area (209kg ha.sup.-1 of LW) when compared to a management of 12% over the year Key words: native pasture, Pampa Biome, sustainability, cattle production. Neste trabalho avaliou-se a influEncia de diferentes ofertas de forragem e suas combinacoes ao longo do ano sobre a dinamica do crescimento da pastagem e o desempenho animal. O experimento foi conduzido em area de pastagem natural com novilhas de sobreano mantidas em pastejo continuo com taxa de lotacao variavel. Os tratamentos foram ofertas de forragem fixas ao longo do ano: 4; 8; 12 e 16kg de materia seca 100kg de peso vivo-1 por dia e combinacoes de 8 na primavera e 12 no outono-inverno-verao (8-12%); 12 na primavera e 8 no outono-inverno-verao (12-8%); 16 na primavera e 12 no outono-inverno-verao (16-12%), constituindo um delineamento experimental de blocos casualizados com duas repeticoes. A producao de forragem e o ganho de peso animal foram medidos na estacao de crescimento de 2007-2008. Os resultados comprovaram que o uso de oferta de forragem muito baixa, como 4%, prejudica o desempenho animal individual e por area. O manejo combinado de ofertas 8-12% promoveu aumento de 35% no desempenho individual (0,345kg animal.sup.-1) aumento de 20% na producao por area (209kg ha.sup.-1 de PV) em comparacao ao manejo 12% ao longo do ano. Palavras-chave: Bioma Pampa, pastagem nativa, sustentabilidade, producao de bovinos.
In this research it was evaluated the influence of different forage allowances and combinations of forage allowances along the year on the pasture accumulation dynamic and animal performance. The ...experiment was conducted in a natural pasture area with yearling beef heifers maintained in continuous grazing with variable stocking rate. The treatments utilized with fixed forage allowances during the year were 4; 8; 12 e 16kg 100kg.sup.-1 of live weight; and the treatments of forage allowance combinations were 8 on Spring and 12 on Autumn-Winter-Summer (8-12%); 12 on Spring and 8 on Autumn-Winter-Summer (12-8%); 16 on Spring and 12 on Autumn-Winter-Summer (16-12%), constituting a experimental design in randomized blocks with two replicates of area. The primary and secondary productions were evaluated on the accumulation period of 2007-2008. The results proved that in situations of very low forage allowances, e.g. 4%, the individual performance of animals and per area were prejudiced. Management of forage allowance combination of 8-12% promoted increase of 35% on the individual performance of animals (0,345kg animal.sup.-1), and of 20% on the production per area (209kg ha.sup.-1 of LW) when compared to a management of 12% over the year
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