Prevalence, outcome, and health consequences associated with persistent infection with bovine viral diarrhea virus in feedlot cattle (original) (raw)
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Journal of the American Veterinary Medical Association, 2014
B ovine respiratory disease remains one of the most common causes of morbidity and death as well as economic loss in the beef cattle industry worldwide. 1 Regarded as a disease complex, BRD has multiple viral and bacterial etiologies. Additional factors contributing to the pathogenesis of BRD include stress associated with the marketing, shipping, handling, and commingling of cattle; insufficient immunity against respiratory tract pathogens; and adverse environmental conditions. Bovine viral diarrhea virus is an important pathogen involved in the development of BRD 2 and is believed to cause profound generalized suppression of nonspecific and specific respiratory tract defense mechanisms, which frequently results in the development of second-Effect of constant exposure to cattle persistently infected with bovine viral diarrhea virus on morbidity and mortality rates and performance of feedlot cattle
The effect of bovine viral diarrhea virus infections on health and performance of feedlot cattle
The Canadian Veterinary Journal La Revue Veterinaire Canadienne, 2008
The aim of this study was to investigate the effect of bovine viral diarrhea virus (BVDV) infections (unapparent acute infections and persistent infections) on the overall health and performance of feedlot cattle. Calves from 25 pens (7132 calves) were enrolled in the study. Overall and infectious disease mortality rates were significantly higher (P , 0.05) in pens categorized at arrival as positive for type I BVDV and lower in pens that were positive for type II BVDV than in negative pens. Mortality attributed to BVDV infection or enteritis was significantly more common (P , 0.05) in the pens containing persistently infected (PI) calves than in pens not containing PI calves (non-PI pens). There were no statistically detectable (P $ 0.05) differences in morbidity, overall mortality, average daily gain, or the dry matter intake to gain ratio between PI and non-PI pens. Although type-I BVDV infections in feedlots appear to contribute to higher mortality rates, the presence of PI calves alone does not appear to have a strong impact on pen-level animal health and feedlot performance. Résumé-Impact des infections au virus de la diarrhée virale bovine sur la santé et la performance des bovins en parcs d'engraissement. Le but de cette étude était d'examiner les effets de l'infection au virus de la diarrhée virale bovine (VDVB) (infections silencieuses aigües et infections persistantes) sur la santé générale et la performance des bovins en parcs d'engraissement. Des veaux provenant de 25 différents enclos (7132 animaux) ont été inclus dans cette étude. Les taux généraux de mortalité et ceux reliés aux maladies infectieuses étaient significativement plus élevés (P , 0,05) dans les enclos classés positifs au type 1 de VDVB à l'arrivée et plus bas dans les enclos classés positifs au type II de VDVB que dans les enclos classés négatifs. La mortalité attribuée aux infections au VDVB ou aux entérites était significativement plus fréquente (P , 0,05) dans les enclos occupés par des veaux infectés de façon persistante (IP) que dans les enclos occupés par des veaux non IP (enclos non IP). Il n'y avait pas de différence significatives (P $ 0,05) dans la morbidité, la mortalité globale, le gain corporel moyen quotidien ou la prise de matière sèche par rapport a l'indice de gain entre les enclos IP et non IP. Bien que les infections de type 1 au VDVB dans les parcs d'engraissement semblent contribuer aux taux plus élevés de mortalité, la présence seule de veaux IP ne semble par avoir d'impact important sur le niveau de santé dans les enclos et sur la performance des parcs d'engraissement.
The epidemiology of bovine respiratory disease: What is the evidence for predisposing factors?
The Canadian veterinary journal. La revue vétérinaire canadienne, 2010
Bovine respiratory disease (BRD) is the most costly disease of beef cattle in North America. It is multi-factorial, with a variety of physical and physiological stressors combining to predispose cattle to pneumonia. However, efforts to discern which factors are most important have frequently failed to establish definitive answers. Calves are at highest risk shortly after transport. Risk factors include purchasing from sale barns and commingling. It is unclear whether or not these practices increase susceptibility, increase exposure, or are proxies for poor management. Lighter-weight calves appear to be at greater risk, although this has not been consistent. Persistent infection (PI) with bovine virus diarrhea virus increases BRD occurrence, but it is unclear if PI calves affect other cattle in the feedlot. The complexity of BRD has made it difficult to define involvement of individual factors. Stressors may play a role as "necessary but not sufficient" components, requirin...
Journal of Animal Science, 2012
Exposure to animals persistently infected (PI) with bovine viral diarrhea virus (BVDV) results in immunomodulation of cohorts that may have health and growth consequences; however, effects may differ in low-risk, preconditioned (PC) vs. high-risk, auction market (AM) beef cattle. Our objective was to compare health and performance of PC or AM management systems with (PI) or without (CON) presence of a PI-BVDV pen mate using a 2 × 2 factorial arrangement. Four shipment blocks of crossbred PC steers (n = 236) from 3 ranch-origins were weaned, dewormed, vaccinated, tested for PI-BVDV, and kept on the ranch for ≥42 d. Subsequently, PC steers were transported to a stocker receiving unit (RU), weighed (251 ± 2 kg), blood sampled, stratifi ed by d −1 BW, and assigned randomly to treatment (PCPI or PCCON) with no additional processing. Simultaneously, 4 blocks of crossbred AM calves (n = 292) were assembled from regional auction markets and transported to the RU ± 36 h from PC arrival. The AM calves were weighed (245 ± 1.3 kg), stratifi ed by gender and d −1 BW, processed under the same regimen used for PC steers at their origin ranch except bull calves were castrated, and then assigned randomly to treatment (AMPI or AMCON). Treatment pens (0.45 ha) were arranged spatially such that PI did not have fence-line or water source contact with CON. Calves were fed identically and followed the same antibiotic treatment protocol. Daily BW gain for the entire 42-d receiving trial was greater (P < 0.001) for PC (1.2 kg) compared with AM (0.85 kg). There was an exposure effect (P = 0.002) on ADG from d 28 to 42; CON gained 1.12 kg vs. 0.90 kg BW for PI cohort. Morbidity was markedly greater (P < 0.001) in AM (70%) vs. PC (7%), resulting in (P < 0.001) an antibiotic treatment cost of 20.52and20.52 and 20.52and2.48/animal, respectively. Treatment with a third antibiotic occurred more often (P = 0.04) for PI cohort, and the percentage of chronically ill cattle was greatest (P = 0.06) for AMPI. Upon arrival, BVDV type 1a, 1b, and 2a titers were greater for PC (treatment × day, P < 0.001), and the percentage seropositive to BVDV type 1a on d 0 was 100% for PC vs. 23% in AM. Platelets increased transiently (P < 0.001) with greater platelets observed in AM (P < 0.001). Results indicate that PC calves gain faster and require fewer antibiotic treatments during the receiving period. Exposure to PI reduced BW gain from d 28 to 42, increased the number of calves treated thrice, and increased chronically ill cattle for AM.
American Journal of Veterinary Research, 2009
Objective—To evaluate economic effects and health and performance of the general cattle population after exposure to cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV) in a feedlot. Animals—21,743 high-risk calves from the southeastern United States. Procedures—PI status was determined by use of an antigen-capture ELISA (ACE) and confirmed by use of a second ACE, reverse transcriptase–PCR assay of sera, immunohistochemical analysis, and virus isolation from sera. Groups with various amounts of exposure to BVDV PI cattle were used. After being placed in the feedlot, identified PI cattle were removed from 1 section, but PI cattle remained in another section of the feedlot. Exposure groups for cattle lots arriving without PI animals were determined by spatial association to cattle lots, with PI animals remaining or removed from the lot. Results—15,348 cattle maintained their exposure group. Performance outcomes improved slightly among the 5 exposure groups as the...
2018
Bovine respiratory disease complex is the most economically significant disease of feedlot cattle[4]. Putative causal organisms include Mannheimia haemolytica, Pasteurella multocida, Histophilus somni and Mycoplasma bovis, bovine herpesvirus, bovine viral diarrhea virus, bovine respiratory syncytial virus, and parainfluenza type 3 virus[5]. Vaccination against the putative causal organisms is a frequently used approach to aid in the prevention of BRD. With a more significant concern for prudent antibiotic use in the beef industry, it is vital that decision making with regards BRDC management be based on an understanding of the efficacy of vaccination programs and management factors that might modify the efficacy of the preventive management practice[6, 7]. Systematic reviews of randomized controlled trials yield the highest level of evidence for the efficacy of treatment under field conditions, and comparative efficacy can be examined using network meta-analysis for multiple comparisons. Establishing the efficacy of monovalent and polyvalent vaccinations for the prevention of BRDC in feedlot cattle will serve to improve decision makers' ability to engage in effective stewardship of antibiotics.
Research Opinions in Animal & Veterinary Sciences, 2013
The aim of this study was to epidemiologically characterize the appearance of clinical bovine respiratory disease complex (BRDC) in a Mexican feedlot. A retrospective study on 260211 records registered over a year and collected from animals housed in 210 pens was performed. In the study period, a total of 67467 steers were housed, with an incoming monthly average of 5190 ± 1252. There were 12783 BRDC clinical cases (18.9% of total steers), representing between 84.5 and 99.9% of all disease cases identified monthly in the pens (95.18 ± 5.10% sick animals per month). Other conditions requiring animal medication were lameness, diarrhea, and balanoposthitis. The average weight at BRDC first treatment was 335.71 ± 9.78 kg, but sick animals lost 15 kg. in average between the weight on arrival and the weight at first treatment. Average rectal temperature in animals affected by BRCD was 39.34 ± 0.94 0 C and 39.23 ± 0.67 0 C in relapsed steers. During the studied period 400 animals died (0.15% of the total), but only 105 died from BRCD (0.04% of the total). Overall monthly BRDC deaths represented 26.5% of total deaths, but the proportion of monthly deaths due to BRDC to the total number of deaths ranged between 0.22% and 48.1%, with higher values between July and September, 2010. BRDC lethality rate had an average value of 0.82% during the period, ranging monthly between 0.17 and 2.21 %. The average success of a first treatment against BRDC was 92.4%. Average monthly relapsed animals were 67 ± 41.3, ranging between 31 and 172 cases in April and February, respectively. Almost twice the number of sick animals was observed in winter (34%) than in fall, which had the lowest proportion of cases (18.1%); spring (22.4%) and summer (25.5%) had intermediate levels. The feedlot had only five animal suppliers, but most steers came from southern Veracruz (54.6%, 35190/67467). The percentage of BRDC sick animals by provenance of origin ranged from 3.68% (Tuxtepec, Oaxaca) to 19.15% (Chiapas). According to provenance, the number of relapsed animals ranged from one (Tuxtepec, Oaxaca) to 493 (south of Veracruz), but animals from more distant places (Tabasco and Chiapas), exhibited the highest value (between 7.65 and 7.85%). The heaviest and the lightest steers were more prone to BRDC relapse than animals in an average weight. Only 11 animals required a third treatment, five of which were treated in February. In conclusion, most susceptible steers to BRDC illness were those transported over larger distances, those which arrive in winter, as well as the heaviest and the lightest.
Acta Scientiae Veterinariae, 2017
Background: Infections are caused by Bovine Viral Diarrhea Virus and still continue to be a worldwide plague in cattle industry. It is responsible for sudden death syndromes in adult cattle with high mortality rates, abortions, acute gastrointestinal and respiratory diseases. The BVDV infection occurs in early pregnancy (40-142 days), in immunosuppressed females or cows results in 100% of persistently infected (PI) calves that are seronegative and asymptomatic at birth. Evidences suggests that BVDV contributes to BRD complex potentiating secondary infections caused by Mannheimia haemolytica e Pasteurella multocida due to its immunosuppressive action. However, the farmers have often associated the respiratory syndrome with other infectious agents. This paper reports the attendance of dairy calves manifesting clinical signs of bronchopneumonia, which led to the screening of the persistently infected animals to control of the BVDV infection in the herd. Materials, Methods & Results: During the technical assistance, ten calves manifesting bronchopneumonia were selected to trans-tracheal lavage (TL) in order to identify possible infectious agents. Reverse transcription polymerase chain reaction (RT-PCR) detected the presence of BVDV in two heifers. Pasteurella multocida was the unique bacterial agent isolated from TL (5/10, 50%). These data motivated the technical team and producers to investigate the PI screening by direct enzyme-linked immunosorbent assay from biopsies of the ear edge. The screening of PI's detected 29 positive within of 2,342 animals tested (1.23%). The re-test of positive was performed only in 24 animals due to the cull of five bovine with severe bronchopneumonia and diarrhea, confirming 18 persistently infected calves (18/24; 75%). Finally, in all PI's live dams were tested. It was observed four positive adult animals. One grand dam was live and tested, but it had negative result for direct enzyme-linked immunosorbent test. The rate of PI's considering the whole herd was 0.81% (22/3,700 animals). Discussion: The involvement of BVDV in the etiology of bronchopneumonia was confirmed by detection of the virus in trans-tracheal lavages in two calves by RT-PCR. The susceptibility for Pasteurella multocida infection could be promoted by BVDV prime-infection, considering that immunossupressive nature of BVDV is a critical factor in the interaction with others viruses and bacteria. At this time, we are aware about any report about the detection of BVDV in trans-tracheal lavages. These findings culminated with the screening of PI animals in the herd, detecting rates of 0.81%. The intensive vaccination and colostrum management of this farm could protected the herd against BVDV, however others facts facilitated the introduction of the virus in the herd. This research was conduced in a high-production dairy farm with around 3,700 animals raised in an open herd, in which some of cows with high genetic potential were transferred for embryo collection in the state of Paraná, Brazil; resulting in the addition of the calves to the herd by others routes. Moreover, the farm used for many years vaccine containing only BVDV-1, which may have favored the entry and spread of BVDV-2 or BVDV-3 in the herd. This research showed the presence of BVDV in trans-tracheal lavage of heifers with bronchopneumonia by RT-PCR. This fact points to the need of BRD control programs that include detection of PI animals.