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Regional distribution of non-human H7N9 avian influenza virus detections in China and construction of a predictive model
2021
Huang, Zeying | Li, Haijun | Huang, Beixun
H7N9 avian influenza has broken out in Chinese poultry 10 times since 2013 and impacted the industry severely. Although the epidemic is currently under control, there is still a latent threat. Epidemiological surveillance data for non-human H7N9 avian influenza from April 2013 to April 2020 were used to analyse the regional distribution and spatial correlations of positivity rates in different months and years and before and after comprehensive immunisation. In addition, positivity rate monitoring data were disaggregated into a low-frequency and a high-frequency trend sequence by wavelet packet decomposition (WPD). The particle swarm optimisation algorithm was adopted to optimise the least squares support-vector machine (LS-SVM) model parameters to predict the low-frequency trend sequence, and the autoregressive integrated moving average (ARIMA) model was used to predict the high-frequency one. Ultimately, an LS-SVM-ARIMA combined model based on WPD was constructed. The virus positivity rate was the highest in late spring and early summer, and overall it fell significantly after comprehensive immunisation. Except for the year 2015 and the single month of December from 2013 to 2020, there was no significant spatiotemporal clustering in cumulative non-human H7N9 avian influenza virus detections. Compared with the ARIMA and LS-SVM models, the LS-SVM-ARIMA combined model based on WPD had the highest prediction accuracy. The mean absolute and root mean square errors were 2.4% and 2.0%, respectively. Low error measures prove the validity of this new prediction method and the combined model could be used for inference of future H7N9 avian influenza virus cases. Live poultry markets should be closed in late spring and early summer, and comprehensive H7N9 immunisation continued.
Afficher plus [+] Moins [-]Potential biomarkers for chronic seasonal heat stress in Kagoshima Berkshire pigs reared in the subtropical region
2022
Ijiri, Moe | Odo, Kenji | Sato, Motohiko | Kawaguchi, Maiko | Fujimoto, Yoshikazu | Miura, Naoki | Matsuo, Tomohide | Hou, De-Xing | Yamato, Osamu | Tanabe, Takashi | Kawaguchi, Hiroaki
Potential biomarkers for chronic seasonal heat stress in Kagoshima Berkshire pigs reared in the subtropical region were investigated by comparing the biomarker changes in the summer (a period of chronic heat stress) and winter (a thermoneutral period) seasons. Pigs were allocated to summer- and winter-finishing cohorts, 12 each. The evaluations included assessment of carcass traits and internal organs’ normality carried out at the time of slaughter, and measurement of biomarkers in whole blood: derivatives of reactive oxygen metabolites (d-ROMs) and biological antioxidant potential as markers of oxidative stress, and serum amyloid A and albumin/globulin (A/G) ratio as markers of acute and chronic inflammation, respectively. The summer-finished pigs reared under subtropical field conditions showed lower carcass quality than the winter-finished pigs, indicating a potential adverse effect of summer temperatures on the swine industry. Marginal changes were observed in d-ROMs and the A/G ratio between the summer- and winter-finishing cohorts. The results demonstrate that d-ROMs and the A/G ratio could be used as sensitive markers for heat stress under field conditions.
Afficher plus [+] Moins [-]Gastrointestinal nematodes of goats: host–parasite relationship differences in breeds at summer mountain pasture in northern Italy
2019
Zanzani, Sergio Aurelio | Gazzonis, Alessia Libera | Olivieri, Emanuela | Villa, Luca | Fraquelli, Cristina | Manfredi, Maria Teresa
The Orobic goat is a hardy breed native to the Orobic Alps (Lombardy, northern Italy). The aim of the study was the assessment of gastrointestinal nematode (GIN) egg excretion in Alpine and Saanen (cosmopolite breeds) and Orobic grazing goats, after a strategic treatment with eprinomectin in late June. Individual faecal samples from a mixed flock of cosmopolite and Orobic goats were collected and analysed by the FLOTAC double technique every three weeks from June to September. Strongylida was the primary GIN infection observed in goats that grazed on Alpine pastures; a strategic treatment with eprinomectin led to a prolonged reduction of egg excretion during the whole study period. Egg excretion was also influenced by breed. Pluriparous Orobic does were able to control reinfection better than the pluriparous cosmopolite does. Regarding Nematodirus sp. eggs per gram of faeces (EPG), the autochthonous Orobic breed presented higher values than the cosmopolite breeds. However, cosmopolite goats presented higher EPG values of Strongyloides papillosus than their Orobic counterparts in August. Further studies on genetic features of local autochthonous goats, such as the Orobic breed, are needed, since they could reveal peculiar characteristics of susceptibility, resistance or resilience to GIN infection, providing genetic resources for selection.
Afficher plus [+] Moins [-]MDA and GSH-Px activity in transition dairy cows under seasonal variations and their relationship with reproductive performance
2017
Colakoglu, Hatice Esra | Yazlik, Murat Onur | Kaya, Ufuk | Colakoglu, Ekrem Cagatay | Kurt, Serdal | Oz, Burcu | Bayramoglu, Rustem | Vural, Mehmet Rifat | Kuplulu, Sukru
Introduction: The purpose of the current study was to evaluate the blood glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels under seasonal variations in dairy cows during transition period, and to assess the relationship between chosen reproductive parameters, GSH-Px, and MDA. Material and Methods: Holstein cows calving in January were assigned into winter group (n = 42), while cows calving in August were assigned into summer group (n = 42). Blood samples were collected from the jugular vein 21, 14, and 7 days before calving, at calving (0 day), and 7, 14, and 21 days after calving. Reproductive parameters obtained from farm records were evaluated. Results: In both groups of cows, GSH-Px activity decreased from 21 days before calving to day 0, and it gradually continued to increase until 21 days after calving. GSH-Px activity was higher in winter group compared to summer group during the transition period (P < 0.05). MDA levels in both groups increased over time starting from 21 days before calving to 0 day, but it gradually decreased thereafter. MDA levels were higher in summer group compared to winter group during the transition periods (P < 0.05). Summer group of cows showed higher intervals of calving-to-oestrus, calving-to-conception, and higher insemination index (P < 0.01). Negative correlation was recorded between GSH-Px and MDA during all examination days (P < 0.01). MDA levels correlated with calving to conception interval on day 21 before calving and day 0 (P < 0.01) and insemination index on day 0 and 21 days after calving (P < 0.01). GSH-Px activity was negatively correlated with calving to conception interval on day 21 before calving, day 0, and 21 days (P < 0.01) after calving. Negative correlation on day 21 before calving and day 0 was also determined between GSH-Px and insemination index (P < 0.01). Conclusion: This study showed that blood oxidant and antioxidant levels have affected the fertility parameters in cows under seasonal variations.
Afficher plus [+] Moins [-]Effect of a syringe aspiration technique versus a mechanical suction technique and use of N-butylscopolammonium bromide on the quantity and quality of bronchoalveolar lavage fluid samples obtained from horses with the summer pasture endophenotype of equine asthma
2018
Bowser, Jacquelyn E. | Costa, Lais R. R. | Rodil, Alba U. | Lopp, Christine T. | Johnson, Melanie E. | Wills, Robert W. | Swiderski, Cyprianna E.
OBJECTIVE To evaluate the effect of 2 bronchoalveolar lavage (BAL) sampling techniques and the use of N-butylscopolammonium bromide (NBB) on the quantity and quality of BAL fluid (BALF) samples obtained from horses with the summer pasture endophenotype of equine asthma. ANIMALS 8 horses with the summer pasture endophenotype of equine asthma. PROCEDURES BAL was performed bilaterally (right and left lung sites) with a flexible videoendoscope passed through the left or right nasal passage. During lavage of the first lung site, a BALF sample was collected by means of either gentle syringe aspiration or mechanical suction with a pressure-regulated wall-mounted suction pump. The endoscope was then maneuvered into the contralateral lung site, and lavage was performed with the alternate fluid retrieval technique. For each horse, BAL was performed bilaterally once with and once without premedication with NBB (21-day interval). The BALF samples retrieved were evaluated for volume, total cell count, differential cell count, RBC count, and total protein concentration. RESULTS Use of syringe aspiration significantly increased total BALF volume (mean volume increase, 40 mL [approx 7.5% yield]) and decreased total RBC count (mean decrease, 142 cells/μL), compared with use of mechanical suction. The BALF nucleated cell count and differential cell count did not differ between BAL procedures. Use of NBB had no effect on BALF retrieval. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that retrieval of BALF by syringe aspiration may increase yield and reduce barotrauma in horses at increased risk of bronchoconstriction and bronchiolar collapse. Further studies to determine the usefulness of NBB and other bronchodilators during BAL procedures in horses are warranted.
Afficher plus [+] Moins [-]Effects of weather variables on thermoregulation of calves during periods of extreme heat
2014
Theurer, Miles E. | Anderson, Daivd E. | White, Brad J. | Miesner, Matt D. | Larson, Robert L.
Objective-To determine effects of ambient temperature, relative humidity, wind speed, relative barometric pressure, and temperature-humidity index (THI) on nasal submucosal and rectal temperatures in cattle during extreme summer conditions. Animals-20 black crossbred beef heifers (mean body weight, 217.8 kg). Procedures-Nasal submucosal and rectal temperatures were monitored every 2 hours for 24 hours on 3 nonconsecutive days when ambient temperature was forecasted to exceed 32.2°C. Ambient temperature, relative humidity, wind speed, and relative barometric pressure were continuously monitored at a remote weather station located at the research facility. The THI was calculated and used in the livestock weather safety index (LWSI). Relationships between nasal submucosal or rectal temperature and weather variables were evaluated. Results-Nasal submucosal and rectal temperatures were related to all weather variables monitored. A positive relationship was determined for ambient temperature and THI with both nasal submucosal and rectal temperatures. A negative relationship was evident for nasal submucosal and rectal temperature with relative humidity, wind speed, and relative barometric pressure. Nasal submucosal and rectal temperatures increased with increasing severity of LWSI category. Conclusions and Clinical Relevance-Effects of environmental conditions on thermoregulation in calves exposed to extreme heat were detected. The positive relationship between nasal submucosal temperature and ambient temperature and THI raised concerns about the efficacy of intranasal administration of temperature-sensitive modified-live virus vaccines during periods of extreme heat. Environmental conditions must be considered when rectal temperature is used as a diagnostic tool for identifying morbid cattle.
Afficher plus [+] Moins [-]Relationship between estimated finishing-pig space allowance and in-transit loss in a retrospective survey of 3 packing plants in Ontario in 2003
2010
Haley, Charles | Dewey, Catherine E. | Widowski, Tina | Friendship, Robert
The objective of this study was to determine the association between space allowance and in-transit loss of finishing pigs going to select abattoirs in Ontario during summer weather conditions. The study included data from 2- or 3-tiered trailers transporting >or= 130 pigs in June, July, and August 2003 to 3 packers that processed 76% of Ontario market pigs. Daily in-transit loss data were merged with packer data to determine the number of pigs on each trailer. Space allowance (in square meters per pig) was estimated from the percentage of each trailer’s capacity that was filled by the load size. Actual pig weights were not available. Hourly temperature and relative humidity were obtained from 2 local Ontario weather stations. In-transit loss increased with environmental temperature, by 6.6 times at temperatures between 28°C and 34.2°C compared with < 17°C. At space allowances between 0.44 and 0.43 m2/pig compared with >or= 0.515 m2/pig, in-transit losses increased 2.12 times when environmental temperatures were < 21°C. Temperature is likely a more important determinant of in-transit loss than space allowance. However, in-transit losses in hot weather are likely to be reduced by increasing space allowance or by adding a cooling device.
Afficher plus [+] Moins [-]Efficacy of concomitant early summer treatment with fenbendazole and clorsulon against Fasciola hepatica and gastrointestinal nematodes in calves in Louisiana
1990
The efficacy, safety, and compatibility of fenbendazole (FBZ) and clorsulon (CLN) were tested after oral administration of label recommended and of higher (5 x) dosage rates to calves naturally infected with gastrointestinal nematodes and Fasciola hepatica. Results for 42 calves allotted to 4 treatment groups indicated a similar efficacy against mature F hepatica by FBZ (5 mg/kg of body weight) and CLN (7 mg/kg) in a combined oral suspension, compared with CLN (7 mg/kg) alone (100 vs 99% reduction). A lesser efficacy was observed against immature flukes (88.6 and 84.9% reduction, respectively). Calves given 25 mg of FBZ/kg and 35 mg of CLN/kg had nearly complete reduction of both mature (99.6%) and immature flukes (99.1%). Fasciola egg counts were reduced by > 99.5% in all treated groups. Against Ostertagia ostertagi, the percentage of efficacy of the combined FBZ (5 mg/kg) and CLN (7 mg/kg) treatment was 94.3% against adults and 81.3% against inhibited larvae. Efficacy against all other nematodes was 100%, except against Cooperia spp adults (98.3%) and immature Oesaphagostomum radiatum (88.0%). At 5 x dosage rates for FBZ and CLN, percentage of removal of adults and inhibited larvae of O ostertagi was 99.3 and 99.0%, respectively, and 99 to 100% for other nematodes. Results indicate that FBZ and CLN are compatible when mixed together and administered as an oral suspension to cattle and that the efficacy is similar to that of the drugs individually. On the basis of further results, we suggest that summer treatment may be superior in preventive value for gastrointestinal nematodes and F hepatica, compared with spring treatment, because of seasonal infection dynamics of the major cattle parasites in Louisiana.
Afficher plus [+] Moins [-]Temporal and spatial dynamics of porcine reproductive and respiratory syndrome virus infection in the United States
2015
OBJECTIVE To measure incidence and estimate temporal and spatial dynamics of porcine reproductive and respiratory syndrome virus (PRRSV) infection in US sow herds. ANIMALS 371 sow herds in the United States from 14 production companies. PROCEDURES The exponentially weighted moving average was used to monitor incident PRRSV infections for onset of an epidemic. The spatial scan statistic was used to identify areas at significantly high risk of PRRS epidemics. A χ2 test was used to estimate whether there were significant differences in the quarterly and annual PRRS incidence among time periods, and a bivariable logistic regression model was used to estimate whether PRRSV infection during a given year increased the odds of that herd being infected in the following year. RESULTS During the 4-year period of this study, 29% (91/319; 2009 to 2010), 33% (106/325; 2010 to 2011), 38% (135/355; 2011 to 2012), and 32% (117/371; 2012 to 2013) of the herds reported new infections. Weekly incidence was low during spring and summer and high during fall and winter. The exponentially weighted moving average signaled the onset of a PRRSV epidemic during the middle 2 weeks of October each year. Disease incidence was spatially clustered. Infection in the previous year increased the odds of infection in 2010 to 2011 and 2011 to 2012. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated a striking repeatability in annual PRRSV temporal and spatial patterns across 4 years of data among herds from 14 production companies, which suggested that efforts to control PRRSV at a regional level should continue to be supported.
Afficher plus [+] Moins [-]Evaluation of serum trace mineral, vitamin D, and sex steroid hormone concentration, and survey data in llamas and alpacas with metacarpophalangeal and metatarsophalangeal hyperextension
2013
Semevolos, Stacy A. | Reed, Shannon K. | Schultz, Loren G.
Objective: To characterize serum trace mineral, sex steroid hormone, and vitamin D concentrations and identify factors associated with metacarpophalangeal and metatarsophalangeal hyperextension in llamas and alpacas. Samples: Serum samples from 79 llamas and 15 alpacas and owner survey data for 573 llamas and 399 alpacas. Procedures: Serum samples were stored at −20°C until analysis and were evaluated for trace mineral, vitamin D, estradiol, progesterone, and testosterone concentrations. Information regarding age of onset, number of affected animals in herd, feed and supplements given, type of housing, and management practices was obtained in an owner survey. Results: Higher serum zinc and iron concentrations were associated with metacarpophalangeal and metatarsophalangeal hyperextension in camelids, compared with controls. In summer and fall months, vitamin D concentrations were significantly higher in affected camelids than controls. Overall prevalence was 13.3% in llamas, compared with 0.7% in alpacas. No management factors were found to be predictive of this condition. No other factors examined were associated with metacarpophalangeal and metatarsophalangeal hyperextension. Conclusions and Clinical Relevance: Despite similar supplementation practices and environmental conditions between affected and unaffected animals, an association of high serum zinc, iron, and vitamin D concentrations in affected camelids, compared with controls, may indicate differences of intake or absorption of dietary supplements.
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