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Ticks (Acari: Ixodidae) infesting cattle and African buffaloes in the Tsavo conservation area, Kenya
2012
Edward K. Kariuki | Barend L. Penzhorn | Ivan G. Horak
Several ixodid tick species are shared between domestic cattle and African buffaloes (<em>Syncerus caffer</em>). So too, are a number of tick-borne diseases. The aim of the study was to compare the species composition of ticks that infest cattle and buffaloes utilising the same habitat within the Tsavo Conservation Area, Kenya. To this end, 25 cattle and 62 buffaloes were each opportunistically sampled for ticks on a single occasion in February 2010. Eight species, namely <em>Amblyomma gemma</em>, <em>Amblyomma lepidum</em>, <em>Hyalomma albiparmatum</em>, <em>Hyalomma rufipes</em>, <em>Hyalomma truncatum</em>, <em>Rhipicephalus evertsi evertsi</em>, <em>Rhipicephalus pravus</em> and <em>Rhipicephalus pulchellus</em> infested both cattle and buffaloes. Three species, <em>Rhipicephalus</em> (<em>Boophilus</em>) sp., <em>Rhipicephalus kochi</em>, and <em>Rhipicephalus muehlensi</em> were collected only from cattle, and three species,<em> Hyalomma impeltatum</em>, <em>Rhipicephalus humeralis</em> and<em> Rhipicephalus praetextatus</em> were present only on buffaloes. The attachment sites of the various tick species were also recorded. New locality records for <em>H. impeltatum</em> and <em>H. truncatum</em> and the first confirmed locality record for <em>Rhipicephalus praetextatus sensu stricto</em> in Kenya were documented.
Show more [+] Less [-]Evaluation of the diagnostic and prognostic utility of ultrasonography at first diagnosis of presumptive bovine respiratory disease
2012
Abutarbush, Sameeh M. | Pollock, Colleen M. | Wildman, Brian K. | Perrett, Tye | Schunicht, Oliver C. | Fenton, R Kent | Hannon, Sherry J. | Vogstad, Amanda R. | Jim, G Kee | Booker, Calvin W.
This project investigated the use of ultrasonography at first diagnosis of presumptive early bovine respiratory disease (BRD) in feedlot cattle from western Canada. One hundred seventy-four cattle (116 cases and 58 controls) at high risk of developing BRD were enrolled in a prospective longitudinal study over 2 y (2006-2007). Cattle with clinical signs relating to the respiratory system and assessed as sick at the time of feedlot arrival (arrival fever cases) or assessed as sick in the pen 3 to 30 d post-arrival (post-arrival fever cases, post-arrival no fevers cases) were eligible for enrollment. Control animals were identified at the time of case enrollments. Ultrasonography was done using a 3.5 sector transducer at enrollment and at 2, 4, and 6 wk post-enrollment. Lung lesions were identified at least 1 time over the course of the trial in 32/116 (28%) cases and 9/58 (16%) controls. At enrollment, lung lesions were identified in 20/115 (17%) cases and 2/55 (4%) controls (data unreadable n = 4). Post-arrival fever cases (14/48) were the most likely to have a lesion identified using ultrasound. In arrival fever cases, average daily gain (enrollment to last ultrasound, average 34 d) was improved (P = 0.007) in cattle identified with a lesion at enrollment using ultrasound compared with those not identified with a lesion at that time, potentially demonstrating the effects of gut fill at arrival weighing, as these sicker animals may have eaten less prior to arrival and, therefore, had more room for improvement in weight over time due to restoration of normal gut fill. None of the ultrasound time points explored (enrollment, 2, 4, or 6 wk post-enrollment) were associated with the animal health outcomes of interest (subsequent treatment, chronicity, wastage, or mortality) for cattle enrolled at arrival or post-arrival.
Show more [+] Less [-]Evaluation of an alternative method of herd classification for infection with paratuberculosis in cattle herds in the United States
2012
Tavornpanich, Saraya | Wells, Scott J. | Fossler, Charles P. | Roussel, Allen J. | Gardner, Ian A.
Objective: To develop a better system for classification of herd infection status for paratuberculosis (Johne's disease [JD]) in US cattle herds on the basis of the risk of potential transmission of Mycobacterium avium subsp paratubeculosis. Sample: Simulated data for herd size and within-herd prevalence; sensitivity and specificity for test methods obtained from consensus-based estimates. Procedures: Interrelationships among variables influencing interpretation and classification of herd infection status for JD were evaluated by use of simulated data for various herd sizes, true within-herd prevalences, and sampling and testing methods. The probability of finding ≥ 1 infected animal in herds was estimated for various testing methods and sample sizes by use of hypergeometric random sampling. Results: 2 main components were required for the new herd JD classification system: the probability of detection of infection determined on the basis of test results from a sample of animals and the maximum detected number of animals with positive test results. Tables were constructed of the estimated probability of detection of infection, and the maximum number of cattle with positive test results or fecal pools with positive culture results with 95% confidence for classification of herd JD infection status were plotted. Herd risk for JD was categorized on the basis of 95% confidence that the true within-herd prevalence was ≤ 15%, ≤ 10%, ≤ 5%, or ≤ 2%. Conclusions and Clinical Relevance: Analysis of the findings indicated that a scientifically rigorous and transparent herd classification system for JD in cattle is feasible.
Show more [+] Less [-]Pharmacokinetics and tissue elimination of tulathromycin following subcutaneous administration in meat goats
2012
Romanet, Jessica | Smith, Geof W. | Leavens, Teresa L. | Baynes, Ronald E. | Wetzlich, Scott E. | Riviere, Jim E. | Tell, Lisa A.
Objective: To determine the tissue depletion profile of tulathromycin and determine an appropriate slaughter withdrawal interval in meat goats after multiple SC injections of the drug. Animals: 16 healthy Boer goats. Procedures: All goats were administered tulathromycin (2.5 mg/kg, SC) twice, with a 7-day interval between doses. Blood samples were collected throughout the study, and goats were euthanized at 2, 5, 10, and 20 days after the second tulathromycin dose. Lung, liver, kidney, fat, and muscle tissues were collected. Concentrations of tulathromycin in plasma and the hydrolytic tulathromycin fragment CP-60,300 in tissue samples were determined with ultrahigh-pressure liquid chromatography–tandem mass spectrometry. Results: The plasma profile of tulathromycin was biphasic. Absorption was very rapid, with maximum drug concentrations (1.00 ± 0.42 μg/mL and 2.09 ± 1.77 μg/mL following the first and second doses, respectively) detected within approximately 1 hour after injection. Plasma terminal elimination half-life of tulathromycin was 61.4 ± 14.1 hours after the second dose. Half-lives in tissue ranged from 2.4 days for muscle to 9.0 days for lung tissue; kidney tissue was used to determine the withdrawal interval for tulathromycin in goats because it is considered an edible tissue. Conclusions and Clinical Relevance: On the basis of the tissue tolerance limit in cattle of 5 ppm (μg/g), the calculated withdrawal interval for tulathromycin would be 19 days following SC administration in goats. On the basis of the more stringent guidelines recommended by the FDA, the calculated meat withdrawal interval following tulathromycin administration in goats was 34 days.
Show more [+] Less [-]Evaluation of diode endoscopic cyclophotocoagulation in bovine cadaver eyes
2012
Harrington, Jay T. | McMullen, Richard J. Jr | Cullen, J. M. (John M) | Gilger, Brian C.
Objective: To evaluate the anterior chamber approach and energy levels for endoscopic cyclophotocoagulation (ECPC) and assess ECPC-induced tissue damage in phakic eyes of bovine cadavers. Sample: 12 bovine cadaver eyes. Procedures: Angle of reach was measured in 6 eyes following placement of a curved endoscopic probe through multiple corneal incisions. In another 6 eyes, each ocular quadrant underwent ECPC at 1 of 3 energy levels (0.75, 0.90, and 1.05 J) or remained untreated. Visible effects on tissues (whitening and contraction of ciliary processes) were scored (scale of 0 [no effects] to 6 [severe effects]), and severity and extent of histologic damage to the pigmented and nonpigmented ciliary epithelium and fibromuscular stroma were each scored (scale of 0 [no effect] to 3 [severe effect]) and summed for each quadrant. Overall mean scores for 6 quadrants/treatment were calculated. Results: Mean ± SD combined angle of reach was 148 ± 24° (range, 123 ± 23° [ventromedial] to 174 ± 11° [dorsolateral]). At the 0.75-, 0.90-, and 1.05-J levels, mean visible tissue effect scores were 3.12 ± 0.47, 3.86 ± 0.35, and 4.68 ± 0.58, respectively; mean histologic damage scores were 4.79 ± 1.38 (mild damage), 6.82 ± 1.47 (moderate damage), and 9.37 ± 1.42 (severe damage), respectively. Occasional popping noises (venting of vaporized interstitial water) were heard at the 1.05-J level. Conclusions and Clinical Relevance: Multiple incisions were necessary to facilitate 360° ECPC treatment in bovine eyes. For ECPC in vivo, the 0.75- and 0.90-J energy levels had the potential to effectively treat the ciliary epithelium.
Show more [+] Less [-]Seroprevalence of Melioidosis among livestock in Malaysia 2000-2009
2012
Hassan L. | Musa H. I.
Melioidosis usually results in chronic debilities that reduce the
productivity of animals and condemnation of carcasses in abattoir. Melioidosis is reemerging among animals and humans, and anecdotal reports suggest an increase in disease observation. This study described the seroprevalence of melioidosis in livestock based on the data obtained from the Department of Veterinary Services, Putrajaya and the Veterinary Research Institute, Ipoh. The data were summarized according to animal species, state, and year. The seroprevalence rate in animals was 7.6, 48.2, 2.6, 13.6 and 3.6% in cattle, buffaloes, goats, sheep and pigs respectively. The
seroprevalence of the disease varies in different states of the federation. For all species, the seroprevalence vary between
2.6% and 48.2%. The seroprevalence over the years increased from 4.2% in 2000 to 12.0% in 2003 after which it varies between
the period 2004- 2007 and apparently declined between 2007 and 2009.
Show more [+] Less [-]A beef fattening decision support system
2012
Wan Zaharil M. | Shanmugavelu S. | Wong, H. K. | Mardhati M.
A beef feedlot production decision support system (DSS) was developed based on Microsoft® Excel. The DSS comprises of three modules i) an ingredient database ii) a least-cost ration formulation module and iii) beef growth simulation module. The program uses empirical equations developed for tropical beef to simulate nutrient requirements and daily body weight gains based on the formulated feed ration. The formulated least cost ration can be pasted automatically into the growth model to evaluate performance and economic viability. The growth model calculates nutrient available and computes body weight gain on a daily basis, summates weight gain and stops at the targeted body weight. The data output include i) days to reach target body weight, ii) cumulative feed consumed, iii) anticipated average daily gain, iv) total cost of feed (concentrates and grass), and v) gross profit per cattle. If a portion of the feed is fed as grass, then the model also computes the pasture land required in hectares, based on the forage species
chosen. It is anticipated that the developed model can assist cattle entrepreneurs and farmers in the development of the beef cattle industry in Malaysia.
Show more [+] Less [-]A genetic improvement program for Kedah-Kelantan cattle
2012
Raymond A. K. | Abu-Hassan M. A.
Kedah-Kelantan cattle (KK) being an indigenous breed are highly adapted to the hot-humid Malaysian climate and can survive in harsh, marginal environments. This makes the KK a valuable genetic resource, given the challenges of climate change and the changing demands of the livestock sector. Hitherto there is no comprehensive programme to genetically improve the purebred KK. Genetic improvement of the KK would be to fulfill the breeding objectives of increasing lean meat growth rate, enhancing meat quality, raising feed efficiency, improving fertility and maintaining adaptability. The breeding structure proposed is a 2-tier breeding structure, with a nucleus tier followed by a commercial tier below it. The nucleus tier would comprise of a number of pedigree farms run as a community
breeding project. A sire reference scheme is proposed, where progeny of reference sires are used as genetic links between pedigree herds and between years. Some guidelines are offered on the establishment
and implementation of the scheme. Modern breeding technology such as BLUP using an Animal Model, artificial insemination, embryo transfer, tissue scanning, MAS and MAI could be used as tools to support the KK genetic improvement programme. To address the problem of genetic erosion, emphasis should be given to the conservation and sustainable utilization of the KK. The programme is expected to have a high impact on the livestock sector. Substantial investments are needed to develop infrastructure and human capital associated with the KK breeding programme. The establishment of a KK breed society will improve awareness concerning the KK and protect the interests
of the KK breeding community.
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