scholarly journals Cross-sectional Prevalence of Helminth Infections in Cattle on Traditional, Small-scale and Large-scale Dairy Farms in Iringa District, Tanzania

2006 ◽  
Vol 30 (1) ◽  
pp. 45-55 ◽  
Author(s):  
J. D. Keyyu ◽  
A. A. Kassuku ◽  
L. P. Msalilwa ◽  
J. Monrad ◽  
N. C. Kyvsgaard
Keyword(s):  
Large Scale ◽  
Dairy Farms ◽  
Small Scale ◽  
Cross Sectional ◽  
Helminth Infections

Large- and small-scale vortical motions in a shear layer perturbed by tabs

1999 ◽  
Vol 382 ◽  
pp. 307-329 ◽  
Author(s):  
JUDITH K. FOSS ◽  
K. B. M. Q. ZAMAN
Keyword(s):  
Shear Layer ◽  
Pitch Angle ◽  
Large Scale ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Small Scale ◽  
Streamwise Vortices ◽  
Streamwise Vorticity ◽  
Cross Sectional ◽  
Scale Population

The large- and small-scale vortical motions produced by ‘delta tabs’ in a two-stream shear layer have been studied experimentally. An increase in mixing was observed when the base of the triangular shaped tab was affixed to the trailing edge of the splitter plate and the apex was pitched at some angle with respect to the flow axis. Such an arrangement produced a pair of counter-rotating streamwise vortices. Hot-wire measurements detailed the velocity, time-averaged vorticity (Ωx) and small-scale turbulence features in the three-dimensional space downstream of the tabs. The small-scale structures, whose scale corresponds to that of the peak in the dissipation spectrum, were identified and counted using the peak-valley-counting technique. The optimal pitch angle, θ, for a single tab and the optimal spanwise spacing, S, for a multiple tab array were identified. Since the goal was to increase mixing, the optimal tab configuration was determined from two properties of the flow field: (i) the large-scale motions with the maximum Ωx, and (ii) the largest number of small-scale motions in a given time period. The peak streamwise vorticity magnitude [mid ]Ωx−max[mid ] was found to have a unique relationship with the tab pitch angle. Furthermore, for all cases examined, the overall small-scale population was found to correlate directly with [mid ]Ωx−max[mid ]. Both quantities peaked at θ≈±45°. It is interesting to note that the peak magnitude of the corresponding circulation in the cross-sectional plane occurred for θ≈±90°. For an array of tabs, the two quantities also depended on the tab spacing. An array of contiguous tabs acted as a solid deflector producing the weakest streamwise vortices and the least small-scale population. For the measurement range covered, the optimal spacing was found to be S≈1.5 tab widths.

scholarly journals Univariate associations between housing, management, and facility design factors and the prevalence of lameness lesions in fourteen small-scale dairy farms in Northeastern Algeria

2020 ◽  
Vol 13 (3) ◽  
pp. 570-578 ◽  
Author(s):  
Zoubida Dendani-Chadi ◽  
Khelaf Saidani ◽  
Loubna Dib ◽  
Fayçal Zeroual ◽  
Faouzi Sammar ◽  
...  
Keyword(s):  
Univariate Analysis ◽  
Indirect Costs ◽  
Dairy Farms ◽  
Site Investigation ◽  
Cross Sectional Study ◽  
Small Scale ◽  
Facility Design ◽  
Cross Sectional ◽  
Housing Management ◽  
Increased Risk

Background and Aim: This cross-sectional study aimed to analyze the associations between different types of housing, management, and facilities on the prevalence of lame, causing lesions in smallholder dairy farms in Algeria. Materials and Methods: The on-site investigation took place between December 2012 and May 2015. All cows were locomotion scored on a four-point scale, and foot lesions causing lame were diagnosed and recorded. Factors related to the farm and the cows' conditions were also assessed. The association between the possible risk factors and lame lesions was assessed using univariate analysis. Results: Of the 349 cows evaluated, 13% were lame (lameness score ≥2), with higher lameness values recorded for the hind feet than for the forefeet. Cows without lameness were classified as healthy. The two most frequent lesion diagnoses observed in lame cows were interdigital dermatitis/heel horn erosion (ID/HE; 39%) and interdigital phlegmon (IP; 35%), followed by traumatic lesions (T; 11%), digital dermatitis (DD; 8.7%), and laminitis-related diseases (L; 6.5%). The risk of being lame was increased in large herds with cows of the Holstein breed, and those in the third parity and above. Tie housing, concrete floor, concentrate feeding, zero-grazing, and the use of foot trimming occasionally were associated with increased risk for the presence of lame lesions. The region and footbathing frequency had no association with the prevalence of lame lesions (p≥0.05). Conclusion: These results have important implications; they indicate that several aspects of housing, management, and facility design are common protective factors for the prevalence of lame lesions. These factors should be maintained correctly to not only reduce the number of lame cows in these herds but also decrease the direct and indirect costs associated with cases of lameness.

scholarly journals HONEYBEE PRODUCTION SYSTEM, CHALLENGES AND OPPORTUNITIES IN SELECTED DISTRICTS OF GEDEO ZONE, SOUTHERN NATION, NATIONALITIES AND PEOPLES REGIONAL STATE, ETHIOPIA

2016 ◽  
Vol 4 (4) ◽  
pp. 49-63
Author(s):  
Teklu Gebretsadik ◽  
Dinku Negash
Keyword(s):  
Production System ◽  
Large Scale ◽  
Market Access ◽  
Production Systems ◽  
Skill Training ◽  
Cross Sectional Study ◽  
Small Scale ◽  
Cross Sectional ◽  
Production Constraints ◽  
Regional State

The study was carried out in selected districts of Gedeo zones of southern Nation nationality and people’s regional state: such as Wonago, Kochere and DillaZuria/chichu/ districts. The objective of the study was to asses production systems, opportunities and constraints of apiculture farming in Gedeo zones of SNNPRs. Beekeeping is a long-standing practice in the study districts and appears as ancient history of the country as a whole. A cross sectional study, in which 90 households were purposively included and conducted in selected district to assess the current beekeeping practices, production potentials and production constraints. Most (72%) of the beekeepers in the study area have owned only traditional hives and produce honey for home consumption. The beekeeping practice was dominated by male.  Despite the area have  production constraints, the area opportunities like existence of large sized natural forest and artificial forest, due attention provision from regional, federal and local government and nongovernmental organizations, yearly flowering and variety floral availability, some small scale farmers highly experienced in apiculture farming, market access and high demand of apicultural products at nationally and international level. Therefore, Designing effective honeybee pests and predators controlling methods, Introduction of full package improved beekeeping technologies with adequate practical skill training on all bee keeping trends and queen rearing practices promoting beekeepers important indigenous knowledge, Producing areal major honeybee plants in large scale, Avoiding discarding of bee colonies after honey harvest, Availing the strategies to support farmers with beekeeping business support services, Improving pre- and post-harvest handling of bee products and Improving the utilization of stingless bee’s resources, without damaging the colony is important to make the honey production system in the area more economical, so as to enhance bee products for national and international need.

scholarly journals Comparison of the population structure of Streptococcus uberis mastitis isolates from Austrian small-scale dairy farms and a Slovakian large-scale farm

2020 ◽  
Vol 103 (2) ◽  
pp. 1820-1830
Author(s):  
Regina Wald ◽  
Martina Baumgartner ◽  
Julia Gutschireiter ◽  
Benjamin Bazzanella ◽  
Katharina Lichtmannsperger ◽  
...  
Keyword(s):  
Population Structure ◽  
Large Scale ◽  
Dairy Farms ◽  
Small Scale ◽  
Streptococcus Uberis ◽  
Small Scale Dairy

scholarly journals Neurobehavioural symptoms and acute pesticide poisoning: a cross-sectional study among male pesticide applicators selected from three commercial farming systems in Ethiopia

2018 ◽  
Vol 75 (4) ◽  
pp. 283-289 ◽  
Author(s):  
Beyene Negatu ◽  
Roel Vermeulen ◽  
Yalemtshay Mekonnen ◽  
Hans Kromhout
Keyword(s):  
Large Scale ◽  
Pesticide Exposure ◽  
Farming Systems ◽  
Cumulative Exposure ◽  
Small Scale ◽  
Pesticide Poisoning ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Pesticide Applicators ◽  
Acute Pesticide Poisoning

ObjectiveTo estimate prevalence of acute pesticide poisoning (APP) and its association with neurobehavioural symptoms in Ethiopian pesticide applicators.MethodsWe performed a cross-sectional survey among 256 pesticide applicators from small-scale irrigated farms, a large-scale open farm and large-scale greenhouses. APP was ascertained using a modified WHO case definition, and neurobehavioural symptoms were collected with a standardised questionnaire (Q16). Exposure to pesticides was estimated using detailed exposure algorithms specifically developed for Ethiopian farms. Multiple logistic regression models were used to estimate risk of APP and its association with neurobehavioural symptoms.ResultsOverall APP prevalence was 16%. Working as an applicator in greenhouses was strongly associated with APP (OR 3.00, 95% CI 1.38 to 6.54). Estimated annual pesticide exposure was also associated with APP (OR 1.14, 95% CI 1.00 to 1.20). Longer duration of employment appeared to be negatively associated with APP. Having had an APP was strongly associated with reporting more neurobehavioural symptoms (OR 2.15, 95% CI 1.01 to 4.58) independent of cumulative pesticide exposure. Cumulative exposure to pesticides appeared to be associated with neurobehavioural symptoms among applicators without and with APP.ConclusionsWe showed a substantial prevalence of APP that differed between farming systems and was strongly associated with neurobehavioural symptoms. Intensity of exposure was also clearly associated with these symptoms. Reduction and control of occupational exposure to pesticides is urgently needed in Ethiopia.

Rift and thrust tectonics associated with a translational block slide, Abbotsford, New Zealand

1986 ◽  
Vol 123 (1) ◽  
pp. 13-25 ◽  
Author(s):  
D. G. Bishop ◽  
R. J. Norris
Keyword(s):  
Large Scale ◽  
Ground Surface ◽  
Failure Surface ◽  
Bedding Plane ◽  
Small Scale ◽  
Trailing Edge ◽  
Cross Sectional ◽  
Thrust Tectonics ◽  
Sudden Decrease ◽  
Translational Block

AbstractThe East Abbotsford translational block landslide failed suddenly on 8 August, 1979, after months and probably years of slowly accelerating movement. A displacement of about 50 m occurred on a bedding plane dipping 7°, about 30 m below ground surface, at or very near the contact between two formations.The complex graben formed around the head of the landslide is a small scale example of extensional (rift) tectonics. A wedge and prism model is developed to fit the geometry, and meet the constraints of preserving the cross-sectional area and stratal length of the beds involved and also to account for the sequential retrogressive failures of the trailing edge of the sliding block.Reconstruction of the failure sequence at the toe shows the compressional zone to be dominated by overthrusting on upward sloping surfaces or ramps, with subsidiary backthrusting and buckling.The energy expended in overthrusting, coupled with the decrease in mass (and hence driving force) resulting from the retrogressive spalling of the trailing edge of the slide block, indicates that the phase of rapid movement was accompanied by a sudden decrease in resistance on the failure surface for a movement of 50 m to have occurred.Both the rift and thrust structures associated with the landslide have large scale tectonic analogues.

scholarly journals Survey of human and bovine tuberculosis infection on dairy farms in southwestern China

2020 ◽  
Author(s):  
Shu Zhang ◽  
Chuang Chen ◽  
Zhengyuan Rao ◽  
Aiguo Yang ◽  
Li Guo ◽  
...  
Keyword(s):  
Large Scale ◽  
Dairy Farm ◽  
Dairy Farms ◽  
Sichuan Province ◽  
Farm Workers ◽  
Skin Tests ◽  
Southwestern China ◽  
23S Rrna ◽  
Small Scale ◽  
Purified Protein Derivative

Abstract Background: Tuberculosis is a zoonotic chronic infectious disease caused by Mycobacterium tuberculosis complex (MTBC) that can be transmitted between humans and cattle. The aim of our study was to identify cross-infections of MTBC between humans and cattle on dairy farms in Sichuan Province, southwestern China. Results: We selected 6 large-scale and 5 small-scale dairy farms in Sichuan Province as research sites. A total of 378 dairy farm workers (except one pregnant woman) were screened for tuberculosis symptoms and examined by X-ray. One worker was diagnosed as tuberculosis, though the sputum culture was negative. In total, 99 of 10,224 (0.97%) cows showed positive results for the purified protein derivative (PPD) skin tests. Esophageal-pharyngeal (OP) secretions from PPD-positive cows were cultured and 21 isolates were obtained. Sequences of 16s rDNA, hsp65 and rpoB and 16s-23s rRNA spacer region were amplified and sequenced. BLAST analysis classified these isolates as nontuberculous mycobacteria (NTM) (18 M. nonchromogenicum, 1 M. hiberniae, 1 M. arupense, and 1 M. chitae isolates). Conclusion: This study indicates that the PPD-positive cows in these dairy farms were infected with NTM rather than MTBC. Tuberculosis cross-infection between humans and cows on dairy farms has been well controlled in this region.

scholarly journals Turbulent transport mechanisms in oscillating bubble plumes

2009 ◽  
Vol 633 ◽  
pp. 191-231 ◽  
Author(s):  
MARCO SIMIANO ◽  
D. LAKEHAL ◽  
M. LANCE ◽  
G. YADIGAROGLU
Keyword(s):  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Large Scale ◽  
Small Scale ◽  
Equivalent Diameter ◽  
Minor Effect ◽  
Reynolds Stresses ◽  
Bubble Plume ◽  
Low Velocity ◽  
Cross Sectional

The detailed investigation of an unstable meandering bubble plume created in a 2-m-diameter vessel with a water depth of 1.5 m is reported for void fractions up to 4% and bubble size of the order of 2.5 mm. Simultaneous particle image velocity (PIV) measurements of bubble and liquid velocities and video recordings of the projection of the plume on two vertical perpendicular planes were produced in order to characterize the state of the plume by the location of its centreline and its equivalent diameter. The data were conditionally ensemble averaged using only PIV sets corresponding to plume states in a range as narrow as possible, separating the small-scale fluctuations of the flow from the large-scale motions, namely plume meandering and instantaneous cross-sectional area fluctuations. Meandering produces an apparent spreading of the average plume velocity and void fraction profiles that were shown to remain self-similar in the instantaneous plume cross-section. Differences between the true local time-average relative velocities and the difference of the averaged phase velocities were measured; the complex variation of the relative velocity was explained by the effects of passing vortices and by the fact that the bubbles do not reach an equilibrium velocity as they migrate radially, producing momentum exchanges between high- and low-velocity regions. Local entrainment effects decrease with larger plume diameters, contradicting the classical dependence of entrainment on the time-averaged plume diameter. Small plume diameters tend to trigger ‘entrainment eddies’ that promote the inward-flow motion. The global turbulent kinetic energy was found to be dominated by the vertical stresses. Conditional averages according to the plume diameter showed that the large-scale motions did not affect the instantaneous turbulent kinetic energy distribution in the plume, suggesting that large scales and small scales are not correlated. With conditional averaging, meandering was a minor effect on the global kinetic energy and the Reynolds stresses. In contrast, plume diameter fluctuations produce a substantial effect on these quantities.

scholarly journals Clinical and Subclinical Bovine Mastitis and Associated Risk factors in Small-scale Dairy Farms in Bahir Dar and its envirion, Amhara region

2021 ◽  
Author(s):  
Mussie Hailemelekot ◽  
Melaku Chalachew ◽  
Sam Laiju
Keyword(s):  
Risk Factors ◽  
Body Condition Score ◽  
Significant Risk ◽  
Dairy Farms ◽  
Small Scale ◽  
P Value ◽  
Bahir Dar ◽  
Biochemical Tests ◽  
Cross Sectional ◽  
Associated Risk Factors

Abstract Background Cross-sectional study was conducted from June 2017 to January 2018 with the objective of determining the prevalence of mastitis and identify the associated risk factors in and around Bahir dar dairy farms. Totally 302 lactating cows were selected using simple random sampling method. Initially, mastitis cases were diagnosed based on California Mastitis Test (MCT) results and the nature of gel formation. Then positive samples were subjected to bacterial culture and isolation using blood agar, MacConkey agar, colony morphology, Gram stain, and biochemical tests. Statistical analysis was carried out using STATA software and association of mastitis with risk factors was analyzed using chi square test. The association was considered as significant when p-value was less than 0.05. Result The overall cow level prevalence of mastitis using CMT was 25.16% (76/302) with clinical and sub clinical mastitis of 3.64% and 21.52%, respectively. Similarly, the quarter level mastitis was 10.43% (126/1208) with clinical and sub clinical cases of 1.49% and 8.94%, respectively. Bacteria identified were Staphylococci Spp, Escherichia coli, Bacillus Spp, and Streptococcus Spp. with a proportion of 66.07% .94%, 8.0% and 7.14%, respectively. Body condition score, cow Hygiene, Parity, history of mastitis, stage of lactation, teat lesion, use of same clothing, lactating mastitis positive animal last were found to be significant risk factors. Conclusion The current study revealed moderate prevalence of mastitis warranting application of appropriate hygienic practices during milking and awareness creation to the dairy farmers.

scholarly journals Survey of human and bovine tuberculosis infection on dairy farms in southwestern China

2020 ◽  
Author(s):  
Shu Zhang ◽  
Chuang Chen ◽  
Zhengyuan Rao ◽  
Aiguo Yang ◽  
Li Guo ◽  
...  
Keyword(s):  
Large Scale ◽  
Dairy Farm ◽  
Dairy Farms ◽  
Sichuan Province ◽  
Farm Workers ◽  
Skin Tests ◽  
Southwestern China ◽  
23S Rrna ◽  
Small Scale ◽  
Purified Protein Derivative

Abstract Abstract Background: Tuberculosis is a zoonotic chronic infectious disease caused by Mycobacterium tuberculosis complex (MTBC) that can be transmitted between humans and cattle. The aim of our study was to identify cross-infections of MTBC between humans and cattle on dairy farms in Sichuan Province, southwestern China. Results: We selected 6 large-scale and 5 small-scale dairy farms in Sichuan Province as research sites. A total of 378 dairy farm workers (except one pregnant woman) were screened for tuberculosis symptoms and examined by X-ray. One worker was diagnosed as tuberculosis, though the sputum culture was negative. In total, 99 of 10,224 (0.97%) cows showed positive results for the purified protein derivative (PPD) skin tests. Esophageal-pharyngeal (OP) secretions from PPD-positive cows were cultured and 21 isolates were obtained. Sequences of 16s rDNA , hsp65 and rpoB and 16s-23s rRNA spacer region were amplified and sequenced. BLAST analysis classified these isolates as nontuberculous mycobacteria (NTM) (18 M. nonchromogenicum , 1 M. hiberniae , 1 M. arupense, and 1 M. chitae isolates). Conclusion: This study indicates that the PPD-positive cows in these dairy farms were infected with NTM rather than MTBC. Tuberculosis cross-infection between humans and cows on dairy farms has been well controlled in this region.

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