Literatura académica sobre el tema "Cattle exposure"
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Artículos de revistas sobre el tema "Cattle exposure"
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Bingham, Howard R., Paul S. Morley, Thomas E. Wittum, Tammy M. Bray, Keith H. West, Richard D. Slemons, John A. Ellis et al. "Synergistic effects of concurrent challenge with bovine respiratory syncytial virus and 3-methylindole in calves". American Journal of Veterinary Research 60, n.º 5 (1 de mayo de 1999): 563–70. http://dx.doi.org/10.2460/ajvr.1999.60.05.563.
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Abstract Objective To evaluate the potential synergy between bovine respiratory syncytial virus (BRSV) and 3-methylindole (3MI) in inducing respiratory disease in cattle. Animals 20 mixed-breed beef calves. Procedure A 2 × 2 factorial design was used, with random assignment to the following 4 treatment groups: unchallenged control, BRSV challenge exposure (5 × 104 TCID50 by aerosolization and 5.5 × 105 TCID50 by intratracheal inoculation), 3MI challenge exposure (0.1 g/kg of body weight, PO), and combined BRSV-3MI challenge exposure. Clinical examinations were performed daily. Serum 3MI concentrations, WBC counts, PCV, total plasma protein, and fibrinogen concentrations were determined throughout the experiment. Surviving cattle were euthanatized 7 days after challenge exposure. Pulmonary lesions were evaluated at postmortem examination. Results Clinical respiratory disease was more acute and severe in cattle in the BRSV-3MI challenge-exposure group than in cattle in the other groups. All 5 cattle in this group and 3 of 5 cattle treated with 3MI alone died or were euthanatized prior to termination of the experiment. Mean lung displacement volume was greatest in the BRSV-3MI challenge-exposure group. Gross and histologic examination revealed that pulmonary lesions were also most severe for cattle in this group. Conclusions and Clinical Relevance Feedlot cattle are commonly infected with BRSV, and 3MI is produced by microflora in the rumen of all cattle. Our results suggest that there is a synergy between BRSV and 3MI. Thus, controlling combined exposure may be important in preventing respiratory disease in feedlot cattle. (Am J Vet Res 1999;60:563–570)
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Pšenka, M., M. Šístková, Š. Mihina y R. Gálik. "Frequency analysis of noise exposure of dairy cows in the process of milking". Research in Agricultural Engineering 62, No. 4 (28 de noviembre de 2016): 185–89. http://dx.doi.org/10.17221/4/2015-rae.
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In the environment of farms and farm buildings, cattle are exposed to various unnatural influences. Such an impact is also noise always arising with a certain energy conversion. In cattle farms, the sources of noise are represented by various mechanical equipment and machines that are used for enabling farm operations. The aim of the paper was to analyse the noise levels in dairy cattle production in the environment, during their day routine. Noise levels were measured at two farms with a different technological layout of milking parlour, with a different way of milking. The noise exposure of dairy cows was measured in three locations, namely in the milking parlour, during standing in the area before milking (in the so-called collection room) and directly in the stabling area. Noise exposure was measured during milking and when the milking parlour was turned off. The values were compared with the hearing sensitivity of cattle at selected frequencies (0.5, 1, 2, 4, 8 and 16 kHz).
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MILLER, M. F., G. H. LONERAGAN, D. D. HARRIS, K. D. ADAMS, J. C. BROOKS y M. M. BRASHEARS. "Environmental Dust Exposure as a Factor Contributing to an Increase in Escherichia coli O157 and Salmonella Populations on Cattle Hides in Feedyards". Journal of Food Protection 71, n.º 10 (1 de octubre de 2008): 2078–81. http://dx.doi.org/10.4315/0362-028x-71.10.2078.
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A study was conducted to determine the impact of exposure to dust in the cattle load-out area in feedyards on pathogen contamination of cattle hides. A total of 250 cattle hides were sampled during summer and fall months, which are associated with elevated prevalence of Escherichia coli O157 in West Texas. Animals were removed from their home pens and restrained in a chute and sampled prior to exposure to dust generated as a result of a simulated loading exercise. The cattle hides were sampled again after exposure to the loading dust to determine total numbers of pathogens on cattle hides on leaving their home pen (before loading) and on cattle hides after exposure to the dust in the loading area. Air and dirt samples from the home pens and the cattle load-out area were also collected. The presence of E. coli O157 and Salmonella was determined in all the samples, and when a positive sample was identified, the total numbers of these bacteria present were enumerated. The total numbers of pathogens increased after dust exposure; Salmonella counts increased from 1.09 log most probable number (MPN)/cm2 to 1.74 log MPN/cm2 after exposure, and E. coli O157 counts increased from 0.80 to 2.35 log MPN/cm2 after sampling. E. coli O157 and Salmonella were recovered from the air samples during dust generation at 6.66 and 11.1%, respectively. Salmonella and E. coli O157 prevalence was not changed and was not associated with the exposure to the dust. Results indicate airborne dust generated as a result of cattle movement and loading could be an important determining factor in total numbers of pathogens recovered on cattle hides.
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Kaufmann, Jillian, Edward W. Bork, Michael J. Alexander y Peter V. Blenis. "Effects of open-range cattle grazing on deciduous tree regeneration, damage, and mortality following patch logging". Canadian Journal of Forest Research 44, n.º 7 (julio de 2014): 777–83. http://dx.doi.org/10.1139/cjfr-2014-0131.
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The impact of summer cattle grazing on deciduous tree regeneration within uncut forests, clearcuts, partially harvested areas, and in-block haul road habitats was examined in four experimental pastures of central Alberta during 2008 and 2009. Sampling of 233 field plots, both inside and outside cattle exclosures, was used to document sapling densities, height, and type of damage. Tree densities (primarily aspen (Populus tremuloides Michx.)) differed among habitats but less so with exposure to cattle. Densities were greatest in clearcuts, followed by partially harvested areas and then uncut forest and haul roads. While exposure to cattle reduced total tree regeneration, sapling densities and sizes remained sufficient to meet postharvest standards for deciduous forest regeneration in Alberta, even with exposure to cattle. Cattle damage in harvested areas was primarily from browsing (≤3.2% of saplings), with proportionally more trees affected in uncut forests (8.6%). Browsing was particularly high on balsam poplar (Populus balsamifera L.) (25%) during 2008. Although sapling damage increased with high cattle stocking in 2008 (to 10.5%), total mortality was limited to 15.5% through 2009. These findings show that despite cattle impacts to some saplings, damage levels were insufficient to alter deciduous regeneration, highlighting the compatibility of cattle grazing and sustainable forest management on public lands in this region.
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Rabaza, Ana, Federico Giannitti, Martín Fraga, Melissa Macías-Rioseco, Luis G. Corbellini, Franklin Riet-Correa, Darío Hirigoyen, Katy M. E. Turner y Mark C. Eisler. "Serological Evidence of Human Infection with Coxiella burnetii after Occupational Exposure to Aborting Cattle". Veterinary Sciences 8, n.º 9 (16 de septiembre de 2021): 196. http://dx.doi.org/10.3390/vetsci8090196.
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Cattle are broadly deemed a source of Coxiella burnetii; however, evidence reinforcing their role in human infection is scarce. Most published human Q fever outbreaks relate to exposure to small ruminants, notably goats. Anti-phase II C. burnetii IgG and IgM were measured by indirect fluorescent antibody tests in 27 farm and veterinary diagnostic laboratory workers to ascertain whether occupational exposure to cattle aborting due to C. burnetii was the probable source of exposure. Four serological profiles were identified on the basis of anti-phase II IgG and IgM titres. Profile 1, characterised by high IgM levels and concurrent, lower IgG titres (3/27; 11.1%); Profile 2, with both isotypes with IgG titres higher than IgM (2/27; 7.4%); Profile 3 with only IgG phase II (5/27; 18.5%); and Profile 4, in which neither IgM nor IgG were detected (17/27; 63.0%). Profiles 1 and 2 are suggestive of recent C. burnetii exposure, most likely 2.5–4.5 months before testing and, hence, during the window of exposure to the bovine abortions. Profile 3 suggested C. burnetii exposure that most likely predated the window of exposure to aborting cattle, while Profile 4 represented seronegative individuals and, hence, likely uninfected. This study formally linked human Q fever to exposure to C. burnetii infected cattle as a specific occupational hazard for farm and laboratory workers handling bovine aborted material.
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Yevstafieva, V., O. Kasianenko, J. Negreba, B. Kyrychko, V. Levytska y K. Havryk. "Ovicidal effectiveness of Hermecid-VS disinfectant against Trichuris spp. nematode eggs isolated from cattle". Scientific Messenger of LNU of Veterinary Medicine and Biotechnologies 25, n.º 110 (18 de junio de 2023): 110–15. http://dx.doi.org/10.32718/nvlvet11018.
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The genus Trichuris is a well-known group of nematodes whose species parasitize humans and many domestic animals, including carnivores, cattle, small ruminants and pigs. These parasites in the embryonic stages of development are quite resistant to adverse environmental conditions, which poses a threat of significant spread of trichurosis in livestock farms. The aim of the work was to determine the ovicidal effectiveness of the Hermecid-VS disinfectant (Vetsintez LLC, Ukraine) on the eggs of Trichuris spp. nematodes isolated from cattle under experimental conditions. To determine the densivasive activity, the disinfectant was used in 0.1 %, 0.25 % and 0.5 % concentrations for different exposures – 10, 30 and 60 minutes. The test-culture of trichurises eggs was obtained from the feces of sick animals using the flotation method and subsequent washing in a physiological solution. According to the research results, it was established that the Hermecid-VS preparation has a high level of ovicidal efficiency against the eggs of Trichuris spp., which parasitize cattle, at a concentration of 0.25 % for exposure of 60 minutes and 0.5 % for exposures of 10–60 minutes . Under these regimes, the disinfectant ensured 100 % death of trichurises eggs at various stages of their development in vitro. Also, a high level of ovicidal efficiency was found when using Hermecid-VS at a concentration of 0.25 % for 10 min (90.91 %) and 30 min (96.59 %) exposures. A satisfactory level of ovicidal efficiency was obtained using the agent at a concentration of 0.1 % for exposures of 10, 30 and 60 minutes, where the indicators of disinfestation activity were at the level of 63.64 %, 68.18 % and 76.14 %, respectively. The obtained research results allow us to recommend the Hermecid-VS disinfectant in 0.25 % concentration for 60-minute exposure and 0.5 % concentration for 10-minute exposure for disinfestation as a component of measures to combat and prevent cattle trichurosis, as well as with for the purpose of maintaining veterinary-sanitary and epizootic well-being in livestock farms.
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Webb, L., D. J. Beaumont, R. G. Nager y D. I. McCracken. "Effects of avermectin residues in cattle dung on yellow dung fly Scathophaga stercoraria (Diptera: Scathophagidae) populations in grazed pastures". Bulletin of Entomological Research 97, n.º 2 (abril de 2007): 129–38. http://dx.doi.org/10.1017/s0007485307004683.
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AbstractThe effects of avermectin exposure on natural populations of the yellow dung fly, Scathophaga stercoraria Linnaeus, were investigated at the field scale on farms in south-west Scotland. Pastures forming the focus of the study were grazed with either untreated cattle or cattle receiving standard, manufacturer-recommended treatment regimes of an avermectin product. Flies were sampled between April and July in 2002 and 2003 using dung-baited pitfall traps. Abundance and wing asymmetry in S. stercoraria populations were examined in relation to a range of environmental and management variables (including avermectin exposure, pasture management intensity, weather and season). Data used for abundance analyses were collected in fields where treated cattle had been dosed with either doramectin or ivermectin, while the data for the asymmetry analyses were from a subset of fields where treated cattle had been dosed with doramectin only. While abundance of S. stercoraria varied significantly between years and with season, there was no difference in their abundance between fields grazed by avermectin-treated or untreated cattle. Asymmetry was significantly higher in fly populations in fields grazed by doramectin-treated cattle, suggesting that exposure to doramectin during development could have imposed some degree of environmental stress. While these results suggest that exposure to doramectin residues in dung on grazed pastures may have sublethal effects on the insects developing in that dung, there was no evident avermectin effect on the abundance of adult S. stercoraria occurring in the pastures.
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Chakraborty, Sulagna, Siyu Gao, Brian F. Allan y Rebecca Lee Smith. "Effects of cattle on vector-borne disease risk to humans: A systematic review". PLOS Neglected Tropical Diseases 17, n.º 12 (19 de diciembre de 2023): e0011152. http://dx.doi.org/10.1371/journal.pntd.0011152.
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Vector-borne pathogens (VBPs) causing vector-borne diseases (VBDs) can circulate among humans, domestic animals, and wildlife, with cattle in particular serving as an important source of exposure risk to humans. The close associations between humans and cattle can facilitate the transmission of numerous VBPs, impacting public health and economic security. Published studies demonstrate that cattle can influence human exposure risk positively, negatively, or have no effect. There is a critical need to synthesize the information in the scientific literature on this subject, in order to illuminate the various ecological mechanisms that can affect VBP exposure risk in humans. Therefore, the aim of this systematic review was to review the scientific literature, provide a synthesis of the possible effects of cattle on VBP risk to humans, and propose future directions for research. This study was performed according to the PRISMA 2020 extension guidelines for systematic review. After screening 470 peer-reviewed articles published between 1999–2019 using the databases Web of Science Core Collection, PubMed Central, CABI Global Health, and Google Scholar, and utilizing forward and backward search techniques, we identified 127 papers that met inclusion criteria. Results of the systematic review indicate that cattle can be beneficial or harmful to human health with respect to VBDs depending on vector and pathogen ecology and livestock management practices. Cattle can increase risk of exposure to infections spread by tsetse flies and ticks, followed by sandflies and mosquitoes, through a variety of mechanisms. However, cattle can have a protective effect when the vector prefers to feed on cattle instead of humans and when chemical control measures (e.g., acaricides/insecticides), semio-chemicals, and other integrated vector control measures are utilized in the community. We highlight that further research is needed to determine ways in which these mechanisms may be exploited to reduce VBD risk in humans.
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Chiuya, Tatenda, Eric M. Fèvre, Noah O. Okumu, Abdullahi M. Abdi, Sandra Junglen y Christian Borgemeister. "Exposure to Arboviruses in Cattle: Seroprevalence of Rift Valley Fever, Bluetongue, and Epizootic Hemorrhagic Disease Viruses and Risk Factors in Baringo County, Kenya". Pathogens 13, n.º 8 (24 de julio de 2024): 613. http://dx.doi.org/10.3390/pathogens13080613.
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Rift Valley fever virus (RVFV) causes disease outbreaks in livestock and humans; however, its inter-epidemic circulation is poorly understood, similar to other arboviruses affecting cattle such as bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV). Serum samples were collected in Baringo County, Kenya from 400 cattle, accompanied by a risk factor questionnaire. Serological tests were then conducted to determine the exposure of cattle to RVFV, BTV, and EHDV. RVFV, BTV, and EHDV IgG seroprevalence rates were 15.5%, 91.5%, and 91%, respectively. Seropositivity for RVFV, BTV, and EHDV was significantly higher in adult cattle, as well as in females for RVFV. Cattle with herd owners aged between 30–39 years were less likely to be seropositive for RVFV compared to those with owners over the age of 60 years. High seroprevalence of BTV and EHDV in cattle indicates significant exposure and the subclinical circulation of these viruses, presenting a risk of outbreaks to sheep and naïve cattle. Moreover, the detection of RVFV-seropositive young cattle born after the last reported outbreak suggests inter-epidemic circulation of the virus. Overall, monitoring these arboviruses in cattle is crucial in understanding their distribution and seroprevalence during inter-epidemic periods.
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Hoesni, Facroerrozi, Silvia Erina, Sri Arnita Abu Tani y Firmansyah. "Resistance of Simmental Cattle Semen to Time Exposure at Room Temperature". Journal of Hunan University Natural Sciences 49, n.º 10 (30 de octubre de 2022): 8–15. http://dx.doi.org/10.55463/issn.1674-2974.49.10.2.
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This research aimed to determine the resistance of Simmental cattle semen with different lifting times at room temperature. It had a completely randomized design (CRD) with seven treatments and five replications. The treatments involved lifting clotted semen at different times from the surface of liquid nitrogen at room temperature: P0 (Control), P1 (straw with lifting time of 5 seconds), P2 (straw with lifting time of 10 seconds), P3 (straw with lifting time of 15 seconds), P4 (straw with lifting time of 20 seconds), P5 (straw with lifting time of 25 seconds), and P6 (straw with lifting time of 30 seconds). Observed variables were motility, percentage of life, and sperm abnormalities. Analysis of variance was used to analyze the data. Duncan's multiple range test determined the significant effect. The results showed that the placement of Simmental cattle clotted semen at room temperature with different lifting times significantly influenced the motility and percentage of sperm life (P < 0.05), but it did not impact sperm abnormality significantly (P > 0.05). The conclusion is that the placement of Simmental cattle-clotted semen up to 20 seconds under a room temperature (28-30℃) was still feasible and a favorite for artificial insemination. The novelty of this research is to find the right and appropriate time for the placement of frozen semen for Simmental cattle so that the percentage of motility and survival of spermatozoa does not change or the resistance of frozen semen of Simmental cattle is still well maintained, making it easier for inseminators perform livestock insemination in the field conditions.
Tesis sobre el tema "Cattle exposure"
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McFadden, Michael Patrick. "Effects of prenatal androgen exposure on postnatal growth, estrous cyclicity and behavior in female beef cattle". Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43050.
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This study assessed the effects of prenatal androgen exposure
during three periods, of gestation on the external genitalia,
estrous cyclicity, postnatal growth, social dominance and
sexual behavior of female beef cattle. Pregnant cows
recieved 17a methyl-testosterone (250 mg/d, sq) on d 40 to
100 (group 1), 70 to 130 (group 2) or 100 to 160 (group 3)
of gestation. Control cows (group 0) received no treatment.
Group 1 females exhibited completely masculinized external.
genitalia. No vulval opening was present and the
ano-genital distance (A-g) was similar to that of control
male calves. Group 2 females exhibited small vulval openings
and enlarged clitoral structures while group 3 females exhibited
normally appearing female external genitalia. Anogenital
distances for the heifers in groups 2 and 3 were
similar to those of the control heifers. Androgen exposure
during the three periods of gestation did not affect age at puberty (P<.80), estrous cycle length (P<.63) or postnatal
growth (P<.60) of the heifers.
At 9, 16 and 21 mo of age, social dominance values (SDV)
were determined for each heifer by 3 min random pair contests
for a restricted feed source. The animal with the greatest
feed source control time was awarded a win. Social dominance
value was calculated as 10 times the number of wins divided
by the number of competitions for each animal. Group 3
heifers had significantly greater SDV values than group 1 and
2 females (P<.03). SDV did not differ among groups at 16 mo
of age (P<.59). Group 1 females had greater SDV than group
2 females at 21 mo of age (P<:.04).
At 9, 16 and 21, mo of age, sexual behavior of the heifers
was characterized by exposure of the heifers to a teaser female in estrus. Sexual behavior, as indicated by the number
of mounts, head placements and interest time, was lower for
group 3 females compared to females in groups 1 and 2 at 9
mo of age (P<.04). There were no treatment differences for
any sexual behavior variable at 16 or 21 mo of age.
These results indicate that there is little potential
for increasing postnatal growth or altering the estrous
cyclicity of female cattle by exposure of the fetus to
testosterone during the periods of gestation selected in this
study. External genitalia of females were masculinized by
androgen exposure during d-40 to 100 of gestation. Social
dominance values were increased and sexual behavior was reduced in females by exposure to androgen during d 100 to 160 of gestation. Social dominance values were increased and sexual behavior was reduced
in females by exposure to androgen during d 100 to 160
of gestation.Master of Science
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Johnson, Jason Wesley Givens Maurice Daniel. "Experimental exposure of naive alpacas to different genotypes of bovine viral diarrhea virus isolated from cattle and alpacas". Auburn, Ala, 2009. http://hdl.handle.net/10415/1841.
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El, Tholth Mahmoud Mohammed El Sayed. "Microbiological risk assessment at the human-animal interface : assessment of human exposure to Mycobacterium avium subspecies paratuberculosis, highly pathogenic avian influenza virus subtype HN51 and Brucella spp". Thesis, Royal Veterinary College (University of London), 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558962.
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Miller, Natalie Ann. "Influence of management factors on reproduction in beef cattle: 1. Effects of melengestrol acetate and growth promoting implants on oocyte quality and subsequent in vitro embryo development 2. Exposure of prepubertal beef bulls to cycling females to enhance sexual development". Thesis, Kansas State University, 2012. http://hdl.handle.net/2097/13968.
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Master of ScienceDepartment of Animal Sciences and Industry
Karol E. Fike
This thesis involves two separate studies that evaluate the effects of different beef cattle management practices on reproduction. The objective of the first study was to determine if feedlot heifers administered melengestrol acetate (MGA) and growth promoting implants could serve as viable oocyte donors for in vitro embryo production. Ovaries from heifers administered MGA and growth promotants (MGA-Implant) and ovaries from heifers not administered either substance (Control) were collected from heifers post-slaughter. Oocytes were harvested and in vitro maturation, in vitro fertilization (IVF), and in vitro culture were completed. Treatment and time interacted to affect the number of oocytes aspirated per ovary (P = 0.07) and the number of zygotes per ovary (P = 0.07). Fertilization (P = 0.90) and cleavage rates (P = 0.80) did not differ between treatments. Blastocyst rates (P = 0.30) and the number of embryos per ovary (P = 0.50) did not differ between treatments. We concluded that beef feedlot heifers fed MGA and implanted with growth promotants seem to be a viable source of oocytes for in vitro embryo production. In the second study, we hypothesized that continuous fenceline exposure of prepubertal beef bulls to cycling beef females would hasten the onset of puberty as well as increase the percentage of bulls passing their initial breeding soundness examination (BSE). Bulls were either exposed to estrous females (exposed) or were not exposed (control). Monthly scrotal circumference (SC) measurements, blood samples, semen evaluations, and bull behavior assessments were conducted. Age at puberty (P = 0.40), SC at puberty (P = 0.50), and weight at puberty (P = 0.30) did not differ between treatments. A similar (P = 0.50) percentage of bulls passed their initial BSE at 363 ± 21.5 d of age (exposed: 87.8%; control: 74.2%). Treatment, month, and stage of the estrous cycle of cows interacted to affect the number of mount attempts (P = 0.05) and the number of flehmen responses (P < 0.001). In conclusion, bulls given continuous fenceline exposure to cycling beef females were neither younger at puberty nor did a greater percentage pass their initial BSE.
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Mathews, Laure. "Vers une meilleure compréhension du risque de transmission alimentaire du virus de l'encéphalite à tiques par la consommation de produits laitiers non pasteurisés en France". Electronic Thesis or Diss., Maisons-Alfort, École nationale vétérinaire d'Alfort, 2024. http://www.theses.fr/2024ENVA0003.
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Le virus de l'encéphalite à tiques (TBEV) - genre Orthoflavivirus - est l'arbovirus le plus fréquent en Europe. Le sous-type européen affecte le système nerveux central chez l'homme et peut être fatal dans 0,5 à 2% des cas. L'homme s'infecte soit par la piqûre d'une tique infectée soit par l'ingestion de produits laitiers contaminés non pasteurisés, principalement de chèvre. Le virus circule naturellement entre la tique Ixodes ricinus et les rongeurs forestiers. La distribution du TBEV en France, plus restreinte que celle de son vecteur, est à ce jour méconnue et peut être plus importante que ne le laisse supposer la surveillance évènementielle des cas humains. Depuis 2016, le nombre de cas tend à augmenter en France avec de nouveaux foyers en dehors de l'Alsace, la Savoie et la Haute-Savoie, zones endémiques historiques. L'année 2020 a été marquée par le premier cluster de contaminations alimentaires dans l'Ain avec 43 cas dus à la consommation de fromage de chèvre non pasteurisé. Ce foyer pose la question du risque de transmission du virus TBEV par voie alimentaire en France. Ce risque dépend notamment de l'excrétion du virus dans le lait par les ruminants (exposition au virus et excrétion virale), de sa persistance dans le lait et les produits laitiers et des pratiques de consommation alimentaire de produits au lait cru. L'objectif général de ce projet est de mieux comprendre ce risque en France en s'intéressant (i) à la distribution du virus, à l'exposition des ruminants au TBEV et aux facteurs associés, (ii) aux spécificités de la filière lait cru petits ruminants en France, en se focalisant sur l'Ain et le Puy-de-Dôme, deux départements avec des cas alimentaires de TBE avérés ou suspectés et (iii) à la persistance de TBEV infectieux dans le lait cru. Pour répondre à ces questions, (i) une enquête de séroprévalence a été conduite sur 4483 bovins dans cinq départements du nord-est de la France pour étudier l'exposition des ruminants domestiques à TBEV. Afin d'adapter la stratégie d'analyses sérologiques, les performances de deux tests ELISA commerciaux pour détecter les anticorps anti-TBEV ont été étudiées au préalable. L'enquête montre que le virus est présent dans la zone d'étude avec des bovins très exposés dans le Massif Vosgien. D'après les résultats d'un modèle multivarié Random Forest spatial, les principaux facteurs associés à une augmentation de l'exposition des bovins vis-à-vis du TBEV dans cette région étaient une température moyenne annuelle basse, une proportion de forêt et une surface de l'interface pâture-bois élevées, zones favorables à l'abondance de tiques. (ii) Par ailleurs, l'étude de filière départementale documente le risque alimentaire lié au TBEV. Elle montre une petite filière peu organisée, d'élevages principalement fermiers qui pratiquent le pâturage souvent à proximité de bois et une production de produits frais au lait cru. (iii) Enfin, nous montrons que le virus reste infectieux jusqu'à 48 h à 4°C et 21°C dans du lait cru de vache et de chèvre artificiellement contaminé par la souche de TBEV isolée dans l'Ain en 2020. De plus, le TBEV est plus stable dans le lait de vache que de chèvre à 4°C. Des études complémentaires sont nécessaires pour mieux comprendre les facteurs qui influencent la distribution du TBEV en France et prédire les zones favorables à sa présence. Du fait des pratiques de la filière caprine, la région Auvergne Rhône-Alpes et le sud de la Bourgogne apparaissent cependant comme des régions à risque pour la transmission alimentaire du TBEV. Limiter le contact des animaux avec les surfaces boisées pourrait être une mesure de gestion en cas de foyer pour diminuer leur exposition. Enfin, l'utilisation de lait artificiellement contaminé introduit un biais. Etudier l'excrétion virale à l'échelle du tissu épithélial mammaire selon les espèces serait nécessaire avant de conclure sur l'influence des conditions de conservation du lait naturellement contaminé sur la persistance de TBEVTBEV, belonging to the Orthoflavivirus genus, is the most prevalent arbovirus in Europe and. Affecting the central nervous system in humans, it can result in mortality in 0.5 to 2% of cases. Humans become infected either through the bite of an infected tick or by ingesting contaminated unpasteurised dairy products. The virus circulates naturally between Ixodes ricinus ticks and forest rodents. TBEV distribution is more limited than that of its vector. To date, the distribution of TBEV in France is hardly known, and it is expected to be more widespread than suggested by event-based surveillance of human cases. Since 2016, the number of human cases has tended to increase in France ( Alsace, Savoie, Haute-Savoie, . In 2020, the first cluster of foodborne cases was identified in the Ain department, with 43 cases due to the consumption of raw goat's cheese. This outbreak raises the question of the risk of food-borne transmission of TBEV in France. This risk is contingent upon the excretion of the virus into the milk by ruminants (exposure to the virus and viral excretion), its persistence in the milk and dairy products, and dietary consumption practices for raw dairy products. The overarching objective of this thesis project is to gain a deeper comprehension of the risk in France. We studied : (i) the distribution of the virus, exposure of ruminants to TBEV and associated factors; (ii) the distinctive characteristics of the small ruminant raw milk sector in France, with a particular focus on Ain and Puy-de-Dôme, two departments with confirmed or suspected cases of TBE in food; and (iii) the persistence of infectious TBEV in raw milk. To address these questions, (i) a seroprevalence survey was conducted on 4483 cattle in five departments of north-eastern France to study the exposure of domestic ruminants to TBEV. To adapt the serological analysis strategy, the performance of two commercial ELISA tests for detecting TBEV antibodies was first studied. The results of this survey demonstrated that the virus is present throughout the study area, with cattle exhibiting a high level of exposure to TBEV in Vosgian Mountains. The results of a multivariate spatial Random Forest model indicated that the main factors associated with an elevated risk of TBEV exposure in this region were a low mean annual temperature, a high proportion of forest, and the surface area of the pasture-woodland interface, which are suitable habitats for ticks. Furthermore, (ii) the study of the departmental dairy industry documented the food safety risk associated with TBEV. The industry is characterised by a small, poorly organised sector of mainly free-range livestock farms, which often graze on the edge of woodland and produce fresh products from raw milk. (iii) Finally, we demonstrate that the virus remains infectious for up to 48 hours at 4°C and 21°C in raw cow's and goat's milk artificially contaminated with the TBEV strain isolated in the Ain in 2020. Additionally, our results indicate that TBEV was more stable in cow's milk than in goat's milk at 4°C. Further studies are required to gain a more comprehensive understanding of the factors influencing the distribution of TBEV in France and to predict the areas where it is most likely to occur. However, given the practices of the goat industry, the Auvergne Rhône-Alpes region and southern Burgundy appear to be at risk for foodborne TBEV transmission. Limiting animal contact with wooded areas could be a management measure in the event of an outbreak to reduce cattle exposure. Finally, the use of artificially contaminated milk introduces a bias, and further studies are required to investigate viral excretion at the level of mammary epithelial tissue, depending on the species
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Albareda, Castellot Bàrbara. "Developmental changes in vowel perception: how input interplays with initial perceptual biases". Doctoral thesis, Universitat Pompeu Fabra, 2010. http://hdl.handle.net/10803/7213.
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The present dissertation aims at analyzing the interplay between initial acoustic biases and language exposure during acquisition of language in the first year of life. This is a critical period in development because it is when phonetic categories are attuned to the native language. This goal is addressed by integrating the results from two developmental studies. The first study explores the presence of asymmetries in vowel perception in infants from 4 to 12 months of age, as a function of the acoustic salience and distributional properties in the test language. The second study investigates the previous contrasting results on vowel perception in 8-month-old infants growing in bilingual environments, and in particular and their relationship with task demands and the properties of the bilingual input. The results emerging from these studies point to two developmental trends. On one hand, asymmetries in vowel perception are modulated by acoustic biases before and during perceptual reorganization, and by distributional cues after perceptual reorganization. On the other hand, discrimination abilities of 8-month-old bilinguals parallel those of monolinguals when tested with an Anticipatory Eye Movement procedure, highlighting the importance of task demands in determining infants' performance.L'objectiu d'aquesta tesis és analitzar la dinàmica que s'estableix entre els biaixos acústics i l'experiència amb el llenguatge durant el primer any de vida. Aquest és un període decisiu durant el qual les categories fonètiques s'ajusten a les propietats de la llengua materna. Aquest objectiu s'assoleix integrant els resultats de dos estudis. En el primer estudi s'explora la presència d'asimetries en la percepció de les vocals en bebès de 4 a 12 mesos d'edat, en funció de la saliència acústica i les propietats distribucionals de la llengua. El segon estudi investiga els resultats contradictoris obtinguts amb bebès de 8 mesos d'edat bilingües, i la seva relació amb les demandes de la tasca i les propietats de l'input bilingüe. Els resultats d'aquests estudis indiquen dos tendències al desenvolupament. Per una banda, que les asimetries en la percepció de les vocals són modulades per biaixos acústics abans i durant la reorganització perceptiva i per les propietats distribucionals després de la reorganització perceptiva; per l'altra banda, els resultats mostren que les habilitats de discriminació dels bilingües de 8 mesos d'edat són corresponents a les dels monolingües quan es fa servir un procediment d'anticipació de la mirada, posant en rellevància la importància de les demandes de la tasca en determinar el rendiment dels bebès.
Libros sobre el tema "Cattle exposure"
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Association, Western Interprovincial Scientific Studies. Western Canada study of animal health effects associated with exposure to emissions from oil and natural gas field facilities: A study of 33,000 cattle in British Columbia, Alberta, and Saskatchewan. Calgary, Alta: WISSA, 2006.
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Swanepoel, R. y J. T. Paweska. Rift Valley fever. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780198570028.003.0043.
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Rift Valley fever (RVF) is an acute disease of domestic ruminants in mainland Africa and Madagascar, caused by a mosquito borne virus and characterized by necrotic hepatitis and a haemorrhagic state. Large outbreaks of the disease in sheep, cattle and goats occur at irregular intervals of several years when exceptionally heavy rains favour the breeding of the mosquito vectors, and are distinguished by heavy mortality among newborn animals and abortion in pregnant animals. Humans become infected from contact with tissues of infected animals or from mosquito bite, and usually develop mild to moderately severe febrile illness, but severe complications, which occur in a small proportion of patients, include ocular sequelae, encephalitis and fatal haemorrhagic disease. Despite the occurrence of low case fatality rates, substantial numbers of humans may succumb to the disease during large outbreaks. Modified live and inactivated vaccines are available for use in livestock, and an inactivated vaccine was used on a limited scale in humans with occupational exposure to infection. The literature on the disease has been the subject of several extensive reviews from which the information presented here is drawn, except where indicated otherwise (Henning 1956; Weiss 1957; Easterday 1965; Peters and Meegan 1981; Shimshony and Barzilai 1983; Meegan and Bailey 1989; Swanepoel and Coetzer 2004; Flick and Bouloy 2005). In September 2000, the disease appeared in south-west Saudi Arabia and adjacent Yemen, and the outbreak lasted until early 2001 (Al Hazmi et al. 2003; Madani et al. 2003; Abdo-Salem et al. 2006). The virus was probably introduced with infected livestock from the Horn of Africa, and it remains to be determined whether it has become endemic on the Arabian Peninsula.
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Karmali, Mohamed A. y Jan M. Sargeant. Verocytotoxin-producing Escherichia coli (VTEC) infections. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780198570028.003.0008.
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Verocytotoxin (VT)-producing Escherichia coli (VTEC), also known as Shiga toxin producing E. coli (STEC), are zoonotic agents, which cause a potentially fatal illness whose clinical spectrum includes diarrhoea, haemorrhagic colitis, and the haemolytic uraemic syndrome (HUS). VTEC are of serious public health concern because of their association with large outbreaks and with HUS, which is the leading cause of acute renal failure in children. Although over 200 different OH serotypes of VTEC have been associated with human illness, the vast majority of reported outbreaks and sporadic cases of VTEC-infection in humans have been associated with serotype O157:H7.VTs constitute a family of related protein subunit exotoxins, the major ones implicated in human disease being VT1, VT2, and VT2c. Following their translocation into the circulation, VTs bind to endothelial cells of the renal glomeruli, and of other organs and tissues via a specific receptor globotriosylceramide (Gb 3), are internalized by a process of receptor-mediated endocytosis, and cause subcellular damage that results in the characteristic microangiopathic disease observed in HUS.The incubation period of VTEC-associated illness is about 3–5 days. After ingestion VTEC (especially of serotype O157:H7) multiply in the bowel and colonize the mucosa of probably the large bowel with a characteristic attaching and effacing (AE) cytopathology. Colonization is followed by the translocation of VTs into the circulation and the subsequent manifestation of disease.The majority of patients with uncomplicated VTEC infection recover fully with general supportive measures. Historically, the case-fatality rate was high for HUS. However, improvement in the treatment of renal failure and the attendant biochemical disturbances has substantially improved the outlook, although long-term sequelae may develop.Ruminants, especially cattle, are the main reservoirs of VTEC. Infection is acquired through the ingestion of contaminated food, especially under-cooked hamburger, through direct contact with animals, via contaminated water or environments, or via personto-person transmission.The occurrence of large outbreaks of food-borne VTEC-associated illness has promoted close scrutiny of this zoonoses at all levels in the chain of transmission, including the farm, abattoir, food processing, packaging and distribution plants, the wholesaler, the retailer and the consumer. While eradication of VTEC O157 at the farm may not be an option, interventions to increase animal resistance or to decrease animal exposure are being developed and validated. Hazard Analysis and Critical Control Programmes are being implemented in the processing sector and appear to be associated with temporal decreases in VTEC serotype O157 illness in humans. Education programmes targeting food handling procedures and hygiene practices are being advocated at the retail and consumer level. Continued efforts at all stages from the farm to the consumer will be necessary to reduce the risk of VTEC-associated illness in humans.
Capítulos de libros sobre el tema "Cattle exposure"
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Alvarez-Gonçalvez, C. V., F. E. Arellano, A. Fernández-Cirelli y A. L. Pérez-Carrera. "Arsenic in cattle: Evaluation of possible exposure biomarkers". En Arsenic in the Environment: Bridging Science to Practice for Sustainable Development As2021, 217–18. London: CRC Press, 2024. http://dx.doi.org/10.1201/9781003317395-90.
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Kraemer, Julia G. y Anne Oppliger. "What Is Known About Zoonotic Bacteria in Cattle and Pig Farms, and What Should Be Done to Prevent Occupational Infections". En Exposure to Microbiological Agents in Indoor and Occupational Environments, 361–89. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-61688-9_18.
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Lascano, Alejandra, Gustavo Patín, Anita Larrea y Thalía San Antonio. "Ergonomic Evaluation of Risk Level by Exposure to Forced Postures in Cattle Slaughterhouse Workers in Ecuador". En Advances in Intelligent Systems and Computing, 212–17. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-94000-7_22.
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Catry, Thibault, Cécile Vignolles, Serge Olivier Kotchi, Stéphanie Brazeau, Antoinette Ludwig, Nicholas H. Ogden, Dominique J. Bicout, Richard A. Fournier y Dirk Werle. "Mosquito-borne diseases." En Earth observation, public health and one health: activities, challenges and opportunities, 11–92. Wallingford: CABI, 2022. http://dx.doi.org/10.1079/9781800621183.0002.
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Abstract The World Health Organization (WHO) has highlighted identification and monitoring of vector populations as an important component of global vector-borne disease surveillance efforts. EO and RVF map data could play a crucial role in identifying risk locations for mosquito-borne diseases globally on the basis of habitat and climate variables. EO and RVF map data are also useful for measuring or mapping a range of environmental parameters that help determine mosquito vector occurrence and abundance and the rate of development of mosquito-borne parasites and pathogens in mosquito vectors. The EO and RVF map data have been sufficiently high spatial and temporal resolution, applied research could develop weather-based and environment-based forecasting of high-risk locations and time periods for mosquito-borne diseases using statistical models. The maps generated by this project indicate and outline the RVF risk areas associated with surface water ponding, mosquito breeding, and cattle grazing for a test area in Senegal. This strategy could include the following recommendations to effectively mitigate the exposure of cattle to RVF, and thus to minimise infection risk for humans: establish a joint communication strategy by integrating information of the forecasted risk bulletins into the National Information System of Surveillance of Epidemics used by the Ministry of Livestock in Senegal and the Headquarters of the Directorate of Veterinary Services of Senegal and its local representatives in rural districts, relocate livestock grazing areas away from risk zones, with warning signs in local languages posted near the ponds to inform breeders to keep their animals at least 500 m away from the ponds, and issue regular bulletins so the Directorate of Veterinary Services of Senegal can organise and optimise vaccination campaigns in the riskiest zones.
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Harrison, Joanne C., Magda Carvajal y R. Colin Garner. "Immunological detection of aflatoxin B1-DNA and AFB1-serum albumin adducts in rat and human tissues". En Human Carcinogen Exposure, 255–65. Oxford University PressOxford, 1991. http://dx.doi.org/10.1093/oso/9780199631858.003.0020.
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Abstract Aflatoxins are secondary metabolites of the moulds Aspergillus flavus and Aspergillus parasiticus and are commonly found as food contaminants. Toxin production is favoured by the warm, moist environments of tropical and subtropical countries and is enhanced still further by poor crop storage. The aflatoxins pose a hazard to populations in the West through the consumption and, in the case of dust-producing crops,2 the handling of contaminated food. There is also evidence that Westerners are exposed to aflatoxin M1 (AFM1) in dairy products and meat from cattle fed aflatoxincontaminated grain.
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Alvarez-Gonçalvez, C. V., F. E. Arellano, A. Fernádez-Cirelli y A. L. Pérez Carrera. "Arsenic in cattle: Evaluation of possible exposure biomarkers". En Environmental Arsenic in a Changing World, 253–54. CRC Press, 2019. http://dx.doi.org/10.1201/9781351046633-101.
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Ng, Jack C., Scott L. Bruce y Barry N. Noller. "Laboratory and field evaluation of potential arsenic exposure from mine tailings to grazing cattle". En Arsenic Exposure and Health Effects V, 181–95. Elsevier, 2003. http://dx.doi.org/10.1016/b978-044451441-7/50015-4.
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Wanjohi, James M., Sebastian K. Waruri, Sammy Gichuhi Ndungu, Leonard Muchenditsi Khaluhi, Erick M. Mungube y Moses Okoth Olum. "Heartwater and Control". En Advances in Environmental Engineering and Green Technologies, 243–62. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-6433-2.ch011.
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Heartwater (HW) is an acute, febrile, tick-borne disease of cattle, sheep, goats, and wild ruminants characterized by nervous signs and high mortality. The disease is caused by a rickettsia agent, Erlichia ruminantium, formally classified as Cowdria ruminantium. The disease is transmitted by several ixodid ticks of the genus Ambylomma. Chemoprophylaxis has been used as a method to facilitate the movement of heartwater susceptible stock into heartwater endemic areas while allowing them to acquire immunity by limited tick exposure.
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Isupova, Alena. "Restoration of Uranium Tailings in the Mountains: A Perspective from the State of the Skin in Persons Living in the Vicinity". En Environmental Sciences. IntechOpen, 2024. http://dx.doi.org/10.5772/intechopen.113915.
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In our work, for the first time, the problem of long-term exposure (more than 50 years) to low doses of radiation to the human body was touched upon. Comprehensive studies of the content of radionuclides in water, soil, meat of cattle, and small cattle, carried out within the framework of the ISTC; prove the entry of radionuclides into the human body through food chains. For the period from 2003 to 2023, studies were conducted on the skin of people living in various regions of Kyrgyzstan. A total of 3650 people were examined. The main group (600 people) is represented by people living near uranium tailings. Analysis of the features of the course and manifestation of dermatoses showed the features of the course of skin pathology. The mean age of stigma manifestation was 32.7 ± 7.5 years compared to the control group 45.2 ± 10.3 years.
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Hand, W. Lee. "Erysipelothrix". En Schlossberg's Clinical Infectious Disease, editado por Cheston B. Cunha, 913–15. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780190888367.003.0134.
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This chapter deals with Erysipelothrix rhusiopathiae, which is a pleomorphic, non-spore-forming, gram-positive bacillus. It analyzes how E. rhusiopathiae causes both a self-limited soft-tissue infection and a serious systemic disease. It also investigates the spread and infection of E. rhusiopathiae of many domestic animals, such as sheep, cattle, horses, chickens, and dogs, as well as birds, fish, crustaceans, seals, and dolphins in some cases. This chapter examines the risk of infection of E. rhusiopathiae in humans due to occupational exposure, namely butchers, abattoir workers, fishermen, farmers, and veterinarians. It discusses the clinical spectrum of human infection that includes localized cutaneous infection, diffuse cutaneous disease, and systemic bloodstream infection.
Actas de conferencias sobre el tema "Cattle exposure"
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Starič, Jože, Geč Veren, Rok Marzel y Jožica Ježek. "Sporadic leukosis in cattle". En Zbornik radova 26. medunarodni kongres Mediteranske federacije za zdravlje i produkciju preživara - FeMeSPRum. Poljoprivredni fakultet Novi Sad, 2024. http://dx.doi.org/10.5937/femesprumns24035s.
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Sporadic bovine leukosis (SBL) is a rare neoplastic disease in cattle. It represents a unique challenge for veterinary medicine due to its sporadic occurrence, peculiar clinical presentation and unclear etiology. SBL manifests in four forms: juvenile lymphosarcoma, adult multicentric leukosis, thymic lymphosarcoma and cutaneous lymphosarcoma. In contrast to enzootic bovine leukosis, which is caused by the bovine leukemia virus (BLV), there is no viral link in sporadic cases. They are thought to be caused by multifactorial interactions between genetic predisposition and environmental factors (e.g. carcinogens or other triggers). The diseases are not contagious. The aim of this paper is to review the current knowledge of SBL, focusing on the clinical presentation, diagnostic challenges and potential risk factors. Although sporadic leukosis accounts for a smaller proportion of leukosis cases in cattle compared to BLV-induced leukosis, the impact on affected individuals is severe. SBL must be differentiated from BLV-induced leukosis (absence of BLV antibodies in the blood and absence of BLV in the tissue), which is a reportable disease in the European Union. SBL usually affects younger cattle, but adult animals can also be affected. Adult multicentric leukosis clinically resembles enzootic bovine leukosis with multicentric lymphoproliferative foci and lymphadenopathy, but the affected animals are negative for BLV antibodies. The diseases are progressive and lead to the death of the animals. Diagnostic confirmation of SBL often requires a combination of histopathologic examination, immunohistochemistry and molecular analyses to differentiate it from other neoplastic diseases in cattle. Risk factors such as exposure to certain environmental toxins or genetic susceptibility are thought to play a role in the development of sporadic leukosis. Further research efforts are needed to elucidate the mechanisms underlying the development of SBL and to develop effective prevention and control strategies to control this sporadic but usually lethal disease in cattle population.
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BLEIZGYS, Rolandas y Reda MAŽEIKIENĖ. "REDUCTION OF AMMONIA EMISSIONS FROM CATTLE MANURE USING BIOPREPARATIONS". En RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.021.
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Experimental studies performed at the laboratory enabled to find out the effect of the biopreparation on the process of ammonia volatilization from manure. Adding biopreparation to manure was found to slow down ammonia emission from manure. Depending on the manure composition, temperature of the environment, and duration of exposure to the biopreparation, the emission was found to decrease by up to 22 %. The maximum effect was observed on the day 6–14, whereas 30 days after biopreparation’s use its effect was significantly decreased. The effect of biopreparation on ammonia volatilization was observed to be higher under more intensive ammonia emissions, i.e. when the manure was fresh, with no crust formed on its surface, under high air flow velocity above the manure and high ammonia concentration gradient in the surface of the manure. Use of the biopreparation is highly recommended for reduction of ammonia emissions in litter-free barns where liquid manure accumulates. Its use is consistent with the modernization tendencies to implement litter-free liquid manure technologies.
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Mlimbila, JS, S. Mamuya, V. Ngowi y BE Moen. "1141 Risk of staphylococcus aureus exposure among workers in selected cattle and small ruminants slaughterhouses in tanzania". En 32nd Triennial Congress of the International Commission on Occupational Health (ICOH), Dublin, Ireland, 29th April to 4th May 2018. BMJ Publishing Group Ltd, 2018. http://dx.doi.org/10.1136/oemed-2018-icohabstracts.833.
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Peixoto, Luiz Felipe M. y Angelo J. P. Sousa. "Geotechnical Activity and Third-Party Damages". En 2008 7th International Pipeline Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ipc2008-64585.
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This article presents an accident that took place at a Petrobras Transporte S.A. - TRANSPETRO pipeline right-of-way (ROW), involving one of its pipes: ORSUB (Southern Bahia diesel, gasoline and LPG 360km Φ10″/Φ8″ pipeline). Basically, the mentioned occurrence shows the influence of collapses in third-party constructions in TRANSPETRO facilities’ integrity. The event in Bahia consisted in the exposure of 70m of the pipeline, caused by a dam breach from a private property nearby. Due to the failure, the water from the reservoir streamed through the terrain, dragging and destroying whatever it came across (small houses wrecks, torn trees and crops were found along the water track), reaching the pipeline ROW around 700m from its origin, in a narrow rocky valley, hence gaining power and speed, and swept away the soil that covered the pipe, provoking a 70m long, 2m deep and 5m across opening. The fact that the water ran along the pipe and did not hit it perpendicularly led to minor damages. The consequences, whether it happened otherwise, would be much more serious, especially in an environmental way, as this happened within the limits of a cocoa and banana farm, with a creek not even 10m away. A number of irregularities were found in the dam wreck, such as under dimensioned valve and intake structure and the lack of a spillway were the main reasons that caused the breach. Major events like this bring to attention the fact that some farmers build their own dams (within the limits of their properties) with no expertise on the matter whatsoever and often without any professional assistance. This represents a tremendous jeopardy for almost everything existing downstream the dam, such as crops, cattle, houses and people. After the dam rupture, the geotechnical engineers from TRANSPETRO started a study which mapped 35 dams only in ORSUB ROW neighbourhood, at least 3 of them were classified as critical. A hydrodynamic simulation, based on the accident described here, is being developed, so the engineers can predict what might happen to the pipeline ROW and, in a worst case scenario, to the pipe itself, whether another dam failure occurs.
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Lester, B., S. Reynolds y T. Stanton. "6. Preliminary Evaluation of Worker and Environmental Exposures From Dairies and Cattle Feedlots". En AIHce 2005. AIHA, 2005. http://dx.doi.org/10.3320/1.2758807.
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Mayengbam, Prava, T. C. Tolenkhomba y R. C. Upadhyay. "Variation in leukocyte counts of Sahiwal and Karan Fries cattle during acute thermal exposures". En Proceedings of the Mizoram Science Congress 2018 (MSC 2018) - Perspective and Trends in the Development of Science Education and Research. Paris, France: Atlantis Press, 2018. http://dx.doi.org/10.2991/msc-18.2018.37.
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"Biochemical Analysis to Study the Nutritive Value of the Fish Catla Catla after Exposure to the Phytotoxin from Lasiophion Eriocephalus". En International Conference on Trends in Economics, Humanities and Management. International Centre of Economics, Humanities and Management, 2014. http://dx.doi.org/10.15242/icehm.ed0814091.
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Hodnik, Jaka, Marko Jankovec, Jožica Ježek, Žiga Krusic, Stefan Mitterhofer y Jože Starič. "UV-B light irradiation during automatic milking for vitamin D supplementation in dairy cows". En Zbornik radova 26. medunarodni kongres Mediteranske federacije za zdravlje i produkciju preživara - FeMeSPRum. Poljoprivredni fakultet Novi Sad, 2024. http://dx.doi.org/10.5937/femesprumns24013h.
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Vitamin D has a significant role in mineral metabolism, bone tissue homeostasis, and immunity. Cattle can synthetize vitamin D in the skin in a linear dose dependent manner of ultraviolet irradiation. The objectives of this study were to investigate the possibility of vitamin D supplementation with narrow-band UV-B irradiation during automatic milking time and to determine the influence of hair and pigmentation of skin and hair on cutaneous vitamin D3 synthesis in dairy cows. Holstein Friesian cows from one farm were enrolled into the study. A narrow-band UV-B light (peak irradiation at 295 nm) was custom-made and mounted into the automatic milking system. Cows were split into three equal random groups using stratified sampling based on milk yield in the previous lactation, days after calving and the percentage of black area on their back. The first group was shaved and exposed to a daily dose during automatic milking, the second group was left unshaved and irradiated during the automatic milking with maximal possible dose and the third group served as control. The cows were blood sampled before and 60 days after the start of irradiation. The concentration of 25-hydroxyvitamin D was measured using an automated immune enzyme fluorescence assay. The increase in the 25-hydroxyvitamin D concentrations before and after the irradiation was statistically significant (p>0.001) between the shaved, unshaved and control groups. The irradiated groups shaved and unshaved produced more milk per day than the control group. Narrow-band UV-B LED light limited to automatic milking time was successful in increasing the concentrations of 25-hydroxyvitamin D in Holstein Friesian cows. Hair was reducing cutaneous vitamin D production. UV-B irradiation of cows during automatic miking is a novel way of vitamin D supplementation that does not expose farm equipment and personnel to UV-B irradiation and does not interfere with the daily routine on farm.
Informes sobre el tema "Cattle exposure"
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Klement, Eyal, Elizabeth Howerth, William C. Wilson, David Stallknecht, Danny Mead, Hagai Yadin, Itamar Lensky y Nadav Galon. Exploration of the Epidemiology of a Newly Emerging Cattle-Epizootic Hemorrhagic Disease Virus in Israel. United States Department of Agriculture, enero de 2012. http://dx.doi.org/10.32747/2012.7697118.bard.
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In September 2006 an outbreak of 'Bluetongue like' disease struck the cattle herds in Israel. Over 100 dairy and beef cattle herds were affected. Epizootic hemorrhagic disease virus (EHDV) (an Orbivirusclosely related to bluetongue virus (BTV)), was isolated from samples collected from several herds during the outbreaks. Following are the aims of the study and summary of the results: which up until now were published in 6 articles in peer-reviewed journals. Three more articles are still under preparation: 1. To identify the origin of the virus: The virus identified was fully sequenced and compared with the sequences available in the GenBank. It appeared that while gene segment L2 was clustered with EHDV-7 isolated in Australia, most of the other segments were clustered with EHDV-6 isolates from South-Africa and Bahrain. This may suggest that the strain which affected Israel on 2006 may have been related to similar outbreaks which occurred in north-Africa at the same year and could also be a result of reassortment with an Australian strain (Wilson et al. article in preparation). Analysis of the serological results from Israel demonstrated that cows and calves were similarly positive as opposed to BTV for which seropositivity in cows was significantly higher than in calves. This finding also supports the hypothesis that the 2006 EHD outbreak in Israel was an incursive event and the virus was not present in Israel before this outbreak (Kedmi et al. Veterinary Journal, 2011) 2. To identify the vectors of this virus: In the US, Culicoides sonorensis was found as an efficient vector of EHDV as the virus was transmitted by midges fed on infected white tailed deer (WTD; Odocoileusvirginianus) to susceptible WTD (Ruder et al. Parasites and Vectors, 2012). We also examined the effect of temperature on replication of EHDV-7 in C. sonorensis and demonstrated that the time to detection of potentially competent midges decreased with increasing temperature (Ruder et al. in preparation). Although multiple attempts were made, we failed to evaluate wild-caught Culicoidesinsignisas a potential vector for EHDV-7; however, our finding that C. sonorensis is a competent vector is far more significant because this species is widespread in the U.S. As for Israeli Culicoides spp. the main species caught near farms affected during the outbreaks were C. imicolaand C. oxystoma. The vector competence studies performed in Israel were in a smaller scale than in the US due to lack of a laboratory colony of these species and due to lack of facilities to infect animals with vector borne diseases. However, we found both species to be susceptible for infection by EHDV. For C. oxystoma, 1/3 of the Culicoidesinfected were positive 11 days post feeding. 3. To identify the host and environmental factors influencing the level of exposure to EHDV, its spread and its associated morbidity: Analysis of the cattle morbidity in Israel showed that the disease resulted in an average loss of over 200 kg milk per cow in herds affected during September 2006 and 1.42% excess mortality in heavily infected herds (Kedmi et al. Journal of Dairy Science, 2010). Outbreak investigation showed that winds played a significant role in virus spread during the 2006 outbreak (Kedmi et al. Preventive Veterinary Medicine, 2010). Further studies showed that both sheep (Kedmi et al. Veterinary Microbiology, 2011) and wild ruminants did not play a significant role in virus spread in Israel (Kedmi et al. article in preparation). Clinical studies in WTD showed that this species is highly susceptibile to EHDV-7 infection and disease (Ruder et al. Journal of Wildlife Diseases, 2012). Experimental infection of Holstein cattle (cows and calves) yielded subclinical viremia (Ruder et al. in preparation). The findings of this study, which resulted in 6 articles, published in peer reviewed journals and 4 more articles which are in preparation, contributed to the dairy industry in Israel by defining the main factors associated with disease spread and assessment of disease impact. In the US, we demonstrated that sufficient conditions exist for potential virus establishment if EHDV-7 were introduced. The significant knowledge gained through this study will enable better decision making regarding prevention and control measures for EHDV and similar viruses, such as BTV.
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Dahl, Geoffrey E., Sameer Mabjeesh, Thomas B. McFadden y Avi Shamay. Environmental manipulation during the dry period of ruminants: strategies to enhance subsequent lactation. United States Department of Agriculture, febrero de 2006. http://dx.doi.org/10.32747/2006.7586544.bard.
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The project resulted from earlier observations that environmental factors, especially photoperiod and temperature, had profound effects on milk yield in dairy cattle during lactation. More recently we had determined that photoperiod manipulation during the dry period altered milk yield in the next lactation, and this was associated with shifts in circulating concentrations of prolactin; specifically exposure to short days during the dry period decreases prolactin but increases milk yield. Because prolactin is also affected by temperature, with heat stress causing an increase in prolactin similar to that of long day exposure, we focused our efforts on determining prolactin signaling provides a common pathway for generation of environmental effects on mammary growth, development and subsequent function during the dry period of dairy ruminants. Over the project period we made significant progress toward testing our hypotheses that (I): In cows, there is a discrete duration of time during the dry period in which exposure to short days will result in optimal enhancement of mammary development and milk yield in the following lactation, and that this effect is mediated through demonstrable changes in mammary gland development, prolactin signaling, and mammary gene expression; and (II): Modulation of photoperiod and temperature during the dry period will affect milk yield in goats in the subsequent lactation via shifts in nutrient and endocrine partitioning, and mammary gene expression, during the dry period and into lactation. Cows exposed to short days for only the final 21 days of the dry period did not produce more milk that those on long day or natural photoperiod when dry. However, cows on short days for the entire 60 days dry did produce more milk than the other 3 groups. This indicates that there is a duration effect of short day exposure on subsequent milk yield. Results of the second study in cows indicate that mammary growth increases differentially during the dry period under long vs. short days, and that short days drive more extensive growth which is associated with altered prolactin signaling via decreases in an suppressors of cytokine signaling that represent an inhibitory pathway to mammary growth. Evidence from the studies in Israel confirms that goats respond to short days during the dry period in a similar manner to cows. In addition, heat stress effects on during the dry period can be limited by exposure to short days. Here again, shifts in prolactin signaling, along with changes in IGF-I secretion, are associated with the observed changes in mammary function in goats. These results have a number of biological and practical implications. For dairy producers, it is clear that we can recommend that cows and goats should be on reduced light exposure during the dry period, and further, cows and goats should be cooled to avoid heat stress during that time. Environmental influences on mammary growth are apparent during the dry period, and those effects have persistent impact in the subsequent lactation. Prolactin signaling is a consistent mechanism whereby extended light exposure and heat stress may depress mammary growth and development during the dry period. Thus, the prolactin signaling system offers an opportunity for further manipulation to improve production efficiency in dairy ruminants.
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Bazer, Fuller W., Arieh Gertler y Elisha Gootwine. Role of Placental Lactogen in Sheep. United States Department of Agriculture, enero de 2001. http://dx.doi.org/10.32747/2001.7574339.bard.
Texto completoResumen
Central problems in sheep and dairy cattle production are reproductive failure due to embryonic/fetal mortality and low birth weights, especially in prolific breeds, and reduced milk yields which adversely affect neonatal survival and economy of production. The sheep placenta expresses lactogenic (ovine placental lactogen, oPL) and somatogenic (ovine placental growth hormone, oGH) hormones. Our research has focused on the biological roles of oPL and oGH in function of the uterine endometrium during gestation and the mammary gland during pregnancy and lactation. Major conclusions were that: ( 1 ) immunization of prepubertal ewes against oPL resulted in increased birth weights of their lambs and their milk production during lactation; (2) neither oPL nor oGH had an antiluteolytic effect on uterine endometrium to affect lifespan of the corpus luteum; (3) only sequential exposure of the progesterone stimulated uterus to oIFNt and oPL or oGH increased endometrial gland proliferation and secretory protein gene expression; (4) oPL signals through a homodimer of ovine prolactin receptor (PRL-R) and heterodimer of oPRL-R and growth hormone receptor (GH-R); (5) exogenous recombinant oPL and oGH stimulated mammogenesis and milk yield during lactation; and (6) mutation of oPL and oGH was used to define specific biological effects and a rational basis for design of a specific receptor agonists or antagonists. This project was very productive in elucidating basic biological effects of oPL and oGH on intracellular signal transduction pathways, uterine development and secretory function, as well as mammogenesis and lactogenesis. We determined that immunization of prepubertal ewes against roPL increased birth weights of their lambs, especially those born as twins and triplets, as well as enhanced lactational performance. These studies significantly extended our knowledge of uterine and fetal-placental physiology and provided a foundation for new strategies to enhance reproductive and lactation efficiency. Based on these results, the major achievements were: 1) creation of a practical and cost effective management tool for producers to increase reproductive performance, neonatal survival, and milk yield of ewes in commercial flocks; and 2) define, for the first time, biological effects of oPL on endometrial functions and gene expression by uterine gland epithelium.
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Wolfenson, David, William W. Thatcher y James E. Kinder. Regulation of LH Secretion in the Periovulatory Period as a Strategy to Enhance Ovarian Function and Fertility in Dairy and Beef Cows. United States Department of Agriculture, diciembre de 2003. http://dx.doi.org/10.32747/2003.7586458.bard.
Texto completoResumen
The general research objective was to increase herd pregnancy rates by enhancing corpus luteum (CL) function and optimizing follicle development, in order to increase conception rate and embryo survival. The specific objectives were: to determine the effect of the duration of the preovulatory LH surge on CL function; to determine the function of LH during the postovulatory period on CL development; to optimize CL differentiation and follicle development by means of a biodegradable GnRH implant; to test whether optimization of CL development and follicle dynamics in timed- insemination protocols would improve fertility in high-yielding dairy cows. Low fertility in cattle results in losses of hundreds of millions of dollars in the USA and Israel. Two major causes of low fertility are formation of a functionally impaired CL, and subsequent enhanced ovarian follicle development. A functionally impaired CL may result from suboptimal LH secretion. The two major causes of low fertility in dairy cattle in US and Israel are negative energy status and summer heat stress; in both situations, low fertility is associated with reductions in LH secretion and impaired development of the ovulatory follicle and of the CL. In Florida, the use of 450-mg deslorelin (GnRH analogue) implants to induce ovulation, under the Ovsynch protocol resulted in a higher pregnancy rates than use of 750-mg implants, and pregnancy losses tended to decrease compared to controls, due probably to decrease in follicular development and estradiol secretion at the time of conceptus signaling to maintain the CL. An alternative strategy to enhance progesterone concentrations involved induction of an accessory CL by injection of hCG on day 5 after the cows were inseminated. Treatment with hCG resulted in 86% of the cows having two CLs, compared with 23% of the control cows. Conception rates were higher among the hCG-treated cows than among the controls. Another approach was to replace the second injection of GnRH analogue, in a timed-insemination protocol, with estradiol cypionate (ECP) injected 24 h after the injection of PGF₂ₐ Pregnancy rates were comparable with those obtained under the regular Ovsynch (timed- AI) program. Use of ECP induced estrus, and cows inseminated at detected estrus are indeed more fertile than those not in estrus at the time of insemination. Collectively, the BARD-supported programs at the University of Florida have improved timed insemination programs. In Ohio, the importance of the frequency of LH episodes during the early stages of the estrous cycle of cattle, when the corpus luteum is developing, was studied in an in vivo experiment in which cows were subjected to various episodic exposures to exogenous bovine LH. Results indicate that the frequent LH episodes immediately following the time of ovulation are important in development of the corpus luteum, from the points of view of both size and functionality. In another study, rates of cell proliferation and numbers of endothelial cells were examined in vitro in CLs collected from cows that received post-ovulation pulsatile LH treatment at various frequencies. The results indicate that the corpora lutea growth that results from luteal cell proliferation is enhanced by the episodes of LH release that occur immediately after the time of ovulation in cattle. The results also show that luteal endothelial cell numbers did not differ among cows treated with different LH doses. In Israel. a longer duration of the preovulatory LH surge stimulated the steroidogenic capacity of granulosa-derived luteal cells, and might, thereby, contribute to a higher progesterone output from the bovine corpus luteum. In an in vivo study, a subgroup of high-yielding dairy cows with extended estrus to ovulation interval was identified. Associated with this extended interval were: low plasma progesterone and estradiol concentrations and a low preovulatory LH surge prior to ovulation, as well as low post- ovulation progesterone concentration. In experiments based on the above results, we found that injection of GnRH at the onset of estrus increased the LHpeak, prevented late ovulation, decreased the variability between cows and elicited high and uniform progesterone levels after ovulation. GnRH at estrus onset increased conception rates, especially in the summer, and among primiparous cows and those with low body condition. Another study compared ovarian functions in multiparous lactating cows with those in nulliparous non-lactating heifers. The results revealed differences in ovarian follicular dynamics, and in plasma concentrations of steroids and gonadotropins that may account for the differences in fertility between heifers and cows.