细化搜索
结果 1-10 的 224
Replacing Subjective Assessment of Dairy Cows with Objective Measures
2021
Caleb Sagwa Barasa
In 2067 dairy farms in developing countries will be modernized and automated systems will replace much of the manual labour on farms. Traditionally, livestock management decisions have been based on almost entirely on observations, judgement, and experience of the farmer. However, such manual systems are inherently subjective, labour intensive, time consuming, invasive and unreliable. Today technology-oriented approaches are widely in use in animal agriculture. New data obtained using fast, real time, and affordable objective measures are becoming more readily available to aid farm level monitoring, awareness, and decision making. Computer vision technology and image analysis, digital twins, artificial intelligence, sensors, big data, and machine learning are a game changer in the livestock industry. This review aims at highlighting the main areas where digital technologies for improved animal monitoring and welfare are most applicable in dairy animals. In particular, body condition scoring, lameness detection, mastitis diagnosis, oestrus detection and pregnancy diagnosis. The environmental sustainability of digital technologies is also discussed. The application of technology offers new possibilities to realize food safety and quality, efficient and sustainable animal farming, healthy animals, guaranteed wellbeing and acceptable environmental impact of livestock production.
显示更多 [+] 显示较少 [-]The effect of Rabies Infection and Vaccination on Pregnancy in Rats as Animal Model
2013
Amani, A. Saleh | A. F. Soliman | A. M. Albehwar | M. B. Shendy
The effect of rabies infection and vaccination on pregnancy was investigated in different groups of pregnant rats as an animal model. Intracerebral and intramuscular experimental infection with CVS rabies virus strain was applied on four pregnant rats groups at the middle (seven days after mating) and late stages of gestation (14 days after mating). Subcutaneous rout vaccination of other three pregnant rat groups five to seven days before; seven and 14 days after mating with the inactivated cell culture local rabies vaccine. Each group of infected rats showed clinical signs of rabies although their fetuses did not show any abnormalities. Virus recovery from the placenta and fetuses from dead and sacrificed animals failed to induce rabies signs in mice inoculated intracerebrally with placenta and fetus suspensions while brains of infected dams; through the routes; revealed positive FA by using fluorescent antibody technique. Vaccinated pregnant rats did not show any abnormalities with normal fetuses and good levels of specific rabies antibodies when estimated by serum neutralization test. These findings indicate that rabies vaccination of pregnant animals is safe and it could be recommended to protect both of dams and their offspring in the first months.
显示更多 [+] 显示较少 [-]Role of animal in occurrence of some zoonotic enteric protozoa in different areas of Nile Delta
2010
A. M. Byomi | H. A. Samaha | S. A. Zidan
A total of 807 stool and fecal samples (251 stool samples from diarrheic children under six years old, 254, and 250 fecal samples from diarrheic and apparently healthy pre-weaned calves and lambs, respectively in addition to 50 fecal samples from dogs) were collected from different localities in Behera and Menoufia Governorates for detection of Cryptospridium spp., Giardia spp. and Entamoeba histolytica). Cryptosporidium spp. has been detected by using modified Ziel-Nelssen Stain (MZN) in 30 (11.95%); 26 (10.24%); 31(12.4%) and 2(3.84%) of the examined stool and fecal samples from children, calves, lambs and dogs, respectively in both Governorates. There were significant relationships between infection of the examined calves with Cryptospordium parvum and their age and healthy status. The same relation was noticed in concern with the examined children. Results of MZN were confirmed by using ELISA which was found sensitive (overall sensitivity 96.6%). In spite of the higher sensitivity of PCR than MZN for detection of C. parvum in fecal specimens especially when oocysts are scanty, the high cost of reagents and lack of expensive instruments which are not available in all clinical laboratories render MZN staining technique acceptable and reliable. By using direct smear and formal ether method, Giardia intestinals has been detected in {27(10.75%); 51(20.08%); 63(29.2%) and 5 (9.61%)} of stool and fecal samples from the examined children, calves, lambs and dogs, respectively from both Governorates. Calves, lambs and dogs seem to be important sources for Giardia intestinalis to man. Entamoeba histolytica has been detected in {19(7.56%); 0 (0),0(0) and 2(3.84%) of stool and fecal samples of the examined children, calves, lambs and dogs, respectively in both governorates. Dogs are regarded as an important source of Entamoeba histolytica to man.
显示更多 [+] 显示较少 [-]Correlation of magnetic resonance images with anatomic features of the equine tarsus
2006
Latorre, R. | Arencibia, A. | Gill, F. | Rivero, M. | Henry, R.W. | Ramirez, G. | Vaquez, J.M.
Objective-To correlate anatomic features of the equine tarsus identified in plastinated sections with images obtained via magnetic resonance imaging (MRI). Animals-4 horses. Procedure-MRI (1.5-Tesla magnet) of the tarsus was performed on the pelvic limbs of 4 clinically normal horses following euthanasia. After imaging, tarsocrural joint spaces and vasculature were injected with colored latex. Sagittal and transverse sections of the tarsi were plastinated to facilitate interpretation of MR images. Results-Relevant anatomic structures were identified and labeled on the plastinated tissue slices and corresponding MR images. Results indicated high correlations between MRI findings and those of plastinated sections. Conclusions and Clinical Relevance-The data obtained provided certain reference standards for normal anatomic structure sizes and positions in the equine tarsus. This information may aid future physiologic or clinical studies of this joint.
显示更多 [+] 显示较少 [-]Effect of exercise on activation of the p38 mitogen-activated protein kinase pathway, c-Jun NH2 terminal kinase, and heat shock protein 27 in equine skeletal muscle
2006
Ginneken, M.M.E van | Graaf-Roelfsema, E de | Keizer, H.A. | Dam, K.G van | Wijnberg, I.D. | Kolk, J.H van der | Breda, E van
Objective-To investigate the effects of exercise on activation of mitogen-activated protein kinase (MAPK) signaling proteins in horses. Animals-6 young trained Standardbred geldings. Procedure-Horses performed a 20-minute bout of exercise on a treadmill at 80% of maximal heart rate. Muscle biopsy specimens were obtained from the vastus lateralis and pectoralis descendens muscles before and after exercise. Amount of expression and intracellular location of phosphospecific MAPK pathway intermediates were determined by use of western blotting and immunofluorescence staining. Results-Exercise resulted in a significant increase in phosphorylation of p38 pathway intermediates, c-Jun NH2 terminal kinase (JNK), and heat shock protein 27 (HSP27) in the vastus lateralis muscle, whereas no significant changes were found in phosphorylation of extracellular regulated kinase. In the pectoralis descendens muscle, phosphorylation of p38 and HSP27 was significantly increased after exercise. Immunohistochemical analysis revealed fiber-type-specific locations of phosphorylated JNK in type 2a/b intermediate and 2b fibers and phosphorylated p38 in type 1 fibers. Phosphorylated HSP27 was strongly increased after exercise in type 1 and 2a fibers. Conclusions and Clinical Relevance-The p38 pathway and JNK are activated in the vastus lateralis muscle after a single 20-minute bout of submaximal exercise in trained horses. Phosphorylation of HSP27 as detected in the study reported here is most likely induced through the p38 signaling pathway.
显示更多 [+] 显示较少 [-]Comparison of B-mode and Doppler ultrasonographic findings with histologic features of benign and malignant mammary tumors in dogs
2006
Nyman, H.T. | Nielsen, O.L. | McEvoy, F.J. | Lee, M.H. | Martinussen, T. | Hellmen, E. | Kristensen, A.T.
Objective-To compare and correlate B-mode and color Doppler ultrasonographic characteristics with the histologic findings of benign and malignant mammary tumors in dogs. Study Population-49 mammary tumors in 26 dogs. Procedures-Before excision, tumors were evaluated via B-mode and color Doppler ultrasonography to assess size, echogenicity, echopattern, acoustic transmission, invasiveness, and vascularity. Paraffin-embedded microsections of the tumors were stained with H&E and examined for presence of necrosis, cysts, cartilage, bone, mineralization, invasion of surrounding tissue, and tissue heterogeneity. To assess vascularity, the number and distribution of vessels that were stained by the Verhoeff van Gieson technique were recorded. Results-Tumor echogenicity and echopattern on ultrasonographic images correlated with tissue heterogeneity detected histologically. Acoustic enhancement was correlated with the presence of necrotic or cystic areas. Tumor invasion into surrounding tissues as determined ultrasonographically did not correlate with the histologic findings. There was a significant correlation between the number of detected vessels and distribution of flow within the tumors determined via ultrasonographic and histologic examinations. Conclusions and Clinical Relevance-In canine mammary tumors, ultrasonographic characteristics appear to be correlated with histopathologic changes. Data suggest that ultrasonography may have an important role in the evaluation of mammary tumors in dogs, particularly in the evaluation of tissue composition and tumor vascularity.
显示更多 [+] 显示较少 [-]Evaluation of porcine ileum models of enterocyte infection by Lawsonia intracellularis
2006
McOrist, S. | Gebhart, C.J. | Bosworth, B.T.
The early interaction of Lawsonia intracellularis with host cells was examined with the use of porcine ileum models. Two conventional swine were anesthetized, and ligated ileum loops were prepared during abdominal surgery. The loops were inoculated with 10⁸ L. intracellularis or saline. After 60 min, samples of each loop were processed for routine histologic and electron microscopic study. Histologic and ultrathin sections of all the loops appeared normal, with no apposition of bacteria and host cells or bacterial entry events in any loop. Portions of ileum from a single gnotobiotic piglet were introduced as xenografts into the subcutis of each flank of 5 weaned mice with severe combined immunodeficiency disease. After 4 wk, 10⁸ L. intracellularis were inoculated into each of 4 viable xenografts with a sterile needle; the other 3 viable xenografts received saline. Histologic and ultrathin sections of all the xenografts 3 wk after inoculation showed relatively normal porcine intestinal architecture, with normal crypts, crypt cell differentiation, and low villous structures; the xenografts treated with the bacteria also showed intracytoplasmic L. intracellularis within crypt and villous epithelial cells. Thus, entry of L. intracellularis into target epithelial cells and multiplication may not be sufficient alone to directly cause cell proliferation. A proliferative response may require active division of crypt cells and differentiation in conjunction with L. intracellularis growth.
显示更多 [+] 显示较少 [-]Prevalence of exposure to Salmonella spp in finishing swine marketed in Iowa
2006
O'Connor, A.M. | McKean, J.D. | Beary, J.H. | Brockus, S.L.
Objective-To describe the prevalence of antibodies against Salmonella spp in swine marketed in Iowa. Animals-Swine marketed by 1,044 low-volume producers and 45 high-volume producers. Procedure-Samples of diaphragm muscle collected from swine carcasses were tested by an indirect ELISA based on lipopolysaccharides from Salmonella spp, in particular Salmonella serovar Typhimurium. Prevalence of positive results for antibodies against Salmonella spp for carcasses, lots, and swine for each producer was determined. Producer-level seroprevalence was used to classify swine from producers as having negligible, low, moderate, or widespread evidence of previous or historical exposure to Salmonella spp. Results-From low-volume producers, 23,609 of 25,478 (92.7%; 95% confidence interval CI, 92.4% to 92.9%) samples had negative results, and 1,863 (7.3%; 95% CI, 7.05% to 7.56%) had antibodies against Salmonella spp. Of the 6,299 lots of swine tested, 1,191 (18.9%) contained at least 1 sample with positive results. From high-volume producers, 203 of 2,486 (8.1 %; 95% CI, 6.8% to 9.3%) samples had antibodies against Salmonella spp, and 124 of 629 lots had at least 1 sample with positive results for antibodies against Salmonella spp. Conclusions and Clinical Relevance-Less than 10% of pigs marketed in Iowa are apparently exposed to Salmonella spp. Most swine marketed by low-volume producers had negligible or little evidence of exposure to Salmonella spp, whereas a higher percentage of swine marketed by high-volume producers had positive results when tested to detect antibodies against Salmonella spp.
显示更多 [+] 显示较少 [-]Lactogenic immunity and milk antibody isotypes to transmissible gastroenteritis virus in sows exposed to porcine respiratory coronavirus during pregnancy
1995
Lanza, I. | Shoup, D.I. | Saif, L.J.
Passive protection provided by sows inoculated with the virulent Miller strain of transmissible gastroenteritis virus (TGEV), or the ISU-1 strain of porcine respiratory coronavirus (PRCV), or both was evaluated in nursing pigs challenge exposed with virulent TGEV. Four sows (group B) were inoculated with PRCV oronasally twice at 4 and 2 weeks before parturition; 1 sow (group C) was inoculated similarly, but in 2 subsequent pregnancies; and 2 sows (group D) were oronasally primed with PRCV at 4 weeks before parturition, and 2 weeks later were administered a booster inoculation of virulent TGEV. Two additional sows (group E) remained uninoculated and served as seronegative controls, and 1 sow (group A) that had been naturally infected with TGEV served as a seropositive control. The degree of passive immunity transferred by these sows to their litters was assessed by challenge exposing the pigs of sows in groups BE (only the second litter of group C) with virulent TGEV at 3 to 5 days of age. After challenge exposure, clinical signs of infection and mortality were noted and fecal and nasal shedding of virus was assessed by ELISA. The IgA, IgG, and IgM antibody titers to TGEV were quantified in colostrum and milk of the sows by use of an isotype-specific monoclonal antibody-capture ELISA, using biotinylated monoclonal antibodies against each porcine isotype as detecting reagents. A plaque-reduction assay was used to quantify neutralizing antibody titers in serum, colostrum, milk, and fractionated whey (IgG and IgA/IgM). In the sow naturally infected with TGEV (group A), there was a pronounced decrease in IgG antibody titers to TGEV in the transition from colostrum to milk, and IgA TGEV antibodies became predominant, with high titers maintained throughout lactation. The 4 group-B sows partially protected their pigs after TGEV challenge exposure; mean mortality was 67%, compared with 100% in pigs suckling the 2 TGEV seronegative control sows (group-E litters). Although IgA TGEV antibodies were detected in colostrum and milk of group-B sows, IgG TGEV antibodies were the most abundant. The sow of group C had a marked increase in IgA TGEV antibody titers in colostrum and milk after reinoculation with PRCV during the second pregnancy, before TGEV challenge exposure of the litter. Its pigs were passively protected to a high degree after TGEV challenge exposure (27% litter mortality). The sows in group D, primed with PRCV and boosted with TGEV, provided the best passive protection after TGEV challenge exposure of their pigs. Not only litter mortality (27%) but also morbidity was reduced, compared with those factors for the other challenge exposed litters, and the sows did not become ill. In these swine, the high degree of passive protection observed could not be associated with the presence of only IgA TGEV antibodies in the milk, but high IgM TGEV antibody titers also were detected in colostrum and milk. Results of this study suggest that PRCV-inoculated sows are able to partially protect their pigs from TGEV challenge exposure and, on the basis of preliminary data, the degree of protection may increase after multiple PRCV exposures or after secondary exposure to TGEV during pregnancy. Also, an IgA respiratory tract-mammary gland link may exist as evident by the low titer of IgA TGEV antibodies in the milk of PRCV-inoculated sows, but may not be as efficient in inducing lactogenic IgA immunity as is the gastrointestinal tract-mammary gland link.
显示更多 [+] 显示较少 [-]Digital Starling forces and hemodynamics during early laminitis induced by an aqueous extract of black walnut (Juglans nigra) in horses
1995
Eaton, S.A. | Allen, D. | Eades, S.C. | Schneider, D.A.
Starling forces and hemodynamics in the digits of 5 horses were studied during early laminitis induced by oral administration of an aqueous extract of black walnut (Juglans nigra). The black walnut extract was prepared from heartwood shavings and was administered by nasogastric tube. Heart and respiratory rates, rectal temperature, central venous and arterial pressures, digital pulses, and signs of lameness were monitored. Blood samples were collected for determination of WBC count, hemoglobin concentration, and PCV and for endotoxin and tumor necrosis factor assays. Total WBC count and central venous pressure were monitored until they decreased by 30 or 20%, respectively. These decreases in WBC count and central venous pressure were observed 2 to 3 hours after dosing with black walnut extract. Respiratory and heart rates, body temperature, systolic and diastolic blood pressures, PCV, and hemoglobin concentration did not change significantly. Anesthesia was induced, heparin (500 IU/kg of body weight) was administered IV, and a pump-perfused extracorporeal digital preparation was established. Digital arterial and venous pressures were maintained at 100 and 30 mm of Hg, respectively. Blood flow, capillary pressure, lymph and plasma protein concentrations, and weight of the isolated digit during rapid increase in venous pressure were measured. Isogravimetric capillary filtration coefficient, vascular compliance, vascular and tissue oncotic pressures, tissue pressure, osmotic reflection coefficient, and precapillary and postcapillary resistances were calculated. Mean digital blood flow was 14 ml/min/100 g, capillary pressure was 52 mm of Hg, and vascular compliance was 0.06 ml/mm of Hg. The vascular and tissue oncotic pressures were 21.49 and 4.93 mm of Hg, respectively. The osmotic reflection coefficient was 0.71, and tissue pressure was 41 mm of Hg. The precapillary and postcapillary resistances were 7 and 2 mm of Hg/ml, respectively. Capillary permeability to proteins was not significantly different from that previously measured in healthy horses, suggesting that the increased capillary filtration coefficient reflected increased capillary hydrostatic pressure and perfusion of previously nonperfused capillaries. Neither endotoxin nor serum tumor necrosis factor activity was detected in any samples. The hemodynamic and Starling forces observed in this study were similar to those observed after laminitis was induced by administration of a carbohydrate gruel. Significant differences between the 2 models were detected for total vascular resistance, postcapillary resistance, and capillary filtration coefficient. It is likely that these differences were identified because the horses administered the black walnut extract were at an earlier stage in the disease process. The findings of this study suggest that the increase in capillary pressure causes transvascular fluid movement, resulting in increased tissue pressure and edema. We hypothesize that further increases in tissue pressure may collapse capillary beds and lead to tissue ischemia.
显示更多 [+] 显示较少 [-]