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Fetal membranes and ancillary structures of llamas (Lama glama).
1990
Fowler M.E. | Olander H.J.
The placenta of llamas is epitheliochorial, with patchy areas of dense folded papillation serving as the placentome. The amnion of the full-term placenta is closely adhered to either the allantois or the chorion and remains with these structures at the time of parturition. Llamas and alpacas, like dromedaries, have an extra fetal membrane that is derived from the epidermis of the fetus. In association with the watery amniotic fluid of llamas, the epidermal membrane is slippery, facilitating delivery of the fetus.
Afficher plus [+] Moins [-]Ovine anaplasmosis: in utero transmission as it relates to stage of gestation.
1987
Zaugg J.L.
Leptospira interrogans serogroup Sejroe serovar Hardjo in aborting cows: two herd cases in Sicily (Italy)
2020
Grippi, Francesca | Giudice, Elisabetta | Pietro, Simona Di | Sciacca, Carmela | Santangelo, Francesco | Galluzzo, Paola | Barreca, Santino | Guercio, Annalisa
The aim of this study was to present two outbreaks of bovine abortion due to Leptospira infection in cattle herds located in the northern part of Sicily (Italy). The animals were positive for Leptospira interrogans serogroup Sejroe serovar Hardjo in a microscopic agglutination test (MAT). A total of 23 Charolaise cows (farm A) and 75 Limousine bulls and Cinisara and Modicana cows (farm B) were enrolled in this study. The blood samples were collected from all subjects at the following time points: before a cycle of intramuscular treatment with oxytetracycline dihydrate (T0), after 5–6 weeks from the treatment (T1), and every 10 weeks until seronegativisation (T2 in Farm A and T3 in Farm B). A serological test (MAT) was used for the diagnosis of leptospirosis. Two samples from farm A (2/23) and 29 samples from farm B (29/75) were positive to Leptospira interrogans, serogroup Sejroe, serovar Hardjo in the MAT. Leptospira spp. DNA was detected by real-time PCR in the urine sample of one positive cow on farm A, and in placenta and brain samples belonging to one aborted foetus on farm B. It is important to use serological and molecular diagnostic techniques complementarily to identify infected individuals.
Afficher plus [+] Moins [-]Clinical signs and their association with herd demographics and porcine reproductive and respiratory syndrome (PRRS) control strategies in PRRS PCR-positive swine herds in Ontario
2010
Young, Beth | Dewey, Cate | Poljak, Zvonimir | Rosendal, Thomas | Carman, Susy
The purposes of this study were to describe the clinical signs observed in PRRS positive herds during a porcine reproductive and respiratory syndrome (PRRS) outbreak in Ontario and to determine associations between these clinical signs and herd demographics and PRRS control strategies. All PRRS polymerase chain reaction-(PCR)-positive submissions to a diagnostic laboratory between September 1, 2004 and August 31, 2007 were identified (n = 1864). After meeting eligibility requirements and agreeing to voluntary study participation, producers from 455 of these submissions were surveyed for information on clinical signs observed in their herds, herd demographics, and PRRS control strategies used in their herds at the time that the PCR-positive samples were taken. Larger herd size was associated with an increased risk of reporting abortion, weakborn piglets, off-feed sows, and sow mortality in sow herds, and with an increased risk of reporting mortality in finishing herds. When disease control strategies were examined, use of a commercial PRRS vaccine in sows and gilts was associated with a decreased risk of reporting weakborn pigs and high pre-weaning mortality, while the use of serum inoculation in breeding animals was associated with an increased risk of reporting off-feed sows and sow mortality. Providing biofeedback of stillborn/mummified piglets, placenta or feces to gilts was associated with an increased risk of reporting respiratory disease and mortality in finishing pigs while all-in/all-out flow in farrowing rooms was associated with an increased risk of reporting sow mortality and weakborn piglets.
Afficher plus [+] Moins [-]Efficacy of domperidone and sulpiride as treatments for fescue toxicosis in horses
1994
Redmond, L.M. | Cross, D.L. | Strickland, J.R. | Kennedy, S.W.
We evaluated the effectiveness of 2 dopamine antagonists as treatments for fescue toxicosis in horses. Sixteen gravid mares were assigned by breed and expected foaling date to 1 of 3 treatment groups: endophyte-infested control 1.1 mg of domperidone/kg of body weight/d; and 3.3 mg of sulpiride/kg/d. Mares were pastured on endophyte-infected fescue and received 0.454 kg of a corn and dried molasses carrier containing the drug treatment. Treatment started 30 days prior to expected foaling date and continued until parturition. Blood samples were collected, and mammary gland scores were recorded every 5 days. Body weight and body condition scores were obtained every 28 days. Serum was analyzed for prolactin, progesterone, and estradiol-17beta concentrations. Domperidone-treated mares had shorter (P = 0.09) gestation duration and foaled closer (P = 0.07) to their expected parturition date than did control mares. Mammary gland scores were higher (P < 0.05) for domperidone-treated mares than for control mares. By 4 and 9 days after the start of treatment, serum prolactin concentration was higher P < 0.05) in domperidone-treated mares and sulpiride-treated mares, respectively, than in control mares. Domperidone- and and sulpiride-treated mares had higher (P < 0.05) serum progesterone and lower (P < 0.01) estradiol-17beta concentrations than did control mares. These results indicate that domperidone may offer considerable potential as a treatment for fescue toxicosis in horses.
Afficher plus [+] Moins [-]Determination of ability of a thymidine kinase-negative deletion mutant of bovine herpesvirus-1 to cause abortion in cattle
1991
Jones, Ever | Whetstone, C.A. | Bello, L.J. | Lawrence, W.C.
The Cooper isolate of bovine herpesvirus-1, which causes abortion in cattle, was used to construct a thymidine kinase-negative (TK-) deletion mutant virus. Twelve heifers were inoculated IV at 25 to 29 weeks of pregnancy with either TK- or thymidine kinase-positive (TK+) Cooper virus. All heifers developed fevers of 1 to 2 C during the first week after inoculation. Temperatures of TK+ inoculates were slightly higher and remained above normal a few days longer than in TK- inoculates. Viremia was detected in 5 of 6 TK+ inoculates and in all 6 TK- inoculates. More virus isolations were made from nasal and vaginal swab specimens of TK+ inoculates than from swab specimens of TK- inoculates. All heifers developed virus neutralizing antibody within 14 days after inoculation and antibody titers were similar between the 2 groups. None of the TK- inoculated heifers aborted and their calves did not have neutralizing antibody at birth. Abortion occurred in 5 of 6 heifers given TK+ virus. All aborted fetuses were infected with bovine herpesvirus-1, as demonstrated by virus isolation or detection of viral antigen in fetal tissues. These results indicate that inactivation of the TK gene reduces abortifacient activity of bovine herpesvirus-1.
Afficher plus [+] Moins [-]Diagnosis of transplacentally induced toxoplasmosis in pigs
1990
Dubey, J.P. | Urban, J.F. Jr
Seventeen sows were fed 1,000 Toxoplasma gondii oocysts of isolates GT-1 or PT-1 at 32 to 92 days of gestation, and the products of conception were examined for T gondii antibodies and parasites. Twelve of these sows were euthanatized near term between 21 and 62 days after being fed T gondii; fetal body fluids or fetal sera were examined for agglutinating T gondii antibodies, and tissues were bioassayed in mice for T gondii parasites. Six sows produced pigs that had been transplacentally infected with T gondii; one of them aborted a T gondii-infected fetus 17 days after ingesting oocytes. Agglutinating antibodies were detected in fetuses infected in utero, but transplacental transfer of T gondii antibodies was not observed in noninfected fetuses. Transcolostrally acquired T gondii antibodies disappeared by 3 months of age. Diagnosis of transplacental toxoplasmosis was confirmed on the basis of detection of T gondii organisms in fetal tissues by use of histologic examination and bioassay in mice. In conclusion, finding of T gondii antibodies in body fluids could serve as a rapid screening test for transplacental T gondii infection in pigs.
Afficher plus [+] Moins [-]Influence of cortisol and different steroidogenic pathways on estrogen synthesis by the bovine placenta
1990
Hoedemaker, M. | Weston, P.G. | Wagner, W.C.
The influence of cortisol on estrogen synthesis by the bovine placenta and the importance of the delta 4 and delta 5 pathway for estrogen production were investigated. For experiment 1, portions of fetal villi (200 mg) were incubated for 48 hours with 0, 10, 100, and 1,000 ng of cortisol/ml with [3H]androstenedione (3H-A) or [3H]pregnenolone (3H-P5). Villi were also incubated for 4, 28, and 52 hours with or without cortisol (500 ng/ml) and with 3H-A or 3H-P5 (experiment 2). The conversion of various [3H]steroid metabolites such as A, P5, 17 alpha-OH-pregnenolone (17 alpha-OH-P5), progesterone (P4), 17 alpha-OH-P4, cholesterol (chol), and chol plus lipoprotein (500 micrograms/ml) into estrogen was measured during a 4-hour incubation (experiment 3). In experiment 1, cortisol increased conversion of 3H-A and 3H-P5 into estrogen by 3 to 41% and 7 to 34%, respectively, in a dose-dependent manner (P < 0.05). In experiment 2, times of incubation did not influence conversion of 3H-A into estrogen, which, however, was increased significantly (P < 0.05) over all times of incubation by administration of 500 ng of cortisol/ml. Conversion of 3H-P5 into estrogen increased over time of incubation and was stimulated by cortisol (P < 0.05). However, there was no interaction between cortisol treatment and time of incubation. In experiment 3, conversion of 3H-A, 3H-P5, and 3H-17 alpha-OH-P5 into estrogen was greater than the conversion of the other precursors tested. Mean conversion of 3H-A, 3H-P5, 3H-17 alpha-OH-P5, 3H-P, 3H-17 alpha-OH-P4, 3H-chol, and 3H-chol plus lipoprotein was 23%, 10.6%, 11.0%, 1.8%, 1.8%, 0.3% and 0.7%, respectively. Our results suggest that, in cows, the delta 5 pathway is the preferred pathway for placental estrogen synthesis and that cortisol directly stimulates estrogen production, probably by activating enzymes involved in this pathway.
Afficher plus [+] Moins [-]Safety and efficacy of two sustained-release intrareticular selenium supplements and the associated placental and colostral transfer of selenium in beef cattle
1990
Campbell, D.T. | Maas, J. | Weber, D.W. | Hedstrom, O.R. | Norman, B.B.
One hundred fifty Se-deficient, pregnant, crossbred beef cows were assigned to 1 of 4 treatment groups: group A, Se-deficient control; group B, 1 Se bolus at 0 and 119 days; group C, 1 Se bolus at 0 days; and group D, 2 Se pellets at 0 days. The Se bolus is an osmotic pump designed to release 3 mg of Se/d into the reticulorumen. The Se pellets weigh approximately 30 g and contain 10% elemental Se, which is liberated in the reticulorumen. The Se bolus is designed to provide Se supplementation for 120 days and the Se pellets provide supplementation for up to 18 months. Cattle were maintained on Se-deficient pasture or forages prepared from these pastures for the duration of the experiment. Blood samples were collected from cows prior to treatment (time 0) and at 28, 52, 119, and 220 days thereafter and analyzed for blood Se (BSe) concentration. Body weights were recorded at each sampling time. Blood Se concentration of cows from all supplemented groups were significantly (P < 0.01) higher than control values at all sample dates after treatments began. By the end of the 220-day study, treatment group-B cattle had significantly (P < 0.01) higher BSe concentrations than any other group. Body weights of treatment groups fluctuated throughout the study, but did not differ (P > 0.05) between groups. One cow and 6 calves born to cows during the experimental period died. Necropsy of 5 calves provided no evidence linking these deaths to treatments. A difference (P > 0.05) in mortality between groups was not detected. Blood samples were collected from calves prior to suckling, and were analyzed for BSe concentration. Colostrum samples were collected from dams and analyzed for total Se concentration. Additional blood samples were collected from calves 24 to 48 hours after suckling and analyzed for BSe concentration and serum creatine kinase activity. Birth weight, gender, and health were recorded for all calves. Calves from cows in Se-supplemented groups had significantly (P < 0.001) higher BSe concentrations, both before and after suckling, than did controls. Postsuckle BSe concentrations within the groups of calves were not significantly (P > 0.05) different than presuckle BSe concentrations for any of the groups. Selenium concentrations in colostrum from Se-supplemented cows were significantly (P < 0.001) higher than from control cows. A difference (P > 0.05) was not determined in serum creatine kinase activities or birth weights between groups.
Afficher plus [+] Moins [-]Protection of mice against Brucella abortus infection by inoculation with monoclonal antibodies recognizing Brucella O-antigen
1989
Phillips, M. | Deyoe, B.L. | Canning, P.C.
Monoclonal antibodies recognizing the O-polysaccharide portion of Brucella abortus strain 2308 provided BALB/c mice with passive protection against challenge exposure with the homologous strain. Numbers of colony-forming organisms in the spleen were reduced by IgM and IgG monoclonal antibodies. Active immunization of mice, using B abortus 2308S lipopolysaccharide, resulted in production of IgM antibody at 14 days. Clearance of organisms in the actively immunized mice after challenge exposure at 14 days was nearly identical to that in passively immunized mice. Mice either passively or actively immunized were effectively protected from 0 to 28 days. Bacterial colonization of the spleen was observed to increase in both groups of mice at 56 days and indicated that humoral responses were effective in eliminating the organism in the early stages of infection, but other immune mechanisms were necessary for protection of mice in the later stage of infection with virulent strains of B abortus.
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