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J L?fstedt J A Roth R F Ross W C Wagner 《American journal of veterinary research》1983,44(7):1224-1228
In a study of susceptibilities of sows from 2 herds to experimentally induced Escherichia coli mastitis, a marked difference was seen. The "susceptible" sows were from a conventional herd and "resistant" sows were from a specific-pathogen-free herd. The purpose of the study was to determine whether deficient neutrophil function was associated with increased susceptibility to E coli-induced mastitis. Four in vitro procedures were used to evaluate polymorphonuclear leukocyte (PMN) function: (i) random migration under agarose, (ii) ingestion of 125I-iododeoxyuridine-labeled Staphylococcus aureus, (iii) quantitative nitroblue tetrazolium reduction, and (iv) iodination. After parturition and intramammary inoculation with E coli, sows from the susceptible herd were neutropenic and the neutrophils which were present in the peripheral blood had reduced function. Specifically, there were depressed random migration under agarose, S aureus ingestion, and iodination when compared with PMN function in resistant sows. These data indicate that susceptibility to E coli mastitis was associated with deficiencies in PMN numbers and function. Potential causes of the neutrophil dysfunction are discussed and include possible systemic hormonal aberrations or the presence of an inapparent viral or bacterial infection. 相似文献
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Key Factors Affecting Reproductive Success of Thoroughbred Mares and Stallions on a Commercial Stud Farm 下载免费PDF全文
EA Lane MLJ Bijnen M Osborne SJ More ISF Henderson P Duffy MA Crowe 《Reproduction in domestic animals》2016,51(2):181-187
To evaluate factors contributing to fertility of thoroughbred mares, data from 3743 oestrous periods of 2385 mares were collected on a large thoroughbred farm in Ireland. Fourteen stallions (mean age 8.3 years; range 4–15 years) had bred 2385 mares (mean age 9.4 years; range 3–24 years). Maiden mares accounted for 12%, mares with a foal at foot for 64%, and barren, slipped or rested mares for 24% of the total. The mean pregnancy rate per cycle was 67.8% (68.6% in year 1 and 66.9% in year 2). Backward stepwise multivariable logistic regression analysis was utilized to develop two models to evaluate mare factors, including mare age, reproductive status, month of foaling, dystocia, month of cover, foal heat, cycle number, treatments, walk‐in status and stallion factors including stallion identity, stallion age, shuttle status, time elapsed between covers and high stallion usage on the per cycle pregnancy rate and pregnancy loss. Old age (p < 0.001) and cover within 20 days post‐partum (p < 0.003) were associated with lowered pregnancy rates. High mare age (p < 0.05) and barren, slipped or rested reproductive status (p = 0.05) increased the likelihood of pregnancy loss. Uterine inflammation or infection, if appropriately treated, did not affect fertility. Only high usage of stallions (used more than 21 times in previous week) was associated with lowered (p = 0.009) pregnancy rates. However, shuttle stallions were more likely to have increased (p = 0.035) pregnancy survival, perhaps reflecting a bias in stallion selection. In conclusion, mare age exerted the greatest influence on fertility; nonetheless, thoroughbreds can be effectively managed to achieve high reproductive performance in a commercial setting. 相似文献
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Zinc and copper status in ewes supplemented with sulfate- and amino acid-complexed forms of zinc and copper 总被引:3,自引:0,他引:3
Hatfield PG Swenson CK Kott RW Ansotegui RP Roth NJ Robinson BL 《Journal of animal science》2001,79(1):261-266
Thirty 6-yr-old Targhee ewes were randomly allotted to one of five supplemental treatments to evaluate supplementation effects on liver and fecal Zn and Cu concentrations and serum alkaline phosphatase activity: 1) control, 2) Zn complex, 3) Zn and Cu (ZnCu) complex, 4) Zn sulfate, and 5) ZnCu sulfates. Supplements were administered daily in gelatin capsules for 56 d. Liver biopsies and serum samples were collected every 14 d starting on d 0. Supplemental Zn and Cu levels were formulated to provide 90 mg/kg Zn and 10 mg/kg Cu, respectively, on a daily dry matter intake basis. Form (complex vs sulfate) x type (Zn vs ZnCu) interactions were not detected (P > 0.35). Therefore, contrast statements were used to make the following treatment comparisons: 1) control vs supplement, 2) Zn vs ZnCu, and 3) complex vs sulfate. Ewe BW at the end of the study (P = 0.09) and ewe BW change from beginning to end of the study (P = 0.07) were greater for supplemented than control ewes. Body weight and BW change did not differ between sulfate and complex (P > 0.39) or Zn- and ZnCu- (P > 0.40) supplemented ewes. Liver Cu concentrations did not differ (P = 0.41) between control and supplemented ewes. Liver Cu concentrations were higher (P < 0.10) for ewes supplemented with ZnCu than Zn and complex than sulfate forms of supplement. Liver Zn concentration tended (P = 0.13) to be higher in ZnCu than Zn-supplemented ewes. Liver and fecal Zn concentration were higher (P < 0.06) in ewes fed complex than sulfate supplements. However, serum alkaline phosphatase activity tended (P = 0.12) to be greater in ewes fed sulfate than complex supplements. Supplementing mature ewes with complexed minerals resulted in higher concentrations of Zn and Cu in the liver. In addition, supplemental Cu tended to increase concentrations of Zn in the livers of ewes; however, high levels of supplemental Zn did not negatively impact liver Cu concentrations. 相似文献
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Schmitt CS Halbur PG Roth JA Kinyon JM Kasorndorkbua C Thacker B 《Veterinary microbiology》2001,78(1):29-37
The objective of this research was to evaluate the efficacy of two antimicrobials (ampicillin and ceftiofur), a modified-live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine, and low dose exposure to Streptococcus suis on disease associated with PRRSV/S. suis coinfection. Fifty-six, crossbred, PRRSV-free pigs were weaned at 10-12 days of age and randomly assigned to five treatment groups. All pigs were inoculated with 2ml of 10(6.4) TCID50/ml of high virulence PRRSV isolate VR-2385 intranasally at 29-31 days of age (day 0 of the study) followed 7 days later by intranasal inoculation with 2ml of 10(8.9)colony forming units(CFU)/ml S. suis type 2 isolate ISU VDL #40634/94. Pigs in group 1 (n=10) served as untreated infected positive controls. Pigs in group 2 (n=12) were treated with 5.0 mg/kg ceftiofur hydrochloride intramuscularly (IM) on days 8, 11, and 14. Pigs in group 3 (n=11) were treated with 11 mg/kg ampicillin IM on days 8-10. Pigs in group 4 (n=12) were vaccinated 14 days prior to PRRSV challenge with a commercial modified-live PRRSV vaccine. Pigs in group 5 (n=11) were exposed to a 1:100 dilution of the S. suis challenge inoculum 19 days prior to S. suis challenge. Mortality was 80, 25, 82, 83, and 36% in groups 1-5, respectively. The reduced dose S. suis exposure had some residual virulence, evidenced by S. suis induced meningitis in two pigs after exposure. Treatment with ceftiofur hydrochloride and reduced dose exposure to S. suis were the only treatments which significantly (P<0.05) reduced mortality associated with PRRSV/S. suis coinfection, significantly (P<0.05) reduced recovery of S. suis from tissues at necropsy, and significantly (P<0.05) reduced the severity of gross lung lesions. 相似文献
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The effects of vaccination of Merino ewes with an attenuated Australian bluetongue virus serotype 23 at different stages of gestation 总被引:1,自引:0,他引:1
SUMMARY A cell culture attenuated Australian bluetongue virus serotype 23 (BLU23) prototype vaccine was assessed for its effects on pregnant Merino sheep. Seventy-six ewes were vaccinated at 5 different stages of gestation, and the failure to lamb at term was as follows: 35 to 43 days of gestation, 20/36 (56%); 57 to 64 days of gestation, 3/10 (30%); 81 to 88 days of gestation, 3/10 (30%); 109 to 116 days of gestation, 0/10 (0%); 130 to 137 days of gestation, 0/10 (0%). Of 30 ewes vaccinated with a cell culture supernatant fluid control between 35 and 43 days of gestation, 6.7% (2/30) failed to lamb at term. Two ewes vaccinated with BLU23 vaccine between 35 and 43 days of gestation had lambs with hydranencephaly. All other lambs born were clinically normal. Three ewes vaccinated with BLU23 aborted. Two of these were vaccinated between 35 and 43 days of gestation, the 3rd between 81 and 88 days of gestation. Five lambs were born with BLU group antibody. Four of these were from ewes vaccinated between 35 and 43 days of gestation, and 2 of these had hydranencephaly. The fifth was from a ewe vaccinated between 57 and 64 days of gestation. The vaccine did not produce disease in adult sheep, but was a potent cause of early foetal death and to a much lesser extent foetal malformation. 相似文献
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