Impact of milking characteristics and morphology of udder and teats on clinical mastitis in first- and second-lactation Norwegian cattle   总被引：1，自引：0，他引：1  

Trond Slettbakk  Asbjrn Jrstad  Thomas B. Farver  John C. Holmes 《Preventive veterinary medicine》1995,24(4):235-244

Data from the Norwegian progeny testing program were used to examine the impact of milking characteristics and morphology of udder and teats on clinical mastitis in first- and second-lactation Norwegian cattle. The study was designed as a 1-1 matched case-control study with herd, parity, days in lactation and calving season as matching variables. Conditional maximum likelihood logistic regression was used to evaluate the effects of three primary (2 min milk, milk leakage and teat-end-to-floor distance) and six other study variables. Treatment records from the Norwegian health card system on acute and chronic clinical mastitis were used to define cases. The chosen model included 565 matched pairs. Significant risk factors of clinical mastitis were decreasing teat-end-to-floor distance (P = 0.02) and periparturient udder edema (P < 0.01).

Borderline effects were demonstrated by larger than herd-average teat diameter (P = 0.04), udder asymmetry (P = 0.05) and increasing 2 min milk (P = 0.08). Results were compared to a previous study on the same data with log_e somatic cell count as the dependent variable. Inclusion of teat-end-to-floor distance in the genetic improvement scheme may increase the efficiency of genetic selection for mastitis resistance.  相似文献   

A preliminary study on the effect of dietary supplementation with cod liver oil on the polyunsaturated fatty acid composition of boar semen   总被引：3，自引：0，他引：3  

H. Paulenz  O. Taugbøl  P. O. Hofmo  K. Saarem 《Veterinary research communications》1995,19(4):273-284

Eight mature Norwegian Landrace boars, of proven fertility and in routine semen production for AI, were fed individually with the same basic diet for 9 weeks. One group of 4 animals served as the control, the remaining 4 boars received a daily supplement of 75 ml cod liver oil (CLO-group). Fifteen consecutive semen samples were collected from each boar. The fatty acid composition of the semen was determined, and the content of the 15 most numerous fatty acids with a chain length longer than 12 carbon atoms was followed over time. In both groups, the proportion of 16:1n-7 decreased significantly, while 16:0 and 22:6n-3 (DHA) increased. By the end of the experiment, DHA had tended to increase and 22:5n-6 to decrease to a greater extent in the CLO-group. A significant difference between the groups was seen for onen-6 PUFA (22:4n-6), which remained unchanged in the control group but decreased in the CLO-group. No change was seen in docosapentaenoic acid (22:5n-3) and eicosapentaenoic acid (20:5n-3) was not found in any sample. These results indicate that CLO supplementation affects the fatty acid composition of boar semen. There were no significant differences in the non-return rates (4–25 days) between the two groups before, during or after the experiment.Abbreviations AA arachidonic acid - AI artificial insemination - area% each fatty acid percentage of the total area of the peaks from gas chromatographic analysis of methylated fatty acids - CLO cod liver oil - DHA docosahexaneoic acid - DPA docosapentaenoic acid - EPA eicosapentaenoic acid - LA linoleic acid - LNA linolenic acid - NR non-return rate - PUFA polyunsaturated fatty acid - T _c the temperature marking the beginning of the phase transition Fatty acid nomenclature: Example, 22:6n-3: 22=number of carbon atoms, 6=number of double bonds,n-3=position of the first double bond counted from the terminate (n or methyl end of the fatty acid chain  相似文献   

Oral biology and beak disorders of birds.     

Glenn H Olsen 《Veterinary Clinics of North America: Exotic Animal Practice》2003,6(3):505-21, vi

The beak, or bill, of the bird is a complicated structure. This article describes beak anatomy as well as disorders of the beak, including trauma and diseases.  相似文献   

First cases of amoebic gill disease (AGD) in Norwegian seawater farmed Atlantic salmon, Salmo salar L., and phylogeny of the causative amoeba using 18S cDNA sequences     

Steinum T  Kvellestad A  Rønneberg LB  Nilsen H  Asheim A  Fjell K  Nygård SM  Olsen AB  Dale OB 《Journal of fish diseases》2008,31(3):205-214

  相似文献   

Occurrence of gyrodactylids on wild Atlantic salmon, Salmo salar L., in Danish rivers     

von Gersdorff Jørgensen L  Heinecke RD  Kania P  Buchmann K 《Journal of fish diseases》2008,31(2):127-134

Three hundred and one parr of wild salmon, Salmo salar L., from three river systems in Denmark were examined in December 2005 and August 2006 for gyrodactylid infections. The species determination was done by morphological analyses of the opisthaptoral hard parts and molecular analyses of the internal transcribed spacer (ITS) region using PCR restriction fragment length polymorphism (RFLP) and sequencing. Five species of the genus Gyrodactylus were found: Gyrodactylus derjavini, Gyrodactylus teuchis, Gyrodactylus truttae, Gyrodactylus arcuatus and Gyrodactylus salaris. The parasite species G. derjavini dominated over G. teuchis and G. truttae and only one specimen of G. arcuatus and one specimen of G. salaris were recovered. This specimen of G. salaris had the same mutation in the ITS-region as a previously described non-pathogenic Danish G. salaris variant. The prevalence of gyrodactylids on the salmon ranged from 0% to 100% but the mean abundance never exceeded 12.8.  相似文献   

Landscape cover type and pattern dynamics in fragmented southern Great Plains grasslands,USA   总被引：7，自引：1，他引：6  

Coppedge  Bryan R.  Engle  David M.  Fuhlendorf  Samuel D.  Masters  Ronald E.  Gregory  Mark S. 《Landscape Ecology》2001,16(8):677-690

We documented land cover and landscape pattern changes in an area of northwestern Oklahoma, USA using aerial photography from 1965, 1981, and 1995. This region of the southern Great Plains is fragmented by agricultural activity, and in recent years many remnant native grasslands have experienced extensive invasion by woody juniper (Juniperus virginiana L.). Concurrently, many cropland areas are being planted into perennial forage grasses and converted to intensively managed introduced grasslands as part of the U.S. Conservation Reserve Program (CRP). Our objectives were to document land cover and landscape pattern changes in the region relative to the expansion of juniper and CRP activity. We then examined how local landscape dominance by either anthropogenic or woody vegetation patches affected landscape pattern indices. Land cover changes from 1965 to 1995 included substantial increases in juniper woodlands and mixed woodlands that resulted from juniper encroachment into deciduous woodlands. Introduced grasslands also increased in many areas as a result of CRP implementation. Changes in landscape pattern generally reflected the influx of juniper into many areas. Landscapes dominated by woody vegetation had significantly more patches, smaller patches and patch core areas, more total edge, and higher patch diversity than landscapes dominated by anthropogenic cover types. Results indicate that expanding juniper is exacerbating the fragmentation process initiated by previous human activity, and represents a serious threat to the continued integrity and conservation of remaining southern Great Plains grasslands.This revised version was published online in May 2005 with corrections to the Cover Date.  相似文献   

A型流感病毒在野禽中的全球分布(续完)     

Bj 《国外畜牧学(猪与禽)》2007,27(3):57-60

3海鸥和燕鸥中的流感病毒1961年,首次报道从燕鸥(sterna hirundo)中分离到流感病毒。该高致病性禽流感H5N3亚型病毒引起了南部非洲禽流感的爆发,并至少造成1300只  相似文献   

Infection with Porcine reproductive and respiratory syndrome virus stimulates an early gamma interferon response in the serum of pigs          下载免费PDF全文

Ronald D. Wesley  Kelly M. Lager    Marcus E. Kehrli  Jr. 《Canadian journal of veterinary research》2006,70(3):176-182

The early release of cytokines by cells involved in innate immunity is an important host response to intracellular pathogens. Gamma interferon (IFN-gamma) is an important cytokine produced during the early stages of an infection by macrophages, natural killer (NK) cells, and other cell types, and it is also a central cytokine mediator for the induction of cellular or Th1 immunity. To better understand innate and adaptive immune responses after infection with Porcine reproductive and respiratory syndrome virus (PRRSV), we investigated serum IFN-gamma concentrations and the duration of viremia. For 2 strains of atypical PRRSV, IFN-gamma was detectable in swine serum soon after infection and lasted for approximately 3 wk. Serum concentrations of IFN-gamma peaked at about 10 d after inoculation and returned to approximately baseline levels by day 22. However, individual pigs manifested short, sporadic increases in the serum concentration of IFN-gamma from 18 to 50 d after inoculation. Prior vaccination blocked the serum IFN-gamma response associated with homologous virus challenge and altered the kinetics of the response after heterologous challenge. Two other respiratory viruses of pigs, Porcine respiratory coronavirus and Swine influenza virus, do not appear to induce serum IFN-gamma. The early production of IFN-gamma in PRRSV-infected pigs might result from activation of NK cells, a response that is more characteristic of immune pathways stimulated by intracellular bacterial and protozoan infections.  相似文献   

Neospora caninum in persistently infected, pregnant cows: spontaneous transplacental infection is associated with an acute increase in maternal antibody.     

C S Guy  D F Williams DJLKelly  J W McGarry  F Guy  C Bj?rkman  R F Smith  A J Trees 《The Veterinary record》2001,149(15):443-449

Nine cows which were naturally and persistently infected with Neospora caninum were housed and observed intensively throughout pregnancy. No recrudescence of a latent infection was detected by PCR tests on maternal blood but fetal infection, implying a recrudescence of maternal parasitosis, was associated with a marked increase in maternal antibody. The increase occurred in the second half of pregnancy in five cows which infected their calves, and before mid-pregnancy in one cow which aborted. There was no change in the avidity of the antibody, which remained high and characteristic of long-term infection. In three infected cows that gave birth to uninfected calves there was no marked increase in maternal antibody. Antigen-specific interferon gamma responses of peripheral blood mononuclear cells were observed in all the infected cattle but they did not vary significantly either during pregnancy, or whether the cows did or did not infect their calves, although the responses were consistently higher in the latter. There was no change in the plasma concentrations of cortisol or acute phase proteins associated with the recrudescence of the parasite. Three uninfected cows housed with the infected cows remained uninfected throughout the experiment. No immunosuppressive event was detected which might have provoked parasite recrudescence but the acute antibody rise associated with transplacental infection provides a valuable, non-invasive marker for further studies to investigate the cause and consequences of parasite recrudescence in N caninum infection in cattle.  相似文献   

Determination of the oxidative burst chemiluminescent response of avian and murine-derived macrophages versus corresponding cell lines in relation to stimulation with Salmonella serotypes     

Mark Chadfield  John Olsen 《Veterinary immunology and immunopathology》2001,80(3-4)

In contrast to mammalian systems, avian species lack a resident or harvestable macrophage population in the abdominal exudate. Peritoneal macrophages in the chicken can be elicited if an inflammatory agent such as sephadex is injected. This study examines the kinetics of different macrophage populations, derived by different methods of isolation and from different hosts, with respect to the elicited oxidative burst upon infection with host-adapted Salmonella serotypes.The nature of the oxidative burst elicited by murine and avian-derived and cell line macrophages was determined after stimulation with phorbol myristate (PMA), zymosan A, and Salmonella serotypes. Both murine and chicken peritoneal macrophages, chicken blood monocytes and corresponding cell lines, J774A.1 and HD-11, were unable to produce a detectable chemiluminescent (CL) response after interaction with Salmonella using the luminescent probe luminol. However, both PMA and zymosan A induced a CL response in all cell types, with PMA eliciting a higher and earlier peak response (pkH) than zymosan A. Lucigenin-enhanced CL in both murine and chicken macrophages was achieved with PMA, zymosan A and Salmonella serotypes. In this case, zymosan A induced higher responses than PMA. In the peritoneal macrophages of both hosts, there were no significant differences in the oxidative burst induced by the different Salmonella serotypes. However, the J774A.1 (murine) cells demonstrated significant differences, with S. enterica serotype Choleraesuis (S. choleraesuis and S. gallinarum producing the highest response. In the HD-11 (chicken) cells, S. choleraesuis and S. dublin elicited the higher CL. With both cell lines, S. abortusovis failed to induce an appreciable CL response.In these experiments it was demonstrated that oxidative burst was not detectable in monocytes/macrophage populations using luminol, which suggests a link to the lack of a myeloperoxidase system in these cells. Lucigenin-enhanced CL appeared independent from the myeloperoxidase system, indicating production of another oxidative species compared with luminol. No discernable effect of host specificity with regard to Salmonella serotype and respective host was seen in host-derived or cell line macrophages, and cell line macrophages displayed altered functional characteristics with regard to oxidative burst in comparison with their primary counterparts.  相似文献