Surgical results and fertility following correction of vesicovaginal reflux in mares

Objective To evaluate the surgical results and fertility of mares bred at various intervals relative to surgical management of urovagina. Design Sixty-one mares underwent surgery to correct vesicovaginal reflux. Surgery was performed at varying times relative to breeding and postoperative fertility was evaluated. Results Five mares were lost to follow-up and a further four were electively not bred. Of the remaining 52 mares, seasonal pregnancy and live foaling rates were 67% (35/52) and 54% (26/48), respectively. When mares were bred in the same cycle as the surgery, the first cycle following surgery, the second cycle following surgery or the following breeding season after surgery the seasonal pregnancy rates were 89% (8/9), 63% (10/16), 67% (2/3) and 63% (15/24), respectively. After censoring four mares that died of natural causes pre-foaling, the foaling rates were 88% (7/8), 50% (7/14), 0% (0/3), 52% (12/23), respectively. All mares bred in the same cycle as surgery or in the next cycle were bred once only that season, so the pregnancy rate per cycle of 72% (18/25) was identical to the seasonal pregnancy rate. Conclusions Good fertility (comparable to a normal population of mares) was achieved following surgery and the results suggest that delaying breeding until the following breeding season is not necessary. In addition, breeding in the same cycle as surgical repair is a previously unreported technique that should be considered to maintain a yearly foaling interval.     

Detection of Mycobacterium avium subsp. paratuberculosis in skeletal muscle and blood of ewes from a sheep farm in New Zealand

Abstract

AIM: To determine whether viable Mycobacterium avium subsp. paratuberculosis (Map) is present in skeletal muscle and blood in ewes with and without Johne's disease confirmed histologically.

METHODS: A total of 51 mixed-aged ewes in poor body condition from a farm with a history of clinical Johne's disease were culled and examined at necropsy. BACTEC radiometric culture was performed on samples of skeletal muscle from the biceps femoris, mononuclear cells in peripheral blood (hereafter referred to as blood), and ileum. Histological sections and Ziehl-Neelsen (ZN)-stained impression smears of terminal ileum and mesenteric lymph nodes were examined. Ewes were defined as having confirmed Johne's disease if there was histopathological evidence typical of the disease within the ileum and adjacent lymph nodes.

RESULTS: Eighteen of 21 (86%) ewes with confirmed clinical Johne's disease were culture-positive for Map from sites peripheral to the alimentary tract, comprising 15 from skeletal muscle and 13 from blood. Five of 30 (17%) ewes that did not have Johne's disease were culture-positive, with four from skeletal muscle and one from blood. The likelihood that ewes with confirmed Johne's disease had systemic Map infection compared with ewes without was determined as OR=30 (95% CI=6.3–142.0; p<0.001).

CONCLUSION: The prevalence of Map infection of skeletal muscle and blood in ewes with confirmed Johne's disease was 71% and 62% respectively, and in unaffected ewes was 13% for muscle and 3% for blood.

CLINICAL RELEVANCE: Skeletal muscle and blood are potential sources of exposure of humans to Map, and the risk appears higher from sheep with Johne's disease.     

Incidence of ryegrass staggers in white rhinoceros (Ceratotherium simum) at Auckland Zoo

Abstract

Extract

Most perennial ryegrass (Lolium perenne) plants in pastures in New Zealand contain a naturally occurring fungal endophyte, Neotyphodium lolii. Endophyte-infected perennial ryegrass produces alkaloids that vary in concentration during the year. Some alkaloids enhance the persistence and productivity of ryegrass pastures by protecting them against insect attack. However, when other alkaloids are consumed they can reduce animal performance and lead to health problems. The alkaloid lolitrem B, for example, causes the neuromuscular disorder ryegrass staggers (Fletcher et al 1999 Fletcher, LR, Sutherland, BL and Fletcher, CG. 1999. “The impact of endophyte on the health and productivity of sheep grazing ryegrass-based pastures”. In Ryegrass endophyte: an essential New Zealand symbiosis Grassland Research and Practice Series Edited by: Woodfield, DR and Matthew, C. Vol. 7, 11–17.  [Google Scholar]). Clinical symptoms of ryegrass staggers in animals range from slight muscular tremors through to staggering and complete collapse. Severely affected animals create management problems and are prone to accidental death. Outbreaks occur sporadically, particularly in summer and autumn and affect sheep, cattle, deer, horses, llamas (Lama glama) and alpaca (Lama pacos). Lolitrem B appears to be a stable compound, which tends to be concentrated in the leaf sheath at the base of the ryegrass plant and in the seed-heads (di Menna et al 1992 di Menna, ME, Mortimer, PH, Prestidge, RA, Hawkes, AD and Sprosen, JM. 1992. Lolitrem B concentrations, counts of Acremo ni um lolii hyphae, and the incidence of ryegrass staggers in lambs on plots of A. lolii-infected perennial ryegrass. New Zealand Journal of Agricultural Research, 35: 211–217. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]; Keogh et al 1996 Keogh, RG, Tapper, BA and Fletcher, RH. 1996. Distributions of the fungal endophyte Acremonium lolii, and of the alkaloids lolitrem B and peramine, within perennial ryegrass. New Zealand Journal of Agricultural Research, 39: 121–127. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]). Hay made from endophyte-infected perennial ryegrass contains large numbers of seed-heads and lolitrem B concentrations can be high, especially if it is made in late summer or autumn and, consequently, animals fed such hay are at risk of developing ryegrass staggers.     

Epidemiology. DNA identifications after the 9/11 World Trade Center attack

The attack on the World Trade Center on 9/11/2001 challenged current approaches to forensic DNA typing methods. The large number of victims and the extreme thermal and physical conditions of the site necessitated special approaches to the DNA-based identification. Because of these and many additional challenges, new procedures were created or modified from routine forensic protocols. This effort facilitated the identification of 1594 of the 2749 victims. In this Policy Forum, the authors, who were were members of the World Trade Center Kinship and Data Analysis Panel, review the lessons of the attack response from the perspective of DNA forensic identification and suggest policies and procedures for future mass disasters or large-scale terrorist attacks.     

The immunogenicity of K99 antigen in whole cell bacterins of Escherichia coli.

K99 antigen in Escherichia coli whole cell bacterins was immunogenic in rabbits and mice. Mice vaccinated subcutaneously and bled three weeks later had a serum antibody response which was dose dependent. The dose response on dilution of bacterins was shown to be mainly due to dilution of K99 antigen, rather than the reduction in adjuvant or bacterial cell concentration. The procedure appears to be a satisfactory one for immunogenicity testing of bacterins containing K99 antigen.