Production of Lambs After the Transfer of Fresh and Cryopreserved in vitro Produced Embryos from Prepubertal Lamb Oocytes and Unsorted and Sex-sorted Frozen-thawed Spermatozoa

Cumulus-oocyte complexes from hormone-stimulated 3-4-week-old (n=43) and 6-7-week-old (n=12) prepubertal lambs were matured in vitro and incubated with unsorted, or X- or Y-spermatozoa separated with a high-speed cell sorter (SX MoFlo)frozen-thawed. Presumptive zygotes were then cultured to the blastocyst stage, and transferred to recipients fresh or after cryopreservation (frozen). Oocyte cleavage was higher (p <0.05) with unsorted (515/926, 55.6%) than X- or Y-spermatozoa (261/672, 38.8% and 229/651, 35.2%, respectively) and blastocyst formation (% zygotes) by Day 9 of in vitro culture was lower (p <0.05) for X- (102/261, 39.1%) than unsorted spermatozoa (249/515, 48.3%), but did not differ between Y-spermatozoa (103/229, 45.0%) and unsorted spermatozoa, or between X- and Y-spermatozoa (p >0.05). For fresh embryos, survival to term was 50.0% (3/6) for unsorted, 0.0% (0/6) for X- and 16.7% (1/6) for Y-spermatozoa-derived embryos (p >0.05), and for frozen embryos was 4.0% (2/50) for unsorted, 9.1% (2/22) for X- and 2.9% (1/34) Y-spermatozoa-derived embryos (p >0.05). Of the two lambs born from X-spermatozoa-derived embryos, one was female (50%), and from the two Y-spermatozoa-derived lambs, both were male (100%), demonstrating that lambs can be produced after the transfer of fresh and cryopreserved IVP embryos derived from prepubertal lamb oocytes and frozen-thawed sex-sorted sperm.     

Efficacies of erythromycin and chloramphenicol in extinguishing fecal shedding of Campylobacter jejuni in dogs

Oral treatment regimens of erythromycin stearate and chloramphenicol were evaluated in naturally infected laboratory colony dogs for their efficacies in extinguishing fecal shedding of Campylobacter jejuni. Of the 25 Campylobacter-infected English Foxhounds in the study, 9 were assigned to erythromycin treatment, 9 to chloramphenicol treatment, and 7 to no treatment. Antimicrobials were administered for 12 days. All of the dogs that received erythromycin stearate ceased shedding C jejuni by the fourth day of treatment and remained negative throughout the treatment period. Chloramphenicol was associated with a reduction in shedding from 100% to 57% by the ninth day of treatment. Within 9 days of the discontinuation of antimicrobial treatment, C jejuni was isolated from all chloramphenicol-treated dogs and 89% erythromycin-treated dogs.     

Development and evaluation of a rapid absorbed enzyme immunoassay test for the diagnosis of Johne''s disease in cattle

An absorbed enzyme immunoassay (EIA) test for Johne's disease in cattle was developed in which absorption of cross-reacting antibodies occurred as a rapid reaction in solution rather than overnight with whole organisms and a subsequent centrifugation step. Total test time was reduced to less than 2 h with a minimum of manipulations. The test was evaluated in cattle herds from Johne's disease-endemic and Johne's disease-free regions of Australia. Specificity was 99.8%. Calculations of sensitivity were affected by the history of the herd under test. However, the EIA detected in excess of 80% of animals before onset of clinical disease and 65% of faecal shedders were EIA positive on, or before, first detection of Mycobacterium paratuberculosis in their faeces. The test should aid epidemiological studies and be a useful tool in the management and control of Johne's disease.     

Paramyxovirus and reovirus infections in wild-caught Mexican lizards (Xenosaurus and Abronia spp.).

Virus isolation attempts were carried out on wild-caught Xenosaurus grandis, X. platyceps, and Abronia graminea from Mexico. These animals were also tested for exposure to paramyxoviruses and reoviruses. Pharyngeal and cloacal swabs were collected from 30 lizards, and blood was collected from 23 lizards. A cytopathogenic virus was isolated from the cloacal swab of one of the X. platyceps. The isolate was identified as a paramyxovirus on the basis of its sensitivity to chloroform, resistance to 5-iodo-2'-deoxyuridine, size and morphology of the viral particles, hemagglutination of chicken erythrocytes, and serologic reaction with paramyxovirus-specific antisera. Antibodies against the paramyxovirus isolated in this study were found in four animals from three species. Antibodies against a different paramyxovirus isolated from a monitor lizard were found in seven animals from three species, showing that all the species tested are susceptible to paramyxovirus infections. Antibodies to a reptilian reovirus were found in three of the X. grandis.     

Dose related effects of the kappa agonist U-50, 488H on behaviour, nociception and autonomic response in the horse

Current opiate receptor theory suggests that kappa agonists should provide good analgesia without producing marked central nervous system stimulation. U-50,488H is an experimental narcotic analgesic that is a selective kappa agonist. In the present study, U-50,488H produced good analgesia in horses using both the skin twitch and hoof withdrawal reflex assays. Further, the analgesia was relatively long lasting (120 mins) compared to other mu-agonists tested in horses. The locomotor response to U-50,488H was less than observed with ethylketazocine and butorphanol, and has yielded the smallest locomotor response of any of the narcotic analgesics tested to date. Other work showed that the autonomic responses to U-50,488H were less than those of other narcotic analgesics, and that the analgesic response to this drug was blocked by naloxone. Based on its ability to produce analgesia with little other stimulatory action, U-50,488H shows promise of becoming a useful narcotic analgesic in equine medicine.     

Investigations of an enteric infection of cockatoos caused by an enterovirus-like agent

An enteric infection in cockatoos associated with a 30 nm diameter enterovirus-like agent seen in faeces and intestinal epithelial cells is described. The disease is characterised by intractable, profuse, mucoid diarrhoea, weight loss, dehydration and death. Lesions in the intestine consist of villous atrophy, villous fusion, enterocyte hyperplasia and, in some cases, chronic inflammation. Affected birds so far examined have concurrent psittacine beak and feather disease.