Indigofera spicata (creeping indigo) poisoning of three ponies

Three ponies continuously grazed a pasture containing an estimated 24% Indigofera spicata (wet weight basis) for 4–6 weeks in April and May 2004. They developed ataxia, paresis, depression, muscle fasciculations, dysphagia, ptyalism and halitosis. Two also developed corneal opacity. One pony recovered with supportive treatment, but the other two were euthanased and necropsied. Neuropathology was not present in either case, but both livers had periacinar and periportal lymphocytic infiltrations and hydropic degeneration of mid‐zonal hepatocytes, with mild to moderate periacinar necrosis also evident in one. The I. spicata contained 2.66 mg 3‐nitropropionic acid (3‐NPA)/g dry matter and 1.5 mg indospicine/g dry matter. Indospicine, but not 3‐NPA, was detected in serum from both of the euthanased ponies and indospicine was detected in heart, liver and muscle from the one pony in which this assay was performed. The clinical syndrome closely resembled ‘Birdsville horse disease’ caused by I. linnaei and was similar to that reported in horses poisoned by the closely related species I. hendecaphylla and to 3‐NPA poisoning of other animals, including humans. 3‐NPA is thought to cause this neurological syndrome. To our knowledge, this is the first authenticated report of I. spicata poisoning in grazing animals. We also report here the first published evidence that 3‐NPA and indospicine exist in naturalised I. spicata in Australia and of the formation of indospicine residues in tissues of animals grazing paddocks infested with I. spicata.     

Meningoencephalitis and other conditions associated with Histophilus ovis infection in sheep

Histophilus ovis was isolated from 29 sheep in 20 flocks and 2 artificial insemination (AI) centres in southern New South Wales from 1984 to 1990. The clinical and pathological findings were consistent with previous reports and included polyarthritis (7 flocks), epididymo-orchitis (5), meningoencephalitis (3), pneumonia (3), septicaemia (2), mastitis (1) and metritis (1). Six sheep had meningoencephalitis, a syndrome not previously associated with H ovis infection in sheep, which was similar pathologically to thromboembolic meningoencephalitis in cattle, caused by the related organism, Haemophilus somnus. H ovis was isolated from the semen of 12-month-old rams in a flock that had polyarthritis due to H ovis, in 4-month-old ram lambs and from the uterus of a ewe in a flock that had sporadic cases of H ovis septicaemia.     

Rearing performance of farmed fallow deer (Dania dama)

The ability of fallow does to rear fawns to weaning age was examined in a group of 243 adult does of known age (Group 1) and 509 adult does of unknown age (Group 2). All does had between 1 and 8 opportunities to rear fawns. There was an increasing proportion of does that failed to rear a fawn to weaning age as the number of rearing opportunities increased, although most does (93.6%) only failed on one occasion. A small percentage of does in groups 1 and 2 failed repeatedly to rear fawns to weaning. At slaughter, the presumed causes of failure in chronic non-breeders included pyometron, cystic ovaries, cervical cysts, a vulval neoplasm and salpingitis. The overall rearing success of both groups of deer was 82.4% and there was no consistent pattern of rearing failure relating to parity or previous rearing history.     

Effects of Exogenous Insulin on Luteolysis and Reproductive Cyclicity in the Mare

Insulin is a pancreatic hormone that classically regulates carbohydrate and fat metabolism, but also appears to play a role in various reproductive processes. A preliminary study suggested insulin production by day 10 to 18 equine conceptuses. The aim of the present study was to examine the hypothesis that insulin is the conceptus signal responsible for maternal recognition of pregnancy (MRP) in the mare, or otherwise influences reproductive cyclicity during the MRP period. Six Warmblood mares were treated daily during days 7 to 17 after ovulation of two successive oestrous cycles with either (short and intermediate acting) insulin or control saline. Mares were assigned randomly to treatment, and crossed over during the subsequent cycle. Time of ovulation and corpus luteum surface area were determined by serial transrectal ultrasonographic examination of the mares' ovaries, and daily jugular vein blood samples were analysed for progesterone and luteinizing hormone (LH) concentrations. On day 14 of dioestrus, the luteolytic drive was examined by measuring systemic 15-ketodihydroprostaglandin F_{2 α} (PG-metabolite) release in response to oxytocin challenge. In addition, yolk sac fluid recovered from 32 day 10 to 14 equine conceptuses was analysed for insulin concentrations. Insulin administration did not affect luteal size, dioestrus length, the interovulatory interval, or circulating LH concentrations. Insulin administration also failed to suppress oxytocin-induced PGF_{2 α} release, and tended to depress systemic progesterone concentrations. Finally, insulin could not be detected in the yolk sac fluid of day 10 to 14 equine conceptuses by radio-immunoassay. It is concluded that insulin administered daily during days 7 to 17 of dioestrus has little or no effect on reproductive cyclicity in the mare, and is unlikely to be the MRP signal.     

Pulmonary alveolar microlithiasis in an alpaca (Vicugna pacos)

Pulmonary alveolar microlithiasis (PAM) is a rare, familial disease of unknown aetiology characterised by intra‐alveolar formation and accumulation of microliths. Multiple formalin‐fixed tissues were submitted from a 5‐month‐old female alpaca that died suddenly without significant clinical signs. No gross abnormalities were observed on postmortem examination. Histological findings included PAM and severe centrilobular hepatic necrosis. Although the hepatic lesion was the likely cause of death, PAM was an incidental finding that has not been reported previously in alpacas. An overview of PAM, including pathogenesis and histopathological characteristics, are discussed in relation to the concurrent hepatic disease in the present case.     

Sperm Pre-Incubation Prior to Insemination Affects the Sex Ratio of Bovine Embryos Produced in vitro

The objective of the present study was to determine whether sperm incubation prior to oocyte insemination in vitro affects the sex ratio of resulting blastocyst. Cumulus–oocyte‐complexes (COCs) collected from slaughterhouse ovaries were matured in vitro and inseminated with frozen‐thawed semen of three proven artificial insemination (AI) bulls pre‐incubated in vitro in Sperm‐Talp for 6 and 24 h. On day‐9 blastocysts were collected and processed for sex determination. More than 80% of blastocyst were successfully sexed. There were no significant differences in cleavage and blastocyst rates using sperm pre‐incubated for 6 h as compared with the 0‐h pre‐incubation control group. The cleavage and blastocyst rates were significantly lower in the 24‐h pre‐incubation group. The male to female ratio, when compared with the theoretical 1 : 1, differed significantly in favour of females among hatched (viable) blastocysts derived from sperm pre‐incubated for 24 h prior to insemination as well as among all blastocytsts in the 6‐h group. Moreover, when the sperm treatment was considered, the sex ratio was affected only among hatched blastocysts in 24‐h pre‐incubation group. It was concluded that prolonged sperm pre‐incubation influences the rate of development and the sex ratio among hatched blastocysts.     

Alternative eucalypts for commercial pulpwood production at moderately dry sites in the warm temperate zone of KwaZulu-Natal,South Africa

During 2001, a series of four site–taxa interaction trials was established in the warm temperate (mean annual temperature range 16–19 °C) forestry climatic zone of KwaZulu-Natal (KZN), South Africa. The main objective was to investigate the commercial forestry potential of a range of alternative Eucalyptus and Corymbia taxa for moderately dry (mean annual precipitation < 850 mm) sites within the zone. At rotation end, all trials received final standing tree measurements. At one of the sites (Rockvale), trees of eight promising alternative taxa were felled, stem measurements and wood samples taken, and wood and fibre productivities determined. On the basis of tree growth and wood and fibre production, C. citriodora subsp. variegata, C. henryi, E. badjensis, E. benthamii and E. dorrigoensis (listed alphabetically) demonstrated the greatest potential as commercial alternatives for moderately dry sites in the KZN warm temperate zone. The majority of these taxa showed strong site specificity. Eucalyptus benthamii was the only taxon showing high growth adaptability to the entire range of site conditions applied in the series. The non-susceptibility of C. citriodora subsp. variegata and C. henryi to the current topical insect pests Thaumastocoris peregrinus, Leptocybe invasa and Glycaspis brimblecombei elevates the appeal of these taxa as potential alternative planting choices for moderately dry sites within lower altitude (<1 100 m asl) areas of the climate zone. The matching of the most promising alternative taxa in the series to the range of sites encountered in moderately dry areas of the KZN warm temperate forestry zone is discussed in this paper.