An outbreak of avian malaria in captive yellowheads/mohua (Mohoua ochrocephala)

CASE HISTORY: Eight mohua, or yellowheads (Mohoua ochrocephala), were held in a large open aviary over the summer months of 2003–2004, following their capture for captivebreeding purposes. Two birds died of transportation trauma shortly after arrival, one became ill and died a month later, and another four died within a 2-week period in February 2004. The eighth bird also became ill at this time but survived for a year following treatment with chloroquine and doxycycline.

CLINICAL AND PATHOLOGICAL FINDINGS: The affected birds were depressed, lethargic and dyspnoeic. Necropsy of three birds showed a slightly pale and swollen liver and spleen. Impression smears of the liver of one bird revealed schizonts resembling Plasmodium spp. within the cytoplasm of many hepatocytes, which was confirmed histopathologically. Similar protozoal organisms were seen within splenic histiocytes and pulmonary endothelial cells of 5/6 birds. Electron microscopy identified these as protozoal schizonts containing merozoites of similar size and structure to those of Plasmodium spp.

DIAGNOSIS: The birds were infected with a protozoal haemoparasite resembling Plasmodium spp.; asexual stages within hepatocytes and endothelial cells of the lung and spleen were typical of this organism.

CONCLUSIONS AND CLINICAL RELEVANCE: The mohua captured from west Otago were highly susceptible to avian malaria as they came from an isolated population that was likely to be naïve and have had no previous contact with this organism. The birds were probably infected by bites from mosquitoes feeding off local populations of blackbirds subsequently found to be infected with Plasmodium spp.     

Systemic protozoal disease in hihi and saddlebacks

Extract

Juvenile hihi or stitchbirds (Notiomystis cincta) and saddlebacks (Philestumus carunculatus) are particularly prone to systemic protozoal infections when kept in high density populations. Granu-lomatous lesions in the intestine, liver and spleen are associated with proliferating intracellular schizonts. Affected birds become anorexic and lose weight or die suddenly without clinical signs. The protozoan in hihi appears most likely to be Atoxoplasma spp whereas that in saddlebacks is more like Plasmodium spp.     

Abomasal parasite syndrome in North American elk (Cervus elaphus canadensis)

CASE HISTORY An 18-month clinical course of chronic ill-thrift, weight loss and emaciation, and eventual death occurred in a group of 520 translocated elk of mixed age and sex. Trans-location was carried out without regard to animal welfare or health risks associated with the translocation. Mortality was approximately 84% (436/520) despite supportive nutritional and medical treatment.

PATHOLOGICAL FINDINGS: General clinical and post-mortem examinations indicated only Se and Cu imbalances and nutritional inadequacy. Additional purposeful post-mortem examination and histological evaluation of tissue sections from four of the affected adult elk demonstrated elevated abomasal pH and proliferative abomasal lesions as the most significant findings, consistent with Type-II ostertagiosis; intra-lesional nematodes were seen in the abomasum of two animals.

DIAGNOSIS: Fading elk syndrome, or abomasal parasite syndrome in elk.

CLINICAL RELEVANCE: Abomasal parasite syndrome initiated by Type-II ostertagiosis should be considered as a differential diagnosis in cases of ill-thrift and wasting in elk or elk-red deer hybrids. Changes to the architecture and secretory function of the abomasal wall lead to apparently irreversible digestive pathophysiology and nutritional disease.     

Improving the Reproductive Efficiency, Pregnancy Diagnosis and Monitoring the Resumption of Luteal Activity in Indigenous Damascus Goats

Seventy‐five female Damascus goats aged between 1.5 and 5.5 years were used to evaluate the effectiveness of the intravaginal sponges and prostaglandin analogue on oestrous synchronization and fecundity; to diagnose pregnancy and to monitor the resumption of the luteal activity. Females were divided randomly, during the breeding season, into three equal groups, S, P and C. Females in group S were fitted with sponges containing 45 mg of flugestone acetate (FGA) for 14 days and injected with pregnant mare serum gonadotrophin (PMSG) at the sponge withdrawal. Females in group P were given two injections of prostaglandin F2α analogue at 11‐day intervals, whereas females in group C (control) received no treatment. The results showed that there was a significant difference (p < 0.001) in oestrous exhibition between females in group S as compared with those in groups P and C, with means being 30 ± 10, 172 ± 115 and 217 ± 75 h for groups S, P and C, respectively. Kidding rates resulting from the first and all matings were 80 and 88, 52 and 88, and 68 and 80% for groups S, P and C, respectively. Fecundity rates were 215, 175 and 180% for groups S, P and C, respectively, with a significant difference (p < 0.05) between the S and both P and C groups. Using an ultrasound pregnancy detector performed on days 57 ± 3 after mating, positive pregnancy diagnosis was 93.3% and 100% for non‐pregnancy. Females in the control group showed functional corpus luteum starting in September. It is concluded that FGA sponges plus PMSG treatment could be successfully used to synchronize oestrus and improve fecundity; whereas prostaglandin treatment was not effective to synchronize oestrus. It is also concluded that pregnancy can be diagnosed accurately and successfully using an ultrasound pregnancy detector. In addition, ovarian activity in the Damascus goat in Syria resumes in September.     

Antral Follicle Populations and Embryo Production – In Vitro and In Vivo – of Bos indicus–taurus Donors from Weaning to Yearling Ages

Interest in indicus–taurus cattle has been increasing, as these animals are likely to present the best characteristics of Zebu and European bovine breeds. The aim of this study was to compare the embryo production of indicus–taurus donors with high vs low antral follicle counts obtained by ovum pickup/in vitro production (OPU/IVP) and superovulation (SOV)/embryo collection. Braford females at weaning age (3/8 Nelore × 5/8 Hereford, n = 137, 9 ± 1 month old) were subjected to six serial ovarian ultrasonographs and were assigned to two groups according to the number of antral follicles ≥3 mm as follows: G‐High antral follicular count (AFC, n = 20, mean ≥40 follicles) and G‐Low AFC (n = 20, mean ≤10 follicles). When the females (n = 40) reached 24 months of age, they were subjected to both OPU/IVP and SOV/embryo collection. The average number of follicles remained highly stable throughout all of the ultrasound evaluations (range 0.90–0.92). The mean number of COCs recovered (36.90 ± 13.68 vs 5.80 ± 3.40) was higher (p < 0.05) for females with high AFC, resulting in higher (p < 0.05) numbers of total embryos among females with high vs low AFC (6.10 ± 4.51 vs 0.55 ± 0.83). The mean number of embryos per collection was also higher (p < 0.05) for G‐High vs G‐Low (6.95 ± 5.34 vs 1.9 ± 2.13). We conclude that a single ultrasound performed at pre‐pubertal ages to count antral follicles can be used as a predictor of embryo production following IVP and SOV/embryo collection in indicus–taurus females.     

Refrigerated Storage of Red Deer Epididymal Spermatozoa in the Epididymis, Diluted and with Vitamin C Supplementation

We have approached the problem of refrigerated storage of epididymal sperm samples from red deer by comparing three options: storing the genital (testicles within the scrotum), diluting the semen in extender or diluting the semen in extender supplemented with an anti-oxidant. Twenty-nine pairs of testes were collected. Spermatozoa from one of each of the pairs were immediately recovered, and diluted to 400 × 10⁶ sperm/ml in Tris-citrate-fructose with 20% egg yolk. Control group was stored as such, and Anti-oxidant group was supplemented with 0.8 m m vitamin C. The remaining epididymides and the diluted samples were stored at 5°C and spermatozoa were analysed at 0, 24, 96 and 192 h for: motility [computer-assisted semen analysis (CASA)], acrosomal integrity, sperm viability (eosine/nigrosine staining), normal tails and chromatin status [sperm chromatin structure assay (SCSA)]. In general, seminal quality decreased with storage time. Vitamin C supported progressive motility better at 24 h (median 42% vs 23% Control and 15% epididymis), reduced the incidence of tail abnormalities and protected chromatin. Storing the semen in the epididymis slowed down motility loss, but slightly increased the occurrence of tail abnormalities and viability was lower at 192 h. However, regarding chromatin status, sperm stored in the epididymis was protected similarly to those diluted in the medium supplemented with vitamin C. Although the differences between the three groups were small, there were some advantages in supplementing the extender with vitamin C. Besides, refrigerating the epididymis may be a good option when immediate processing is not available.     

Antioxidant properties of peel and pulp hydro extract in ten Persian pomegranate cultivars

This study compares the antioxidant activity of ten different pomegranate cultivars grown in Iran using the ferric reducing power assay (FRAP assay), which is based on the reduction of a ferric-tripyridyl triazine complex to its ferrous, colored form in the presence of antioxidants. Aqueous solutions of known Fe(+2) concentration, in the range of 100-1000 micromol L(-1) were used for calibration. The results showed that among pulp and peel fractions the sour alac and sweet white peel cultivars had more FRAP value respectively. The pomegranate peel extract had markedly higher antioxidant capacity than the pulp extract. The peel extract of sweet white peel cultivar appeared to have more potential as a health supplement rich in natural antioxidants compared to the pulp and peel extracts of other pomegranate cultivars.     

Twinning and embryonic mortality in a free-living kaka (Nestor meridionalis)

Abstract

Compared to mammals, twinning in birds is rare. The reported incidence in domestic chickens (Gallus gallus) is 0.11 % (Byerly and Olsen 1934 Byerly, TC and Olsen, MW. 1934. Polyembryology in the domestic fowl. Science, 80: 247–248.  [Google Scholar]) and in pigeons (Columba livia) only 0.07% (Riddle 1923 Riddle, O. 1923. The causes of twinning and abnormal development in birds. American Journal of Anatomy, 32: 199–252.  [Google Scholar]). Monozygotic twins occur following the fission of an early embryo and may or may not share the same yolk. Dizygotic twins are thought to occur following 2 simultaneous ovulations or perhaps by the slow passage of an ovum down the oviduct, resulting in it being caught by a succeeding yolk and then being incorporated into the same membrane and shell (Harrison 1986 Harrison, GJ. 1986. “Reproductive Medicine”. In Clinical Avian Medicine and Surgery, Edited by: Harrison, GJ and Harrison, LR. 620–633. Philadelphia: WB Saunders.  [Google Scholar]). Regardless of their origin most avian twins do not survive beyond hatching.     

Magnetic microstructure of magnetotactic bacteria by electron holography

Off-axis electron holography in the transmission electron microscope was used to correlate the physical and magnetic microstructure of magnetite nanocrystals in magnetotactic bacteria. The magnetite crystals were all single magnetic domains, and the magnetization directions of small superparamagnetic crystals were constrained by magnetic interactions with larger crystals in the chains. Shape anisotropy was found to dominate magnetocrystalline anisotropy in elongated crystals. A coercive field between 300 and 450 oersted was determined for one chain.