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The anatomy of the sheep cervix is highly variable between animals and may explain the differing success of transcervical AI between individuals. This study aims to quantify the variation in cervical morphology between ewes and investigate the relationship between cervical anatomy and cervical penetration. Two series of reproductive tracts were collected.(More)
Transcervical artificial insemination in sheep is limited by the inability to completely penetrate the cervix with an inseminating pipette. Penetration is partially enhanced at estrus due to a degree of cervical relaxation, which is probably regulated by cervical prostaglandin synthesis and extracellular matrix remodeling. Prostaglandin E(2) acts via(More)
A pathogen which has been shown to commonly contaminate in vitro bovine embryo production system is bovine pestivirus (bovine viral diarrhea virus). Three experiments were designed to evaluate the in vitro maturation (experiment I), fertilization (experiment II) and embryo development (experiment III) of immature oocytes, inseminated oocytes and presumptive(More)
On 10 northern Australian properties, the number of calves sired (calf output) by individual bulls in multiple-sire matings was measured by DNA typing for paternity. There were 235 bulls (92 Santa Gertrudis, 25 5/8 Brahman and 119 Brahman) from 37 multiple-sire mating groups. Number of bulls in groups ranged from 2 to 25 and ages of bulls ranged from 2 to 5(More)
The FASTPlaqueTB assay is an established diagnostic aid for the rapid detection of Mycobacterium tuberculosis from human sputum samples. Using the FASTPlaqueTB assay reagents, viable Mycobacterium avium subsp. paratuberculosis cells were detected as phage plaques in just 24 h. The bacteriophage used does not infect M. avium subsp. paratuberculosis alone, so(More)
Although transplacental virus infections account for considerable morbidity and mortality in both animals and humans, very little is so far known about the pathways whereby virus reaches the conceptus, the subsequent virus-host interactions in the early phases of the infections, and the establishment of persistent non-lethal infection. Using a natural(More)
Bovine pestivirus infection has been mainly recognized as the cause of mucosal disease, a syndrome which occurs sporadically in weaned and adult cattle as a late sequel to foetal infection during the first 3-4 months of gestation. Infection has also been associated with the occurrence of congenital malformations, especially of the central nervous system.(More)
The objective was to investigate the ovarian response of Brahman heifers to two modified ovulation synchronisation protocols developed to increase the proportion of normal synchronous ovulations. Experiment 1 characterised the growth of the ovulatory follicle in heifers (n=19) treated with an intravaginal progesterone releasing device (IPRD) and oestradiol(More)
This study compared pregnancy rates (PRs) and costs per calf born after fixed-time artificial insemination (FTAI) or AI after estrus detection (i.e., estrus detection and AI, EDAI), before and after a single PGF2α treatment in Bos indicus (Brahman-cross) heifers. On Day 0, the body weight, body condition score, and presence of a CL (46% of heifers) were(More)
This study investigated the epidemiology of Neospora caninum in three tropical dairy herds in North Queensland, Australia. All animals in the herds were bled, and the sera were tested by ELISA for N. caninum antibodies. Herd records were examined, and the number of calves carried to term and the number of abortions which occurred over the lifetime of each(More)