K. Betteridge

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Tetrapod limb development has been studied extensively for decades, yet the strength and role of developmental constraints in this process remains unresolved. Mammals exhibit a particularly wide array of limb morphologies associated with various locomotion modes and behaviors, providing a useful system for identifying periods of developmental constraint and(More)
A co-culture system using a suspension of detached bovine oviducal epithelial cells (BOEC) has been developed as an effective culture method for supporting the development of bovine embryos derived from oocytes matured and fertilized in vitro. Four commercially available culture media (Waymouth's, Ham's F-10, TCM 199 and Ménézo's B2) supplemented with 10%(More)
The development rate of bovine chimeric embryos reconstituted at the 4-cell stage is relatively low. If chimerism is to be used as an approach in producing transgenic livestock, it is important to investigate whether this rate is affected by the sex of the blastomeres being combined and if all blastomeres survive equally well. In Experiment 1, blastomeres(More)
Confusion exists as to whether the oocytes of the domestic horse are ovulated at the first meiotic metaphase (MI) or the second (MII). In this study eight oocytes were collected from the preovulatory follicles of 16 mares 36 h after human chorionic gonadotropin CG treatment. Six of the eight oocytes were judged to be at MII by the presence of the first(More)
New Zealand dairy farmers are facing increasing pressure to reduce nutrient losses from grazing ruminants to the environment. Research suggests that the major source of nutrient loss is animal excreta which, for nitrogen (N), relates to cattle urine in particular. Most models used to describe N cycling and predict loss assume homogeneous distribution of(More)
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