Field fertility of sex-sorted and non-sorted frozen-thawed stallion spermatozoa

In the 2004/2005 breeding season, the fertility of sex-sorted (SS) and non-sorted (NS) frozen stallion spermatozoa from two Hannovarian stallions was compared. A hysteroscopic insemination technique [Morris, L.H., Tiplady, C., Allen, W.R., 2003a. Pregnancy rates in mares after a single fixed time hysteroscopic insemination of low numbers of frozen-thawed spermatozoa onto the uterotubal junction. Equine Vet. J. 35, 197-201] was used to deposit low doses (6, 13 or 25 x 10(6) frozen-thawed SS or NS spermatozoa) onto the utero-tubal junction at 32 or 38 h after the administration of Chorulon (2500 IU, Intervet). Fertility was low, with one pregnancy (13 x 10(6) Spermatozoa, 500 mu L) obtained after artificial insemination with frozen SS spermatozoa (n=29 cycles) which resulted in the birth of a filly. Two pregnancies were obtained in mares inseminated with 6 x 10(6) NS spermatozoa in 250 mu L (n= 31 cycles). Mares failing to conceive on two experimental cycles were allocated to the conventional insemination group. Insemination with >500 x 10(6) motile NS frozen-thawed spermatozoa, yielded satisfactory per cycle conception rates (35.5%, 22/62) for both stallions combined and was within the values of their normal fertility as quoted by the stud's records. This suggests that the quality of the frozen semen was acceptable and that the freezing processes yielded viable spermatozoa capable of fertilisation. The poor fertility after hysteroscopic insemination with low doses of sex-sorted or non-sorted spermatozoa from the same stallions may be directly attributable to the low dose insemination conditions with frozen-thawed rather than sex-sorted spermatozoa. (C) 2007 Elsevier B.V. All rights reserved

A guide to using species trait data in conservation

Species traits have much to offer conservation science. However, the selection and application of trait data in conservation requires rigor to avoid perverse or unexpected outcomes. To guide trait use, we review how traits are applied along the conservation continuum: the progression of conservation actions from assessing risk, to designing and prioritizing actions, to implementation and evaluation. We then provide a framework for their use as proxies for more nuanced empirical data on species and ecosystems. Framework steps include identifying information needs relative to conservation goals, choosing relevant traits using theory and expanding via expert elicitation, and defining and addressing the limits of trait information. Worked examples for contemporary plant and amphibian conservation show how traits should be selected and applied based on theory and/or evidence (rather than data availability or untested assumptions). Finally, we forecast the use of trait data in several conservation applications globally