student profile: Miss Alicia Steel


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Thesis work

Thesis title: Improving the early selection of replacement gilts: Assessment of ovarian hormones from 60 to 100 days of age

Supervisors: Christopher GRUPEN

Thesis abstract:

A major inefficiency of the pig industry is the low retention rate of sows to parity three. In Australia it is estimated that as many as 27% of gilts selected as sow replacements are culled before their first parity and up to 50% of selected gilts are culled before their third. This represents an enormous reproductive wastage and major economic loss to producers when one considers the costs associated with maintaining unproductive animals from slaughter age (about day 150) to their first mating (about day 220). Currently, the selection of gilts as sow replacements is quite rudimentary. The only information considered as an indicator for a gilt's reproductive potential is body condition and conformation, teat number and the history performance of her dam. Therefore, producers require an early predictor of an individual gilt's reproductive performance.

Evidence suggests that ovarian hormones oestradiol (E2) and anti-mullerian hormone (AMH) may be useful markers of reproductive potential in gilts. Serum E2 levels can be measured to readily determine when gilt ovaries become responsive to gonadotropins (from 60 days of age). Serum AMH has been shown to be predictive of ovarian reserve and antral follicle populations in other species such as humans, mice, cattle and sheep. Furthermore, AMH hormone has also been correlated with fertility at first mating in ewes.

The aim of this project is to determine whether a simple blood test quantifying serum AMH and E2 levels can be useful markers of future reproductive performance of juvenile gilts aged between 60 and 100 days. Serum hormone levels will be compared with parameters of ovarian development, pregnancy rates at first mating and reproductive performance to the third parity.

Selected grants

2014

  • Improving the early selection of replacement gilts: assessment of ovarian hormones from 60 to 100 days of age; Steel A, Grupen C, Athorn R, Johnston R; Australian Pork Limited/Project Support.

Note: This profile is for a student at the University of Sydney. Views presented here are not necessarily those of the University.