OvuGel^® is a novel, intravaginal gel which has proven to stimulate the release of luteinising hormone (LH) in weaned sows, leading to ovulation within 48 hours. This controlled and timed response allows the development of a structured, reliable artificial insemination programme which results in normal fertility.

^{OvuGel® uses a needle-free administration system that reduces the risk of accidental injury to animals or applicator. Anyone proficient in AI techniques can easily be trained to administer OvuGel® effectively. Image: OvuGel}

Researchers in the US set out to better understand the mechanism and efficacy of the hormone-stimulating gel in a research trial investigating the dosage of the gel required to synchronise ovulation, and the optimum time at which to administer it.

Highlights from the trial

OvuGel® was developed to deliver the GnRH agonist triptorelin as an intravaginal gel.

OvuGel use in weaned sows, has been effective for synchronising ovulation.

OvuGel use with a single fixed time AI results in similar fertility to control sows mated multiple times based on oestrus.

The lowest dose of triptorelin that induced the most gilts to show an LH surge was 100 μg in 1.2% methylcellulose gel.

Administration at 96 h induced more sows to ovulate (58%) by 48 h compared to treatment at oestrus (45%) or for controls (34%), but the desired level of ovulation synchrony was not achieved. The best synchrony of ovulation occurred when given at 96 h after weaning compared to earlier or later intervals.

Greater doses of triptorelin were tested, and 200 μg given at 96 h after weaning induced 81% of sows to ovulate within 48 h after treatment.

Concluding remarks

A SFT-AI at 22 ± 2 h after OvuGel achieved the highest fertility and was practical for staff during the normal work day. In field trials, a SFT-AI 22 ± 2 h after all weaned sows were treated with OvuGel improved (P = 0.04) farrowing rate to 82.5% compared to control sows weaned (80.1%), with no effect on numbers of pigs born alive (12.1).

Researchers will continue to investigate the potential advantages for using OvuGel in swine reproduction systems, including its use in gilts.

^{R.V. Knox, K.R. Stewart, W.L. Flowers, M.E. Swanson, S.K. Webel, R.R. Kraeling (2018). Design and biological effects of a vaginally administered gel containing the GnRH agonist, triptorelin, for synchronizing ovulation in swine. Theriogenology, 112:44-52}

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