Before puberty, gilts experience a pre-puberty period during which boar exposure could induce and synchronize the first ovulation. To develop practical non-invasive tools to identify this period and improve detection of the gilts to stimulate, we searched for salivary biomarkers of the pre-puberty period. Saliva samples were collected from 30 Large-White x Landrace crossbred gilts from 140 to 175 days of age. Gilts were exposed to a boar twice a day and subjected to oestrus detection from 150 to 175 days of age. They were then slaughtered to ascertain puberty.
Among the 30 gilts, 10 were detected in oestrus 4 to 7 days after introduction of the boar and were considered receptive to the boar effect, 14 were detected in oestrus more than 8 days after boar introduction, six did not show oestrus before slaughter and were considered non-receptive. Salivary steroidome analysis was performed for six receptive and six non-receptive gilts using gas chromatography coupled to tandem mass spectrometry. Four saliva samples per gilt were analysed: 26 days and 11 days before boar introduction (day0-26 and day0-11), the day of boar introduction (day0), 3 days later for receptive gilts (day0+3) or 7 days later for non-receptive gilts (day0+7). Saliva analysis detected 30 steroids. The concentrations of six of them were higher in receptive gilts than in non-receptive gilts at day0-26 (progesterone), day0-11 (3α5β20α-hexahydroprogesterone, 3β5α20β-hexahydroprogesterone, dehydroepiandrosterone, androstenediol) and day0 (3β5α-tetrahydroprogesterone). Their low and variable concentrations in saliva require expensive analysis and limit their use in pig farms. However, progesterone could be an interesting biomarker of the pre-puberty period.
Ghylène Goudet, Philippe Liere, Doryan Grivault, Cécile Douet, Jonathan Savoie, Stéphane Ferchaud, Florence Maupertuis, Antoine Roinsard, Sylviane Boulot, Armelle Prunier. Analysis of steroids in gilt salivato identifybiomarkers of the period of receptivity to the boar effect. 51èmes Journées de la Recherche Porcine.