Salivary biomarkers of sexual development for hormone-free pig reproduction
The animal article of the month for April is ‘Salivary and urinary metabolome analysis for pre-puberty-related biomarkers identification in porcine’
In pig farms, creation of batches of sows has developed extensively due to advantages for the management of reproductive females and offspring. Estrus synchronization of gilts is necessary for their integration into the batch. Swine breeders commonly use synthetic hormones to synchronize estrous cycles in gilts. However, their wide use results in contamination of environment by hormones and their metabolites from animal manure and urine. Thus, our aim is to develop non-hormonal alternatives for estrus synchronization in gilts.
contact, called the boar effect, is able to stimulate and synchronize puberty
attainment in gilts, although its success is variable. Part of this variability
is linked to differences in sexual maturity of the gilts at onset of boar
exposure. Before puberty, gilts exhibit a pre-puberty period during which
external stimulations, such as boar exposure, could induce and synchronize
first estrus. Targeting more effectively this period when gilts are able to
respond to boar exposure would enhance the efficacy of the boar effect. Thus,
the identification of biomarkers of this receptivity period would allow the
detection of optimal time for application of the boar effect in pre-pubertal
gilts. Urine and more clearly saliva is easily accessible and
can be sampled noninvasively without stress or pain. Our aim was to identify in
urine and/or saliva biomarkers of the pre-puberty period.
In our study, nine 144 to 147-day-old Large White gilts were subjected to trans-abdominal ultrasonography for puberty detection and to urine and saliva samples collection until puberty detection. We performed metabolome analysis in urine and saliva samples using 1H-nuclear magnetic resonance spectroscopy to detect potential biomarkers of the pre-puberty period within the metabolites.
analysis allowed the identification of 23 low-molecular-weight metabolites in
salivary samples, and 42 in urine samples. In gilts saliva, we identified six metabolites
as biomarker candidates of the pre-puberty period: formate, malonate,
propionate, 5.79 ppm (putatively uridine), butyrate and 2HOvalerate. We also
identified three steroids as salivary biomarkers candidates in another study. Further
experiments on a greater number of gilts from different breeds and environments
are necessary to validate these candidates.
These results show that painless sampling of saliva could be a non-invasive tool for the identification of the physiological hormonal status of the gilts and possibly the optimal time for application of the boar effect. This could contribute to synchronize estrus and hence to develop non-hormonal breeding tools.
This article is freely available for one month: ‘Salivary and urinary metabolome analysis for pre-puberty-related biomarkers identification in porcine’
Author: G. Goudet, L. Nadal-Desbarats, C. Douet, J. Savoie, C. Staub, E. Venturi, S. Ferchaud, S. Boulot, A. Prunier