Determination of puberty in gilts: contrast of diagnostic methods

Antonio Vela; Andrés Suárez-Usbeck; Laura Lafoz; Olga Mitjana; María Teresa Tejedor; Sofía Martín; Marina López; María Victoria Falceto

doi:10.1186/s40813-022-00271-0

Determination of puberty in gilts: contrast of diagnostic methods

Porcine Health Manag. 2022 Jun 16;8(1):28. doi: 10.1186/s40813-022-00271-0.

Authors

Antonio Vela^{1

2}, Andrés Suárez-Usbeck², Laura Lafoz¹, Olga Mitjana², María Teresa Tejedor³, Sofía Martín⁴, Marina López⁴, María Victoria Falceto²

Affiliations

¹ THINKINPIG S.L., Avenida Gómez Laguna, 41 10ºA, 50009, Zaragoza, Spain.
² Department of Animal Pathology, Reproductive and Obstetric Area, Faculty of Veterinary Medicine, Agroalimentary Institute of Aragon-IA2, Universidad de Zaragoza-CITA, Zaragoza, Spain.
³ Department of Anatomy, Embryology and Animal Genetics, CIBERCV, Genetics Area, Faculty of Veterinary Medicine, Universidad de Zaragoza, Zaragoza, Spain. ttejedor@unizar.es.
⁴ , KUBUS Calle Varsovia, 20, 28232 Las Rozas de Madrid, Madrid, Spain.

Abstract

Background: Early onset of a gilt´s puberty is needed for adequate economic performance in farms, because it indicates her reproductive performance and longevity. Therefore, an effective diagnosis is needed. Our purpose was to compare different procedures (external characteristics, blood progesterone analysis and ultrasonography diagnosis) to detect puberty in 70 gilts (Topigs TN70; 240 days old) on farm conditions. Postmortem examination was the standard reference. Multiple logistic regression analysis was used to identify which combination of independent variables (predictors) best predicts the status of gilts.

Results: Puberty (46/70 gilts; 65.71%) was characterized by the presence of follicles larger than 6 mm, corpus albicans, corpus rubrum, and corpus luteum (postmortem examination). Vaginal length, body condition, backfat, carcass weight and progesterone blood concentration were significantly higher in pubertal than prepubertal gilts (P < 0.05). Two types of ultrasonography equipment (DELTA and W3) were compared and performed by the same senior technician (V1). The results obtained by two technicians with different levels of experience (V1 and V2, a junior technician) using W3 were also compared. Ultrasonography provided better results than other diagnostic techniques, although the effectiveness of the ultrasonography changed with technological improvements and with increased expertise of technicians. The most accurate results were found by V1/DELTA (Nagelkerke´s R² = 0.846; Sensitivity = 0.956; Specificity = 0.958; Positive predictive value = 0.978; Negative predictive value = 0.920; Area under ROC curve = 0.957). Results using the W3 equipment could be improved when used in conjunction with vaginal length (V1; Nagelkerke´s R² = 0.834; Sensitivity = 0.933; Specificity = 0.958; Positive predictive value = 0.977; Negative predictive value = 0.885; Area under ROC curve = 0.972) or progesterone concentration (V2; Nagelkerke´s R² = 0.780; Sensitivity = 0.955; Specificity = 0.826; Positive predictive value = 0.915; Negative predictive value = 0.905; Area under ROC curve = 0.970).

Conclusions: Ultrasonography provided better results than other diagnostic techniques. The effectiveness of the ultrasonography changes with technological improvements and with increased expertise of technicians. Results using the W3 equipment could be improved when used along with vaginal length (V1) or progesterone concentration (V2). Accuracy parameters are a guide to choose puberty diagnosis, but the farms must also evaluate effect on gilts, ease and cost of administration.

Keywords: Gilts; Multiple logistic regression analysis; Negative predictive value; Positive predictive value; Puberty diagnosis; Sensibility; Specificity; Ultrasonography.