![]() ![]() Up to 30–40% of gilts older than 8 months did not show any sign of estrus and consequently were culled. An increase in the age at first AI (220–300 days) was associated with 2.1% increased risk of culling due to fertility failures. Reproductive failure by delayed puberty after 7–8 months was reported as the main reason for discarding gilts. The first estrus involves the efficiency of genetic potential and the physiological mechanisms that affect the sexual maturation and reproductive management in gilts. The onset of puberty is a reliable indicator of gilt reproductive performance and longevity. Gilts reach puberty between 150 and 220 days-of-age therefore, accurate detection of first estrus is key to optimize the correct time of AI in their second or third estrus. In fact, almost 10% of gilts are slaughtered before their first artificial insemination (AI), mainly due to reproductive problems. ![]() Early onset of gilt puberty is needed for adequate economic performance in commercial pig farms. Therefore, an efficient reproduction control greatly impacts on the overall production. In most farms, 30%-50% of the sow herd is annually replaced. Gilt productivity is important in pork production enterprises because gilts account for 20–25% of the farrowing group. Accuracy parameters are a guide to choose puberty diagnosis, but the farms must also evaluate effect on gilts, ease and cost of administration. Results using the W3 equipment could be improved when used along with vaginal length (V1) or progesterone concentration (V2). The effectiveness of the ultrasonography changes with technological improvements and with increased expertise of technicians. Ultrasonography provided better results than other diagnostic techniques. Results using the W3 equipment could be improved when used in conjunction with vaginal length (V1 Nagelkerke´s R 2 = 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 R 2 = 0.780 Sensitivity = 0.955 Specificity = 0.826 Positive predictive value = 0.915 Negative predictive value = 0.905 Area under ROC curve = 0.970). ![]() The most accurate results were found by V1/DELTA (Nagelkerke´s R 2 = 0.846 Sensitivity = 0.956 Specificity = 0.958 Positive predictive value = 0.978 Negative predictive value = 0.920 Area under ROC curve = 0.957). 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 results obtained by two technicians with different levels of experience (V1 and V2, a junior technician) using W3 were also compared. ![]() Two types of ultrasonography equipment (DELTA and W3) were compared and performed by the same senior technician (V1). Vaginal length, body condition, backfat, carcass weight and progesterone blood concentration were significantly higher in pubertal than prepubertal gilts ( P < 0.05). 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). Multiple logistic regression analysis was used to identify which combination of independent variables (predictors) best predicts the status of gilts. Postmortem examination was the standard reference. 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. Therefore, an effective diagnosis is needed. Early onset of a gilt´s puberty is needed for adequate economic performance in farms, because it indicates her reproductive performance and longevity. ![]()
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