Follicular dynamics and ovulation time in gilts and post-weaning sows.

Ultrasonography was used to study follicular dynamics from the beginning of estrus to ovulation in pubertal gilts and post-weaning sows. Ultrasound turned out to be a useful tool to determine patterns of growth of preovulatory follicles, to predict ovulation time, and to design protocols for fixed time insemination.

Dynamique folliculaire et moment de l'ovulation chez les cochettes et les truies en période post-sevrage. On a utilisé l'échographie pour étudier la dynamique folliculaire du début de l'oestrus jusqu'à l'ovulation chez les cochettes post-pubertaires et les truies en période post-sevrage. L'échographie s'est avérée un outil utile pour déterminer les tendances de croissance des follicules pré-ovulatoires, prédire le moment de l'ovulation et concevoir des protocoles pour une insémination à un moment fixe.(Traduit par Isabelle Vallières).

Accuracy of pregnancy diagnosis in swine by ultrasonography.

Early and accurate diagnosis of nonpregnant sows and gilts has the potential to increase reproductive efficiency and the financial income in pig production by reducing non-productive days per sow per year. The objectives of this study were to compare the efficiency of pregnancy diagnosis between Doppler Echo+ and real time ultrasonography (RTU) and to compare the efficiency by using RTU at different days post-mating (days 17 to 24) under commercial conditions. In the 1st study, using crossbreed sows and gilts (n=107), pregnancy diagnoses were done with Doppler Echo+ and then with RTU. Between 28 and 65 days of gestation, Doppler Echo+ had 85% sensitivity and 32% specificity, and efficiency was 73%. In the 2nd study, sows (n=142) were scanned for pregnancy diagnosis between 17 and 24 d post-mating (PD1) and reconfirmed between 38 and 45 days of gestation (PD2). After 21 days of gestation, RTU had over 90% sensitivity and 45% specificity, and 70% efficiency. Accuracy between PD1-farrowing was 75.5% and between PD1 and PD2 was 80.6%. In the 3rd study, sows were diagnosed pregnant by RTU (n=151) at 17 to 24 days of gestation or A-mode ultrasound (n=172) at 28 to 30 days of gestation. There were no significant differences in conception rate (P > 0.09) and farrowing rate (P > 0.67) between both groups. Hence, there was no improvement in fertility and farrowing rate by using RTU instead of A-mode ultrasound under commercial conditions.