altrenogest and Premature-Birth

This study investigated the effect of altrenogest treatment on the farrowing development of sows, and birth weight (BW) and piglet survival until the third day of life. Three control groups were used: (i) sows that farrowed spontaneously before 114 day of gestation (CONT <114); (ii) sows that spontaneously farrowed at ≥114 day of gestation (CONT ≥114); (iii) sows that farrowed at ≥114 day with cloprostenol treatment (CONTCLOPR). Other sows were treated with altrenogest (Regumate(®) ) for 3 days (days 111, 112 and 113 of gestation): one group gave birth spontaneously (ALT) and the other group received altrenogest until day 113 and cloprostenol on day 114 (ALTCLOPR). There were no differences (p > 0.05) in farrowing duration, BW, coefficient of variation (CV) of BW, stillborn piglets, mummified foetuses, percentage of light piglets and survival until Day 3 between sows with and without cloprostenol treatment, in both control (CONT ≥114 vs CONTCLOPR) and altrenogest-treated sows (ALT vs ALTCLOPR). Further comparisons were performed taking into account three groups: sows with early delivery (CONT <114 - farrowing before 114 days of gestation; n = 56), sows with longer gestation (CONT ≥114 - with and without cloprostenol treatment sows; n = 103) and ALT sows (with and without cloprostenol treatment; n = 105). Gestation length of CONT ≥114 and ALT sows was similar (p > 0.05), but higher than in CONT <114 sows. There were no differences (p > 0.05) between groups in farrowing duration, CV of BW, and percentages of stillborn piglets and mummified foetuses. Sows of CONT <114 group had a larger litter size and a lower BW than sows of the other two groups (p < 0.05). Sows of CONT <114 group had a higher percentage of lighter piglets and a lower piglet survival rate (p < 0.05) than ALT sows. In conclusion, altrenogest treatment proved to be an efficient method to avoid early parturition in 3-5 parity sows resulting in heavier piglets at birth.

Topics: Animals; Birth Weight; Cloprostenol; Female; Labor, Induced; Luteolytic Agents; Pregnancy; Pregnancy Outcome; Premature Birth; Progestins; Swine; Trenbolone Acetate

A retrospective study, based on 60,990 farrowing records from 35 commercial herds, was performed to determine the incidence of early parturition (<114 d) and to investigate the relationship between early parturition and total number of piglets born, number of piglets born alive and percentage of stillborn piglets per litter. The mean gestation length was 115.4 ± 1.62 d, and early parturition occurred in 10% of all farrowing records. Sows with early parturition had significantly more stillborn piglets and a larger litter size compared to sows with a normal gestation length (114-117 d). Sows with a gestation length <114 d were 1.2 times (95% CI: 1.19-1.21; p<0.001) more likely to have an early parturition at the subsequent parity. A second study was performed in four herds (n=329) to investigate the efficacy of altrenogest administration on 110-112 d (T112) or 111-113 d (T113) of gestation for preventing early parturition and to investigate the effect of this treatment on the reproductive performance of sows. The interval between the last altrenogest treatment and the onset of parturition was 3.3 ± 1.32 (T112) or 2.0 ± 0.89 (T113) days. The gestation length of sows of the altrenogest group (T112 + T113) (115.3 ± 1.23 d) was significantly longer compared to gestation length of the non-treated sows (114.7 ± 1.69d) (p<0.01). Altrenogest treatment had no negative effect on the reproductive performances of the sows. In conclusion, the administration of altrenogest in late gestation is an effective and safe method to prevent early parturition and can counteract the reproductive losses because of premature farrowing, which may occur in a substantial part of the farrowing events.

Topics: Animals; Female; Gestational Age; Litter Size; Pregnancy; Premature Birth; Progestins; Reproduction; Retrospective Studies; Sus scrofa; Swine; Swine Diseases; Trenbolone Acetate