TY - JOUR AU - Fernández, L AU - Díez, C AU - Ordóñez, JM TI - Reproductive performance in primiparous sows after postweaning treatment with a progestagen T2 - Journal of Swine Health and Production JF - Journal of Swine Health and Production J2 - JSHAP SN - 1537-209X DP - American Association of Swine Veterinarians PB - American Association of Swine Veterinarians DA - 2005/Jan// PY - 2005 VL - 13 M1 - 1 IS - 1 M2 - 28 SP - 28-30 L2 - https://www.aasv.org/shap/issues/v13n1/v13n1p28.html UR - https://www.aasv.org/shap/abstracts/abstract.php?v13n1p28 L1 - https://www.aasv.org/shap/issues/v13n1/v13n1p28.pdf KW - swine KW - altrenogest KW - primiparous KW - reproductive performance N2 - The purpose of this study was to determine whether administration of altrenogest (Regumate; Roussel-Uclaf, París, France) to primiparous sows would improve estrus synchronization rate and reproductive efficiency of the herd, measured in terms of the weaning-to-estrus interval (WEI), the weaning-to-first-fertile-estrus-interval (WFEI), rate of sows repeating estrus, and conception rate at first estrus. First-parity sows (Landrace x Large White) from a commercial herd received altrenogest, 20 mg per sow per day, for 5 consecutive days starting the day after weaning. A group of untreated sows acted as controls. The percentage of sows showing estrus 4 to 7 days postweaning (controls; 65.6%) or 4 to 7 days after treatment ended (8 to 11 days postweaning) was higher(P < .05) in the altrenogest-treated group (86.2%). Sows were matednaturally twice at the first estrus after weaning and pregnancy was diagnosedby ultrasonography 23 to 24 days later. There were no differences between treatedand control sows in means of WEI, WFEI, rate of sows repeating estrus, or conceptionrate to first service. Litter size at farrowing, number of live born piglets,number ofstillborn piglets, preweaning mortality, and weaned litter size were alsosimilar between groups. ER -