PSX-28 - Using estrus detection patches or a ram wearing a marking harness to monitor estrus in synchronized hair sheep ewes
Thursday, July 23, 2020
7:00 AM – 5:00 PM
Location: Poster Sessions
Determining when a ewe is in estrus is important when using estrous synchronization and artificial insemination in sheep. This study was conducted to compare the efficacy of estrus detection patches (Estrotect™) and rams wearing marking harnesses for monitoring estrus in synchronized hair sheep ewes. St. Croix White (STX) ewes (3.5 ± 0.3 y of age, 89.7 ± 2.2 d post-partum) were synchronized using progesterone releasing inserts (Eazi-Breed™ CIDR) for 12 d. On the day of CIDR removal (d 1) ewes were administered prostaglandin (Lutalyse®; 15 mg i.m.) and placed with fertile STX rams in 0.55 ha pastures. One group of ewes (n =10; MH) was placed with a ram wearing a marking harness and a second group (n = 16; EP) had estrus detection patches placed on their rumps before being placed with a ram without a harness. Estrus detection was conducted using visual observations twice a day through d 7. A ewe was considered to be in estrus when crayon marks were observed on the rump or the patch was activated, based on product guidelines. Cumulative percentage of ewes in estrus was analyzed using the CATMOD procedure with treatment, day and the interaction in the model. All patches stayed in place on the EP ewes through d 7. By d 4 90% of MH ewes and 75% of EP ewes had been observed in estrus (P < 0.05). By d 7 90% of MH ewes and 81.25% of EP ewes had been observed in estrus (P < 0.05). With costs of $1.33 per patch or $29.33 for one harness and crayon the patches may be more economical when dealing with up to 21 ewes per ram. Estrus detection patches can be used on hair sheep ewes to detect estrus just as effectively as a ram with a marking harness.