Project description:The estrous cycles of Limousin heifers (n = 30) were synchronized by insertion of a controlled internal drug release (CIDR) device (1.94 g progesterone; Pfizer Animal Health) placed into the vagina for 8 days. A 0.5 mg intramuscular injection of a prostaglandin F2α (PG) analogue (PG, Estrumate, Shering-Plough Animal Health, Hertfordshire, UK) was administered 1 day before CIDR removal. Heifers were checked for standing estrus and only those exhibiting estrus (Day 0) were used. All animals were expected to come in heat between 48 and 72 hours after CIDR removal. Cervical tissues were collected at slaughter from heifers 12h after CIDR removal (Group 1: CIDR + 12 h, n = 6), 24h after CIDR removal (Group 2: CIDR + 24 h, n = 6), at the onset of estrus (Group 3: Estrus, n = 4), 12 h after the onset of estrus (Group 4: estrus + 12 h, n = 5), 48 h after the onset of estrus (Group 5: Estrus+48h, n = 4) and on day 7 after the onset of estrus (Group 6: Luteal phase, n = 5).
Project description:The estrous cycles of Limousin heifers (n = 30) were synchronized by insertion of a controlled internal drug release (CIDR) device (1.94 g progesterone; Pfizer Animal Health) placed into the vagina for 8 days. A 0.5 mg intramuscular injection of a prostaglandin F2α (PG) analogue (PG, Estrumate, Shering-Plough Animal Health, Hertfordshire, UK) was administered 1 day before CIDR removal. Heifers were checked for standing estrus and only those exhibiting estrus (Day 0) were used. All animals were expected to come in heat between 48 and 72 hours after CIDR removal. Cervical tissues were collected at slaughter from heifers 12h after CIDR removal (Group 1: CIDR + 12 h, n = 6), 24h after CIDR removal (Group 2: CIDR + 24 h, n = 6), at the onset of estrus (Group 3: Estrus, n = 4), 12 h after the onset of estrus (Group 4: estrus + 12 h, n = 5), 48 h after the onset of estrus (Group 5: Estrus+48h, n = 4) and on day 7 after the onset of estrus (Group 6: Luteal phase, n = 5). Cervical tissue from 30 animals taken at 6 timepoints in the peri-oestrus period. +12hrs post CIDR, Onset of Oestrus,+12hrs post Oestrus, +48hrs post Oestrus, Luteal phase
