Abstract #M232
Section: Physiology and Endocrinology
Session: Physiology and Endocrinology: Estrous synchronization and detection of estrus in cattle
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
Session: Physiology and Endocrinology: Estrous synchronization and detection of estrus in cattle
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
# M232
Using estrus-detection patches to optimally time artificial insemination improved pregnancy rates in suckled beef cows in a timed AI program.
Scott L. Hill*1, David M. Grieger1, K. C. Olson1, John R. Jaeger1, Jason K. Ahola2, Mariah C. Fischer2, Teresa L. Steckler3, G. Allen Bridges4, Jamie A. Larson5, Carl R. Dahlen6, Sarah R. Underdahl6, George A. Perry7, William D. Whittier8, John F. Currin8, Jeffrey S. Stevenson1, 1Kansas State University, Manhattan, KS, 2Colorado State University, Fort Collins, CO, 3University of Illinois, Dixon Springs, IL, 4University of Minnesota, Grand Rapids, MN, 5Mississippi State University, Mississippi State, MS, 6North Dakota State University, Fargo, ND, 7South Dakota State University, Brookings, SD, 8Virginia Tech, Blacksburg, VA.
Using estrus-detection patches to optimally time artificial insemination improved pregnancy rates in suckled beef cows in a timed AI program.
Scott L. Hill*1, David M. Grieger1, K. C. Olson1, John R. Jaeger1, Jason K. Ahola2, Mariah C. Fischer2, Teresa L. Steckler3, G. Allen Bridges4, Jamie A. Larson5, Carl R. Dahlen6, Sarah R. Underdahl6, George A. Perry7, William D. Whittier8, John F. Currin8, Jeffrey S. Stevenson1, 1Kansas State University, Manhattan, KS, 2Colorado State University, Fort Collins, CO, 3University of Illinois, Dixon Springs, IL, 4University of Minnesota, Grand Rapids, MN, 5Mississippi State University, Mississippi State, MS, 6North Dakota State University, Fargo, ND, 7South Dakota State University, Brookings, SD, 8Virginia Tech, Blacksburg, VA.
A multiple-location study examined pregnancy rates after delaying AI in suckled beef cows from 60 to 75 h when estrus had not been detected by 60 h after a 7-d CO-Synch + progesterone insert (CIDR) timed AI (TAI) program (d 0: progesterone insert [CIDR] concurrent with injection of GnRH; d 7: prostaglandin F2α injection and removal of CIDR; and GnRH injection at TAI [60 or 75 h after CIDR removal]). A total of 1,519 suckled beef cows at 14 locations in 8 states (CO, IL, KS, MN, MS, ND, SD, and VA) were included. Before applying the TAI program, BCS were assessed. Estrus was defined to occur when an estrus-detection patch was > 50% colored (activated). Pregnancy was determined 35 d after AI via transrectal ultrasound. Cows in estrus 60 h (n = 689; 45.6%) after CIDR removal were inseminated and injected with GnRH (control). Remaining nonestrus cows were allocated to 3 treatments: (1) GnRH injection and AI at 60 h (Early-Early = EE; n = 281), (2) GnRH injection at 60 h and AI at 75 h (Early-Delayed = ED; n = 270), or (3) GnRH injection and AI at 75 h (Delayed-Delayed = DD; n = 279). Binomial data were analyzed using procedure GLIMMIX. More cows (P < 0.05) that showed estrus by 60 h conceived to AI at 60 h than those not showing estrus (65.9 vs. 44%). Further, more (P < 0.001) cows showing estrus by 75 h conceived to AI (64.9 vs. 38.5%) than cows not showing estrus. Control cows had a greater (abcP < 0.05) pregnancy rates (65.9%a) than other treatments (ED = 54.6%b, DD = 53.0%b, and EE = 44.0%c). Cows not in estrus by 60 h but with activated patches by 75 h (49.8%) were more (P < 0.05) likely to become pregnant than nonestrus herd mates when they were in the DD (71.6 vs. 39.1%), ED (70.2 vs. 46.0%), and EE (53.7 vs. 41.4%) treatments, respectively. Pregnancy rates also were greater (P < 0.05) in early-calving (>76 d postpartum) than later-calving (≤76 d postpartum) cows (57.5 vs. 51.4%) but were not affected by parity or BCS. Use of estrus-detection patches to delay AI in cows not in estrus by 60 h after CIDR removal optimized time of AI and improved pregnancy rates to TAI.
