Life Sciences Commons^™

Daily Activity Measures And Milk Yield Immediately Before And After A Fertile Estrus, J. S. Stevenson

Kansas Agricultural Experiment Station Research Reports

The objective was to characterize changes in milk yield and other physical measures during a 7-day periestrual period encompassing estrus (day 0) and insemination. Lactating dairy cows milked thrice daily were fitted with CowManager SensOor ear tags capable of assessing real time eating, rumination, resting, high activity (estrus), ear-surface temperature, and providing heat alerts. Daily milk was unchanged during the periestrual period. Daily ear-surface temperature was greater during days 1 to 3 compared with day 0. Daily rumination and resting times reached nadirs on day 0, with decreases occurring 48 hours before estrus. Both rumination and resting times increased by …

Resynchronizing Returns To Estrus After A Prior Insemination, J. S. Stevenson, J. A. Sauls-Hiesterman

Kansas Agricultural Experiment Station Research Reports

In two experiments, GnRH and a progesterone insert (CIDR) were applied to cows after insemination (day 0) to reprogram or synchronize the returning estrus of cows that failed to conceive to that previous insemination. The combination of GnRH (day 14) and a CIDR insert (days 17 to 24) in experiment 1 (n = 347 cows) increased the proportion of nonpregnant cows returning to estrus before pregnancy diagnosis on day 32 by 7.4 percentage points, increased the synchrony of their return by 24.4 percentage points, but delayed that return by 2.3 days compared with controls. In experiment 2 (n = 863 …

Two Split-Time Artificial Insemination Programs In Suckled Beef Cows, J. Stevenson, S. L. Hill, D. M. Grieger, K C. Olson, J. R. Jaeger, K. R. Harmoney, J. Ahola, G. E. Seidel, R. K. Kasimanickam

Kansas Agricultural Experiment Station Research Reports

Successful programs to manipulate estrus and ovulation to maximize pregnancy out­comes in suckled beef cattle have been developed to limit animal handling and to elimi­nate the need to detect estrus, thereby providing more opportunity to incorporate AI to start the breeding season. The most successful and consistent synchronization scheme employs an intravaginal progesterone insert (controlled internal drug release, CIDR) in place for 7 d concurrent with GnRH treatment, and, upon removal of the insert, injection of PGF_2α, followed by timed AI at 60 to 66 h concurrent with a second dose of GnRH (CO-synch + CIDR).

Inseminating cows …

Delayed Insemination Of Non-Estrual Beef Heifers In 7-Day Co-Synch Timed Artificial Insemination, D. C. Shaw, K. E. Fike, David Grieger

Kansas Agricultural Experiment Station Research Reports

Reproductive performance in cattle is considered to be the most economically important trait and is essential for the success of an operation. In the last decade, timed artificial insemination (AI) in the beef cattle industry has increased in popularity due to the decreased amount of labor required for estrous detection. To increase the use of AI; however, cost and time inputs need to be further decreased. The objective of this study was to determine if fertility could be improved in beef heifers that are not expressing estrus before timed AI by delaying insemination.

Using Estrus-Detection Patches To Vary Time Of Insemination Improves Pregnancy Rates Compared With One Single Timed Insemination, S. L. Hill, D. M. Grieger, K C. Olson, J. R. Jaeger, J. S. Stevenson

Kansas Agricultural Experiment Station Research Reports

Timed artificial insemination (TAI) of beef cows at a predetermined time is a management tool that reduces labor costs associated with conventional heat detection before insemination. Multiple research trials have examined timing of the individual components of the developed protocols associated with TAI. The 7-day CO-Synch + progesterone insert (controlled internal drug release; CIDR) protocol has been shown to initiate ovulation effectively in cycling and noncycling suckled beef cows, often producing pregnancy rates greater than 50% in beef cows. In the current research, we examined using two targeted insemination intervals depending on the occurrence of estrus. We hypothesized that by …

Comparing Standing Heat And Estrotect Heat Detection Patches, S. K. Johnson, J. R. Jaeger

Kansas Agricultural Experiment Station Research Reports

A recent survey showed that 66% of producers surveyed used some amount of heat detection in their artificial insemination program, and 74% of producers that used heat detection aids had tried Estrotect (Rockway, Inc.; Spring Valley, WS) heat detection patches. The peel-and-stick application made Estrotect more popular than types that required adhesive application. The patches are designed so that when the animal is mounted the top surface layer is removed, much like scratching a lottery ticket. After several mounts the entire layer is removed, leaving a bright-colored surface behind. A new type of patch, Standing Heat (Standing Heat, LLC; Dannebrog, …