Paul Fricke, MS, PhD
Professor of Dairy Science, School of Veterinary Medicine, University of Wisconsin – Madison, Madison, Wisconsin
Fertility Programs for First AI
Use of detection of estrus alone for submitting lactating dairy cows for first AI results in poor reproductive performance due to problems with estrous detection as well as estrous expression and the presence of anovular cows. Modifications to the original Ovsynch protocol can now yield high P/AI to timed AI in high‐producing dairy cows. This talk will overview the latest iterations of protocols for synchronization of ovulation which are now better described as fertility programs.
New Technologies for Detection of Estrus
Detection of estrus plays an important role in the reproductive management program on most dairies in the U.S. Increased physical activity is a secondary sign of estrus in dairy cattle, and a new generation of electronic systems that continuously monitor physical activity to predict timing of AI have been developed and marketed to the dairy industry. This talk will overview strategies to integrate activity monitoring systems into reproductive management programs.
Strategies for Nonpregnancy Diagnosis
Early identification of nonpregnant cows after AI coupled with a strategy to resynchronize nonpregnant cows for second and greater timed AI further increases the 21‐d pregnancy rate by decreasing the interval between AI services, thereby increasing the AI service rate. This talk will overview new methods for nonpregnancy diagnosis in lactating dairy cows including transrectal ultrasonography and pregnancy‐associated glycoproteins as well as the effects of early pregnancy loss on the accuracy of pregnancy outcomes.
Whereas presynchronization strategies have yielded significant increases in fertility to first TAI, many herds struggle with poor fertility to an Ovsynch protocol used for TAI at second and greater services (i.e., Resynch). This talk will overview strategies for increasing fertility to Resynch TAI in lactating dairy cows including strategies for presynchronization, modifications to Resynch protocols, and differential treatment of cows lacking a CL at the onset of a Resynch protocol.
Management of Twinning in Dairy Cows
Twinning in Holstein dairy cows has increased over time concurrent with increased milk production. More than 95% of twins in Holsteins arise due to double ovulations resulting in dizygotic twins, and it is now clear that low progesterone during growth of a preovulatory follicle increases the incidence of double ovulation. This talk will overview strategies to prevent double ovulations and twinning in dairy cows and potential methods to manage cows diagnosed with twins.
The Randomness of Reproduction
From a statistical perspective, many reproductive outcomes (i.e., pregnancy outcomes, calf sex, twinning, etc.) are binomial variables with only two possible outcomes. These binomial variables require a large number of observations to assess but can lead to misinterpretation when too few outcomes are assessed. This talk will discuss the problems and pitfalls that occur when assessing reproductive outcomes on dairy farms.
M. Daniel Givens, DVM, PhD, DACT, DACVM (Virology Subspecialty)
Associate Dean for Academic Affairs, College of Veterinary Medicine, Auburn University, Auburn, Alabama
Control of Bovine Reproductive Pathogens
Bovine reproductive pathogens can cause infertility, early embryonic death, mummification of fetuses, abortions, or the birth of weak or malformed calves. The objectives of this session are to develop a thorough differential list, diagnostic plan, and control plan for causes of reproductive loss in cattle.
Does MLV Administration to Heifers or Cows Lack Substantial Risk?
Attendees will be able to characterize and quantify the risks associated with administration of modified live vaccines (MLV). Consideration will be given to (a) the risk causing temporary infertility in cycling heifers or cows, (b) the risk of stimulating abortion, and (c) the risk of failing to protect the fetus from viral exposure of the pregnant cow.
Diagnosing, Differentiating, and Managing Infections with BVD Virus
Attendees will be able to diagnose and differentiate various infections in cattle resulting from bovine viral diarrhea virus. Once the type of infection is determined, appropriate management to control BVDV while mitigating the constraints on production will be discussed.
Systemic Large-Scale Programs to Control BVD Virus
Successful methods to control BVDV within a large production unit, state, or nation bear some key similarities. The goal of this session is to enable attendees to effectively develop and manage systemic control programs for BVD on large operations.