This exam is completely open-book. Therefore, I expect a lot of detail and extra research to go into your responses to the case studies outlined below. Remember to CITE YOUR SOURCES in Journal of Animal Science format! Please use both in-text citations for each question and include a Works Cited page for the entire exam.

Reproductive Management 

You are hired to consult a producer that has reproductive issues in their herd. List 3 things that you would ask this producer about their management practices.

This producer tells you that they implement artificial insemination. The producer generally checks heat for heifers, but this year wants to implement the 7-day CoSynch protocol. Please discuss the positive and negative impacts of using a fixed timed-artificial insemination protocol. Also, discuss some other estrous synchronization protocol options that are available for use in heifers.

Compare and contrast the mature body weight percentage debate related to heifer development. Researchers have discussed both advantages and disadvantages to feeding heifers during the development period to achieve either 50-55% of their mature body weight or 60-65% of their mature body weight prior to the breeding season. Discuss in detail the advantages and disadvantages of each approach to heifer development. In addition, consider the cost of heifer development. Provide relative heifer development costs and the payback period required before heifers will become profitable members of the herd. 

Please describe in detail the physiological process of attaining puberty in beef heifers. Describe the hormones involved and the relevant changes in reproductive tract growth and development. Also, describe the reproductive tract scoring system and how it can be utilized for heifer selection.

The producer has little to no record keeping for the herd. This makes determining the cause of poor reproductive performance difficult. However, the producer mentions that they have been noticing irregular heat periods and a few abortions in the herd. In addition, more cows are open at the end of the breeding season than normal. How do you know if this is a management issue or a health-related issue? Discuss at least 2 management practices that could be a problem and at least 2 health-related problems that could be an issue.

Case Study 4: Reproductive Technologies

Embryo transfer is utilized by approximately 3% of US beef producers. As a beef cattle consultant, you are tasked with investigating this process to help producers learn more about embryo transfer in beef cattle to encourage more widespread use of the technique. 

When did embryo transfer become commercially available in North America? Provide a general overview for producers about the process and the potential benefits. Also, provide a relative cost of embryo transfer and the expected levels of embryo production and pregnancy rates for beef cattle.

Please describe the physiology of embryonic development in detail. Describe the hormones involved in ovulation and fertilization. In addition, describe how the embryo and placenta start to develop.

Describe in detail how producers should choose and manage donor and recipient females for the embryo transfer process. Please list potential problems and solutions with management of these females.

Discuss the following procedures and how they are accomplished in detail:

Superovulation of the donor cow

Embryo evaluation (quality standards)

Embryo transfer

Sexing embryos

Describe cryoprotectants in the context of embryo transfer. Provide examples of at least 2 cryoprotectants.

• Describe in detail factors that influence superovulatory response in cows.  Please discuss any possible differences based on breed types, even within the same subspecies of cattle (e.g. Angus versus Hereford; Bos taurus). 
• Finally, some of your producers approach you about utilizing sex-sorted semen in beef cattle production. First, describe how semen is sex-sorted. Then, discuss any problems with utilizing sex-sorted semen and also the opportunities for beef producers.