A Research Summary in Animal Sciences

Note: Make sure you review each assignment ahead of time and print out required reports before you move on to the next round of selection. Once you move on, you cannot go back!!!!

Overview:

Continue breeding until your herd reports for year 19 are completed. At this point you have completed the SIMBULL breeding assignment. At the completion of year 19, print out the following reports:

1. Herd Summary, Herd Status, and Herd Performance Reports.
2. Print a copy of the Herd Profile for your herd.

Do not discard your Simbull files until after you have completed Assignment 4. You will need the Simbull data files for one final operation that will be described in Assignment 4.

At your option: You may continue to breed your herd beyond year 19 if you wish, but do your final report based on the year 19 results. Beyond year 19, you can change your trait for selection, do random mating, try inbreeding, use herd bulls etc. Try out those ideas that you have considered but not utilized during the assignment.

Your grade on this assignment will not be based on the amount of genetic progress your herd has made. There are three parts to this assignment:

Part I:     A summary of genetic and phenotypic progress for all traits from year 11 to year 19.

Part II:    A graph of progress in actual and estimated breeding value for your trait by year.

Part III:   A narrative summary of your selection methods and results (not more than 2 pages).

SIMBULL Assignment 3 Part III: Narrative Summary:

The narrative summary should not exceed 2 pages. You may wish to go back to previous assignments to see how your ideas have changed with experience. Whenever appropriate, use terminology introduced in the course. As you think about and discuss genetic progress, don’t overlook the time that elapses from making a mating until the progeny from that mating enters the milking herd and is included in the herd average. Your use of animal breeding concepts, logic, completeness, grammar, clarity, sentence and paragraph structure, and spelling will be considered in grading your report.

1. Briefly describe your breeding objectives; summarize your goals for the herd.
2. Discuss briefly the progress in your herd’s average performance and transmitting ability. Was your rate of progress greater or less than you expected? Explain the cause of any unusually rapid or slow periods of genetic improvement. How did your selection for one trait affect the other traits? What caused the discrepancies between estimated breeding value and true breeding value in your herd? (i.e., compare the differences between the two lines on your graph of genetic progress.)
3. Discuss your selection policy for bulls. How did you select bulls? Be as specific as possible when describing what information you used as the basis for selection. In what ways did your selection policies change from the early years to the late years? Approximately how many bulls did you use each year? Did you select progeny-tested bulls, sampling bulls or bulls of your own breeding?
4. Discuss your selection policy for cows. How did you select cows (or heifers or calves) to cull? In what ways did your selection scheme change over time?
5. How did you mate the cows and bulls? Were heifers mated the same way as cows?
6. Did inbreeding cause you to alter your selection or mating schemes? If so, in what way?
7. What do you consider your worst mistake in breeding decisions? Why? What would you do differently if given another herd to breed
8. What were the two most important genetic concepts you learned (or were strongly reinforced) from this exercise? Be specific; avoid broad, general statements.