Methods of Animal Breeding
Catalog No. 8407
SELECTED STUDENT ACTIVITIES
short answer/LISTING: Answer the following questions or statements.
1.List four methods of assisted reproductive technologies.
2.Why do producers practice inbreeding?
3.Why do producers practice crossbreeding?
4.Define the following terms:
Estrus -
Estrous -
Ovulation -
Gestation -
5.In your own words, explain the purpose of estrous synchronization?
6.List and describe three types of crossbreeding methods.
Matching: Match the term in the left column with its definition in the right column.
_____7.InbreedingA.The mating of animals within the same breed that is eligible for registration.
_____8.CrossbreedingB.The mating of animals of different breeds within the same species.
_____9.PurebreedingC.The mating of closely related ancestors.
_____10.Grading upD.A breeding system that maintains a close relationship of highly regarded ancestors.
_____11.LinebreedingE.Mating purebred males to commercial females.
true/False: Circle the "T" if the statement is true or the "F" if it is false.
TF12.When an animal has reached puberty, its body growth and development is always of the proper breeding age and capable of reproducing efficiently.
TF13.When breeding female swine for the first time, it is desirable that the gilts weigh a minimum of 225 pounds.
TF14.Inbreeding increases heterosis.
TF15.Pasture mating is a natural method of breeding where the female is kept separate from the male at all times except when mating is to occur.
TF16.On average, a ratio of 12 to 15 males per 100 females is practiced in poultry breeding when using a flock mating system.
FILL-IN-THE-BLANK: Complete the following statements.
17.______refers to the process of removing an embryo from the female reproductive tract during its early development, and then transferring the embryo to another female reproductive tract for further development and subsequent birth.
18.Hormonal injections of FSH cause the female to ______or develop and release more eggs than normal.
19.______is a method that can be used in conjunction with any breeding program to ensure that all females come into heat at or near the same time.
20.______-______refers to the period of time when the female reproductive tract is returning to its original shape and tone following parturition.
THOUGHT QUESTIONS: Answer the following questions and activities.
21.If a cow was bred on January 1 of this year, in which month and year would her female offspring reach the age of puberty, assuming her progeny was average for the species? (You will need to refer to Tables 1 and 3 from the lesson.)
22.Compare and contrast the advantages and disadvantages of using the reproductive technologies of artificial insemination versus cloning. (Use complete sentences for your answer.)
Advanced Activities
1.Choose a species of livestock and design your own method of breeding for a two-year program. Be sure to include the reproductive cycles of your particular species. Your goal is to reproduce as many females for replacement and males for the market as possible. When choosing a system of mating, assume that your current inventory consists of 50 mature females. Also assume that you have access to an unlimited number of males and to all of the reproductive technologies discussed. You must keep your operating expenses as low as possible and deal with a lack of labor. Compare your results with your classmates' plans and discuss the pros and cons of your operation with your class.
2.Assume the conception rate of your operation is 88% for all species. Further, assume that crop percentage is 140% for ewes and goats, 100 % for mares and cows, and 8 pigs per litter for sows. If the offspring from your operation in the previous problem were 50% female and 50% male, how many males could be sent to market and how many females kept for replacements? (For the purpose of this activity, ewes, goats, mares, and cows will produce one offspring per year, while sows will farrow two litters per year.)
3.Select an assisted reproductive technology that was discussed in this topic or find one of your choosing, and summarize the process. Then prepare a presentation for your class describing how the process works. Be sure to include the advantages and disadvantages of this process as opposed to other methods. Also, be sure to use appropriate teaching techniques (e.g., visual aids) while making your presentation. (This activity may be lengthy, so you may want to work with a partner.)
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