Know the body parts of the dairy cow that are circled on the BSC/Unified Score Card overview handout (found on D2L).
Be able to describe what body condition score is, what the range of scores is, and why it is important to producers.
Linear classification: what breed uses it? What is the range of scores? What are the five groups of traits?
Dairy Cow Unified Score Card: Know the information in the paragraph on the overview handout mentioned above.
How many chromosomes do cattle have? What is a chromosome? When was the bovine genome sequenced?
Know the definition of gene, allele, loci, phenotype, genotype, inheritance, dominant, recessive.
Know the correct answers to Questions #1 & 2 on Quiz #4 (qualitative vs. quantitative traits). Expect to see questions very similar to those.
Describe & give an example of dominance in inheritance. Describe & give an example of co-dominance in inheritance.
Define heritability. (Phenotypic expression of a trait.) What two factors affect heritability? (Inheritance & environment) Describe how those two factors affect heritability. (Inheritance is the genetic potential for a trait and environment is the opportunity to express the trait.)
What are the three sources of herd sires available to the dairy producer?
Be able to name and describe the three systems of breeding discussed in class.
Know the two national goals of dairy cattle selection (as discussed in class). Be able to distinguish between voluntary and involuntary culling.
In class we discussed the roles of eight different groups/associations in the improvement of dairy genetics. Choose ONE of those eight groups and be able to THOROUGHLY discuss their role (as described on the slide or slides in class). There will be a question on the exam about this.
Does single trait selection always result in positive changes for the whole animals (i.e. can other traits be negatively affected)?
What are the four factors in the key equation of genetic progress/change? Be able to briefly describe each of those four factors.
Know that artificial insemination can increase accuracy and intensity of selection but decreases genetic variation. Embryo transfer can decrease generation interval.
What are the advantages and disadvantages of gender enhanced semen (i.e. sexed semen)? How is flow cytometry used to sex the semen?
Know the three stages of biosecurity.
How can we optimize immunity on our farms?
Be able to name a number of ways to reduce pathogen spread on the farm.
Name three biosecurity goals discussed in class.
What is the best time/place to diagnose a sick cow? Discuss what should be done when a cow is labeled as abnormal.
What are the two types of diagnostic tests? Ones that measure levels of antibody, not actual virus or bacteria (serum titer levels) & those that measure the actual presence of pathogen (ELISAs or cultures).
What are the three types of costs that come about through diseases in the dairy industry?
What are the four major types/classes of diseases that are problems in the dairy industry?
What are the two major changes that a dairy cow encounters during the transition period?
Be able to define overconditioning and negative energy balance.
Review the slides for each of the five metabolic diseases discussed in class. Be prepared for matching & true/false questions about symptoms, treatments, and causes.
What are the symptoms of Johne’s disease? What makes it such a high impact disease for the dairy industry?
Be able to discuss PI-BVD.
Be able to identify brucellosis, vibriosis, and metritis in a matching question.
The parts of the male and female reproductive system will appear on the exam as matching and fill in the blank questions.
Hormonal control of reproduction: Know where testosterone production occurs; know where GnRH (gonadotropin releasing hormone) is secreted from (hypothalamus) and what part of the brain it targets (anterior pituitary). FSH (follicle stimulating hormone) and LH (luteinizing hormone) are secreted from the anterior pituitary in response to GnRH. FSH and LH act on the ovaries.
FSH causes follicular growth and estrogen release (from the Graafian follicle) and LH causes CL (corpus luteum) formation and when there is an LH surge, ovulation occurs. Progesterone is secreted from the CL until the uterus signals that the cow is not pregnant. The hormone that comes from the uterus is PGF2 (prostaglandin). Prostaglandin causes a regression (or killing) of the CL and progesterone secretion drops.
Estrous Cycle: be very familiar with the four stages of the estrous cycle. You will see them on the exam. I will probably have the slide that shows the four stages with the progesterone and estrogen lines. You will have to label each part and then describe what is happening. I would suggest knowing the last two slides from 10/15/09 very well.
Estrus Synchronization: What is heat detection and why is it important? What are the two methods of synchronization? (Prostaglandin & progestagens…how do they work?). Know ovsynch and how it works. Don’t worry about the exact timeline but you should understand the basics. Be able to differentiate among ovsynch, cosynch, and presynch. What makes them different?
Reproduction Technologies: Know the basics about AI, superovulation, ET, and IVF. They will show up as either matching or fill in the blank questions.
