Biology Flashcards
The Association of American Feed Control Officials (AAFCO) nutrient profiles are based on what?
The NRC of the United States National Academy of Sciences.
What is AAFCO? What does it provide?
An advisory body comprising state representatives from across the US. Provides mechanism for developing and implementing uniform and equitable laws, regulations, standards, and enforcement policies, and establishes nutrient profiles for dog and cat foods.
What is the maintenance energy requirement (MER)? How can it be calculated?
The amount of energy used by a moderately active adult dog in a thermoneutral environment. MEW = BW (kg) x 0.75 x 550 kJ digestible energy
What is an open formula diet?
Defined concentrations of all ingredients and the information is publicly available. Changes in formulation to maintain nutrient composition or meet changing requirements are made open.
What is a closed formula diet?
Meet and label the minimum requirements for protein and fat and the maximum volume for ash and fiber, but exact composition of ingredients may vary from batch to batch. Manufacturer applies least cost strategy by formulating diets to maximize profit by using least expensive ingredients. Ingredients are listed but quantitative ingredient formula not publicly available.
What is a fixed-formula diet?
Quantitative ingredient formulation does not change, but this information is proprietary and not publicly disclosed.
Describe semi-purified and purified diets.
Formulated from purified components: amino acids, lipids, carbs, vitamins, and minerals. Terms generally interchangeable. Purified-ingredient diets open formula.
As a general rule, how long are diets safe for consumption following the manufacture date when stored at room temperature?
6 months
Beagles at what age have the best conception rate and litter size with lowest neonatal mortality? At what age do conception rats and litter size decline and neonatal mortality increase?
Ideal between 2 and 3.5 years. Decline after 5 years old.
Approximately where is the cervix in relation to the ovaries and vulva? When can be it palpated in the abdomen?
Halfway between ovaries and vulva. Palpated in the abdomen in proestrus and estrus.
Describe general reproductive characteristics of female dogs.
Monoestrous, nonseasonal, spontaneous ovulators. Spontaneous luteal phase 5 days longer than the 65 +/- 1 days of pregnancy followed by obligate anestrus.
When does female puberty occur? What is it positively correlated with?
6-14 months. Positively correlated with body size.
What are the four stages of the canine estrus cycle?
Proestrus, estrus, diestrus, and anestrus.
How long does proestrus last? What hormonal and physical changes take place?
5-20 days, average of 9. Follicular phase rise in estrogen. Vulva enlarged and turgid, serosanguinous vaginal discharge present.
How long does estrus last? What are the endocrine features? What are physical characteristics?
5-15 days, averages 9 days. First abrupt increase in progesterone which occurs concomitantly with the LH surge, followed by ovulation in 24-72 hours. Vulva softer and smaller, vaginal discharge persists and may remain serosanguinous or become straw-colored.
When does diestrus begin? How long does it last? How is it behaviorally defined? Which hormone peaks?
Begins 9 days after onset of standing heat. Ends 60 days later, which would coincide with whelping if pregnancy occurred. Defined behaviorally as starting when estrous behavior ceases. Represents peak progesterone.
How long is anestrous? How is it characterized?
80-240 days. Stage of repro quiescence with an absence of ovarian activity and serum progesterone levels less than 1 ng/mL.
When does male puberty occur? How is this process initiated? Describe the hormonal pathway.
5 to 12 months. Initiated by secretion of LH from anterior pituitary, which stimulates the production of testosterone by the interstitial/Leydig cells. Testicular growth is rapid, seminiferous tubules begin to differentiate, and Sertoli cells form blood-testis barrier. Secretion of FSH by anterior pituitary stimulates Sertoli cells to produce inhibin, androgen binding protein, and estrogen. FSH stimulates spermatogenesis in presence of testosterone, inhibin and estrogen provide negative feedback to pituitary to decrease FSH production.
How long does spermatogenesis take? How long must sperm mature for in the epididymis? Thus, the entire process from initiation of spermatogonial mitosis to the delivery of mature sperm to the ejaculate takes how long?
45 days, 15 days, 60 days total.
What can cause suppression of sexual behavior and problems with libido in male dogs?
Early weaning, isolation, or inherited abnormalities.
What correlation exists between scrotum circumference and number of sperm produced?
Positive correlation
What characteristics of ejaculate are good indicators of normal male fertility?
Ejaculate (5 mL) with approx 500 million progressively motile sperm without sig. morphological abnormalities.
What occurs to the vaginal epithelium due to estrogen? When does this peak?
Increase in the percentage of vaginal epithelial cell cornification. Peaks 2 days prior to estrogen peak and 4 days prior to standing heat.
When does vaginal cytology of the bitch change from predominantly cornified to noncornified? What does this coincide with?
6 days after ovulation. Coincides with first day of diestrus.
