Exam 1 Review

Question 1

List and briefly describe the 3 stages of parturition

Answer 1

Stage 1: primarily behavioral; looks almost like colic as mare gets up and down and may sweat, bite at flank, paw, and look nervous; lasts 1-6 hours
Stage 2: begins with rupture of chorioallentois (placental membrane); will have 3-4 forcible contractions and then rest; will see amnion appear, blueish, and then forelimbs and shoulders; ends with foals birth and will last 10-20 min
Stage 3: expuslion of placenta; should occur 3-4 hours after foaling

Question 2

describe the similarities and differences of Merychippus to the modern horse (5)

Answer 2

1. the merychippus developed grinding teeth like the modern horse; was the first model to adapt to eating plains grasses
2. Merrychippus had three toes on the front leg, with lateral toes regressed and not reaching the ground
3. Merychippys had a strengthened central toe but not quite the hoof of the modern horse
4. merychippus was also thefirst hipsodon, same as the modern horse today
5. merychippus was the first model to be gregarious/herdbound

Question 3

when was the Morrill Land Grant passes and what was its function?

Answer 3

in 1862; established agricultural colleges

Question 4

If you want a horse to foal on February 1st of 2024, approximately when would you begin an artificial lighting program?

Answer 4

breed March 1st of 2023ish, so being lights in December of ‘22 (60-90 days before breeding)

Question 5

Thoroughly desacribe the physiologic process associated with photo period and cyclicity in mares; how does light stimulate cyclicity?

Answer 5

Light travels from the retina via nerve tracts to the suprachiasmatic nucleus in the hypothalamus, then via nerve tracts to the superior cervical ganglion and then to the pineal gland, which converts tryptophan to seratonin and then to melatonin, which acts on the hypothalamus to alter levels of GnRH, which will control production of FSH and LH to control cyclicity; horses are seasonal polyestrous long day breeders, so increased melatonin inhibits cyclicity. Artifical lighting/increased light stimulates an inhibitory pathway for melatonin production and induces cyclicity which decreased lighting inhibits the inhibitory pathway for melatonin production, increasing melatonin concentrations and inhibiting cyclicity

Question 6

how does the suspensory ligament differ from other ligaments? what is its main function?

Answer 6

it contains some tendinous tissue, so is considerably more elastic than other ligaments; its main function is to maintain stability of the fetlock while still allowing movement but also protecting the fetlock from extreme hyperextension

Question 7

Regarding horses, what does the term cob describe?

Answer 7

a cob is a docile, sturdy horse that is not heavy enough to be considered a draft horse

Question 8

describe the basic function, anatomy, location, and insertion of the superficial digital flexor tendon

Answer 8

the SDFT runs down the back of the leg in a synovial sheath. at the lower end of the canon it splits and forms a ring around the deep digital flexor tendon; then, below the fetlock, the SDFT branches and each branch inserts on eitherside of the lower long pastern bone and upper short pastern bone. the SDFT helps with flexion of the leg and maintains the integrity of the pastern joint

Question 9

compare the value/use of oxen vs. horses in agriculture in the 1800s

Answer 9

oxen are cheaper to maintain and eat less than horses; they can also be eaten when they can no longer work; however,horses were more suited to the farming equipment used and produced in the 1800s and their hoof was more stable than the oxen hoof, so horses were the preferred agricultural work animal in the 1800s

Question 10

what are the attributes/breed characteristics of the arabian horse?

Answer 10

1. 14.2-15.2 hands
2. 800-1,000lbs
3. stamina/endurance horses
4. dished face
5. main colors are grey, bay, chestnut
6. refined muscle

Question 11

when was domestication of the horse?

Answer 11

5,000-6,000 years ago

Question 12

what is the function of a check ligament?

Answer 12

to “check” or support the tendon it inserts into

Question 13

what are the characteristics of the isthmus and why is this important?

Answer 13

it is narrow, extremely tortuous, and coils at its juncture with the uterus to allow the fertilized ovum time to mature before entering the uterus (appriximately 5 days after fertilization to entering the uterus)

Question 14

compare the mare’s ovary to other animals

Answer 14

considered inside out with the medulla being on the outside and the cortex on the inside

Question 15

what can affect the position of the mare ovary? (3)

Answer 15

1. GI tract content
2. parity number
3. age of mare

Question 16

be able to describe justin morgan horse

Answer 16

go look in notes!

Question 17

be able to describe tendons

Answer 17

go look in notes

Question 18

be able to describe thoroughbreds

Answer 18

go look in notes!

Question 19

how are horses classified?

Answer 19

1. can be based on size, weight, build, color, abreed, and use
2. pony, light, or draft
3. ponies can be draft or heavy harness or saddle type

Question 20

who is considered the founding sire of the saddlebred breed?

Answer 20

Denmark

Question 21

who was Eclipse?

Answer 21

a descendent of the Darley Arabian and winner in every one of his18 races and probably the most famous race horse of all time

Question 21

who was Eclipse?

Answer 21

a descendent of the Darley Arabian and winner in every one of his18 races and probably the most famous race horse of all time

Question 22

when does ovulation occur in the mare?

Answer 22

24-48 hours prior to the end of the estrus period

Question 23

who was Peter McCue?

Answer 23

the most famous (most important) sire in the establishment of the Quarter Horse breed

Question 24

what is diestrous?

Answer 24

the period during the estrous cycle where the mare is not in heat

Question 25

describe the inferior check ligament

Answer 25

located between the suspensory ligament and the flexor tendons; fuses with the deep digital felxor tendon

Question 26

give the order and family of the horse

Answer 26

Order: perissodactlya
family: equidae

Question 27

describe differences and similarities between 3 and 5 gaited saddlebreds

Answer 27

three gaited horses: roached mane and set tail; emphasis on animation and precision; walk, trot, canter
five gaited: full mane and set tail; emphasis on speed in a controlled, animated form; walk, trot, canter, slow gait, and rack (slow gait and rack ar artifical 4 beat gaits)

Question 28

what bones are associated with the feetlock joint?

Answer 28

cannon bone (m3), upper long patern, and proximal sesamoids

Question 29

how did that standardbred breed get its name?

Answer 29

these horses meet a standard or running one mile in or under one minute and 55 seconds

Question 30

what are the two purposes of the follicle?

Answer 30

1. protect and maintain the growing ovum
2. produce estrogen

Question 31

what were the 4 major trends in the line of descent from eohippus to equus?

Answer 31

1. reduction in number of toes
2. enlarging size of cheek teeth
3. elongating the skull
4. increasing body size

Question 32

with the decline of horses in the early 20th century, two breeds were particularly hard hit; which breeds were they and why did their numbers decrease more quickly than other breeds?

Answer 32

Shires and Clydesdales; the feathering above their hooves makes them prone to sratches, which is a dermatitis on the heel and back of the legs, if they work on farms. they were not used on farms much because this predisposition made maintenance difficults, so once mechanization occurred their populations declined dramatically