Horse Flashcards
sexual dimorphism
the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs
breeds used to re-create the tarpan
polish koniks, icelandic ponies, swedish gotlands and polish primitive horses - these mares where mated to przewalski stallions - were thought to serve as a catalyst to draw out latent tarpan characteristics. 1933 was the first.
taxonomy: family, genus, subgenus
family equidae
- genus equus: wild horses, przewalski, tarpan, domestic
- subgenus asinus(ass): equus africanus asinus
evolution; 4 main
over 60 million years:
- Eohippus
- mesohippus
- mio-, mery-, pliohippus
- equus
domestication; where
central asia, then later in persia, egypt and europe 3000-4000BC
- extict in north america 10 000yrs ago
non-domestic horses - types
wild horses: przewalski horse is the only remaining spp
feral horses: domestic ancestors but born and live in wild, e.g. mustangs in north america, and brumby in australia
size variation: weight and hight
- *weight**: 50 - 1200kg
- *height**: (at withers) 50-180cm
- *dwarfism**: falabella, shetand pony
puberty and sexual maturity
puberty: 16-18 months
full sexual maturity: 2+yrs (3-5 is average)
general reproductive features
single offspring, low reprod. potential, late puberty, seasonal sexual activity, frequent miscarriages, low pregnancy rate, long pregnancy, rare twin pregnancy (2 eggs, 30% abortion/resorption)
heat signs
vet.: palpation, ultrasound, measure hormone levels
signs:relaxed+incr. blood to genitals, frequent urination, raising tail, mucous discharge, desire for company, teasing other mares, presenting to teasing stallion
pros to artificial insemination
no contact(accidents), less stress(no travel), less disease spread, more mares can be bred - even after death of stallion, international breeding programs
what are the signs of pregnancy
no heat after covering, clinical signs: thick muscous discharge, assymetric uterus/foetal fluid and featus found during rectal exam, ultrasound 14th-45th day, measure hormone levels
pseudopregnancyd
false pregnancy: embryonic death after 35th day, the corpus luteum cannot react to drugs to induce heat.
how can the environment affect the pregnancy
the photoperiod is the length of day where daylight is present, increase “length of day”, and the ovary activity will increase with it.
what can we do if we dont want a competition mare to go out of training
embryo transfer, egg transfer, gamete intrafallopiantransfer(placing the two gametes in another mares fallopian tube
foal upbringing
live with mother(imprinting) e.g. free on pasture. Several times a week its checked for navel hernia. they are also taken in for hoof trimming. imp to give mother correct food to give right nutrition to the foal
basic and modifies colors
basic: black, bay (brown with black mane/tail), chestnut (redish brown with same or lighter color mane and tail)
modified: roan is an even mixture of colored and white hairs on the body, while the head and “points”—lower legs, mane and tail—are mostly solid-colored
Inbreeding coefficient
The coefficient of relationship is a measure of the degree of biological relationship between two individuals, should not exceed 0.1-0.3
backcrossing
a type of inbreeding where crossing of a hybrid with one of its parents or an individual genetically similar to its parent, to achieve offspring with a genetic identity which is closer to that of the parent
⇒ one or more relatives occur more than once in a pedigree (record showing ancestors to be purebred - all belonging to same breed)
blood refreshment
crossing incuviduals of same breed but different families to increase genetic variability for better strength and health
cross breeding types
getting characteristics form 2 or more breeds
- *- single crossing**
- *- grading up:** several crossings to improve breed/make new
- synthetic breeds: planned gene pool of a breed
- terminal cross: two (different) breeds of animal that have been crossbred. The female offspring of that cross is then mated with a male (the terminal male) of a third breed, producing the terminal crossbred animal.
gated horses
possess specialized gaits, faster than walk, usually slower than canter, inhertited or taught by minimal training
- *Missuri foxtrotter:** 4 beat diagonal gait
- *peruvian paso:** smooth gait
- *five-gaited american saddlebred:** 4 beat gait, snap hock and knee up quickly
- *tennessee walking horse:** 4 beat lateral gait, running walk
- *icelandic horse:** tolt/flying pace
eventing
horse and rider combine and compete against other combinations across the three disciplines of dressage, cross-country, and show jumping.
types of horse shows
- *equitation:** rider judged on form, style, ability/handling
- *under saddle:** horses are ridden on the flat, judged by manners, performance, movement, style, quality
- *in-hand/conformation:** horse judged by conformation and/or breeding ability
- *jump classes:** show jumping, show hunter(hunting abilities)