Intro to Repro Flashcards
why do we study repro today
improvements in animal repro performance-> increased efficiency of food production->increased profit
for dairy what is the measure of efficiency
days open
for dairy what is the national average
150 days
for dairy what is the realistic goal
110 days
for beef what is the measure of efficiency
% calf crop
for beef what is the national average
86%
for beef what is the realistic goal
95%
for sheep what is the measure of efficiency
% lamb crop
for sheep what is the national average
108%
for sheep what is the realistic goal
175%
for swine what is the measure of efficiency
weaned pigs/ sow
for swine what is the national average
15 pigs/sow
for swine what is the realistic goal
20 pigs/sow
for equine what is the measure of efficiency
% foal crop
for equine what is the national average
60% of eligible mares foal
what would happen if there was a 3% increase in repro rate
1 million more beef calves per year
3.2 million more pigs per year
3.7 million more gallons of milk per year
what is asexual repro
reproduce by mitosis, characteristics of unicellular organisms
what is advantage and disadvantage of asexual repro
advantage- simple and fast
disadvantage- no new genotypes formed, cant adapt to environmental change (except mutations)
what is sexual repro
reproduce by meiosis, fusion of male and female gametes (higher forms), separate sexes
what is advantage and disadvantage of sexual reproduction
advantage- new genotypes each generation
disadvantage- complex and length process
what are oviparous
fish, amphibians, reptiles and birds
explain oviparous
egg laying
embryonic development, and possibly fertilization occurs exterior to the bodyw
what is ovoviviparous
certain reptiles and fishes
explain ovoviviparous
fertilization and embryonic/ fetal development takes place in female repro as an egg
live young are born
what are viviparous
almost all mammals
explain viviparous
fertilization and all embryonic development occurs in female repro tract
give birth to living young
what is an exception of viviparous
monotremes who are mammals but they lay eggs