Lecture 15 Secondary Products - Beyond Milk and Wool Flashcards
CHICKENS &
EGGS
¡ Chickens in Egypt (1750BC)
-fighting birds, exotic
menageries
* Likely already laying eggs
daily (historic texts)
* Not common commodity
until 1000BC
¡ Constructed artificial incubators, eggs turns 3-5 times per day
MEDIEVAL SELECTION FOR EGG?
¡ TSHR gene = thyroid-stimulating hormone receptor, linked to photoperiod and reproduction
¡ TSHR allele frequency in ancient chicken reveals selection ca. 920AD
¡ Coincides with major changes in chicken husbandry, relating to urbanization and in preference for eggs over meat
¡ Christian fasting practices
CHICKENS AS MEAT
¡ Roman prized larger birds for meat
- Castrated males = capons(become bigger)
¡ Large organised farms, feeding numerous chickens protection from predators
- Increase in chicken skeleton in Roman period,
¡ Medieval period - decrease in chicken size, more consumption of hardier fowls such as geese and partridge
chicken has become bigger since 1950’s
SERICULTURE
silk worms > produces silk
SILK CAN BE A SECONDARY
PRODUCT – PEACE SILK
- traditional silk process they have to die (primary product)
but
- theres a more sustainable way to alow the worm to become a moth(seconday product)
DOMESTICATION SYNDROME – SILK MOTH
- Bombyx mori (domesticated) (Bombyx mandarina – wild species)
-
Domestication syndrome
o Cannot fly
o Blind
o Loss of colouration - Entirely dependent on humans for breeding and survival.
BEES AND HONEY
- Evidence for managing honey bees in artificial hives since 7000 BP.
- Western honey bee (Apis mellifera)
domestication was motivated by crop
pollination and honey production. - Early evidence of “honey hunting” found in pottery from West Africa 3500 BP
-
Domestication syndrome
o Not efficient pollinators
o Dependent on humans for survival
o Domesticated honey bees have more genetic
variation than wild species
