Domestication and Genetics

Lecture 1: Domestication and Genetics

• Domestication is the process of genetically changing a population of living organisms through selective breeding, accentuating desirable traits that benefit humans
• Domestic animals include pets, cats, dogs, horses, and cows

Degrees of Domestication

• Wild animals exhibit "fight or flight" behavior
• Tamed animals show some dependence on humans
• Semi-domesticated animals have a human-animal relationship
• Domesticated animals are reliant on humans

Common Changes in Traits Due to Domestication

• Adrenal glands relate to tameness
• Melanocytes affect coat color
• Chondrocytes relate to skull size
• Odontocytes relate to teeth size
• Morphological changes occur
• Floppy ears develop

Belyaev's Fox Experiment

• Foxes were selected based on temperament, starting with 465 foxes
• The main goal was to simulate the process that turned wolves into present-day dogs
• Initial fox behavior percentages: 30% extremely reactive, 40% moderately reactive, 20% fearful, and 10% quiet & exploratory
• Breeding criteria focused on flight threshold distance to assess tameness

Tameness and Hormones Involved

• Tameness involves a reduction in the release of stress hormones, including a reduced fight-or-flight response and decreased reactivity to new situations
• Hormones are produced by adrenal glands (top of the kidney)
• Long-term hormones include Glucocorticoids (cortisol), regulating neonatal development
• Short-term hormones include Catecholamines (epinephrine and norepinephrine)
• Domestic animals have reduced levels of these hormones compared to wild animals

Neural Crest Hypothesis

• Genetic changes to neural crest cells are believed to cause domestication traits
• Domestication involves a decrease in the size of the neural crest, reducing the population of cells derived from it
• Tameness occurs due to reduced stress hormone synthesis, as cells that produce these hormones originate from the neural crest
• A smaller number of cells involved results in domestication syndrome

Wolf Domestication

• Wolves with a short flight distance took advantage of food waste from humans, gaining a competitive advantage
• These wolves bred with each other and developed domestication syndrome

Commensal and Prey Domestication Pathways

• The commensal pathway involves habituation, partnership, and directed breeding
• The prey pathway includes prey, game management, herd management, and directed breeding

Lecture 2: Animal Production Systems

Extensive vs. Intensive Animal Systems

• Extensive systems minimize capital inputs, use unprocessed diets with low nutrient and high fiber density, involve non-confinement, and minimize handling
• Beef cattle, sheep, and goats are examples of animals raised in extensive systems
• Intensive systems involve significant capital inputs, processed nutrient-dense diets, confinement production, and economies of scale
• Pork, dairy, and poultry are examples of animals raised in intensive systems

Animal Lifecycle, Sector Types, and Production Systems

• Cow-calf operations are primary in extensive production, utilizing pasture and rangeland
• Backgrounding/stocker involves managing animals with forage/pasture diets and slow growth
• Feedlot/finishing is an intensive production system using primarily concentrate diets
• Packing sector is an intensive production system with primarily feedlots and some pasture

Animal Lifecycle Terms

• Cow: mature female
• Heifer: young female
• Bull: sexually mature uncastrated male
• Steer: castrated male before sexual maturity
• Calf: neonatal to 5 months of age
• Gestation period is 283 days, with 82 days to get pregnant post calving

Pork Terms

• Sow: mature female pig
• Gilt: immature female pig before the 2nd pregnancy
• Boar: mature male pig
• Barrow: castrated male pig
• Piglet: neonatal pig before weaning
• Farrowing: giving birth to piglets

Modern Swine Production in Canada

• Pigs are typically raised in total confinement throughout their life
• Biosecurity on commercial farms is very important, with limited visitors
• Breeding is done through artificial insemination
• Gestation lasts for 3 months, 3 weeks, and 3 days

Farrowing Practices

• Sows are kept in individual crates
• Average litter size is 15 piglets, with an average birth weight of 1.2 kg
• Colostrum intake is critical in the first 6 hours
• Most sows have 12 teats

Weaning Practices

• Weaning is abrupt
• Piglets are moved to a nursery and transitioned from milk to a solid feed
• Piglets are mixed with other piglets at 21-28 days old

Grow-Finish Stage

• After 5 weeks in the nursery, pigs are housed in large groups
• Diets are changed as pigs mature and they are ready for market in 15 weeks, weighing 125 to 130 kg

Dairy Production

• The lifecycle involves lactation cycle, lifespan, and calves
• Parturition and milk fever require cows to mobilize large amounts of calcium from the skeleton.
• Insufficient calcium can cause muscle tremors, staggering, lying flat, heart failure, and death
• Treatment involves intravenous calcium

Supply Management in Canada

• Milk production is designed to meet the demand of Canadians, with limited exports and imports
• The quantity of milk required is established for each province
• Quotas are licenses to produce up to a set amount of milk, with limits set by a national marketing agency
• Producers are guaranteed a minimum price, and high tariffs make imported products expensive, favoring Canadian products

Importance of Colostrum

• Calves are born without immunoglobulins in their bloodstream
• The small intestine of the newborn can absorb immunoglobins into the blood for the first 24 hours after birth, providing passive immunity
• Antibodies are Y-shaped proteins that bind to bacteria and viruses to help prevent disease

Lecture 3: Beef Industry and Forages

Production System for the North American Beef Industry

• A sectored production system involves cow-calf, backgrounding, feedlot, and packer operations
• There are over 90,000 producers in the industry
• The Canadian beef industry involves 15 million cattle and calves, with most operations being family-run

Forages in Cow-Calf Nutrition and Management

• Forages are the "Foundation of the Beef Industry" and include pasture, hay, straw, and silage
• Forage is a major feed component, and feed is the single greatest variable cost in beef production
• Main focuses include energy, protein, minerals, vitamins, and water

Canada's Traceability Program

• This is based on animal identification tags and premise identification; cattle must have individual IDs and premise IDs to leave property
• Premise identification and animal movement records are necessary

Cattle Breed Varieties

• Common dominant breeds include Angus, Simmental, Hereford, Charolais, and Limousin
• Cattle vary in color, carcass quality, behavior, frame size, and feed efficiency

Weaned Calf Sales

• Calves are sold in groups at auction markets to feedlot buyers
• Internet/video sales are common
• Forward contracts with feedlots eliminate the 'sale barn'

Lecture 4: Poultry Terminology and Production

Poultry Terminology

• Broiler: meat chicken
• Layer: table egg production chicken
• Rooster: male chicken
• Tom: male turkey
• Hen: female turkey or chicken

Chicken Consumption in Canada

• Chicken is the most consumed meat because Canada uses a supply management system, producing as much as consumed

Supply Management System for Poultry

• Family farms in Canada use this
• The USA does not use this
• Producers receive steady income
• Many vaccines are available, but politicians often restrict their use
• Operations with >1000 broilers are commercial

Advantages and Disadvantages of Poultry Supply Management

• Advantages: producers get a steady income, steady supply without oversupply, enough money to support additional welfare initiatives and boards have a say in practices for animal welfare of birds
• Disadvantages: products are more expensive for consumers and future producers must purchase quota

Lecture 5: Horse Evolution and Domestication

Evolution and Domestication Timeline

• Equus evolved in North America, with ancestral migration to Eurasia
• They spread across the Eurasian steppes
• Horses were hunted for food
• They were raised in captivity and were domesticated

Expansion of Horse Use and Domestication Costs

• First they were used for carrying and hauling
• They were then used for effective war tactics
• Followed by riding of horses

Coat Colors and Selective Disadvantages

• Selective disadvantages are associated with certain colors in wild horses
• Some colors have negative pleiotropic effects
• Melanomas can be grey
• MCOA- eye disorder can be silver
• CSNB can be leopard spotting
• OLWFS can be Overo Pinto
• Splashed white and Overo can result in deafness
• White can be embryonic lethal
• Roan can be embryonic lethal

Detrimental Effects of Specialization

• Breeding for small size can cause dwarfism
• Breeding for heavily muscled quarter horses can cause periodic paralysis
• Breeding for speed can propagate fragility
• "Popular sire" results in disequilibrium between detrimental genes and performance genes

Lecture 6: Swine Production

Origin and Latin Name of Domestic Swine

• Pigs were domesticated (probably) in China (490 B.C) and England (800 B.C)
• Its Latin name is Sus scrofa domesticus

Major Canadian Swine Breeds

• Yorkshire (42% of herd)
• Landrace (32%)
• Duroc (25%)

Terminology in Swine Production

• Swine is another word for pig
• Pork is pig meat
• Sow is the mother pig
• A gilt is of breeding age, but hasn’t had piglets
• Weaning is the removal of young from their mother
• Hog is the pig ready to be processed
• Process/harvest is slaughter for meat
• Boar is the adult male pig kept for breeding
• Farrowing is the act of parturition in pigs

Pork Production in Saskatchewan (SK)

• Saskatchewan has 8.5% of all pig production
• SK is the 5th largest producer in hogs

Changes in Swine Operations

• Changes are due to advances in technology, transportation, and economies of scale

Lecture 7: Dog and Cat Domestication

Dog and Cat Ownership Trends

• Cat ownership surpasses that of dog ownership
• There are 8.5 million cats and 7.9 million dogs kept as pets
• Pet cat cost = 2,542 dollars
• Pet dog cost = 2,500 + 1,000 dollars
• Ontario had 770 pet stores in 2021.
• Brick and mortar stores are declining while online purchases are increasing

Domestication Impact on Dogs and Cats

• Dogs originated with hunter-gatherer societies, descended from an unknown wolf. Their relationship started as mutual co-existence then companionship.
• The way dogs look and behave has changed
• They have an increased ability to digest carbohydrate-rich diets through amylase enzyme increase.
• Cats are more recent and aren't as dependent or responsive to humans as dogs.
• Domestication has not changed the way cats look and behave
• Cats easily revert to feral
• Their diet preference and metabolism is unchanged from wild cats

Health Benefits and Risks of Pet Ownership

• Benefits: social support, companionship, improved mental health, motivates exercise, animal-assisted therapy and activities, teaches empathy, social skills, and self-esteem
• Risks: infections, parasites, allergies, bites, injury, financial burden, psychological burden when pets die, neglect of animals

Animal Assisted Therapy vs Activities

• Animal assisted therapy is part of treatment for physically, socially, emotionally, or cognitively challenged
  • Stated goals for each sessions
  • Individual treatment
  • Scheduled
  • Detailed notes
  • Administered by trained health professionals
• Animal assisted activities are casual activities involving pets and people
  • No specificity's
  • Typically volunteer run
  • Can be as long or short as necessary

Lecture 8: Dairy Cattle Management

Supply Management:

• Milk production is designed to meet the demand of Canadians
• Limited exports and imports of milk and milk products
• Quantity of milk required is established for each province.

Dairy Cattle Management:

• Mainly bred through artifical insemination
• Want to produce a calf every 365 days
• Calves are housed indoors and fed milk or milk replacer
• Shifts to a grower phase promoting rapid lean tissue growth
• Breed at 13-15 months of age
• Have first calf at 22-24 months of age

Key Aspects of Management:

• Colostrum management and Passive transfer

• Changes in milk yield of dairy cattle over time

• Importance of cow-comfort

• Characteristics of the mammary gland

• Cows cannot reach genetic potential without a great environment, adequate nutrition and calm handling

Mammary Gland:

• "Take it or lose it policy"
• Frequent milking in early lactation stimulates cell development in the mammary galnd
• Increased cell development has carry-over effects
• Nutrient demand increases tremendously in lactation.

Lecture 9: Indigenous Aquaculture

Distinctions Between Indigenous Peoples:

• First Nations, Métis, and Inuit are all distinct Indigenous peoples of Canada with their own culture, history, practices, and beliefs

Principles for Sustainable Aquaculture

• Transparency and First Nations inclusiveness
• Social and environmental responsibilites
• Economic responsibility

Differences in Approach:

• Includes aspects that are cultural and spiritual
• Links to the land that are unique
• Mistrust of conventional science
• Access to aquatic resources and other rights
• Job creation and high food prices

Lecture on the domestication process, including degrees of domestication and trait changes due to domestication. Includes Belyaev's fox experiment and how it simulates the process of wolves becoming dogs. Covers changes in adrenal glands, melanocytes and other morphological changes.