Domestication and Genetics

Lecture 1: Domestication and Genetics

• Domestication involves genetically altering a population of living organisms through selective breeding to enhance traits beneficial to humans.
• Domestic animals include pets like cats and dogs, as well as 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

• Tameness is linked to adrenal glands.
• Coat color involves melanocytes.
• Skull size is reduced due to changes in chondrocytes.
• Tooth size is reduced due to changes in odontocytes.
• Morphological changes occur, including the development of floppy ears.

Belyaev's Fox Experiment

• Foxes were selected based on temperament.
• The experiment started with 465 foxes.
• The goal was to simulate the transformation of wolves into modern-day dogs.
• Initial assessment of fox behavior: 30% extremely reactive, 40% moderately reactive, 20% fearful, and 10% quiet and exploratory.
• Breeding criteria focused on flight threshold distance.

Tameness and Hormones

• Tameness is a reduction in the release of stress hormones.
• This leads to a reduced fight-or-flight response and decreased reactivity to new situations.
• Hormones are produced by the adrenal glands.
• Long-term hormones include glucocorticoids like cortisol, regulating neonatal development duration.
• Short-term hormones include catecholamines like epinephrine and norepinephrine.
• Domestic animals have reduced levels of these hormones compared to wild animals.

Neural Crest Hypothesis

• Genetic changes to neural crest cells cause domestication traits.
• Domestication involves decreasing the size of the neural crest.
• This reduces the population of cells derived from the neural crest.
• Tameness results from reduced stress hormone synthesis.
• Cells that produce these hormones originate from the neural crest.
• A smaller number of neural crest cells involved results in domestication syndrome.

Wolf Domestication

• Wolves with a short flight distance benefited from human food waste.
• These wolves tended to breed with each other, developing domestication syndrome.

Commensal and Prey Domestication Pathways

• The commensal pathway involves habituation, partnership, and then directed breeding.
• The prey pathway involves managing prey, then herd management, and directed breeding.

Lecture 2: Animal Production Systems and Lifecycle

Extensive and Intensive Animal Systems Defined

• Extensive systems have minimized capital inputs.
• Extensive systems use mainly unprocessed diets of low nutrient, high fiber density.
• Extensive systems involve non-confinement and minimized handling.
• Examples of animals in extensive systems are beef cattle, sheep, and goats.
• Intensive systems have significant capital inputs.
• Intensive systems use processed, nutrient-dense diets.
• Intensive systems involve confinement production and economies of scale.
• Examples of animals in intensive systems are pork, dairy, and poultry.

Sector Types in Animal Production

• Cow-calf is a primary sector in extensive production on pasture and rangeland.
• Backgrounding/Stocker involves managing animals with forage/pasture and slow growth.
• Feedlot/Finishing is an intensive production system primarily using concentrate diets.
• The packing sector is also part of intensive production.
• Primarily feedlots use some pasture.

Animal Lifecycle Terminology

• A mature female cow is a cow.
• A young female cow is a heifer.
• A sexually mature, uncastrated male is a bull.
• A castrated male before sexual maturity is a steer.
• A neonatal to 5-month-old animal is a calf.
• Gestation period for cows is 283 days, with 82 days to get pregnant post calving.
• A mature female pig is a sow.
• An immature female pig before her 2nd pregnancy is a gilt.
• A mature male pig is a boar.
• A castrated male pig is a barrow.
• A neonatal pig before weaning is a piglet.
• Farrowing is giving birth to piglets.

Modern Swine Production in Canada

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

Farrowing Practices

• Sows are kept in individual crates.
• Average litter size is 15 piglets.
• Average birth weight is 1.2 kg.
• Colostrum intake is vital in the first 6 hours.
• Most sows have 12 teats.

Weaning Practices

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

Grow-Finish Phase

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

Dairy Production and Milk Fever

• A dairy lifecycle is lactation cycle, lifespan until the birth of calves.
• Parturition and milk fever require cows to mobilize large amounts of calcium from their skeleton.
• Insufficient calcium leads to muscle tremors, staggering, lying flat, heart failure, and death.
• Treatment involves intravenous calcium,

Supply Management in Canada

• Quotas are licenses to produce up to a set amount of milk.
• National marketing agencies determine production amounts and set quotas for each province.
• Producers are guaranteed a minimum price for their products.
• High tariffs make imported dairy products expensive, favoring Canadian products.

Colostrum Importance

• Calves are born with no immunoglobulins in their bloodstream.
• The small intestine of the newborn can absorb immunoglobins into blood for the first 24 hours after birth which is passive immunity.
• Antibodies are Y-shaped proteins that help prevent disease by binding to bacteria and viruses.

Lecture 3: Beef Industry and Traceability

North American Beef Industry Production System

• A sectored production system is used in the North American beef industry.
• The system includes cow-calf operations, backgrounding, feedlots, and packers.
• There are >90,000 producers.
• The Canadian beef industry has 15 million cattle and calves.
• Majority family-run operations.

Forages for Cow-Calf Nutrition and Management

• Forages, including pasture, hay, straw, and silage, are the foundation of the beef industry.
• Feed is the single greatest variable cost in beef production.
• Forages provide energy, protein, minerals, vitamins, and water.

Canada's Traceability Program

• The traceability program is based on factors like animal identification using radio frequency identification tags, premise identification, and animal movement.
• Cattle must have individual identification and premise identification when leaving property.

Cattle Breed Varieties

• Dominant breeds include Angus, Simmental, Hereford, Charolais, and Limousin.
• Breeds vary based on color, carcass quality, behavior, frame size, and feed efficiency.

Weaned Calf Sales

• Calves sales in groups through auction marts to feedlot buyers are common.
• Calves are sold through Internet/Video sales.
• Forward contracts with feedlots eliminating sale barns occur.

Lecture 4: Poultry Terminology and Production

Poultry Terminology

• Broiler refers to meat chicken.
• Layer refers to table egg production chicken.
• Rooster refers to male chicken.
• Tom refers to male turkey.
• Hen refers to female turkey or chicken.

Chicken Consumption in Canada

• Canada has a supply management system, so the country produces as much as it consumes.

Supply Management System - Poultry

• Poultry farms are family farms in Canada, but not family-owned in the USA.
• Producers receive steady income.
• Many vaccines are available, but political restrictions limit their use.
• Poultry operations with >1000 broilers are considered commercial.

Advantages and Disadvantages of Poultry Supply Management

• Producers get a steady income, with a steady supply preventing oversupply.
• Producers earn enough to support additional welfare initiatives.
• Boards have say in practices for animal welfare of birds.
• Product is more expensive for consumers.
• Future producers must purchase quota.

Lecture 5: Horse Evolution and Coat Colors

Evolution and Domestication of Horses

• Equus evolved in North America.
• Ancestral migration to Eurasia occurred.
• Horses spread across the Eurasian steppes.
• Horses were initially hunted for food.
• Later, horses were raised in captivity, initiating domestication.

Expansion of Horse Use and Domestication Costs

• Horses were first used for carrying and hauling.
• Horses were used for effective war tactics.
• Horses were then used as riding animals for war and transport.

Horse Coat Colors and Selective Disadvantages

• Certain coat colors have selective disadvantages for wild horses related to negative pleiotropic effects.
• Grey horses get melanomas.
• Silver horses have MCOA - eye disorder.
• Leopard Spotting horses get CSNB.
• Overo Pinto horses get OLWFS.
• Splashed white horses get Deafness.
• Overo horses get Deafness.
• White horses have Embryonic lethal effect.
• Roan horses have an Embryonic lethal effect.

Detrimental Effects of Specialization in Horses

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

Lecture 6: Swine Production

Origin and Latin Name of Domestic Swine

• Domestic swine probably originated in China (490 B.C) and England (800 B.C).
• The Latin name is Sus scrofa domesticus.

Major Canadian Swine Breeds

• Yorkshire makes up 42% of the herd.
• Landrace makes up 32% of the herd.
• Duroc makes up 25% of the herd.
• Other breeds include Hampshire, Lacombe, Pietrain, and Berkshire.

Swine Production System Terms

• Swine refers to the animal pig.
• Pork refers to pig meat.
• Sow refers to a mother pig.
• Gilt refers to a pig of breeding age without piglets.
• Weaning refers to the removal of young ones from their mother.
• Hog refers to a slaughter-ready pig.
• Process/harvest refers to the slaughter of meat animals.
• Boar refers to an adult male pig kept for breeding purposes.
• Farrowing refers to the act of parturition in pigs.

Pork Production in Saskatchewan (SK)

• SK accounts for 8.5% of all pig production.
• SK is the 5th largest producer of hogs.

Changes in Swine Operations

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

Lecture 7: Domestication of Dogs & Cats

Dog and Cat Ownership Trends

• Cat ownership is greater than dog ownership.
• There are 8.5 million cats as pets.
• There are 7.9 million dogs as pets.

Pet Costs

• Pet cat cost is $2,542.
• Pet dog cost is $2,500 + $1,000.
• There were 770 pet stores in Ontario in 2021.
• Brick and mortar stores are declining as online purchases increase.

Domestication Impact on Dogs and Cats

• Dogs began with hunter-gatherer societies, descended from unknown wolf, became mutual coexistence then companionship.
• Domestication changed the way dogs look and behave.
• Domestication Increased ability to digest carbohydrate-rich diet through amylase enzyme increase.
• Cats are more recent and less dependent/responsive to humans.
• Domestication has not changed the way cats look and behave
• Cats easily revert to feral.
• Cat diet preference and metabolism remain unchanged from wild cats.

Health Benefits and Risks of Pet Ownership

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

Animal Assisted Therapy vs. Activities

• Animal assisted therapy is part of treatment for people with physical, social, emotional, or cognitive challenges,
• Animal assisted therapy has stated goals, individual treatment, scheduled sessions, detailed notes, and is administered by trained health professionals.
• Animal assisted activities refers to casual activities involving pets and peoples, no specificity, typically volunteer-run, and varies in length.

Lecture 8: Dairy Cattle Management

Dairy Cattle Management

• Milk production is designed to meet the demand of Canadians.
• There are limited exports and imports of milk and milk products.
• Quantity of milk required is established for each province.
• Cows mostly bred through artificial insemination.
• Producers want to produce a calf every 365 days.
• Calves are housed indoors and fed milk or milk replacer.
• Calves shift to a grower phase, promoting rapid lean tissue growth.
• They're bred at 13-15 months, with first calf at 22-24 months.

Dairy Cattle Management - Key Aspects

• Key aspects of management include colostrum management, passive transfer, changes in milk yield, cow comfort, and mammary gland characteristics.
• Cows cannot achieve genetic potential without a great environment, adequate nutrition, and calm handling.

Mammary Gland

• Mammary gland management functions on a "take it or lose it" policy.
• Frequent milking stimulates cell development in the mammary gland.
• Increased cell development has carry-over effects.
• Nutrient demand increases tremendously in lactation.

Lecture 9: Indigenous Aquaculture Principles

Indigenous Understanding

• The indigenous peoples of Canada are the First Nation, Metis, and Inuit.
• They exhibit distinct cultures, histories, practices, and beliefs.

Indigenous Aquaculture Principles

• Indigenous aquaculture prioritizes transparency, First Nations Inclusiveness, social responsibility, environmental responsibility, and economic responsibility.

Distinctions in Aquaculture

• Aboriginal aquaculture may include unique cultural and spiritual aspects.
• They exhibit unique connections to the land.
• there may exist some mistrust of conventional science.
• Aboriginal aquaculture exhibit Unique rights and special access to aquatic resources, job creation, and high food prices.

Explore domestication's impact on animal genetics through selective breeding. Learn about varying degrees of domestication, from wild to fully dependent animals. Discover trait changes and insights from Belyaev's fox experiment, shedding light on the transformation of wild species.