Animals and Livestock Welfare

Animal Welfare Concerns

• Higher prices are obtained by transporting animals long distances (live export) instead of transporting meat.
• Problems and diseases induced by population environment, such as mastitis in dairy cows, are caused by poor housing hygiene.
• Poor handling during transport or slaughter is an active act of malpractice.

Continuous Improvement

• Regulation and product assurance methods incentivize farmers to adhere to animal welfare standards, resulting in higher profits.
• New technologies, such as immunocastration and 'in ovo' sex identification, improve animal welfare.

Welfare of Sport and Entertainment Animals

• Horse racing is a $5 billion industry with various welfare concerns, including:
  • Treatment of lower-value breeding mares
  • 'Wastage' of young stock before racing (82% of horses entered training, 34% of which died from fractures, wounds, digestive disorders, and tendon/ligament injuries)
  • 2-year-old racing (damage/developmental issues)
  • Quality of life for racehorses outside of training and racing
  • Catastrophic injury and death (rate of 0.4 in 1000 starts)

Animal Rights

• Animal rights is a philosophical position that animals have inherent moral rights, and animal utilization by humans contravenes animal rights.

Welfare of Farmed Animals

• The five freedoms for animal welfare are:
  • Freedom from hunger or thirst
  • Freedom from discomfort
  • Freedom from pain, injury, or disease
  • Freedom to express most normal behavior
  • Freedom from fear and distress
• The five domains of animal welfare are:
  • Nutrition
  • Environment
  • Health
  • Behavior
  • Mental state

Welfare Issues in Farming

• Confinement of animals affects freedom of movement and access to resources.
• Surgical husbandry practices, such as mulesing and castration, cause pain.
• Long-distance transport of animals for economic reasons affects animal welfare.
• Environmental factors, such as climate change, deforestation, pollution, and human interaction, impact animal welfare.

Historical Development of Animal Welfare

• The circle of influence and concern for animal welfare has increased over history, with:
  • Ancient philosophers advocating for not eating animals (500 BCE)
  • Religious edicts forbidding the consumption or mistreatment of certain animals (400 BCE)
  • Prevention of Cruelty legislation (early 20th century)
  • Concept of 'duty of care' (late 20th century)
  • Change driven by public behavior rather than legislation (now)

Clinical Signs of Cold Stress

• Increased metabolic rate, leading to weight loss
• Increased feed intake
• Decreased feed conversion efficiency (FCE)
• Altered body composition
• Reduced neonatal survival
• Death from hypothermia

Air Quality and Its Effects on Animals

• Bioaerosols: airborne particles containing living organisms, toxins, and waste products
• Possible health effects: exposure to infectious diseases, allergic reactions, respiratory symptoms, and lung function impairment
• Noxious gases: ammonia, hydrogen sulfide, carbon dioxide, and methane
• Ammonia: toxic, causes destruction of cilia and mucosal barrier, leading to airway obstruction
• Hydrogen sulfide: highly toxic, affects CNS, can cause respiratory paralysis, convulsions, and death
• Particular matter: potential health effects related to particle size

Soil and Water Quality

• Presence of infectious organisms
• Toxins
• Mineral deficiencies/excesses
• Dissolved oxygen concentration
• Organic matter build-up
• Replacement selection: selecting new animals to become parents, using artificial insemination or culling
• Index selection: calculating a total score for each animal based on merit in each trait, selection indices expressed as net profit per cow mated

Mating Systems

• Random mating: mates chosen at random, any male has an equal opportunity to mate with any female
• Assortative mating: mating individuals according to their phenotypes, can be positive or negative
• Inbreeding: mating individuals more closely related than the average of the population, can lead to genetic defects
• Outbreeding: mating individuals with unlike pedigrees, reduces homozygosity and increases heterozygosity, increases population mean
• Outcrossing: mating individuals within a breed, minimizes inbreeding

Toxin Distribution and Metabolism

• Toxins distributed into different body fluid compartments
• Eventual distribution determined by tissue affinity
• Metabolism: alters physical properties of toxins from lipophilic to hydrophilic, mostly occurs in the liver
• Phase 1 reactions: catabolic, often involve cytochrome P450 enzymes, form more reactive products
• Phase 2 reactions: anabolic, lead to inactive products, mostly occur in the liver and kidney

Rabies and Australian Bat Lyssavirus

• Rabies caused by Rabies lyssavirus (Rhabdoviridae), affects all warm-blooded animals, primarily mammals
• Virus concentrates in animal saliva and is transmitted through contact with fresh wounds or mucous membranes
• Signs of illness may appear within 10 days and several months, death typically occurs within 10 days after clinical signs are present
• Course of infection follows behavioural change, progressive paralysis, coma, and then death

Zoonoses and One Health

• Investigating novel diseases: identify origin, determine pathogen type, use genomic sequencing, test disease transmission
• Investigating sources of disease: antibody test animals, humans, local wildlife, and the environment
• Bats as reservoir hosts: ability to fly causes damage at the cellular level, dampened inflammatory response, well-protected against viruses
• Examples of viruses implicating bats as reservoir hosts: MERS, SARS, Ebola