Why, What and How Do We Feed Animals? LEC 1

1. Moral & Ethical Reasons

• Humans keep animals in captivity for many different reasons.

• The #1 concern should be keeping animals healthy and well.

2. Food Security Reasons

Humans keep animals for:

• Food

• Fibre

• Labour

• Protection

• Companionship

Animals can be an important source of food for humans.

Animals can use resources humans cannot:

• Example: ruminants can convert forages → milk and meat.

Animals as a  reserve

• Animals can be kept alive during times of food shortage.

• Animals can:

  • Be milked regularly for food.

  • Be slaughtered when food is needed.

• Meat does not need to be preserved while the animal is alive.

Animal product consumption

• Humans generally have an appetite for animal products.

• Consumption of animal products tends to increase as economic power increases.

3. Economic Reasons

Animals are kept for economic reasons because they produce:

• Meat

• Milk

• Fibre (wool, fur)

• Eggs

• Other products that provide income.

Improving production

• We constantly try to improve productivity and efficiency of food animal production.

• Animals are genetically selected for high potential for:

  • Growth/meat production

  • Milk production

  • Egg production

Importance of feeding

Animals need to be well fed so they can:

• Stay healthy

• Express their production potential

• Produce the desired products:

  • Meat

  • Milk

  • Eggs

  • Wool, etc.

Costs and profitability

• There are different ways to care for and feed animals.

• Different methods can have different:

  • Costs

  • Profitability

• Intensifying production can generally increase profitability, but not always.

• It depends on the value of the final product.

Productivity + profitability = very important to agricultural businesses

No profits = no future for the business

Weight Gain

• Average Daily Gain (ADG)

• Measures average weight gained per day.

• Usually expressed as g/day or kg/day.

4. Product Quality Reasons

Important factors include:

• Price & marketability

• Nutritional composition

• Organoleptic properties

• Food safety

Organoleptic properties

• Properties of food related to how it is experienced by the senses.

5. Human Well-Being & Hedonistic Reasons

Animals are also kept because of:

• Emotional attachment

• Service

• Entertainment

• Cultural/religious significance

• Hobby

• Sport

Food

• Self-selected items

• Animal chooses what it eats in the wild → food

• Often refers to items intended/reserved for humans.

• Generally has a higher degree of sanitation.

  • Example: food-grade

Feed

• Imposed items

• Farm animals receive an imposed ration → feed

• Generally has a lower degree of sanitation.

  • Example: feed-grade

Foods/Feeds

• Individual items.

Diet

• The sum of food/feed consumed by an individual.

Complete Feed

• A thoroughly blended mixture of different feed ingredients.

• Formulated to meet specific nutrient requirements/specifications.

Ration

• The 24-hour feed allowance for an individual animal.

What are forages?

• Bulky plant feeds such as:

  • Grass

  • Hay

• Commonly used for horses and ruminants.

cont

• Annual

• Biennial

They are grown to be:

• Grazed (pasture)

• Harvested as a whole crop

Types of Forages

cont

Grass/Pasture

• Standing forage where animals graze.

• >70% moisture

Conserved Forages

Forages that are preserved for later feeding.

Hay

• Low-moisture feed.

• Target: <15% moisture

• Can be stored, ideally under cover.

Silage

• High-moisture feed.

• 50–80% moisture

• Uses microbial fermentation to preserve the forage.

• Fermentation produces acids that help preserve it.

• Oxygen exposure should be limited.

• Goal is to maximize anaerobic fermentation rather than aerobic respiration.

Natural Diet

Animals naturally forage/scavenge for different food items.

Mash

• Homogeneous mixture of ingredients.

• Ingredients are more or less finely ground.

Pelleted Feeds

• Homogeneous mixture of feed ingredients.

• Ingredients are compacted into pellets.

How do we know what/how much to feed?

1. Tradition / know-how

2. Let the animal choose

3. Feed what we have / what we always fed

4. Systematically and scientifically

Modern approach

• Driven by science

• Called nutrition/nutritional sciences

American Medical Association (AMA)

Nutrition is the:

• Science of food and nutrients

• Study of their actions, interactions and balance

• Relationship to health and disease

• Processes by which the body:

  • Digests

  • Absorbs

  • Transports

  • Uses

  • Excretes food substances

Kellems & Church (2002)

Nutrition is the series of processes by which an animal:

• Takes in feed

• Assimilates feed components

• Uses them for:

  • Growth

  • Milk production

  • Fibre production

  • Replacing worn or injured tissues

Nutrition & Feeding of Animals: History

• Animal nutrition and feeding have been approached systematically for thousands of years.

Ancient Egyptians

• Developed a system to determine how much feed different types of cattle needed.

18th & 19th Centuries

• Animal nutrition became a focus of scientific research.

• Important efforts occurred in:

  • Italy

  • France

  • United Kingdom

  • Germany

20th Century

• Animal nutrition research became especially important in the USA.