💊 How Are We Feeding Animals?

How Should We Feed Animals?

The Main Question

• What to feed?

• How much of each nutrient to provide?

Traditional Approach

• Tradition / know-how → based on experience and established practices

• What we always fed → continue using familiar feeds

Animal-Driven Approach

• Let the animal choose → allow the animal to select what it eats

Availability-Based Approach

• Feed what we have → use whatever feed is available

Scientific Approach

• Systematically + scientifically → determine what + how much to feed based on scientific evidence

• Nutrition / nutritional sciences → science that drives feeding decisions

Nutrition: Definitions

American Medical Association (AMA)

• Human-focused definition

• Nutrition → science of food, nutrients + substances, including their actions, interactions + balance

• Relates to health + disease

• Includes processes by which the organism:

  • Digests food substances

  • Absorbs food substances

  • Transports food substances

  • Utilizes food substances

  • Excretes food substances

Kellems and Church (2002)

• Animal production-focused definition

• Nutrition → series of processes by which an animal takes in + assimilates feed components

• Supports:

  • Growth

  • Milk production

  • Fiber production

  • Replacement of worn or injured tissues

Key Difference

• AMA → focuses on nutrition + health/disease

• Kellems & Church → focuses on nutrition + animal production

Human Nutrition vs. Animal Nutrition?

Important Context

• My old boss’ view (1990s) → presented for discussion

• The lecturer does not agree with this view

Human Nutrition

• Called “Social Dietetics?”

• Focuses on social + medical aspects

• Goal → minimize risks to health

Animal Nutrition

• Called “True science, serious + systematic?”

• Focuses on maximizing growth + efficiency of livestock

• Goal → minimize cost

Main Comparison

• Human nutrition → health + social/medical concerns

• Animal nutrition → growth + efficiency + cost

The Boundary Between Animal and Human Nutrition

Changing Boundary

• The boundary between animal nutrition and human nutrition is no longer clearly defined

• The two fields increasingly overlap

Why This Matters

• Animal nutrition is not only about growth, efficiency + cost

• Human nutrition is not only about health + social/medical aspects

• Both can involve health, nutrition, food quality + well-being

Similarities Between Human and Animal Nutrition Research

Human Nutrition Group’s Mission

• Advance knowledge about the role of nutrition in human health

What They Study

• Whole foods

• Individual nutrients

• Non-nutritive food components

• Their roles at the:

  • Whole body level

  • Cellular level

  • Molecular level

Research Groups

• Studied in different population groups

• Also studied using model systems

Food Choices

• Environmental determinants → factors affecting food choices

• Social determinants → social factors affecting food choices

• Individual determinants → individual factors affecting food choices

• Examines food choices + eating patterns

Animal Nutrition Research

• This description could also be applied to much of the animal nutrition research carried out around the world

Nutrition and Feeding of Animals

Long History

• Nutrition + feeding of animals → systematically approached for millennia

Ancient Egyptians

• Developed a system to determine how much feed resources different types of cattle would need

18th + 19th Century

• Animal nutrition became a focus of scientific efforts

• Important work in:

  • Italy

  • France

  • United Kingdom

  • Germany

20th Century

• Animal nutrition research became especially important in the USA

The Ahmes Papyrus – 1650 B.C.E.

Historical Record

• Ahmes Papyrus → dates to 1650 B.C.E.

• Shows the long history of systematic knowledge in ancient Egypt

Time Period

• 1650 B.C.E. → Ancient Egypt

Lavoisier and Laplace: Caloric Measurements on Animals and Humans

Time Period

• 1776–1791

• 17th + 18th Century

• Part of the “Chemical Revolution”

Studies

• Conducted caloric measurements on animals + humans

• Performed complete mass + energy balance

Historical Significance

• Important early work in understanding energy balance in animals and humans

• Their work is associated with one of the best museums in Paris

Protein as a Nutrient

17th + 18th Century

• Part of the “Chemical Revolution”

Protein

• Protein → called “animal substance”

• Considered the sole nutrient

Early Nutrient Requirements

Wolff, 1874

• Requirements given in kg per day per 1,000 kg live-weight

• Oxen at rest

  • Protein → 0.7 kg

  • Carbohydrate → 8.0 kg

  • Fat → 0.15 kg

• Milch cow

  • Protein → 2.5 kg

  • Carbohydrate → 12.5 kg

  • Fat → 0.40 kg

Haecker, 1903

• Maintenance requirements given in kg per day per 1,000 kg live-weight

  • Protein → 0.7 kg

  • Carbohydrate → 7.0 kg

  • Fat → 0.10 kg

Milk Production

• Requirements also given in kg per day per kg milk

• 2.5% milk fat → Protein 0.0362 kg, Carbohydrate 0.164 kg, Fat 0.0124 kg

• 2.6% milk fat → Protein 0.0369 kg, Carbohydrate 0.167 kg, Fat 0.0126 kg

• 2.7% milk fat → Protein 0.0376 kg, Carbohydrate 0.171 kg, Fat 0.0128 kg

• 7.0% milk fat → Protein 0.0677 kg, Carbohydrate 0.313 kg, Fat 0.0229 kg

Memory Trick

Wolff = 1874 → oxen + milch cow
Haecker = 1903 → maintenance + milk production
More milk fat → higher nutrient requirements

Requirements of Animals – Information Sources

NRC – National Research Council

• NRC → National Research Council

• Provides information on the nutrient requirements of animals

• Used as a reference for determining what nutrients animals need

Requirements of Animals – Authoritative Sources

Other Authoritative Documents

• Published by different organizations

• Provide information on requirements of animals

National or Regional Resources

• Resources developed at a national or regional level

Poultry Nutritional Specifications – Public Guidelines

Major Public Guidelines

• National Research Council (NRC)

• INRAE-CIRAD-AFZ

• Centraal Veevoederbureau (CVB)

• Brazilian Tables (CBPA)

• Agricultural Research Council (ARC)

• Swedish Poultry Council (SPC) / AFZ

• New Zealand Poultry Feed Tables (NZWG)

• Foundation for Animal Nutrition (FEDNA)

• Australian Poultry Standards

• Chinese Poultry Nutrient Requirements → China Feed Database / NRC-Chinese adaptation

• Japanese Poultry Feeding Standards (JPFS)

• Korean Feeding Standards for Poultry (KFSP)

Guidelines from Major Broiler Breeders

• Cobb Breeders

• Ross Breeders

• Hubbard Breeders

• Arbor Acres Breeders

• Hy-Line / ISA Layers

Genetic Potential & Feeding Management

Different Breeds

• Different breeds have different genetic milk yield potential

• This means their genetics determine how much milk they are capable of producing

Individual Animals

• All animals have different genetic potential for:

  • Milk

  • Fat

  • Protein

  • Etc

Feeding Challenge

• Different animals have different production potentials

• Different production potentials mean different nutritional needs

Key Question

• How do you manage the feeding of different animals with different production potentials and therefore different nutritional needs?

Animal Performance & Feeding

Constant Genetic Improvement

• There are constant improvements in the performance of farm animals

• Animals are rapidly “changing” over time

Feeding Must Change

• As animals change over time, their feeding must also change

• Feeding needs to keep up with improvements in animal performance

Different Genetic Potentials

• Animals have different genetic potentials

• Animals with different genetic potentials must be fed differently

Factorial Model – NRC, 1978

Basic Idea

• Factorial Model → used to determine the animal’s nutrient requirements

• Developed by NRC, 1978

• Looks at the nutrients supplied by feed and the nutrients required by the animal

• The goal is to achieve a BALANCE

Crude Protein Balance

FEED

• Crude protein

↓

ANIMAL

• Urine N

• Scurf N → nitrogen lost from the skin

• Metabolic fecal N → nitrogen lost in feces from the animal’s own metabolism

• Protein yield

Net Energy Balance

FEED

• Net energy

↓

ANIMAL

• Dry matter intake

• Body weight

• Milk yield

• Fat %

Key Idea

• Feed nutrients → Animal needs → BALANCE

• Crude protein → balanced against nitrogen losses + protein yield

• Net energy → related to dry matter intake, body weight, milk yield + fat %

Absorbed Protein Model – NRC, 1988

Basic Idea

• Absorbed Protein Model → determines whether the animal receives enough absorbed protein and net energy

• Developed by NRC, 1988

• Uses BALANCE+ and BALANCE− to compare what is supplied by the FEED with what the ANIMAL requires

FEED

Protein

• Undegradable protein → protein that is not degraded in the rumen

• Degradable protein → protein that is degraded in the rumen

Energy

• Net energy

↓

ANIMAL

Protein Balance

• UIP → undegradable intake protein

• DIP → degradable intake protein

• Absorbed protein

• Endogenous N → nitrogen coming from the animal itself

• Scurf N → nitrogen lost from the skin

• Metabolic fecal N → nitrogen lost in feces from the animal’s own metabolism

• Bacterial protein

• Protein yield

Net Energy Balance

• Net energy

• Dry matter intake

• Body weight

• Milk yield

• Fat %

Key Idea → Feed protein + energy → absorbed protein + net energy → animal production

Mechanistic Digestion Model – CNCPS, 1992 + NRC, 2001

Basic Idea

• Mechanistic Digestion Model → describes how different feed components are digested and used by the animal

• CNCPS, 1992

• NRC, 2001

• The model follows nutrients through digestion to determine metabolizable protein and metabolizable energy

• The nutrients are then compared with what the ANIMAL needs to maintain BALANCE

FEED

Protein Components

• NPN → non-protein nitrogen

• B1 protein

• B2 protein

• B3 protein

Other Feed Components

• Sugar

• Starch

• Fat

• Avail fibre → available fibre

↓

DIGESTION

• Ammon → ammonia

• NSC bacteria → bacteria using non-structural carbohydrates

• SC bacteria → bacteria using structural carbohydrates

↓

ANIMAL

Protein Balance

• Metabolizable protein

• Metabolic fecal N

• Endogenous scurf N

• Protein yield

Energy Balance

• Metabolizable energy

• Body weight

• Milk yield

• Protein %

• Fat %

Key Idea → Feed components → Digestion → Metabolizable protein + metabolizable energy → Animal balance

Nutrient Requirement Models – Basics & Differences *FROM CHAT

1⃣ Factorial Model – NRC, 1978

Basic Idea

• Looks at the nutrients going into the animal from the feed

• Compares them with the nutrients used or lost by the animal

• Goal → achieve a BALANCE

Main Nutrients

• Crude protein

• Net energy

What it considers

• Urine N

• Scurf N

• Metabolic fecal N

• Protein yield

• Dry matter intake

• Body weight

• Milk yield

• Fat %

Main Concept → Feed nutrients → animal needs/losses → balance

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2⃣ Absorbed Protein Model – NRC, 1988

Basic Idea

• Focuses more specifically on protein absorbed by the animal

• Separates feed protein into different types based on how they behave during digestion

• Also considers net energy

Main Nutrients

• Undegradable protein

• Degradable protein

• Net energy

What it considers

• UIP

• DIP

• Absorbed protein

• Endogenous N

• Scurf N

• Metabolic fecal N

• Bacterial protein

• Protein yield

• Dry matter intake

• Body weight

• Milk yield

• Fat %

Main Concept → Feed protein → digestion + absorption → absorbed protein → animal production

---

3⃣ Mechanistic Digestion Model – CNCPS, 1992 + NRC, 2001

Basic Idea

• Gives a more detailed description of what happens during digestion

• Breaks feed into multiple components and follows how they are digested and used

• Determines metabolizable protein and metabolizable energy

Main Feed Components

• NPN

• B1, B2, B3 protein

• Sugar

• Starch

• Fat

• Available fibre

What it considers

• Ammonia

• NSC bacteria

• SC bacteria

• Metabolizable protein

• Metabolic fecal N

• Endogenous scurf N

• Protein yield

• Metabolizable energy

• Body weight

• Protein %

• Milk yield

• Fat %

Applying Systematic Approaches to Animal Nutrition

Back to Basics: Intake ↑, MP:ME Dialled In, Results Followed

• Systematic approaches → based on scientific principles and current knowledge

• Presented by Maria Antonieta Puerto, MSc Animal Science, McGill University

• Main approach → focus on intake, MP:ME, and then follow the results

Results

• Herd improved from:

  • 36 kg milk/cow/day → 43 kg milk/cow/day

  • 1.5 kg fat/cow/day → 1.9 kg fat/cow/day

What Changed?

Make DMI the North Star

• DMI → dry matter intake

• Stopped guessing intakes and started measuring them

• Feed access was improved with:

  • 24/7 push-ups

  • Consistent TMR

  • Correct chop length

  • Correct particle size

• Cows moved from 22 kg to 25 kg DM/day

• The new ration's fuel → the increased DMI

Forage Quality

• Forage quality was considered non-negotiable

• Selecting forages with higher fiber digestibility → more nutrients available per bite

Starch Digestibility

• Starch digestibility is not static → it can change depending on several factors

• Factors affecting total-tract starch digestibility:

  • Hybrid

  • Maturity

  • Moisture

  • Kernel processing score

  • Particle size

  • Storage time

• Meta-analyses show that improving kernel processing and particle size increases total-tract starch digestibility

• Increased starch digestibility can drive higher milk production

• Key point → “Corn is corn” is false

• Test it → adjust it → model it

Protein Sources Are Not All the Same

• “Canola is just canola” → isn't

• Protein sources are not created equal

• Factors affecting MP supply and efficiency:

  • RDP/RUP balance

  • Amino acid profile

  • Fiber content

  • Processing method

Canola Meal

• Canola meal is a good example of differences between protein sources

• Different extraction methods can alter nutrient availability

• Studies and meta-analyses show variation in:

  • Milk yield

  • N-use efficiency

  • Depending on the source

Other Protein Sources

• The same principle applies to soybean meal and other commodities

Big Picture

• Measure DMI → improve feed access → select quality forages → evaluate starch digestibility → evaluate protein sources → adjust the ration → follow the results

Applying Systematic Approaches – Why the Jump Happened

Source + Quality Matter

• The proof is simple → source and quality matter

• Test your commodities instead of relying on generic values

• Use lab values, not generic tags

• Goal → protect the MP:ME ratio

Why the Jump Happened

More to Eat → Higher DMI

• DMI → dry matter intake

• More DMI → more fermentable energy available

MP Matched to ME

• MP → metabolizable protein

• ME → metabolizable energy

• MP matched to ME using tested ingredient values

• This allows microbes to run efficiently

• Amino acid (AA) supply meets demand

Higher Digestibility

• Higher full-tract digestibility of:

  • Fiber

  • Starch

• More of what is fed becomes nutrients, rather than manure

Outcome

• +7 kg milk/cow/day

• +0.4 kg fat/cow/day

• Achieved by:

  • Measuring intakes

  • Testing feeds

  • Dialling MP:ME using real numbers

Big Picture

• Back to basics → but with precision

• Measure → test → balance MP:ME → follow results

Technology to Monitor Feed Composition

Feed Composition Monitoring

• Technology can be used to monitor the composition of feed resources

• These tools help assess the nutritional composition of feeds

Technologies / Systems

• ProxiScout

• ProxilMate

• NIR-Online Solutions

• NIRFlex™

Technology in Animal Feeding

Emerging Role of Technology

• Technology is playing an emerging role in the feeding of animals

• Notably, automation is becoming important in animal feeding

Large Emphasis on “Equipment”

• Large emphasis is placed on the “equipment” used for feeding

• Automation + equipment are important parts of modern animal feeding systems

Automation in Animal Feeding

Autonomous Self-Driving Vehicles

• Autonomous self-driving vehicles are based on:

  • Sensors

  • Robotics

  • A powerful “brain” → needed to process information and make decisions

Automatic Feeding Systems

• The same is true for most automatic feeding systems

• They require:

  • Sensors

  • Robotics

  • A powerful “brain”

Key Question

• Who will develop those systems?

Module 1 – Things We Have Discussed

1. Why Do We Feed Animals?

• Why do we feed animals?

2. Important Considerations

• What is important to consider when feeding animals?

3. Feed Resources

• What do we feed animals?

• Various feed resources

4. Feeding Requirements

• What determines what and how much we feed a certain type of animal?

5. Food vs Feed

• What is the difference between “food” and “feed”?

6. Science + Technology

• The role of science and technology in animal nutrition