Tropical grasses (C4) more lignified 2 step approach Temperate species (C3) better digestible 1 step approach 1:18 ff nog keer kijken

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From feed to milk

40 important questions on From feed to milk

What are the two main feedstuffs?

Roughages

mainly vegetative plant parts (leaves, stems) (e.g. grass or mais)

Concentrate feedstuffs

mainly reproductive plant parts (seeds)

What are the characteristics of roughages

Relatively low dry-matter content
Relatively high fibre / cell-wall content
Relatively low digestibility

What are the characteristics of concentrate feedstuffs

High in energy, protein and digestibility
Low in water and fibre

What are the two types of roughages?

Fresh roughage

Grazed forage (graasvoer)
cut forage (snij voer)

Conserved roughage

Silage (kuilvoer)
Hay (hooi)
Artificially dried roughage (bales, pellets) (kunstmatig gedroogd ruwvoer)

Give some aspects of high-quality roughage

Essential for ruminants (=herkauwers) as it is

a high-quality source for nutrients
essential for the rumen microbes
essential for rumination
regulating rumen pH
allowing a high milk yield

Forage is the cheapest feed source

especially true for grazed forage

What are the main forages (=voedergewassen)?

(grassland species)

Grasses
legumes
other herbs

(rangelands)

tree leaves
crop residues
by-products

Concentrates come in two forms and compose of a wide range of ingredients. What are they

Meal or pellets

Grains
By-products of the food industry
Premixes with vitamins and minerals

What are the characteristics of fodder crops and what is their growth pattern?

Often annual
cultivation on arable land

species

Forage maize
Fodder beet
Lucerne (alfalfa)

What do you know about Grassland species?

Forages are edible plant species present in grasslands

grasses (Poaceae or Gramineae)
Legumes (Fabaceae or Leguminosae)
Forbs (non-leguminous herbs; many species from different plant families)

For grass species mixtures are used in temperate climates including:

Perennial ryegrass (Lolium perenne; Engels raaigras)
Timothy (Phleum pratense; timothee)
Meadow fescue (Festuca pratensis; beemdlangbloem)
Others, e.g. Smooth-stalker meadowgrass (Poa pratensis; veldbeemdgras)

There are two types of clovers

White clover

(Trifolium repens, witte klaver)
in mixtures for grazed grasslands

Red clover

(Trifolium pratense, rode klaver)
Mainly for cut grasslands

What is the availability of the forage?

Due to seasonal production patterns, fresh forage is not always available
There is no fresh grass during winter in temperate zones, in other areas there is no fresh grass during the dry season
A solution is to provide other feed (e.g. Fodder crops or more concentrates) or to conserve surplus forage and store it
other solutions....?

What is the aim and method of preservation-conservation

Aim: conserve plant material for later use
Method: stop activity of plant enzymes and of micro-organisms to prevent decay

different methods:

Drying
Acidification (ph verlagen
Freezing
Etc.
ph verhogen

What is ensiling - silage making

Fermentation of sugars by anaerobic bacteria

Lactic acid
Acetic acid
Propionic acid

Classified based on moisture level

High moisture silage (>70% moisture)
Wilted silage (60-70% moisture)
Haylage or low-moisture silage (40-60% moisture)

How are the positive microorganisms playing a rol in ensiling

Lactic acid bacteria (LAB)

Strong pH decline- acidification
Lactic acid as end product

Enterobacteria

Less strong pH decline
Have acetic acid as end product
Compete for sugars; increase buffering capacity; produce CO2 (energy loss)

How are the negative microorganisms playing a role in ensiling

Clostridia bacteria

Ferment sugars, organic acids and proteins (including their amino acids and amides)
Increase dry-matter losses (produce NH3 and CO2)
Produce butyric acid, which has a pungent odour and makes silage unpalatable for animals
Ammonia increases pH, which allows other undesirable micro-organism to proliferate

Fungi

Yeasts
Moulds

Protein in the forages (what do you know)

75% of the N in fresh forages is protein
In silage, only 20% of the N may be protein
Proteases break down protein to non-protein N forms, such as peptides, amino acids, amides, amines and ammonia (NH3)

Bacterial spores can end up in cheese, how does this develop?

Bacterial spores, resulting form silage making, can enter the milk
If milk contains spores of butyric acid bacteria, there is a problem with cheese making
Especially Edam, Gouda, Parmesan and Emmenthal cheese are very susceptible (=vatbaar) to spores
Therefor in som regions it is not allowed to feed silage to cows, whose milk is used for precessing these cheeses

Ration effects on flavour(, why, how)?

Apart from the well-known effect of certain specific plant species (like cabbage, garlic, onion) on milk or cheese of-flavours, the specific effect of the floristic composition of the grass has been relatively poorly studied
The composition of a ration consumed by a ruminant can have a marked influence on the composition, appearance and sensory characteristics of milk and meat and there products

Protected designation of origin (PDO) =

A protected designation of origin (PDO) status of cheese from a region is based on associations between the botanical typology of pastures and sensory typology of cheeses

Botanical diversity could be associated with more diversified and numerous cheese aroma attributes

What kind of contaminations of milk through the feed are there?

Extraneous components may enter milk via the cow, generally through the feed

Grass, often home-grown
Maize, either home-grown or bought in the local market
Concentrates and by-products, bought or obtained through feed-manufacturing companies

Contaminants may include

pesticide residues
Polychlorinated biphenyls and dioxins
Mycotoxins
Heavy metals and radionuclides

What happens with the pesticide residues?

The problem has drastically decreased since the ban on persistent organochlorines. These substances are lipophilic and therefore tended to accumulate in the milk
Other pesticides are completely broken down by the cow, in contrast with persistent organochlores used in the past
in grassland management and forage production, pesticide use limited compared with food production.

Feeding value encompasses:

Composition of nutrients in the forage
Ability of the animal to utilise these nutrients (i.e. Efficiency of conversion of ingested nutrients into body tissue or milk)
Amount of forage the animal will eat
Feeding value = nutrient intake x food conversion efficiency
Nutrient intake = herbage intake x nutrient concentration

There is a diet selection; what are the diets eaten by grazing animals?

Higher proportions of leafy material
Less stem and dead material
Preference and selection for specific species

Therefore higher nutritive value with grazing than with stall feeding (cut and carry)

What is a normal intake by the cow?

A cow weighing 500 kg eats

25% of her live wight of fresh herbage per day
i.e. 12-16 kg of herbage dry matter
i.e. A volume of 1 m3
Herbage dispersed over an area of 100-500m2

The intake of water by the cow

Herbage contains water and dry matter
A highly productive dairy cow may need more than 100 L of water per day
Free access to fresh water is essential for milk production: 87% of milk is H2O

Water is also needed for vital body functions including

Regulation of body temperature
Digestion
Metabolism
Excretion
Blood volume

Water from fresh forage

Internal (in cell content)

70-80% of fresh forage is water

External

Rain
Dew

Daily requirements of a dairy cow: 30-130 litres of H2O

Where does dry matter exist of

Organic matter

Carbon
Hydrogen
Oxygen
Nitrogen

Inorganic matter (ash)

Minerals
Sand

Mass concentrations expressed in g per kg dry matter

What kind of vitamins are in herbage?

Vitamins are essential is small amount to maintain health and include:

Water-soluble

9 B-complex vitamines
Vitamin C

Fat-soluble

beta-carotene or provitamin A
Vitamin D2, D3
Vitamin E
Vitamin K

Forages are rich in fat-soluble vitamins
Vitamin E is high in fresh grass but low in conserved or dried forages

When do mineral deficiencies occur?

Tropical grasses can have low concentrations of minerals resulting in deficiencies and disorders in the animal
Important macro-minerals for dairy cows are: Ca, P, Mg, Na, Cl, S and K
Important micro-minerals include: Fe, Cu, Mn, Zn, I, Co and Se

What is the positive effect of secondary metabolites on the animal?

Some forages contain secondary metabolites that are important:

Sustainable control of internal parasites (chicory, sulla)
Enhancing reproduction in sheep
Reducing bloat risk in cattle (lotus, sulla)
Reducing methane production to combat greenhouse gas emissions (chicory, sulla)

What is the negative effect of secondary metabolites on the animal?

Tannins

Tannins are naturally occurring polyphenolic compounds
condensed tannins (CT) are the most common type found in forage legumes, trees and shrubs
CTs lower palatability, voluntary intake and digestibility
However, tanniferous herbage might enhance ruminant productivity (improved protein supply, boat safety) and health (anti-parasitic properties)

What kind of animal health problems are there (waneer we naar voedsel kijken)

Mineral deficiencies
Direct poisoning (e.g. Oxalates, syanide, alkaloids, amino acids)
Secondary poisoning (e.g. Photosensitivity)
Fertility problems (e.g. Oestrogenic isoflavones)
Ohter (e.g. Bloat)

What is the crude protein content in
Grass (poorly fertilised)
Grass (highly fertilised)
White clover
Maize silage

Grass (poorly fertilised)

100-150 (g kg DM-1)

Grass (highly fertilised)

250-300 (g kg DM-1)

White clover

200-250 (g kg DM-1)

Maize silage

70-80 (g kg DM-1)

Carbohydrates are the largest energy source for herbivores. 50-80% of the total fry matter is carbohydrate. Which two types of carbohydrates are there?

Structural carbohydrates (crude fibre)

Hemicellulose
Cellulose
Lignin

Non-structural carbohydrates

Sugars (e.g. Glucose, fructose, sucrose)
Storage compounds, such as starch

Structural carbohydrates - fibre are

Encompass cell wall material
Provide structure and strength to the plant
Increase with maturity
Are indigestible for monogastric animals

Ruminants can digest fibre

Symbiosis with microorganisms
Rumination

Energy value of forages

See the image

loss as faeces energy
Loss as methane enegery and bring energy
Loss as heat associated with the work of digestion, absorption and metabolism of nutrients

The Net energy will remain

for maintenance of body function, accumulation of body tissue, and lactation

What are the factor influencing the chemical composition and digestibility?

Species
Maturity
Climate/weather
Breeding
Management

C3 versus C4 plants

Tropical grasses (C4) more lignified

2 step approach

Temperate species (C3) better digestible

1 step approach

1:18 ff nog keer kijken

The question on the page originate from the summary of the following study material:

Milk in the Dairy Chain

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