Lecture 1: grassland and fodder crops

Question 1

Sample of a Dutch spring

Answer 1

• Grazing season starts around April
• Grazing season ends around October
• Grass growth is rapid: per day 100-150 kg DM per hectare

Question 2

On what depends the importance of grass as animal feed?

Answer 2

• Climate and soil
• Important in humid regions: sufficient rainfall in all seasons and grass grows well on peat and clay soils
• Less important in dry regions: Sandy soils and dry summers (subtropical climates)

Question 3

What are the types of grass and forages?

Answer 3

• Grasses (Perennial and annual)
• Grass clover
• Legumes (Grain products or forage legumes)
• Cereals (graan) and maize
• Fodder beets

Question 4

What are legumes?

Answer 4

• the family of foods that encompasses beans, peas, and lentils (linzen)

Question 5

What are protein-rich crops?

Answer 5

• Grasses and legumes

Question 6

What are energy-rich crops?

Answer 6

• maize
• Cereals
• Potatoes, fodder beets
• Because of high amounts of carbohydrates, starch and sugars

Question 7

What are the stages of development of grass?

Answer 7

• Vegetative: leaves form from nodes
• Elongation: Grass grows rapidly
• Reproductive: Grass starts flowering
• Dying off

Question 8

What is the grass growth rate?

Answer 8

• Grass has two peaks in its growth
• First peak; Spring from April to July
• Second peak: Fall recovery from September till december
• Summer knows a decline

Question 9

Maize (corn)

Answer 9

• Fed as roughage (whole crop) or concentrates (grain, ears)
• Energy rich feed
• starch (in mature stage 50% ‘rumen-resistant’starch)
• low protein content; low mineral content
• less suitable for horses

Question 10

Grass clover

Answer 10

• Biological N fixation, i.e. by organisms
• Grassclover ley:
  • nodules formed at roots
  • Rhizobium bacteria –> Exchange sugars (energy) and nitrogen = symbiosis

Question 11

What divisions are made in the Weende analysis?

Answer 11

• Crude fiber
• Sugar, starch and other carbohydrates
• Crude ash
• Crude protein
• Crude fat

Question 12

What divisions are made in the Soest-analysis?

Answer 12

• Cell walls = NDF

- Cell content

Question 13

What does NDF consist of? - Neutral detergent fibre

Answer 13

• Hemicellulose
• Cellulose
• Lignin

Question 14

What is ADL? - Acid detergent lignin

Answer 14

• Lignin

Question 15

What is ADF - Acid detergent fibre

Answer 15

• Cellulose & lignin

Question 16

What does the high tech analysis with NIRS use?

Answer 16

reflection of infrared light due to the molecular composition of materials

Question 17

What is all incorporated in the chemical composition of feed?

Answer 17

• Dry matter
• Crude protein
• Carbohydrates
  Structural: fibre, cellulose, hemicellulose, lignin
  Non-structural: sugars
• Minerals
• Other components like fat

Question 18

What is the chemical composition of grass?

Answer 18

• WSC (Water solulable carbohydrate) content variable; fructan in stems)
  • CWC (Cell wall constituents) variable; high when mature: lots of hemicellulose
  • Differences between grass species

Question 19

What is the chemical composition of legumes?

Answer 19

• WSC content low
• CWC lower % than grass but mainly cellulose (+ lignine)
• starch in stems

Question 20

What are energy rich forages?

Answer 20

• Maize
• Cereals
• Carrots
• Potatoes

Question 21

What are the feeding value ranges?

Answer 21

Dry Matter%
– Fresh material 15%
– Silage 20-35%
– Haylage 40-75%
– Hay 85-90%
Crude Protein % range below 5 up to 25% of DM
Carbohydrates WSC%
– Sugars below 10 up to more than 20%
Minerals: Ash %
Energy : TDN (total digestible nutrients) 50-80%, Energy Value Horse
VEM (digestible energy milking cows) 700-1000

Question 22

What factors are important in feeding value?

Answer 22

Weather, season (climat factors)
– Light intensity (LUX)
– Temperature (°C)
– Rainfall (mm)
Stage of development
– Stage of growth: heavy or light cuts (management)
Fertilization (Nitrogen = management)