Calculating regional gross nutrient balances

Anne Miek Kremer & Kees Olsthoorn

from statistical and administrative data

Statistics Netherlands

A Working Program

Main Flows in Nitrogen Balances

Livestock manure

Two regions feed rations for ruminants

Silage grass

Silage maize

Excretion coefficients and feed balances

What livestock consumes must result either in urine/manure or in product (milk, meat etc).

Ruminants: regional feed balances to calculate excretion coefficients

Other livestock: national averaged excretion coefficients

Regional feed balances for ruminants

Feed available for ruminants in the region:• Silage grass and hay: annual survey• Silage maize: annual survey• Concentrates: national sales statistics, index numbers • Meadow grass: unknown, calculated in the feed balance• Dairy cows: consumption of conserved roughage and concentrates

is variable• Other ruminants: consumption of conserved roughage and

concentrates based on norms• Feed is expressed in VEM (measure for the feeding value)

Feed requirements • Dairy cows: feed requirement is depending on milk production• Other ruminants: standard feed requirements

Regional feed balances for ruminants

kVEM per

animal

Concentrates Silage grass and hay

Silage maize

Meadow grass

Dairy

cowsx ? ? ? ?

Other Ruminants

x x x x ?

Total x x x ?

kVEM per

animal

Concentrates Silage grass and hay

Silage maize

Meadow grass

1 Dairy

cow6000 = ? + ? + ? + ?

1 Other cow

3000 = 500 + 1000 + 1000 + ?

Total 2500 3000 2500 ?

kVEM per

animal

Concentrates Silage grass and hay

Silage maize

Meadow grass

1 Dairy

cow6000 = ? + ? + ? + ?

1 Other cow

3000 = 500 + 1000 + 1000 + 500

Total 2500 3000 2500 ?

kVEM per

animal

Concentrates Silage grass and hay

Silage maize

Meadow grass

1 Dairy

cow6000 = 2000 + 2000 + 1500 + ?

1 Other cow

3000 = 500 + 1000 + 1000 + 500

Total 2500 3000 2500 ?

kVEM per

animal

Concentrates Silage grass and hay

Silage maize

Meadow grass

1 Dairy

cow6000 = 2000 + 2000 + 1500 + 500

1 Other cow

3000 = 500 + 1000 + 1000 + 500

Total 2500 3000 2500 1000

Problems with the feed balance for ruminants

Two regions:

Very low consumption of meadow grass by dairy cows

NUTS-2 regions:

Negative consumption of meadow grass by dairy cows in some regions

meadow grass consumption per dairy cow

0

200

400

600

800

1000

1200

1400

1600

1800

2000

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

kg d

s SE

NW

meadow grass consumption per dairy cow 2006

-1.000

-500

0

500

1.000

1.500

2.000

GR FR DR OV FL GL UT NH ZH ZL NB LB

kg

ds

Underestimation of feed requirements

Underestimation of feed requirements of dairy cows

Underestimation of feed requirements of other ruminants

Overestimation of VEM-value of meadow grass

Overestimation of silage maize

Maize available for ruminants in year t = production year t-1

Not taken into account:

• Exports of maize

• Energy production

• Stock changes

14 ton ds/ha CBS, 12,5 ton ds/ha other research

bruto production maize

10

11

12

13

14

15

16

ton

ds/h

a

Overestimation of silage grass and hay

Silage grass and hay available year t = production year t + stock

changes

Response silage grass harvest: Grass in pit or field production?

Response grassland area in use: Grassland survey > FSS

Raising results:• 1) production region survey * grassland area region survey (FSS)

total grassland area region (FSS)

• 2) average production per ha region * total grassland area region (FSS)

Underestimation of grassland production (meadow grass, silage grass, hay)

Other problems effecting feed availability

Consumption of grass by animals not counted in the FSS

• FSS 135.000 horses; reality between 300.000-500.000 horses

Consumption of concentrates by other ruminants in pasture

season

Allocation of feed between regions

Export and import of feed between regions

Regional differences in feed rations of other ruminants

Regional differences in intake of concentrates by dairy cows

consumption of meadowgrass per dairy cow

-1.000

-500

0

500

1.000

1.500

2.000

GR FR DR OV FL GL UT NH ZH ZL NB LB

kg/c

ow

Conclusions

Expert discussion on problems, causes and solutions

• Improvement of excretion coefficients for ruminants for two regions

• Data on export and import of feed between regions

Option 1: calculating excretion coefficients on the NUTS-2 level for dairy cows.

Option 2: calculating excretion coefficients for two regions for ruminants