lactic acid, g/kg DM

Federal Departement of Economic Affairs DEA Agroscope Liebefeld-Posieux Research Station ALP

Influence of cutting height and use of additives on silage quality

Ueli Wyss

Introduction

The silage quality is influenced by different

factors. Especially in autumn, it is difficult to pre- wilt the forage and there is a higher risk of soil contamination.

The objective of the study was to investigate the

influence of cutting height, pre-wilting degree

and use of silage additives on the silage quality.

Materials and Methods

Two different cutting heights

7-8 cm High (H)

3-4 cm

Low (L)

Materials and Methods

A part of the forage was directly ensiled (A),

the rest of the forage was tedded and ensiled the next day with a higher dry matter (DM) content (B).

The forage was ensiled in

laboratory silos (1.5 l) with

or without additives.

Materials and Methods

Inoculant X contained Lactobacillus plantarum

Inoculant Y contained Pediococcus acidilactici, Lactobacillus paracasei and Lactobacillus lactis

0.53 g Inoculant X (liquid application)

50 g Inoculant Y (dry application)

350 g Chemical additive

- Without additive

Dosage (for 100 kg forage)

Variant

Pre-wilting

Cutting height high low high low

Dry matter, % 17.4 17.9 24.4 22.3

Ash, g/kg DM 145 237 140 150

Crude protein, g/kg DM 216 180 215 205

Crude fibre, g/kg DM 230 215 227 238

Sugar, g/kg DM 72 59 75 71

NEL, MJ/kg DM 6.0 5.2 6.1 5.8

Nitrate, g/kg DM 9.5 10.5 9.6 11.6

Fermentation coefficient 25 26 32 31

NEL: Net energy for lactation

Low (A) Medium (B)

Influence of pre-wilting degree and cutting height on nutritive values of the green forage

Values < 35:

forage difficult to ensile

Pre-wilting (PW) SE

Cutting height (CH) high low high low PW CH PW*CH

Dry matter, % 16.7 16.6 24.1 21.4 0.19 ** ** **

Ash, g/kg DM 177 267 170 173 7.8 * * *

Crude protein, g/kg DM 224 183 216 205 2.1 NS ** **

Crude fibre, g/kg DM 242 231 236 244 2.7 NS NS NS

Sugar, g/kg DM 7 5 8 8 0.1 ** ** *

NEL, MJ/kg DM 5.6 4.7 5.7 5.5 0.05 ** ** **

NEL: Net energy for lactation

NS = P>0.05; * = P<0.05; ** = P<0.01

Low (A) Medium (B) Significance

Influence of pre-wilting degree and cutting

height on nutritive values of the silages

Influence of pre-wilting degree and cutting height on fermentation parameters of the silages

Pre-wilting (PW) SE

Cutting height (CH) high low high low PW CH PW*CH

pH 4.9 4.9 4.6 4.6 0.02 ** NS NS

Lactic acid, g/kg DM 80 67 130 112 2.2 ** ** NS

Acetic acid, g/kg DM 87 77 55 53 2.7 ** NS NS

Propionic acid, g/kg DM 9 9 2 2 0.5 ** NS NS

Butyric acid, g/kg DM 0 0 3 3 0.1 ** NS NS

Ethanol, g/kg DM 7 7 4 2 0.8 * NS NS

NH

-N/N total, % 12.5 14.5 10.9 11.7 0.26 ** * NS

Gaseous losses, % 6.6 6.3 4.9 4.8 0.18 ** NS NS

DLG-Points 20 28 49 52 2.9 ** NS NS

NS = P>0.05; * = P<0.05; ** = P<0.01

Low (A) Medium (B) Significance

0 20 40 60 80 100 120 140 160 180 200

high low high low

cutting height

la c ti c a c id , g /k g D M

without additive chemical additive Inoculant X Inoculant Y pre-wilting low pre-wilting medium b

ab a a

b

a

b b b c bc ab a b b b a

Influence of silage additives on lactic acid

Values within the same PW and CH variants with different letters differ significantly (P>0.05)

0 20 40 60 80 100 120 140 160 180 200

high low high low

cutting height

a c e ti c a c id , g /k g D M

without additive chemical additive Inoculant X Inoculant Y pre-wilting low pre-wilting medium a

ab ab b a b a a a b b c a a a b

Values within the same PW and CH variants with different letters differ significantly (P>0.05)

Influence of silage additives on acetic acid

3.0 3.5 4.0 4.5 5.0 5.5

high low high low

cutting height

p H

without additive chemical additive Inoculant X Inoculant Y pre-wilting low pre-wilting medium ab

bc ab a a b a a a b b c a a a b

Values within the same PW and CH variants with different letters differ significantly (P>0.05)

Influence of silage additives on pH

0 2 4 6 8 10 12 14 16 18 20

high low high low

cutting height N H

-N /N t o ta l %

without additive chemical additive Inoculant X Inoculant Y pre-wilting low pre-wilting medium a

b a bc ab c a bc a b a b b bc a c

Values within the same PW and CH variants with different letters differ significantly (P>0.05)

Influence of silage additives on NH ₃ -N/N total

Values within the same PW and CH variants with different letters differ significantly (P>0.05)

Influence of silage additives on gaseouses losses

0 2 4 6 8 10

high low high low

cutting height

g a s e o s e s l o s s e s , %

without additive chemical additive Inoculant X Inoculant Y pre-wilting low pre-wilting medium bc

b a c a c a b a b b c a c b d

0 10 20 30 40 50 60 70 80 90 100

high low high low

cutting height

D L G P o in ts

without additive chemical additive Inoculant X Inoculant Y pre-wilting low pre-wilting medium

b

b b a b a b b c b b a b b b a

Values within the same PW and CH variants with different letters differ significantly (P>0.05)

Influence of silage additives on DLG points

Conclusions

In autumn the forage can have a high soil

contamination, especially when the cutting height is low.

As a result of the high nitrate contents no or only traces of butyric acid were produced.

In the silages with less than 20 % DM high levels of acetic acid were found. These silages had little DLG points.

The right silage additive can still improve the silage

quality under these conditions.

Thank you for your attention