Basim Refat

Topic of presentation

Effect of forage particle size on silage quality

Effect of forage particle size on dairy cow

performance

Topic of presentation

Effect of forage particle size on silage quality

Effect of forage particle size on dairy cow

performance

Chop length for silage

Roughage value and rumen function Compaction and fermentation

Density

DM concentration

permeability

Aerobic Deterioration

Factor Correlation Coefficient Correlation Coefficient

Initial layer thickness -0.279*

Average packing tractor weight 0.262*

Average wheel load 0.224*

Dry matter content 0.29*

Total weight of packing tractor(s) 0.20*

Average particle size 0.194*

Packing time (min/t as-fed) 0.162*

Speed of packing (1 ≥ 8 km/h; 4 ≤ 1.6 km/h) 0.147

Number of packing tractors 0.146

Wheels per packing tractor 0.126

Tire pressure 0.098

Crop (1 = corn; 2 = alfalfa) 0.086

Packing time (min/t DM) 0.078

* Significant correlations (P < 0.05). Muck 2000

ab

0

5

10

15

20

25

30

35

40

DM content % pH value lactic/acetic

acid

NH3-N /total N Dm-lossess

%DM

aerobic stability

days

stability lossess

%DM

yeast (log

cfu/g FM)

moulds (log

cfu/g FM)

CL7 CL 22

Mahlkow and Thaysen 2005

24.8

67.8

45

4.9

27.7 28.5

49.8

33.7

4.8

0

10

20

30

40

50

60

70

80

DM CP (%DM) NDF(%DM) ADF (%DM) WSC (%DM) nh3(Total N) Ph

T1 T2 T3 T4 T5

Moisture PS additives

T1 F L no

T2 F S no

T3 W L no

T4 F L (ground pearl Millet grain)

T5 F S microbial additives

Paziani et al 2005

2.4

ab

b

ab

2.2

b

a

b

3.4

ab

ab

a

2.2

a

ab

ab

2

b

a

ab

0

20

40

60

80

100

120

140

160

180

Mean Particle size cm DM density porosity spoilage lossess

Physical parameters

T1 T2 T3 T4 T5

Moisture PS additives

T1 F L no

T2 F S no

T3 W L no

T4 F L (ground pearl Millet grain)

T5 F S microbial additives

OA, Open-air storage condition;

SC, semi-closed storage condition;

CS, Closed storage condition

Toruk and Gonulol, 2011

163

204

0

50

100

150

200

250

UC UC UC UC C C C C

trail 1(1stcut DM35)

trail 1 cutDM50)

trail 2 (firstcut)

trail3(second

cut)

trail 1(1stcut DM35)

trail 1 cutDM50)

trail 2 (firstcut)

trail3(second

cut)

Density

Borreani and Tabacco (2006)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

pH Lactic acid, % of DM Acetic acid, % of DM Ammonia, % of DM

Fermentation

Long Medium Short

Yang and Beauchemin 2006

Effects of reducing dietary particle size on silage fermentation

Theoretical cut length (TCL)Long: 28.6mmMedium:15.9mm Short: 4.8mm

The recommended theoretical length of cut (TLC)

3 ⁄ 8 to 3 ⁄ 4 inch for corn silage

▪ 3 ⁄ 8 for processed corn

▪ 3 ⁄ 8 for not processed corn

3 ⁄ 8 to 1 ⁄ 2 inch for alfalfa silage.

Chopping too long makes compaction difficult

trapping air in the forage mass and resulting in silage that

heats and spoils.

Conclusion first part

Topic of presentation

Effect of forage particle size on silage quality

Effect of forage particle size on dairy cow

performance

feed high energy diets In large amounts

While maintaining the cow in a normal

physiological state?

Forage amount in the ration

The amount and type of grains

Physical form

The addition of additives

Measuring the Effectiveness of NDF

Is the fraction of fiber that stimulates chewingand contributes to the floating mat of largeparticles in the rumen = % remaining on 1.18 mmscreen after dry sieving

The concept of peNDF incorporates the chemical NDF

content of the diet in a manner that predicts the

physical effectiveness of the diet

(Mertins 1997)

dietary particle length

chemical NDF

content

peNDF

(Mertens 1997)

Pore diameter of sieve (mm)

Poppi et al. 1980

Why 1.18?This size below whichparticles have potential toescape from rumen-

DM retained

1.18-mm sieve

NDF content peNDF

Proposed by Mertens 1997

Penn State Particle Separator (PSPS)

Lammers et al. (1996)

DM retained by the 19- and 8-mm sieves of

the PSPS

NDF content peNDFps-2s

Type

Corn Silage Haylage TMR

Sieve Size % of DM retained

>19.0 mm 5 ± 3 15 ± 5 5 ± 3

19.0 – 8.0 mm 55 ± 10 60 ± 15 40 ± 10

8.0 – 1.18 mm 40 ± 10 30 ± 10 40 ± 10

<1.18 mm <5 < 5 < 20

Forage and TMR particle size

recommendations based on two

experiments that fed either alfalfa haylage

or corn silage, with or without cottonseed

hulls, to cows in early lactation.

(Heirichs and Kononoff, 2002)

+ 1.18-mm sieve to the PSPS

DM retained by 19-, 8-, and

1.18-mm sieves

NDF content peNDFps-3s

Kononoff et al. 2003

1- The Penn State Particle Separator

pefps-2s = physical effectiveness factor

determined as the proportion of particles

retained on 2 sieves (Lammers et al., 1996)

pefps-3s = physical effectiveness factor

determined as the proportion of particles

retained on 3 sieves (Kononoff et al., 2003)

(Yang and Beauchemin 2006)

Particle length Effects

Long Medium Short Linear Quadratic

PSPS

% DM retained on sieves

19 mm 10.2 8.3 2.7 0.01 0.02

8 mm 61.3 59.8 38.7 0.01 0.01

1.18 mm 24.0 27.6 51.5 0.01 0.01

Pan 4.5 4.3 7.2 0.01 0.01

peNDFps-2s, % of DM 35.2 31.5 17.4 0.01 0.01

peNDFps-3s, % of DM 47.0 44.3 44.4 0.07 NS

(Yang and Beauchemin 2006)

2- dry sieving

vertical oscillating sieve shaker equipped

with a stack of sieves arranged in

descending mesh size;

Dietary peNDF effect

Long Medium Short Linear Quadratic

Dry sieving

% DM retained on sieves

9.5 mm 9.9 5.8 4.1 0.02 NS

6.7 mm 11.1 14.4 9.1 NS NS

3.35 mm 24.6 26.3 22.5 NS NS

1.18 mm 33.0 34.4 40.3 0.03 NS

0.6 mm 11.6 10.3 14.5 0.12 0.10

0.15 mm 6.2 5.6 7.3 NS NS

<0.15 mm 3.6 3.2 2.1 0.03 NS

peNDF1.18 % 24.9 24.7 23.7 NS NS

(Yang and Beauchemin 2006)

Finely chopped alfalfa Silage (FS)

Cracked shelled corn (DC; low RFC)

Ground high-moisture corn

(HMC; high RFC)

Coarse alfalfa Silage (CS)

Cracked shelled corn (DC; low RFC)

Ground high-moisture corn

(HMC; high RFC)

Krause et al. (2002a,b)

HMCFS DCCS HMCCSDCFS

Effects of, and interactions between, level

of dietary ruminally fermentable

carbohydrate (RFC) and forage particle

size on milk production,

Mean (mm) SD (mm)

Dry cracked shelled corn 1.55

High-moisture shelled corn 1.60

Coarse alfalfa silage 13.6

Fine alfalfa silage 3.7

HMC FS 3.0

HMC CS 6.0

DC FS 2.8

DC CS 6.3

Mean geometric particle size of corn grain, forage, and TMR

14% NDF, % of DM

reduce rumination time and cause milk fat

depression when dairy cows are fed

chopped alfalfa hay as forage

(Woodford et al. 1986)

6.4 mm

Treatments

Foragesignificance HMCFS HMCCS DCFS DCCS

Time/DMI per d,

min/kg24.9 30.6 21.7 30.9 ***

Total chewing time increased 7.5 min/kg of DM consumed.

0

5

10

15

20

25

30

35

Time/DMI per d, min/kg

HMCFS HMCCS DCFS DCCS

Krause et al. (2002a,b)

Effects of level of ruminally fermentable

carbohydrates and forage particle size

on intake

Dig, %

Treatments significance

HMCFS HMCCS DCFS DCCS RFC ForageRFC ×Forage

DM 75.5 74.5 72.8 69.9 * NS NS

OM 76.6 75.5 73.9 70.8 ** NS NS

NDF 54.3 47.6 46.2 47.7 NS NS NS

ADF 58.9 52.9 51.8 54.2 NS NS T

Starch 97.7 97.1 94.5 91.6 ** * NS

Krause et al. (2002a,b)

TreatmentsP- value

HMC FS HMC CS DC FS DC CS RFC × Forage

Milk, kg/d 45.6 43.6 42.9 43.7 0.06

SCM, kg/d 41.0 41.1 39.6 40.0 NS

SCM/DMI 1.76 1.68 1.59 1.59 NS

Fat, % 3.42 3.60 3.48 3.62 NS

Fat yield, kg/d 1.55 1.59 1.49 1.57 NS

Protein, % 3.05 3.12 3.15 3.10 NS

Protein yield, kg/d 1.38 1.37 1.35 1.33 NS

Effects of level of ruminally fermentable

carbohydrates and forage particle size on

milk yield and milk composition

Krause et al. (2002a,b)

TreatmentsP-VALUE

Forage PSHMCFS HMCCS DCFS DCCS

VFA, mM

Total 161.5 148.4 151.1 144.9 NS

Acetate (A) 78.9 77.4 82.8 82.5 NS

Propionate (P) 52.4 43.7 39.8 35.2 NS

Butyrate 19.6 19.6 20.8 22.5 NS

A:P ratio 1.60 1.90 2.23 2.45 NS

Effects of level of ruminally fermentable

carbohydrates and forage particle size on

ruminal fermentation and pH

Krause et al. (2002a,b)

Treatments (P-value)

HMCFS HMCCS DCFS DCCS RFC Forage RFC × Forage

Mean ruminal pH 5.72 5.98 5.9 6.07 * *** NS

Time belowpH 5.8, h/d

14.3 7.2 9.3 5.5 ** *** NS

Effects of level of ruminally fermentable carbohydrates and forage particle size on ruminal pH.

Decreasing forage particle size decreased

pH from 6.02 to 5.81, whereas replacing

DC with HMC decreased pH from 5.99 to

5.85.

Krause et al. (2002)

Effect of forage particle size on rumen pH pattern post-feeding

CS ♦ = Coarse silage FS ■ = Fine silage

Krause et al. (2002)

Hours post-feeding

Ru

min

al p

H

49.3 46.3 47.8

0

20

40

60

80

100

120

DM, % OM, % of DM NDF, % of DM ADF, % of DM Starch, % of DM CP, % of DM

Corn Silage

Theoretical cut length (TCL)Long: 28.6mmMedium:15.9mm Short: 4.8mm

(Yang and Beauchemin 2006)

Dietary peNDF

High Medium Low P-Value

Min/kg of DM 38.2 36.4 32.5 NS

Effects of reducing dietary physically

effective fiber (peNDF) on chewing

activity of dairy cows

(Yang and Beauchemin 2006)

Dietary peNDFSig

Long Medium Short

Mean pH 6.08 6.06 5.99 NS

pH <5.8, h/d 3 4.1 4.8 NS

pH <5.5, h/d 0.8 1 2 0.13

Effects of reducing dietary physically effective fiber (peNDF) on ruminal pH and fermentation of lactating dairy cows

(Yang and Beauchemin 2006)

Dietary peNDF

High Medium Low P- VALUE

Total, mM 128.3 138.7 128.7 NS

Acetate (A), % 53.3 52.4 53.3 NS

Propionate (P), % 26.9 23.1 25.8 NS

Butyrate, % 14.6 18.3 15.7 NS

A:P 2.1 2.5 2.2 NS

NH3 N, mM 8.5 11.0 8.8 *

Mean pH 6.08 6.06 5.99 NS

(Yang and Beauchemin 2006)

Effects of reducing dietary physically

effective fiber (peNDF) on ruminal pH

and fermentation characteristics of

dairy cows

CL7 CL22

FI (kg DM/day) 21.6 20.5

Milk Yield (Kg/d) 36.1 35.5

Milk Fat (Kg/d) 1.5 1.51

Milk Protein (Kg/d) 1.16 1.16

Effect of two different chopping lengthsof maize silage on dairy cowperformance ; cut length 7-mm or 22mm

Mahlkow and Thaysen 2005

UnchoppedChopped SED P-value

Intake of WCBS

Dry matter, kg day− 1

3.42 4.20 0.147 0.001

Dry matter, g kg−1

live weight

16.3 19.7 0.51 < 0.001

Neutral detergent fibre, kg day

− 1 1.55 1.93 0.066 < 0.001

Neutral detergent fibre, g kg

− 1live weight

7.38 9.06 0.229 < 0.001

LWG

Initial weight 182 184 4.6 0.728

Final weight 236 249 4.5 0.027

LWG, kg 53.9 64.8 1.45 < 0.001

LWG, kg day− 1

0.855 1.028 0.0230 < 0.001

Chopping of whole-crop barley silage

improves intake and live-weight gain of

young dairy steers

Rustas and Nadeau 2011

PSPS with 2 sieves provided a better description of the variationin dietary physical effectiveness and the potential of the diet topromote chewing and prevent ruminal acidosis.

Differences in particle size do not always result in differences in mean rumen pH.

When evaluating a diet to determine a possible risk of subclinicalacidosis, we should review levels of fiber and nonstructuralcarbohydrates, along with their associated fermentability

THANK YOU

http://images.vancepublishing.com/pdfs/dairyherd/NDF_DairyRations.pdf

unclear which measure of peNDF and what peNDF

contents provide the most accurate estimation of

chewing activity and ruminal pH in dairy cows

These different methods of peNDF estimation result in

very different values

Feed particles retained on a 1.18-mm sieve had a high resistance

to passage from the rumen of sheep.

Important to fractionate the larger feed particles requiring chewing

to pass from the rumen,

Standard laboratory assessment for measuring pef for feeds using

dry sieving techniques.

Poppi et al. (1980)

what is the critical particle size for passage from the rumen?

which fraction of particles remains in the rumen to stimulate

chewing?

Although the peNDF system has become

firmly established using the 1.18-mm sieve

to measure pef,

Critical size for cattle is actually closer to a

fraction of particles that would be retained on

a 3.35-mm sieve.

Oshita et al. (2004)Yang et al. 2001

Larger critical size may be more appropriate for cattle

Ruminal outflow rate of particles: 1.18 mm averaged 5.57%/h a

3.35-mm sieve = 1.75%/h.

Feed particles retained on sieves with apertures >4.0 mm would be

retained in the rumen of dairy cows and contribute to chewing

activity.

Yang et al. (2001)

Cardoza and Mertens (1986)

UnchoppedWCBS

Chopped WCBS

Dry matter, g kg− 1 fresh weight 334 319

Crude protein 83.0 83.4

Sugar 27.7 24.3

Starch 173 157

Neutral detergent fibre 449 460

IVDOM, g kg− 1 OM(96h) 756 752

Indigestible NDF(288h-in situ) 150 146

pH 4.1 4.1

NH3-N, g kg−1 total N 100 103

Lactic acid 51.3 45.6

Acetic acid 7.7 7.2

Butyric acid 1.2 1.1

Ethanol 9.2 8.4

Rustas and Nadeau (2011)

chemical composition of whole-crop barley

silage (WCBS) (g kg− 1 dry matter)