Feeding Weather Damaged Forage

to Beef CattleJuanita Kopp, Ph.D., P.Ag.

Manitoba Agriculture, Food & Rural InitiativesFarm Production Extension Specialist – Beef

Livestock Knowledge CentreP.O. Box 180, 8 Fraser St., Pilot Mound, MB

Cell: 204-825-4302Juanita.Kopp@gov.mb.ca

What is weather damaged forage?

• Weathered due to: Excessive sun exposure Over drying Precipitation

• Rain leaches the most soluble nutrients Loss is greatest with the higher quality forages Leaching loss can be as high as 15% of the total DM Moulds & other microbes greater growth during wet

weather, these organisms utilize the most nutritious portions

Weathered Forage

• Forage in a windrow harvested too late or rained on Lower energy Lower protein

• Heat damaged Moulds

• Mycotoxins

• Forage species, growing conditions & stage of maturity affect nutritive value

Once cut--rain, rain--Go Away

• Each rain event can have an affect on quality• The closer to fresh forage the less damage

Within a few hours very little damage is done

• As the length of time increases from cutting to when it rains, losses increase

• Utah research found Alfalfa receiving 1” of rain 3 hours after cutting lost ~ 2% of

CP yield & 3.7% DM yield compared to alfalfa with no rain If the rain fell 12 hours after cutting, CP yield was reduced

3.5% & DM yield was reduced 5%

• As the amount of rainfall increases, losses increase Alfalfa that received 0.2” of rain yielded about 5% less dry

matter & 4% less CP/acre than hay that received no rain When the amount of rainfall increased to 0.8 inches, DM

yield & CP were reduced by 10%

• As a general rule, the loss in quality & yield due to a 1” rain event will exceed the losses in quality caused by allowing alfalfa to mature an additional week

• This is not true for grasses since the decline in quality due to maturity is much more rapid than it is for alfalfa

Rainfall effect on energy content of hay Description Rainfall % Decrease in Energy Content

Alfalfa Hay 0.50 inches (Sept 30 – Oct 20)

0.70

Timothy Mixture 0.98 inches(Aug 15 – Aug 31)

3.9

Alfalfa-Timothy* 1.5 inches(July 15 – Aug 12)

17.9

Timothy 1.3 inches(Aug 15 – Sept 14)

5.6

Brome-Timothy-Alfalfa 1.5 inches(July 16 – Aug 13)

14.0

Mean 8.4

*Raked before baling, U of A 1980 –raking losses of 5 to 10% of total DM for one event

Loss of nutritive value with advancing maturity

• Decreased proportion of leaves & the corresponding decrease in protein Legumes – 70% of protein in the leaves

• Increased proportion of stem & the corresponding increase in fibre

• Increased lignification of the stem & the corresponding decrease in energy value

Feeding value of forages as influenced by stage of growth at harvest

TDN % CP % Grass

CP %Legume

Intake % Body Weight

Vegetative 63 15 21 3.0

Boot or Bud 57 11 16 2.5

Bloom 50 7 11 2.0

Mature 44 4 7 1.5

Fisher, L.J. 1980

Heat damaged protein

• Brownish colour –useful protein content 80% of original value

• Dark brown or black –less than 50% of protein may be digestible ADIN

Maturity effects on forage quality of alfalfa & quackgrass

Growth Stage DDM % CP% ADF % NDF % DMI % Body Wt

RFV

Alfalfa

Mid-bud 69.2 22.2 25.2 33.3 3.6 199

10 % bloom 65.1 20.7 30.6 39.4 3.0 159

80 % bloom 59.8 18.4 37.4 48.2 2.5 125

Quackgrass

Pre-head 67.3 22.2 27.7 53.5 2.3 119

Heading 63.3 19.4 32.9 58.5 2.0 98

Anthesis 61.1 15.0 35.7 62.6 1.9 89

NDSU 1993

RFV

0

20

40

60

80

100

120

140

160

180

200

Early Mid Late

Alfalfa

QuackgrassBeef Cow

Replacement HeifersBackgroundersLactating Cows

23.27

56.8

19.77

50.2

18.33

45.3

15.6

46.2

13.9

44.4

11.73

41.0

9.7

38.0

9.3

34.3

0

10

20

30

40

50

60

May LateMay

MidJune

LateJune

MidJuly

MidAug

Sept LateOct

Avg CP%

Avg IVDMD%

Crested Wheat Grass quality during the grazing season

Theoretical amounts of DMI required to meet the energy (TDN) requirements of a 1200 lb lactating beef cow (20 lb milk/d) when grazing Crested Wheat Grass with different protein and energy concentrations

0

1

2

3

4

5

6

7

8

9

May LateMay

MidJune

LateJune

MidJuly

MidAug

Sept LateOct

DMI for Requirments

Forage Intake Guidelines as a percent of body weight Straw & Poor Forage

Medium Quality Forage

Excellent Quality Forage

Dry Mature Cows & Bulls

1.25 to 1.5 % 1.8 to 2.0 % 2.3 to 2.6 %

Suckled Cows 1.6 to 1.8 % 2.0 to 2.4 % 2.5 to 3.0 %

Growing & Finishing Cattle

1.0 % 1.8 to 2.0 % 2.5 to 3.0 %

Feed Test!!!!

Beef Nutrition

Cattle Need:• Water• Energy• Protein• Minerals • Vitamins

Cattle Nutrition• Nutrient requirements of cattle change throughout

the year based on the stage of the production cycle Age Sex Breed Level of activity Pest load Environment

• All these factors have an additive effect on the nutrient requirements

Nutritional Priority: Where the Feed Nutrients Go

Alive & moving

Including weight gain

Milk for calf

Requirements increase

Heat cycles & conception

Fat deposition

Protein

Third most important dietary component“Building Blocks” of the body

Degradable intake protein (DIP) requirements need to be met for microbial growth first

• Then & only then consider bypass protein or undegradable intake protein (UIP)

• Manage for heat damaged protein if hay/feed baled too wet

ADIN!!!

Energy Requirements (TDN %) for Beef Cattle

50

5862.5

68

80

0

10

20

30

40

50

60

70

80

Dry Cow EarlyGest.

Dry Cow LateGest.

Lactating Cow Bckgrd 2 lb/d Finishing

Crude Protein (%) Requirements for Beef Cattle

7

9.5

11.5

13

11

0

2

4

6

8

10

12

14

Dry Cow EarlyGest.

Dry Cow LateGest.

Lactating Cow Bckgrd 2 lb/d Finishing

• Needed when feeding: Slightly over-heated hay

• Denatures protein, molds use sugars– Browning of forage

» Carmalized sugars, tobacco smell

Rained damaged hay Poor quality hay, straw

Energy & Protein Supplementation

Energy Supplements

Feed NameDry Matter

% TDN % CP % Ca % P %

Barley Screening Pellets 88.0 75.2 14.0 1.0 0.4

Canola Screening Pellets 87.0 68.6 15.7 0.7 0.5

Grain Screening Pellets 89.0 75.2 15.0 0.6 0.4

Barley Grain 88.5 83.1 12.5 0.1 0.4

Oats Grain 90.2 76.2 11.3 0.1 0.3

Corn Grain 89.0 88.2 10.0 0.03 0.3

Roughage Type Recommended Grain Intake, lb/d

Dry Beef Cows Straw 4 to 8

Suckled Beef Cows Straw 6 to 12

Good Hay 0 to 8

Bulls Straw 6 to 10

Good Hay 3 to 7

Grain supplementation

Cowbytes Ration Guidelines

Protein Supplements

Feed Name Dry Matter% TDN % CP % Ca % P %

Canola meal 91.9 70.3 39.2 0.8 1.3

Soybean meal 89.7 86.1 52.4 0.4 0.8

Wheat DDGS 90.0 82.0 40.0 0.2 1.0

Corn distillers dry grain 90.0 88.0 29.5 0.1 0.4

32-11 Beef supplement 90.0 64.1 35.6 5.6 1.1

Moulds

Mould• Estimated to reduce feed value by at least 10%• Vitamins destroyed

Vitamins A, D, E, K & thiamine

• Mould requires oxygen, heat, moisture & nutrients to grow Moulds grow rapidly at 75 to 90◦F Above 15% moisture

Mouldy Feeds• Very dusty

Mold organisms & spores • Inhaled dust

– fungal pneumonia– Some spores may pass through lesions in rumen wall &

carried to blood stream– Settle in the uterus

» uterine infections & mycotic abortions

Mouldy Feeds• Estrogenic metabolites may affect lactation

& cycling• Do not give mouldy feeds to pregnant or

lactating cows• Dilute moldy feed with good quality feed

reduce potential for problems when feed non-pregnant, dry, older animals

• Supply adequate levels of Vitamin A

• FEED TEST!!!• Supplement for deficiencies in energy &

protein• Balance rations

Feed vitamins & minerals Check for mineral interactions

• Ca:P, K/Mg+Ca, S

To utilize weathered forages

Questions???