1. HARVESTED FORAGES Green Chop and Hay pp. 250-253

2. WHY MECHANICALLY HARVEST FORAGES?

3. FORAGE MOISTURE DETERMINES THE APPROPRIATE HARVEST METHOD

4. GREEN CHOP Forage is chopped and fed directly from field Works well with legumes, forage sorghums, and corn Advantages –Minimal harvest losses Greater harvest efficiency than grazing –No fencing required –Reduces bloat problems with legumes Limitations –No storage –Fuel, equipment and wagon requirement –Weather dependence –Difficulty in controlling maturity.

5. HAY Forage harvested at a moisture level of 15% or less Factors affecting nutritional quality –Forage species –Maturity –Losses during harvest, storage and feeding StepLoss, % of standing DM Mowing1 to 6 Raking5 to 20 Swathing with conditioner1 to 10 Plant respiration2 to 16 Baling1 to 15 Storage, Outside5 to 30 In-barn2 to 12 Transporting1 to 5 Feeding, With feeder1 to 10 Without feeder2 to 45 Total losses10 to 80

6. LOSSES IN HAY HARVEST Leaf loss –Compared to stems, leaves contain: More protein, sugars, carotene, and minerals Less NDF and ADF –Loss greater from legumes than grasses –Loss increased by: Raking at higher DM concentrations Baling with a large round baler compared to square bales Rain, particularly if the forage is relatively dry Cell respiration –Metabolism of plant soluble carbohydrates by plant enzymes at moisture concentrations above 48% –Losses range from 2 to 16% of dry matter –Losses affected by rate of drying

7. Heat damage –Occurs when hay is stored at moisture concentrations greater than 18% –Stimulates growth of aerobic bacteria and mold Metabolizes soluble carbohydrates Causes heating –Temperatures > 120 o F causes heat-damage to proteins –Temperatures > 160 o F may cause spontaneous combustion Results in decreased net energy concentration and protein digestion Leaching –Loss of soluble nutrients in rainfall or snow melt –Occurs during: Rainfall during prior baling Outside storage of bales –Losses greater from legumes than grasses

8. HAY MANAGEMENT TO MAXIMIZE QUALITY Mowing –Goal To mow at high quality and to maximize rate of drying –Managing for forage quality Stage of harvest Plant stage Crop High quality Maximum yield Legumes Late bud Mid-bloom Grasses Boot stage Flowering Cereal grains Boot stage Soft dough Timing of harvest –Mowing at end of day will have higher concentration of sugars than mowing in morning

9. –Rate of drying Drying process –80 to 60% moisture - Rapid –60 to 40% moisture - Slow –40 to 15% moisture - Very slow Rapid drying desirable –Limits cell respiration –Reduces rain damage risk Factors affecting drying rate –Weather »Prefer high temperatures and low humidities –Timing of mowing »Mowing early in day maximizes solar drying –Wide, thin windrows »Exposure to wind and sunlight –Tedding hay »Fluffs windrows –Mechanical conditioning »Cracks stems to release moisture –Chemical conditioners »Potassium or sodium carbonate Applied at 5 to 7 lb / acre Reduces drying time by ½ day Effective on legumes, but not grasses

10. WHY CONCERNED ABOUT RAIN DAMAGE? Probability of 3 days without rain in Iowa –May - 26% –June - <40% –July - <50% Rain damage –Leaf loss –Decreased concentrations of sugars, protein, vitamins, and soluble minerals Alfalfa, Bud:Rainfall, in No rain1”1.65”2.5” % DM loss Leaf loss7.613.616.617.5 Respiration & leaching 2.06.630.136.9 Total9.620.246.654.4

11. Windrowing –Goal is to get forage into a form for continued aeration and baler pickup with minimal leaf loss –Done with a rake or windrower –Factors Species –Alfalfa, 15-25% loss –Grass, 5-10% loss Moisture level –Avoid windrowing before forage is above 50% moisture –Avoid windrowing when forage moisture is <35%

12. BALING Small square –60 – 100 lb –1 to 5% harvest loss from alfalfa –Easily handled –Marketable –Labor intensive –Requires barn storage Large round bales –800 – 2,000 lb –5 to 30% harvest loss from alfalfa Affected by field speed, windrow size, chamber rotation speed, and wrapping rotations –Requires equipment for handling –Less marketable than rectangular bales –Less labor than small rectangular bales –May be stored outside or inside Large square –600 – 3,000 lb –Lower harvest losses than round bales –Requires equipment of handling –Marketable –Less labor than small rectangular bales –Better stored inside than round bales

13. FACTORS AFFECTING HAY STORAGE LOSSES Inside storage vs outdoors –Under Iowa conditions Necessary for small rectangular bales Preferred for large rectangular bales Depends on hay price and use for large round bales –Storage losses from large round bales

14. EFFECTS OF WEATHERING ON LARGE ROUND BALES STORED OUTSIDE Weathering effects Decreases –DM weight and concentration –DM and protein digestibility Increases –NDF, ADF and ADIN Greatest effects on outside of bales Composition of hay after 4 to 10 months of storage

15. MANAGEMENT PRACTICES TO REDUCE STORAGE LOSSES FROM LARGE ROUND BALES STORED OUTSIDE Baling –Moisture level < 18% –Dense package –Net wrapping Drained surface (Crushed rock, pallets etc) Plastic cover Pyramid stack with plastic cover Plastic sleeve or wrap Place bales end-to-end in rows Place bale rows in a north/south direction with a minimum of 3 ft between rows Place bales rows up and down slopes of hills Do not place bales in shaded areas

16. PRICE FOR BARN STORAGE TO PRESERVE DM OR DIGESTIBLE DM OF LARGE ROUND BALES COMPARED TO OTHER STORAGE METHODS* $10.50/sq. ft. $3.00/sq. ft. * Doesn’t consider changes in hay quality.

17. FACTORS AFFECTING HAY STORAGE LOSSES (Continued ) Harvest moisture –Excessive hay moisture Increased loss of DM and nutrients during storage –Decreased DM digestibility and carotene content –Increased NDF, ADF, and ADIN concentrations Losses greatest in large bales –Unable to transpire moisture –Worsens weathering damage to bales stored outdoors –Problems worse in bales stored in barn or under plastic May result in spontaneous combustion Low moisture = 15%; High moisture=19%

18. HAY PRESERVATIVES Types –Propionic acid Application rates –Hay moistureLb/ton hay 20-25% 10 25-30% 20 30-35% 30 Effective if properly used on bales stored indoors –Others Sodium diacetate at 5 lb/ton for hay up to 25% moisture ??? Anhydrous ammonia at 60 lb/ton –Effective fungicide –Do not use on high quality hay Salt (NaCl) –No Controlled studies

19. USE OF PROPIONIC ACID AS A HAY PRESERVATIVE Must apply correct amount of active ingredient Must get uniform application Advantages –Allows barn-stored hay to be harvested at higher moisture concentrations Less leaf loss Reduces rain risk Limitations –Cost –Water soluble –Corrosive May be controlled by using ammonium propionate

20. FACTORS AFFECTING FEEDING LOSSES OF HAY Form –Ground Minimizes forage loss Allows for hay feeding in total mixed rations (TMR) Requires some type of bunk for feeding –Long Hay losses affected by feeder type Adequate space around feeder –900 lb hay = 30 cows/day –Usually space for 10 cows to each at once around round bale feeder

21. Length of access to feeder –For gestating beef cows fed moderate quality alfalfa-orchardgrass hay, compared to 24 hour/day access to large round bales in bale feeders: 12 hour access reduced hay disappearance by 4.4% 8 hour access reduced hay disappearance by 17.6% 4 hour access reduced hay disappearance by 37.2% –But 4 hour access also reduced cow weight gain –Recommend limiting access to bale feeders to 6 to 8 hours Assumes moderate quality hay Adequate feeder space

22. HAY GRADES Composition Alfalfa (<10% grass)Grass Hay grade Relative feed value* ADFNDFTDNCP % DM Supreme>185<27<34>62>22- Premium170-18527-2934-3660.5-6220-22>13 Good150-17029-3236-4058-6018-209-13 Fair130-15032-3540-4456-5816-185-9 Utility<130>35>44<56<16<5 *RFV calculated as the relative digestible DM intake using the NDF and ADF concentrations.

23. HAY GRADES Physical description Maturity GradeAlfalfaGrassLeafinessStemsColorOther SupremePre- bloom -Extra leafy Fine soft stems ExcellentDamage free PremiumPre- bloom Pre-headExtra leafy Fine stems GreenDamage free GoodEarly to mid- bloom Early head LeafyFine to medium stems Slight discolored Damage free FairMid to late bloom HeadedModerateGenerally coarse Light browm Light damage UtilityMature seed pods Mature head LowCoarseDark brown Excess damage, weeds, mold

24. MATCH HAY QUALITY TO ANIMAL NUTRIENT REQUIREMENTS Supreme Premium Good Fair Utility

25. EFFECTS OF HAY GRADES ON HAY PRICE Rock Valley, IA in February, 2013 AlfalfaGrass GradeSmall square Large square Large round Small square Large square Large round $/ton, as-fed Supreme285275 Premium250260 210220 Good240180 Fair160 Utility Corn stalks 90 Wheat straw 12085