FORAGES Gwinyai E. Chibisa, Ph.D.

Transcription

1 FORAGES Gwinyai E. Chibisa, Ph.D.

2 Haymaking Objectives i. Produce a high yielding, high quality crop ii. iii. iv. Rapid curing Minimize leaf loss Minimize cell respiration v. Avoid leaching losses & molding vi. Maintain quality in storage

3 Haymaking Phases Harvesting/Cutting Curing Raking Baling Storage

4 Harvesting

5 When to Harvest? Impact of plant maturity on DMI & digestibility Ball et al, American Farm Bureau Federation Publication 1-01

6 When to Harvest? Forage Species Time of Harvest Alfalfa Bud stage (1 st cutting); 1/10 bloom for 2 nd and later cuts Orchardgrass, Tall Fescue Red Clover Barley, Oats, Rye, Wheat Sudan-sorghum hybrids Weather conditions? Boot to early head (1 st cut); every 4-6 weeks after Early to ½ bloom. Boot to early head stage. Early boot stage.

7 Curing What is the objective of curing??

8 Curing (cont.) Factors that affect the duration of curing Initial DM% Environmental i. Temperature ii. iii. iv. Humidity Wind speed Solar radiation Conditioning

9 How Does Rain Affect Hay Quality i.? ii.? iii.? iv.? v.? vi.?

10 Make Hay While The Sun Shines Ball et al, American Farm Bureau Federation Publication 1-01

11 What Would You Do? If forage is ready to harvest for hay, but rain is in the forecast?

12 Curing (cont.) Factors that affect the duration of curing Initial moisture % Environmental i. Temperature ii. iii. iv. Humidity Wind speed Solar radiation Conditioning

13 Conditioning What is conditioning?

14 Mechanical Conditioning Conditioners bruise, lacerate, crush or crimp plant to reduce differential drying of leaves vs. stems

15 Chemical Conditioning Desiccants/ drying agents E.g., K 2 CO 3, NaCO 3

16 Reducing Drying Time Tedding

17 Reducing Drying Time Raking

18 Baling Has to be done at the correct moisture % moisture? Consequences of baling when too wet or dry?

19 DM Losses During Haymaking Ball et al, American Farm Bureau Federation Publication 1-01

20 DM Losses During Haymaking (cont.) Process % DM Respiration 2-16 Conditioning (crimper) 1-4 Raking at 40-50% moisture 2-5 Raking at 10-15% moisture Baling (rectangular) 2-5 Baling (large, round) 15-40

21 Baling When Too Wet Growth of spoilage microbes (aerobic) Spoilage bacteria, e.g., bacilli Yeasts, molds, fungi Hay (plant sugars, protein) + O 2 CO 2 + H 2 O + Heat

22 Effect of Feeding Moldy Hay in Cattle Parameter Good Hay Moldy Hay Hay intake, kg Rumen fermentation characteristics Total VFA, µ mol/ml Rumen ammonia, mg/dl Digestibility, % DM CP Performance Average daily gain, kg/d Feed:Gain Mohanty et al. (25)

23 Hay Preservatives Hay preservatives Reduce losses due to molds & heating Reduce drying times (can bale at higher T C) Roberts,

24 Hay Preservatives (cont.) Preservative Mode of Action Application Method Moisture Content of Hay Pros & Cons Weak acid e.g., Propionic acid Controls mold & bacterial growth by altering ph Liquid-added before baling Up to 30% Can be stored Corrosive Buffered acid e.g., Ammonium propionate Controls mold & bacterial growth Liquid-added before baling Up to 30% Not as corrosive Not as effective Bacterial inoculants Compete with other microbes in hay Liquid-added before baling Up to 23% Cannot be stored Designed for silage prodn

25 Hay Storage Recommended % moisture for safe storage Bale type % Moisture Small rectangular bales Round bales (soft center) Round bales (hard center) Large rectangular bales Export hay < 12

26 Hay Storage (cont.) Protect from the elements

27 Hay Storage and Forage Quality Ball et al, American Farm Bureau Federation Publication 1-01

28 USDA Hay Market Prices Feb 16, February html

29 USDA Hay Market Prices Feb 16, February html

30 USDA Hay Market Prices Feb 16, February html

31 USDA Hay Market Prices Feb 16, February html

32 Relative Feed Value (RFV) Widely used index to market hay RFV = % Digestible DM DM intake (% of BW) 1.29

33 Total Digestible Nutrients (TDN) Index that estimates energy supply Earlier equations based on ADF; TDN Legumes and grasses = 88.9 (0.79 ADF%) NRC, 2001 TDN = dnfc + dcp + (dfa 2.25) + dndf 7

34 Relative Feed Quality (RFQ) Another forage quality measure RFQ = TDN DM intake (% of BW) 1.23

35 Summary????