HAMILTON Tatyoon _ Penshurst _ Woorndoo Dr Steve Cotton
Outline • Importance of testing • Coring silage • Subjective assessment • Objective assessment • DM • NDF • Digestibility • ME and CP • WSC and Ash • Factors affecting quality • Comparing the cost of silages • Review of 12-13’ season • Stock requirements
How can you make an informed decision on how much to feed your stock if you don’t know the quality? Question……. Answer……. You can’t! You need to have it tested!
Importance of testing? • Test before you feed – • Determine if stock requirements can be met • Calculate feed rations • Budget for feed gaps • Informed management decisions • Utilise feed efficiently, manage stock effectively • Test before you buy – • Insist on knowing what you are purchasing
AFIA guidelines • Use a hay corer (We have loan corers available) • Core 10 -15 bales • Select at random until bag is full Testing silage - Coring • Core “across” not with the flakes • Tape up holes immediately
Core Vs Grab Sample Core sample Grab Sample • Takes longer to obtain sample • Uniform stalk length • Representative of bale and paddock • Reduces processing time by ¾ • Results accurate and meaningful • Easy • No uniformity • Not representative • Increases processing time • Results less accurate
Subjective assessment- Colour Greeny/brown Light amber brown Dark brown • Normal • Good mix of yield & quality • Indicates good fermentation • Cut too late • > % mature grasses • > DM but < quality • Indicates heating • < DDM & CP • Poor sealing &/or compaction
Subjective assessment- Aroma Not Desirable 1. Musty/mouldy/composty = poor compaction Tobacco/caramel/burnt sugar = heat damaged Vinegar = poor fermentation Common with low DM and low sugar silages 4. Sweet/fruity = > % yeasts present, high ethanol levels 5. Slightly sweet = heavily wilted low fermentation 6. Mild/acidic/yoghurt = normal Desirable
Objective silage quality Digestibility NDF ADF CP ME Ash WSC
Dry Matter As tested Vs As Fed • Labs traditionally report on DM(%) basis (after oven drying), BUT: • When feeding out silage it is not oven dried SO: • Need to correct values to “As Fed” • Use the formula DM(%) x ME as tested/100(This is calculated for you in your Feed Logic report)
Consider Dry Matter (DM) Based on a 300kg weaner gaining 0.5kg/day
Too low Dry Matter Too high < 30% > effluent, < fermentation Loss of nutrients • >50-55% • < anaerobic conditions • > chance of heating & mould growth Baled silage can have > DM(%) than pit
Neutral Detergent Fibre (NDF) Predictor of dry matter intake (DMI) High NDF reduces intake Example: Based on a 500kg cow Target variable but < 55% of DM is good
Importance of Fibre • Assists in rumen movement, mixing and rumination • Stimulates saliva production • Fibre slows the flow through the rumen to give the microbes more time to digest the feed Feeds high in fibre Hay Long stemmy pasture Silage Straw
Digestibility of Pasture Source: Horizon Ag Website Grass plant Clover plant
Digestibility 10 Kg eaten Measure of how much food is digested by the animal Silage target > 66% + of DM 3 Kg Dung 70% Digestible
ME and CP The higher the ME values the better! CP is less critical – no point exceeding min req. Target: > 10MJ ME/kg DM > 12% CP for pasture silage (to satisfy stock requirements) > 18% CP for legume silage(vetch/clover/lucerne) Remember: Livestock requirements vary The better the feed quality, the less you need to feed!
WSC & Ash WSC concentration important in parent material Usually low in silage – not reported • Ash value maybe irrelevant • Includes inorganic minerals that are not burnt off at 550oC • Will vary within and between paddocks • Target < 10%
Factors affecting quality • Harvest Date Source: Steen (1992) A 7-day delay in harvest decreases quality by 0.25-0.6 MJ/kg DM. A 1% increase in digestibility in cattle will increase milk production by approx. 0.3 kg/day Weight gain by 45 g/day
Remember: • Good quality silage has: • Digestibility > 66% • ME > 10 MJ ME/kg DM • CP > 12% • NDF < 55% DM • DM 30-55% Good Vs poor quality silage
Quality Perennial Ryegrass Lucerne Source: Successful Silage – Top Fodder Manual 2006
Before Making Silage……… • Consider testing parent material for: • Quality – NIR testing • Quantity – DM only Silage quality is only as good as the materials that go into it!
Comparing the cost of silages Consider: Cost/MJ of ME not $/t Source: Successful Silage – Top Fodder Manual 2006
12’-13’ season average • Small reduction in quality from previous season • Variation in: • Where samples come from • 2. What the season is doing in local areas
How much silage to feed? Need to know: 1. Animal requirements 2. ME and CP from pasture 3. Is there a deficit? 4. If yes, how much supplement you feed depends on the quality of the feed. You need to have the feed tested!
Stock requirements DRY SHEEP (maintenance) LATE PREGNANCY (day 150) 9.6MJ ME/day 15MJ ME/day (single) 6-8% CP 17MJ ME/day (twin) 10-12% CP LACTATING (Day 30) 19.5MJ ME/day 24MJ ME/day 29MJ ME/day ~ 12% CP 14% CP 15+ % CP
Stock requirements DRY COW (maintenance 600kg) WEANERS 300kg 80 MJ ME/day 35 MJ ME/day maintenance 8-10% CP 57 MJ/day gaining 0.5kg/day 76 MJ/day gaining 1.0kg/day 8,10, 13% CP respectively COW WITH CALF AT FOOT (up to 4 mths) 100 MJ ME/day 10-11% CP
Stock requirements 600kg Fresian 63 MJ ME/day maintenance + 1MJ ME/day if pregnant (1-5 months) + 20MJ ME/day at 9 months pregnant + 5MJ ME/km walked to and from dairy on hilly terrain + 5 MJ ME/L milk produced (3.2% protein, 3.6% fat) TOTAL > 200MJ ME/day + 12-18% CP (depending on production)
Summary • Coring silage is important – We can loan you a corer! • Subjective assessment (aroma & colour) • Consider DM • Harvest time affects quality • Think about cost of silage in c/MJ ME NOT in $/t • Stock requirements change over the season • Measure to manage Before you feed it, buy it or sell it, TEST IT!
For further information on ewe nutritional management DEPARTMENT OFPRIMARY INDUSTRIES • Lifetime Ewe Management • A program for sheep producers • KEY TOPICS: • Weaning and preparing ewes for next year’s joining • Setting up for joining/manipulating ewe condition • Linking ewe condition at joining with lambing potential • Mid-pregnancy-looking forward and planning for lambing • Late pregnancy and lambing • Economicanalysis of different feeding strategies RIST Cattle Health Course meeting 1 Fertility& Reproduction Aug 2009David Rendell