8 Managing organic feeding

Transcription

1 8 Managing organic feeding While organically-fed cows have exactly the same nutrient requirements as conventionally managed animals, meeting them under organic standards is considerably more complicated in many respects. Being able to use only organic feeds means greater emphasis on home-grown forage and concentrate production, while maintaining this at high levels in the absence of inorganic fertilisation presents its own particular challenges. Ensuring the healthiest and most productive swards through good day-to-day management and a flexible approach to grazing is especially important in organic systems, as is good feed purchasing and utilisation with minimum wastage. What s in this section? Appreciating current performance levels and feeding constraints Ensuring the best possible use of home-grown forages Growing or purchasing other feeds as cost-effectively as possible. 8 Managing organic feeding Forage output from organically-farmed units can be as good as many non-organic ones. However, higher purchased feed prices and less feeding flexibility puts the onus on good forward planning and stockmanship to a far greater extent than under conventional management. Contents Action plan Page 8:3 Organic performance Page 8:4 Feeding constraints Page 8:5 Forage feeding Page 8:6 Non-forage feeding Page 8:12 Nutrient budgeting Page 8:14 Improvement through feeding 8:1

2 Summary As the precise rules for full organic and organic conversion are subject to amendment it is essential to check the standards with the inspection body to which the farm is signed-up wherever there is any doubt over the acceptability of a feed or ingredient Legume nitrogen fixation can amount to 100kg N/ha (in come cases up to 200kg N/ha) each year, and is the main source of nitrogen on organic farms Most legume-rich pastures carry a risk of bloat but cows that are used to grazing high legume leys and are not turned out to them with empty rumens rarely suffer Wholecrop cereals, maize and a variety of buffer crops also provide very valuable sources of forage nutrients for organic herds While home-grown forages are the backbone of organic dairy systems, the nutrient requirements of all but the lowest yielding cows mean a considerable amount of supplementary energy and protein in the form of concentrates will be essential for most units Particular care needs to be taken to ensure all purchased feeds including any mineral and vitamin supplements are both approved for organic use and sourced from organically-approved producers. A high and consistent daily rate of sward dry matter production is especially important in making the most of grazing in organic systems if production costs are to be kept as low as possible See also... Section 2: Section 3: Section 4: Section 5: Planning your nutrition Planning your feeding Assessing your feed options Managing your forage feeds Section 6: Managing your non-forage feeds Section 7: Section 11: Section 12: Managing your feeding Factsheet 5: Common ration ingredients Factsheet 8: Out-wintering on brassicas Worksheet 5: Relative feed valuation Worksheet 6: Feed budgeting 8:2 Improvement through feeding

3 Action plan To make the most of your organic feeding: 1. Evaluate your current performance Evaluate your current feeding performance against national benchmarks and establish your potential for improvement (Page 8:4). 2. Appreciate your feeding constraints Ensure you keep up-to-date with organic production standards and appreciate the precise constraints they place on your feeding (Page 8:5). The Grass+ programme provides practical advice on making the most of grass. For detailed guidance on sward productivity and renewal see Sections 10 and 12. For detailed guidance on managing organic swards see Section Make the most of forages Use legumes and other crops like maize, wholecrop and buffer forages to maximise your herd s nutrient supply from home-grown feed (Page 8:6). 4. Make the most of non-forage feeds Plan to grow sufficient additional energy and protein or purchase it as cost-effectively as possible to supplement forage nutrient supplies (Page 8:12). 5. Maintain farm nutrient budgets Keep a close check on the balance between farm N, P & K inputs and off-take to monitor critical soil nutrient status (Page 8:14). Improvement through feeding 8:3

4 Organic performance Previous Kingshay Dairy Manager costings show organic herds producing less milk per cow but more from grazed forage, in particular, than comparable conventionally-managed units (Table 8.1). This results in a lower rate of concentrate use both per cow and per litre, although very much higher concentrate feed prices give higher per litre purchased feed costs. Table 8.1 Organic herd performance Organic Herds Non-Organic Herds Difference Yield (litres/cow) Yield from all forage (litres/cow) Yield from forage (%) Concentrate use (kg/cow) Concentrate use (kg/litre) Concentrate price ( /tonne) Total purchased feed cost (p/litre) Milk price (p/litre) Margin over purchased feed (p/litre) Margin over purchased feed ( /cow) Kingshay Dairy Manager: Annual rolling annual average, December :4 Improvement through feeding

5 Feeding constraints Official standards, overseen by the EU and Defra and implemented by various certification/inspection bodies, govern the farming practices required to maintain organic status. By growing as much feed as possible on the farm, among other things, organic production seeks to minimise the environmental impact of feed transport over long distances. Some purchased feed usage is almost inevitable for most units and there are clear rules governing what is acceptable. Units converting to organic production have separate rules with somewhat more leeway, designed to make conversion practicable. As the precise rules for full organic and organic conversion are subject to amendment it is essential to check the standards with the inspection body to which the farm is signed-up wherever there is any doubt over the acceptability of a feed or ingredient. The ending of the derogation from January 2008, allowing a small proportion of the feed (5%) to be non-organic if organic feeds are not available means all feed for dairy cows has to be organic. In addition to this: All purchased feeds must be certified GM free No solvent extracted feeds are permitted (limiting oilseeds to expeller cakes) Fat supplements are not permitted At least 60% of the daily diet DM must be forage. Improvement through feeding 8:5

6 Forage feeding Research and experience underline the particular value of white clover, red clover and other legumes in optimising pasture output and quality by increasing sward yields and protein contents. Together with organic manures, they also play a vital role in building and maintaining soil fertility in the absence of inorganic fertilisation. Legume nitrogen fixation can amount to 100kg N/ha (in come cases up to 200kg N/ha) each year, and is the main source of nitrogen on organic farms. Organic production requires an effective legumebased rotation that includes a balance of N-fixing crops (including red and white clover and lucerne) and N-demanding crops (like cereals, grass and other forages). On farms where all the land cannot be included in the rotation for practical reasons, slot seeding with legumes, feeding untreated clover seeds to stock, slurry injection and the application of composted manure can increase the productivity of permanent pastures. The Grass+ programme provides practical advice on making the most of grass. For detailed guidance on managing organic swards see Section 13. Legumes may be incorporated either as part of short or medium-term leys or in the permanent pasture component. The most valuable short-term legume forages are: Red clover mixed with hybrid ryegrass primarily for silage-making Forage peas, lucerne, birdsfoot trefoil, sainfoin and vetches as catch or multi-season forages for conservation. The most valuable legumes for medium-term leys are: White clover with ryegrasses for grazing and conservation Red clover with ryegrasses for conservation and grazing Birdsfoot trefoil alone or with ryegrasses for conservation and grazing. Given their particular importance, it is vital to maintain output by re-seeding organic swards on a regular basis. Typical yields of herbage from good quality organic swards are: Italian ryegrass/red clover leys 9-14 tonnes DM/ha Perennial ryegrass/white clover leys 8-11 tonnes DM/ha Permanent perennial ryegrass/white clover pastures 7-10 tonnes DM/ha. Most organic farms need to combine legume leys with arable cropping in rotation on a proportion of their unit to provide sufficient home-grown forage and concentrates. 8:6 Improvement through feeding

7 Making the most of legumes White clover White clover is the single most valuable UK pasture legume. With good management white clover can persist in swards indefinitely, increasing their feeding value and reducing their fertilisation requirements substantially (Section 4). For dairy pastures, a blend of medium and largeleafed varieties is recommended to combine yield with grazing persistence. The amount of white clover in the sward will vary throughout the grazing season but in organic systems the target is an annual contribution of 30+%. In practice this means white clover will vary between 20% and 40% of the sward over the growing season. Growth is later than grass in the spring but by midsummer white clover can start to dominate a sward and take-over by September. As a result the sward protein content can change markedly over the season, rising to 24-28% during September. To counteract the resulting imbalance of energy and protein, late-season swards can often profit from supplementation with a low protein buffer feed or straight cereals concentrate instead of a relatively high protein compound. White clover containing swards should be established and managed in much the same way as in nonorganic systems (Section 5). The removal of large amounts of P and K in silagemaking makes this especially important where swards are regularly cut for conservation. White clover leys will usually persist for five years or more and should be reseeded as soon as production falls off. Muck and slurry on clover sward publication gives guidance on the care of white clover throughout the season. Red clover Red clover is a high-yielding, rapidly-establishing crop more suited to short-term leys than permanent pasture. When grown together with hybrid ryegrasses it can be used to produce high quality silage. Like white clover, early spring growth tends to be relatively slow, so first cut silage is usually lower in protein than later cuts, which often have analyses of 20% crude protein. Red clover is increasingly being grown in pure stands, producing yields equivalent to mixed ryegrass swards with a protein percentage some 30% higher. Pure red clover swards are normally cut four times a year, producing silages with a typical 18-20% protein content. Red clover will yield very well for around three years, after which disease often reduces yields. Fields coming out of red clover are best put into a winter arable crop to make the most of the accumulated reserve of fixed N. Particular attention is needed to ensure soil P and K status is not depleted, given the limited supplies of these nutrients available to organic producers. Improvement through feeding 8:7

8 Lucerne Lucerne is a deep-rooted, drought-resistant perennial that can be grown with or more usually, without companion grass to give up to four silage cuts per year. Yields usually range from tonnes DM/ha with a higher protein content than most forages at 19-22%. Lucerne will yield 10-20% more protein/ha than clover/ryegrass swards and can make an especially useful contribution to the protein requirements of organic cows. It does, however, need well-drained, high ph soils. Birdsfoot trefoil Birdsfoot trefoil is a non-bloating legume best used in medium or long-term pastures. Sainfoin has excellent nutritional properties, with a high level of protein and less structural fibre than grass. Its good intake characteristics make it well-suited to restoring intake after ill health. Vetches Usually grown as annual catch crops, winter vetches can be sown in the south west following winter cereals. Alternatively, spring vetches can be sown from February to April. In wetter conditions spring sowing should be preferred in a mixture with whole crop cereals for support. Bloat risk The establishment of birdsfoot trefoil may be limited in aggressive ryegrass swards and it is better suited to soils with a lower nutrient status. Following early grazing, birdsfoot trefoil can be conserved as either silage or hay. It may be possible to take 2-3 cuts depending on growing conditions. While grasses will challenge its persistence, growing birdsfoot trefoil in a mixed sward can increase yield and help to avoid lodging. Most legume-rich pastures carry a risk of bloat but cows that are used to grazing high legume leys and are not turned out to them with empty rumens rarely suffer. It is always prudent to keep a bloat treatment available for emergency use. Legume silages Sainfoin Sainfoin is a non-bloating legume with very good intake characteristics (higher than grass, clover or lucerne), winter-hardiness and drought-resistance. It grows reasonably well on well-drained, high ph soils (such as Cotswold brash or chalk). The rapid acidification essential for good silage makes it more difficult to achieve stable fermentations with higher buffering capacity legume species. 8:8 Improvement through feeding

9 Increasing the acidity of crops for ensiling can best be achieved with acid-based additives but since additive use is highly restricted in organic systems, specific scheme requirements must be verified in advance. Alternatively, sugar-based supplements can be used to enhance the fermentation process. To achieve a good fermentation without an additive it is important to aim for 30% dry matter in the ensiled crop and prepare the field early in the year to minimise the risk of picking-up soil with the forager. Rapid clamp filling and plenty of time spent rolling are equally essential for a reliably good fermentation. Minimising silage wastage through the best possible ensiling, handling and feeding practice is particularly important in organic systems (Section 5). The Grass+ programme provides practical advice on making the most of grass. For detailed guidance on managing organic swards see Section 13. Making the most of other forages Wholecrop cereals, maize and a variety of buffer crops also provide very valuable sources of forage nutrients for organic herds. Wholecrop cereals Wholecrop cereals are a very effective way of providing starch in organic diets and especially valuable when spring sown to provide a cover crop for new leys, increasing output significantly from the reseeded area in its first year. Although fresh yields are considerably lower 6-10t/ha as against 9-15t/ha with winter cereals spring-sown crops often make the best quality wholecrop as their stems are less lignified at harvest. Organic standards effectively rule out urea-treatment, so fermentation is the only realistic option, producing a 30-40% DM silage with reasonable but not high energy and protein contents (Section 4). Some inoculant silage additives permitted under organic standards may be helpful in reducing the aerobic spoilage that can be a serious problem with wholecrop cereals. Amongst other things, it is important to appreciate that harvesters must be fitted with grain processing mills to break the grains if efficient digestion is to be achieved (Section 5). Forage maize Forage maize can be very valuable in organic systems, not least for the extent to which it thrives on slurry and farmyard manure rather than bagged fertiliser. It produces a high yield of relatively high DM silage with a good energy but relatively poor protein content from a single late-season harvest (Section 4). On favourable sites yields of over 35t/ha are perfectly achievable, although care does need to be taken with manuring to ensure the rest of the farm is not left short of nutrients. In this context, maize grown following a red clover ley is a very useful way of reducing the level of manure that needs to be applied. Harvesting delays can result in difficult conditions and significant soil contamination, making well-planned growing and good silaging practice particularly important (Section 5). Improvement through feeding 8:9

10 Two or three mechanical hoeings may be required in May and June to ensure the crop establishes and grows away well without excessive weed competition. Buffer crops Green crops like forage rape or stubble turnips established from May to August can also be useful additions to extend grazing in organic systems or to fill the mid-season period of reduced grass growth. Together with kale, swedes, turnips, fodder beet and forage rye, their variable and often quite low feeding values makes these crops best suited to late lactation or dry cow feeding (Section 4). Provided they are established well, yields will be similar to non-organic farms (Section 5). Insect infestations which cannot be controlled chemically can devastate some spring-sown stubble turnip crops, although forage rape is usually less affected. In addition to achieving the highest possible feed yield, management must be geared to ensuring maximum utilisation by minimising the amount of feed value wasted in grazing or harvesting and storage. Factsheet 8 provides guidance on systems utilising forage brassicas. Managing organic swards A high and consistent daily rate of sward dry matter production is especially important in making the most of grazing in organic systems if production costs are to be kept as low as possible. Particular management attention needs to be focused on maintaining leafy swards with the highest possible nutritional value for grazing and conservation (Section 5). Inorganic fertiliser limitations make it all the more essential to ensure all possible restrictions to sward productivity are eliminated and clover levels are maintained. Flexibility is the single most important key to a good grazing system to cope with factors like the weather which can ruin even the best-laid plans. Maintaining a highly productive sward requires regular assessment of sward growth to ensure fields are grazed at the appropriate pre-graze point and cows removed as soon as pastures are grazed down to the post-graze point. 8:10 Improvement through feeding

11 Stocking densities in organic systems are likely to be somewhat lower than under regimes where N fertiliser inputs allow rates of 2 cows/ha or more. The Grass+ programme provides practical advice on making the most of grass. For detailed guidance on managing organic swards see Section 13. While stocking is likely to fall markedly in the process of conversion, experience indicates densities can be built back-up again once the organic regime becomes more established. The rotation length between successive grazings of a field may also be longer in organic systems as re-growth cannot be accelerated by regular postgrazing applications of fertiliser-n. Achieving sufficient pasture growth for an early turnout may also be more challenging in organic systems. Equally, limitations on herbicide use make good management and tight-grazing especially vital to prevent the incursion of weeds. Accurate sward budgeting is very important as a means of shortening the winter feeding period as far as possible to reduce the costs and management time associated with this period. Improvement through feeding 8:11

12 Non-forage feeding While home-grown forages are the backbone of organic dairy systems, the nutrient requirements of all but the lowest yielding cows mean a considerable amount of supplementary energy and protein in the form of concentrates will be essential for most units. Table 8.2: Organic cereal yield expectations Cereal Grain yield (t/ha) Winter wheat 4.0 Spring wheat 3.2 Winter barley 3.7 Spring barley 3.2 Winter oats 4.0 Spring oats 3.5 Accurate feed planning and budgeting is essential to avoid unnecessary extra costs and risks in securing sufficient supplementary feed supplies. Worksheet 6 provides a pro forma for individual feed budgeting. Making the most of home-grown energy Cereals are the main source of energy supplementation, the bulk of these being home-grown or produced on neighbouring organic farms. Strict limitations on fertiliser use and weed, pest and disease treatment mean that organic cereals have significantly lower yield expectations than those produced under conventional systems (Table 8.2). Winter triticale 4.5 Source: Farm Management Handbook. N Lampkin & M Measures (2007) Their nutrient values and limitations are, effectively, identical to non-organic cereals (Section 4). On farms without suitable dry grain storage facilities, crimping at 25-30% moisture content has been shown to be a valuable preservation alternative. All cereals are suited to crimping although it produces feeds of a slightly lower feeding value than dry rolled grain. With crimping it is vital to ensure the additive used is approved for organic use. Making the most of home-grown protein Beans both winter and spring grown and peas are the most valuable sources of home-grown protein for organic producers. 8:12 Improvement through feeding

13 Their considerable nitrogen-fixing abilities also mean they make a very valuable fertiliser contribution to subsequent crops. Under organic production, winter beans typically produce grain yields of 3.5t/ha, and spring beans and peas around 3.0t/ha. Like cereals, their nutritive value is similar to nonorganic pulses (Section 4). Lupins are much higher in protein than beans or peas but weed competition and late-ripening tend to make them unreliable performers in organic systems. Both peas and beans can be crimped if dry storage is a problem but high levels of wastage can occur as their high protein contents cause higher buffering of the preservatives used. Making the most of purchased feeds Commercially-produced organic compound feeds and blends are readily available but need to come from approved feed mills. A relative shortage of raw materials means organic concentrates are likely to continue trading at a considerable premium to conventional feeds for the foreseeable future. The relative value of commercially available organic feed ingredients can be compared on the basis of their nutrient specification and price in the same way as conventional materials (Section 4). Worksheet 5 provides a pro forma for calculating relative feed values. While perfectly acceptable, these ingredients are of limited value due to their low energy content, highlighting the importance of securing full lists of ingredients and percentage inclusions as the basis for effective product comparisons (Section 6). Factsheet 5 sets out the key attributes of common ration ingredients. Moist feeds suitable for organic feeding are, understandably, in far more limited supply, with most food and beverage processing by-products unsuitable. Small amounts of organic brewers grains may be available from specialist local brewers, with organic stockfeed vegetables also generally only obtainable through neighbouring organic producers. Particular care needs to be taken to ensure all purchased feeds including any mineral and vitamin supplements are both approved for organic use and sourced from organicallyapproved producers. The very high cost of concentrates makes good feed storage and handling and accurate allocation especially important in organic systems to minimise wastage (Sections 3 & 6). Accurate ration formulation and fine-tuning on the basis of continued performance monitoring is equally essential (Section 7). Pelleted forages like dried lucerne tend to be used fairly widely in organic concentrates. Improvement through feeding 8:13

14 Nutrient budgeting One of the key objectives in organic farming is to maintain a healthy soil with a high content of organic matter; its nitrogen content and availability determining sward productivity. Figure 8.1: Annual Budget for N, P and K from Organic Dairy Farm at Trawsgoed ( ). 200 Nitrogen (kg N/ha) Phosphorus (kg P/ha) Potassium (kg K/ha) Since organic units are limited in the sources of nutrients they can bring on to their farms there is a risk that nutrient exports may exceed imports, depleting soil reserves. It is important to balance the nutrient inputs and outputs on both a field and farm scale in order to avoid losses of productivity. Nitrogen is the main nutrient to consider but P and K are also important. Matching soil supply to plant demand in nitrogen budgeting is particularly difficult for organic farmers because the amounts are not precisely known. Planning N inputs and off-take on a field-by-field basis helps to identify where manures can be used to best effect Inputs Outputs Inputs Outputs Inputs Outputs Inputs Outputs Nitrogen fixation Milk Purchased feed & bedding Livestock Source: IGER and Organic Centre Wales, Organic Milk Production, Leaflet 1: Farm Production and Performance. The Grass+ programme provides practical advice on making the most of grass. For detailed guidance on managing organic swards see Section 13. Other Establishing the balance between inputs and off-take will show whether the underlying soil N, P and K status is improving or deteriorating. Data from Trawsgoed highlight the balance of N, P and K inputs and outputs typically reported on organic dairy farms (Figure 8.1). 8:14 Improvement through feeding