Making poultry feed more sustainable:

Transcription

1 Making poultry feed more sustainable: The potential of home-grown sunflowers Cliff Nixey, Poultry Xperience Rachel Marsh, Capestone Organic Poultry Ltd Tony Little, Organic Centre Wales January

2 Executive summary Most poultry producers are heavily reliant on imported feed. This leaves them very vulnerable to price increases on the global commodity markets, and in the case of organic farmers, is not consistent with the principle that feed should be produced on the farm or at least locally. This project explored the contribution that sunflower, grown under Welsh conditions, could make to poultry diets and the extent to which it could substitute for imported ingredients such as soya. Two hectares of sunflower were grown by Capestone Organic Poultry near Haverfordwest. Agronomic data was collected and observations made throughout the crop s development. Samples were taken at regular intervals during the ripening process to track the changes in nutritional composition of the seeds and to assess the best time to harvest for optimum feed value. The results indicate that sunflowers grown in Wales can make a highly significant contribution to energy part of poultry rations due unexpectedly high oil and starch levels. Protein levels, conversely, were unexpectedly low. However, by combining sunflower with other complementary home grown ingredients such as dehulled beans, is possible grow significantly more of our feed in Wales than is currently the case. The high moisture content of seed, which is harvested unripe, is a problem. This can be tackled either by drying or crimping. There is an opportunity for farmers to work together to access to the necessary equipment and facilities. The residue of the crop is also potentially useful, for example as a ruminant feed (fresh or ensiled), or as a green manure. With respect to the latter, the deep tap root means that the plant effectively mines nutrients, especially potash, from lower down in the soil profile and makes them available to the following crop. As potentially promising as this work is, it is based on a single crop in a single location in a single (particularly unfavourable) season. These findings need to be confirmed by statistically robust research trials across a range of sites, but this study indicates that it is well worth spending the money to do so. Background Most poultry producers identify feed issues and feed costs as one of their biggest challenges. Part of the problem is that the UK poultry industry depends heavily on imports, leaving producers at the mercy of global commodity prices for key feed ingredients. For organic farmers, the problem is even more acute; organic and, indeed, Non-GM soya is getting harder to come by and therefore more expensive. There are also the organic principles to consider; self-sufficiency and the idea that stock should be fed, as far as possible from the farm, is one of the cornerstones of organic thinking. However, a report prepared by the Soil Association in 2010 shows that a significant proportion of feed 2

3 ingredients come from as far afield as Russia, Australia, Ukraine, Kasakhstan, South America and China. Clearly there is some way to go. If we want to build resilience into our farming systems; if we want quality, traceable feed at prices we can control; and if we want to reduce the environmental burden of our feed system, then it seems logical that we need to produce more of it at home. Organic Centre Wales has been working on poultry feed issues for several years, through the better Organic Business Project. We have looked at several different aspects including: Growing better quality cereals and fostering direct relationships between arable and poultry producers. Improving the quality of our homegrown protein crops such as peas and beans by dehulling the grain (also see our video on Sustainable organic feed ) Exploring opportunities for growing new crops such as sunflowers. This video Feed from the farm explores the issues in more details This project used funding from the Farming Connect Innovations Projects to explore the practicalities of growing sunflowers in Wales for feed. There is nothing new in sunflower as feed ingredient. They are grown for their oil in many parts of the world and the meal that is left behind after the oil has been extracted has long been a valuable part of poultry rations. However, if we were to grow sunflowers primarily for feed rather than oil, what impact would that have on the conditions under which we could grow them? A major problem with growing sunflowers in the UK is the autumn conditions prevailing when the crop is ripening. It is normal to have a heavy dew at that time of the year and it is often very showery or worse. This can cause the flower heads to face disease challenges. If the crop could be harvested earlier in a slightly unripe stage it would minimise this risk. While this would mean sacrificing some oil content, it could be partly compensated by increased protein content. This tactic could open up the possibility of more sunflowers being grown in the UK and particularly parts of Wales. The project Capestone Organic Poultry, based in Haverfordwest, sowed 2ha of sunflowers. The original intention was to harvest a seed crop and feed it to batches of birds to assess their performance at different levels of inclusion for sunflower seed. In the event, 2013 was not a good year for sunflowers and we were not able to get a seed crop. This spring was one of the coldest on record, which meant a very late sowing, and even the warm summer could not make up for the lost time. We therefore switched the focus of the project to look at how the nutrient content of the seed changed in the maturing crop and using this information to make a theoretical assessment of the contribution sunflowers, grown under Welsh conditions, could make to poultry rations. 3

4 We recorded agronomic data such as the variety, sowing date, seed rate and management operations and made general observations on crop growth and development. Once the crop was showing signs of maturity we harvested 20 representative heads from the field at weekly intervals between 25 September 16 October, and sent the seed off for analysis. We used this data to look at how the nutritional composition of the seeds changed over the ripening period and to make an assessment of the contribution that homegrown sunflower seed could make to the ration. Growing the crop For a detailed discussion of sunflower agronomy, read this report and summary. These studies combine weather data with agronomic information to conclude that production is, at least on paper, possible in certain parts of Wales including Pembrokeshire. Key information about the crop at Capestone is summarised in the table below. Variety Sowing Date Sowing rate (Kg/ Ha) Belinda CS 17 May 4.8 Kg or 80,000 Seeds per ha Seed cost ( /Ha) Cropping history of site Wheat (2010); Potatoes (2011); Wheat (2012) Grass (2013) Table 1: Agronomic information More detailed observations were made just prior to and during the sampling period and these are recorded in Table 2 below. Belinda CS is an early maturing variety with good disease resistance and a high oil content, which we believed were important in the context of using it as a feed crop under Welsh conditions. Weeds were a problem, and there are several factors that could have contributed to this: The sunflower crop went in after an extended period of cropping, preceded by 3 hungry crops with only an overwintering grass crop in Winter/spring At these low levels of fertility, the crop probably struggled to compete with weeds. While sunflower, by virtue of its deep tap root is able to thrive in relatively low fertility conditions, being a 4 th exploitative crop (the grass crop would not contribute to net fertility gain) was probably a step too far. The short period under grass may not have been sufficient to smother the weeds, especially as it was an over wintering crop. The cold spring meant a slow start for the crop, which gave the weeds the opportunity to establish before the sunflower foliage closed the canopy. 4

5 There were some gaps in the plant stand which allowed the weeds to take hold in some areas. We have evidence as to the cause of these gaps, but slugs are a likely candidate. On the basis of this trial, a weed management strategy could include: Placing the crop as the 2 nd or 3 rd exploitative crop in the rotation to improve fertility and promote vigorous growth in the early stages of development to achieve canopy closure faster. Having a longer fertility building phase to smother weeds more effectively. Increasing the seed rate to compensate for slug damage and ensuring the canopy closure occurs faster. We followed the breeder s advice on seed rate, but HGCA recommends 90, ,000 seeds/ ha, so there is certainly room to do this. Inter row weeding prior to canopy closure. The lack of uniformity in crop development/ ripening was the other issue of note. It is harder to pin down what the cause of this might be. If we accept that, as a commercial hybrid variety, the seeds are genetically fairly uniform, then it is mostly likely to be attributable to field factors such as weed competition, slug/ insect damage, differences in soil fertility/ compaction across the field. 5

6 Table 2: Field observations Date Observations Crop Individual Plant 26 August Weather: Sunny and dry Plants at different stages. Some are still green, not having developed petals, others are completely yellow. Also very variable plant heights and head sizes. Very few heads have gone brown and dry but on those that have seeds are still very sticky and impossible to harvest. Lots of insects attracted to the yellow flowers. 16 September Weather: Sunny and dry Flowers at different stages of growth. Very few are still green & many are turning brown and losing their petals. Some of the very large seed heads look like they could be harvested soon. The stems are still very green. Many more insects present this week, attracted to both the yellow flowers and those that have gone brown. 25 September (1 st sample) Weather- misty and wet but warm More have gone brown since last week, but still many yellow flowers. The medium- small heads had a lot of the seeds but were white inside and immature which made them sticky. The larger heads were dryer and much easier to sample. 6

7 2 October (2 nd sample) 10 October (3 rd Sample) 17 October ( 4 th Sample) Weather- Light rain, warm and humid. Flowers rapidly becoming browner. Bigger heads starting to droop under their own weight. Still a lot of variation in head size. Most are medium with a few very large, more mature, ones. Insects present but fewer than previously (due to the weather?). Sampling was a lot easier because the seeds were drier especially in the larger heads. Weather- Cold, windy, sunny and dry. Flowers have developed a lot since last week. Very few yellow petals left and not many insects. Some large, very mature sunflowers are missing seeds, possibly due to pest attack. Sampling was much easier today as the seeds dropped off very easily. The foliage seems to be yellowing but still very leafy and lush. Weather- Windy, cold, misty Nearly all flowers are brown and ready to be harvested. Some have lodged and some have lost a lot of their strength and are drooping. Many stems are becoming yellow in colour. Many flowers were missing their outer brown layer, possibly blown off or eaten. The seeds came off very easily. Table 2: Field observations 7

8 Sunflower as a feed nutritional value Table 3 below shows the nutrient content of the seeds at each of the sampling dates. Sample 1 (25/09/2013) Sample 2 (01/10/2013) Sample 3 (10/10/2013) Sample 4 (17/10/2013) NDF Crude protein (%) Crude fibre (%) Moisture (%) Total oil (B) (%) Sugar (%) Starch (%) Phosphorus (%) Non phytate P (%) Lysine (%) Methionine (%) 0.06 Cystine (%) Threonine (%) Arginine (%) 0.13 Table 3 Nutritional content of sunflower seeds over the ripening period Levels of protein, oil, starch, and phosphorous increased as the seed ripened, and sugar decreased as it was converted to starch. This suggests, in terms of feed quality and under Welsh conditions, the later you can leave the harvest the higher the feed value. The biggest problem was high moisture content which was still over 70% on the final sampling date. Indeed, sample 2 deteriorated so rapidly it was only possible to get limited data from it. Had we been able to plant the crop in April, the ripening period would have coincided with the warm, dry months of August and September and the moisture content would have been much lower. Even so, growing for feed instead of oil implies harvesting unripe so even in good years, moisture content is likely to be higher than cereal crops and the crop will usually need to be dried after harvest. Alternatively it could be crimped and fed as whole grain. In terms of nutrient content, the high moisture levels depressed the proportion of other nutrients. In order to draw comparisons with commercial sunflower meal, we adjusted the nutrient levels to be consistent with a 12% moisture content (Table 4), presuming that the crop would be dried after harvest. Levels of protein, which was the initial focus of the project, were significantly lower than that of commercial meal, even when adjusted to 12% moisture content. The difference is partly because the meal was derived from de-hulled seeds which would have increased the proportion of protein in the meal, but even so on the strength of these results it is unlikely that growing sunflowers will contribute much to increasing the supply of home grown 8

9 protein until the crop is grown in sufficient volume to justify dehulling and oil extraction equipment. In terms of energy, however, the seed is extremely promising; at the final sampling date the ME was 17.3 MJ/ Kg compared to 6.2 MJ/ Kg for meal. Adjusted for 12% moisture, the oil content was up to 40% by the final sampling date, much higher than we had anticipated under Welsh conditions. Starch, for reasons that are not immediately clear, was nearly three times that typically found in meal. Furthermore, the nutrient profile of the seed means it is highly complementary with field beans especially if the latter were dehulled; where sunflower is high in ME, beans are low; sunflower is strong in methionine and weaker in lysine whereas the opposite is true for beans. Combining the two raises the possibility of being able to grow significantly more of our feed in Wales than is currently the case. Sample 1 (25/09/2013) Sample 3 (10/10/2013) Sample 4 (16/10/2013) Sunflower meal (oil extracted)* NDF Crude protein (%) Crude fibre (%) Moisture (%) Total oil (B) (%) Sugar (%) Starch (%) Phosphorus (%) Non phytate P (%) Lysine (%) Methionine (%) Cystine (%) Threonine (%) Arginine (%) Calculated ME * Published data. Source Premier Atlas 2011 Table 4: Nutrient content adjusted to 12% moisture compared to sunflower meal Sunflower as a feed economic value We attempted to put an economic value on sunflower as a feed by calculating the opportunity cost (Table 5) as part of a least cost formulation (see box), using market prices at November We calculated this for three diets (Broiler finisher, turkey grower and chicken layer) and for three products; the seed from the trial adjusted for 12% moisture; a hypothetical meal from the trial after oil extraction; and a commercially available meal. 9

10 Least cost rationing aims to meet the nutritional requirements of the animal for the lowest possible cost. The dietary requirements of the birds which vary according to species (chickens, turkeys, ducks), enterprise (layer or table birds) and stage of development (starter, grower, finisher, layer), are programmed into a computer software programme. This programme then uses standard nutritional data and current market prices to arrive at the target specifications by the cheapest possible route. The cost at which one particular ingredient becomes lower than its competitors and makes it into the ration is called the opportunity price. Diet Full fat trial seed Meal from trial seed (oil extracted, not dehulled) Commercial meal (oil extracted, dehulled) Broiler Finisher ( /tonne) Turkey Grower ( /tonne) Chicken Layer ( /tonne) Table 5: Opportunity costs for various forms of sunflower. The broiler finisher diet, with its high ME requirement, would benefit most from the inclusion of sunflower seed. The benefit is less clear for the other two species, although there could be a role in layer rations because of their higher requirements for essential fatty acids (a determinant of egg size) which are found in the oil. If offered in least cost formulations in conjunction with field beans or peas, the opportunity price of each would be increased because as stated earlier, they complement each other. Conclusions and next steps These observations are based on a simple one off experiment, so the following conclusions are preliminary. However, based on these findings: Sunflowers grown in Wales can make a very significant contribution to the energy part of poultry rations. By including sunflower seed and dehulled beans in poultry rations we can grow significantly more of our feed in Wales than is currently the case. High moisture content is a problem. This can be tackled either by drying or crimping. There is an opportunity for farmers to work together to access to the necessary equipment and facilities. The unexpectedly high oil content may mean that it is, in fact, economic to extract oil from sunflowers grown in Wales. Blodyn Aur in North Wales processes rapeseed oil and may be interested in sunflower. Some thought needs to be given to using the crop residue. This could have a major benefit on the economics of the crop. For example it could be used as a ruminant feed (fresh or ensiled) or as a green manure. With respect to the latter, the deep tap 10

11 root means that the plant effectively mines nutrients, especially potash, from lower down in the soil profile and makes them available to the following crop. Next steps As potentially promising and exciting as this work is, it is based on a single crop in a single location in a single (particularly unfavourable) season. Before rolling out it this idea, it is vital that the findings of this report are confirmed in statistically robust research trials across a range of sites. This is beyond the remit of Farming Connect, but it there is a good case for including it in some of the DEFRA funded research programmes, or other funding streams such as the Agri-Tech Catalyst programme. In addition to the agronomic aspects of production we also need to look closely at different options for harvesting and storage and the best way to feed sunflower, for example as a wholegrain or part of a mix and mill formulation. 11