The potential of home-grown sunflowers · the yellow flowers. 16 September Weather: Sunny and dry...
Transcript of The potential of home-grown sunflowers · the yellow flowers. 16 September Weather: Sunny and dry...
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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 2014
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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
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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.
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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 Belinda CS
Sowing Date 17 May
Sowing rate (Kg/ Ha) 4.8 Kg or 80,000 Seeds per ha
Seed cost (£/Ha) 37.27
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 2013. 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 4th 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.
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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 2nd or 3rd 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 – 150,000 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.
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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
(1st 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.
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2 October
(2nd 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.
10 October (3rd Sample)
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.
17 October
( 4th Sample)
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
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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 4.6
6.1 6.3
Crude protein (%) 1.8 2.3 3.1 3.6
Crude fibre (%) 3.2
3.3 3.6
Moisture (%) 86.9 82.5 73.4 71.8
Total oil (B) (%) 2.06
11.73 13.09
Sugar (%) 1.31
1.1 0.27
Starch (%) 0.4
2.3 2.7
Phosphorus (%)
0.09 0.13 0.16
Non phytate P (%)
0.05 0.07
Lysine (%)
0.18 0.21 0.15
Methionine (%)
0.06 Cystine (%)
0.03 0.05 0.04
Threonine (%)
0.1 0.14 0.11
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
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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 30.9 20.18 19.66 43
Crude protein (%) 12.09 10.26 11.23 28
Crude fibre (%) 21.5 10.92 11.23 28.5
Moisture (%) 12 12 12 11
Total oil (B) (%) 13.84 38.81 40.85 2.6
Sugar (%) 8.8 3.64 0.84 4.5
Starch (%) 2.69 7.61 8.43 3
Phosphorus (%)
0.43 0.5 1
Non phytate P (%) 0.17 0.22 0.27
Lysine (%)
0.69 0.47 0.98
Methionine (%)
0.3 0.17 0.63
Cystine (%)
0.17 0.12 0.46
Threonine (%)
0.46 0.34 1.02
Arginine (%)
0.86 0.53 2.24
Calculated ME 8.22 16.65 17.27 6.2 * 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 2013. 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.
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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) 734 381 531
Turkey Grower (£/tonne) 210 226 435
Chicken Layer (£/tonne) 303 235 337
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
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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.