Energy doesn’t get any cheaper, raw material prices continue to climb and margins are squeezed. There is no doubt that pelleting improves efficiency and biosecurity but can it be made more cost effective?
Pellet production to save energy, improve feed efficiency and safety
www.gfmt.co.uk
Energy doesn’t get any cheaper, raw material prices continue to climb and margins are squeezed. There
is no doubt that pelleting improves efficiency and biosecurity but can it be made more cost effective?
Efficiency of the pelleting process is the key to feed mill profitability. With 90 percent of animal feed in Europe being pelleted, every feed mill needs to optimise their pel-leting efficiency.
Pelleting positivesPelleting feed increases the bulk density
of the ration, allowing more tonnage to be delivered per truck, saving costs for the farmer and space in storage. Pelleted feeds are easy to use in either bulk or bags. Pellets also improve conveying by screw augers, and discharge from feed bins due to reduced bridging.
Pelleted feed is nutritionally consistent from pellet to pellet with each pellet con-taining the correct balance of amino acids, minerals and vitamins. This means that there is no opportunity for ingredient selection during consumption by fussy feeders and
subsequently less wastage. All these benefits however depend on pellet quality after the cooler.
If pellet quality is expensive to achieve then costs increase and financial benefits are lost and the selection of a low inclusion binder makes sense for so many reasons.
Nutritionally, pelleted feeds are more digestible as a result of starch pregelatinisa-tion and protein denaturation. The finer grist size used in pellets has been found to increase digestibility in pigs.
In birds, weight gain and feed efficiency are improved when the pellet quality is good. Even when pelleted diets are re-ground to the consistency of mash, the performance benefits are still found indicating direct ben-efits from the pelleting process.
Body weight improvements and mon-etary returns are inversely proportional to the level of fines in finisher diets. Birds need to use less energy to consume the same level of nutrients in pellets as those fed mash feeds; in fact birds fed pellets can ingest their total energy requirements in four percent of the day compared with 15 percent of the day for mash feeds.
In pig production, heat treatment dur-ing pelleting improves the digestibility of maize which can result in a six to eight percent improvement in daily gain and feed conversion.
Reduced fines and improved digestibility lead to further improvements that are often overlooked. For example, improved feed conversion and
nutrient utilisation reduces the volume of excreta which benefits the environment, so we have less feed being used to improve growth rates and improve to the environ-ment.
However, probably the best-known indirect benefit of pelleting is biosecurity. Most of the common pathogens such as Salmonella, Escherichia and Campylobacter are non-spore forming bacteria and are therefore sensitive to heat. The temperature required is often not as high as expected with S. typhimurium being killed after just 10 seconds at 70°C but requiring 7 minutes at 60°C.
Binding benefitsNone-the-less, pelleting is a very high
cost process (and is becoming more so with energy prices increasing). The use of high efficiency pellet binders can reduce energy requirements in three ways:1: Poor pellet quality results in higher
fines levels and more returns which is energetically inefficient.
2: Pellet binders help lubricate the die which reduces energy requirements as well as increasing mill throughput. Lubricating dies minimises wear so they should last for 25-30,000 tonnes with just one refurbishment. Changing dies takes upwards of 2 hours during which time the line cannot operate.
3: Pellet quality can be enhanced at lower temperatures that still permit the biosecurity benefits but where starch gelatinisation may not be sufficient to contribute to pellet quality. This saves energy and speeds up throughput.To achieve good pellets moisture is
essential; typically 16 percent moisture con-tent is required in the conditioner to hydro-lyse the starches. Moisture content and temperature are related because it is the steam that provides both the heat and the water for adequate pellet production.
Temperature should ideally reach 80°C
Pellet productionto save energy, improve feed efficiency and safety
Figure 1: The effect of temperature on viscosity of a gum and corn starch
by Murray Hyden C Biol, MSB, Director of Biosecurity, Kiotechagil, United Kingdom
Grain&feed millinG technoloGy16 | September - october 2012
FEATURE
Energy doesn’t get any cheaper, raw material prices continue to climb and margins are squeezed. There
is no doubt that pelleting improves efficiency and biosecurity but can it be made more cost effective?
Efficiency of the pelleting process is the key to feed mill profitability. With 90 percent of animal feed in Europe being pelleted, every feed mill needs to optimise their pel-leting efficiency.
Pelleting positivesPelleting feed increases the bulk density
of the ration, allowing more tonnage to be delivered per truck, saving costs for the farmer and space in storage. Pelleted feeds are easy to use in either bulk or bags. Pellets also improve conveying by screw augers, and discharge from feed bins due to reduced bridging.
Pelleted feed is nutritionally consistent from pellet to pellet with each pellet con-taining the correct balance of amino acids, minerals and vitamins. This means that there is no opportunity for ingredient selection during consumption by fussy feeders and
subsequently less wastage. All these benefits however depend on pellet quality after the cooler.
If pellet quality is expensive to achieve then costs increase and financial benefits are lost and the selection of a low inclusion binder makes sense for so many reasons.
Nutritionally, pelleted feeds are more digestible as a result of starch pregelatinisa-tion and protein denaturation. The finer grist size used in pellets has been found to increase digestibility in pigs.
In birds, weight gain and feed efficiency are improved when the pellet quality is good. Even when pelleted diets are re-ground to the consistency of mash, the performance benefits are still found indicating direct ben-efits from the pelleting process.
Body weight improvements and mon-etary returns are inversely proportional to the level of fines in finisher diets. Birds need to use less energy to consume the same level of nutrients in pellets as those fed mash feeds; in fact birds fed pellets can ingest their total energy requirements in four percent of the day compared with 15 percent of the day for mash feeds.
In pig production, heat treatment dur-ing pelleting improves the digestibility of maize which can result in a six to eight percent improvement in daily gain and feed conversion.
Reduced fines and improved digestibility lead to further improvements that are often overlooked. For example, improved feed conversion and
nutrient utilisation reduces the volume of excreta which benefits the environment, so we have less feed being used to improve growth rates and improve to the environ-ment.
However, probably the best-known indirect benefit of pelleting is biosecurity. Most of the common pathogens such as Salmonella, Escherichia and Campylobacter are non-spore forming bacteria and are therefore sensitive to heat. The temperature required is often not as high as expected with S. typhimurium being killed after just 10 seconds at 70°C but requiring 7 minutes at 60°C.
Binding benefitsNone-the-less, pelleting is a very high
cost process (and is becoming more so with energy prices increasing). The use of high efficiency pellet binders can reduce energy requirements in three ways:1: Poor pellet quality results in higher
fines levels and more returns which is energetically inefficient.
2: Pellet binders help lubricate the die which reduces energy requirements as well as increasing mill throughput. Lubricating dies minimises wear so they should last for 25-30,000 tonnes with just one refurbishment. Changing dies takes upwards of 2 hours during which time the line cannot operate.
3: Pellet quality can be enhanced at lower temperatures that still permit the biosecurity benefits but where starch gelatinisation may not be sufficient to contribute to pellet quality. This saves energy and speeds up throughput.To achieve good pellets moisture is
essential; typically 16 percent moisture con-tent is required in the conditioner to hydro-lyse the starches. Moisture content and temperature are related because it is the steam that provides both the heat and the water for adequate pellet production.
Temperature should ideally reach 80°C
Pellet productionto save energy, improve feed efficiency and safety
Figure 1: The effect of temperature on viscosity of a gum and corn starch
by Murray Hyden C Biol, MSB, Director of Biosecurity, Kiotechagil, United Kingdom
Grain&feed millinG technoloGy16 | September - october 2012
FEATURE FEATURE
Grain&feed millinG technoloGy September - october 2012 | 17
y NIRT Analyser on whole grain and powdery products y Measure chemical composition as soon as you receive your raw materials. y Estimate technical values of flours, semolinas, grits, glutens, starches (and other powders products).y Moisture, protein, ash content, zeleny, hydration*. (* choose from over 60 calibrations available)
can result in reduced pellet quality which is because the main binding agent, starch, has been removed to produce ethanol. Whilst enzyme systems have been developed to improve the digestibility of the DDGS, a pellet binder is often required to achieve a suitable pellet quality from this high fibre ingredient.
One other important factor of pellet binders is that they help maintain pellet qual-ity during seasonal changes in raw material quality. The pelletability of freshly harvested cereals is often quite different to the last of the previous harvest grains. So it is likely that this year’s UK harvest, which has been subjected to an abnormal weather pattern, will be reflected in pellet quality.
Improving pellet qualityA low inclusion binder, like Kiotechagil’s
Mastercube, can really help overcome many of the problems associated with the feed for-mulation and can also help overcome some of the engineering shortfalls such as short conditioners or poor steam quality.
Mastercube is both a binder and a hard-ener and it uses only EU approved ingre-dients. The primary binder is a gum that gelatinises at much lower temperatures than traditional starches (Figure 1) and provides higher viscosity and improved lubrication at the die. The result is faster throughput and lower fines.
As the pellet cools the hardener in Mastercube, a high quality calcium sulphate, which is approved as a nutrient, has a dual function as a calcium source and a hardener. Pellet breakage during transport and storage due to soft or badly formed pellets is also wasteful. The hardener increases pellet dura-bility to enable pellets to be blown, augured and transported without being crushed.
The selection of a low inclusion binder has the advantage that it minimises the impact of nutrient density so feed costs can be maintained.
A feed mill operating efficiently and dust-free is a pleasant place to work. It is safe for the operators and easier to keep clean.
From a biosecurity viewpoint, fines, set-tling as dust on floors and equipment, will soon pick up moisture and will become a habitat for enteropathogens. The require-ment today must be for pellet binders that do not compromise nutrient density, throughput or biosecurity.
Genetic selection of meat producing animals that maximise feed intake ensures that the response to pelleted diets much more significant than was reported just twenty or thirty years ago.
Using an effective pellet binder is cost effective in so many ways and can be a real benefit in terms of digestibility, biose-curity and mill throughput thus making a quality pellet binder pay for itself many times over.
More inforMation:Website: www.kiotechagil.com
• Broiler – 1.5 bar / 20 psiRecommended conditioning temperatures
for different products are:• Ruminant (fibrous) – 50/60°C• Pig – 65/70°C• Pig creep (milk powder) – 45/50°C• Broiler – 80/85°C
Pelleting larger fibrous materials for rumi-nants requires a different approach to the smaller broiler pellets where biosecurity is paramount.
The thermal processing during pelleting is not the only cost consideration. It is gener-ally accepted that using a roller mill is less expensive that using a hammer mill mainly as a result of lower maintenance costs.
Feed formulation issuesFeed formulation plays a major part in
final pellet quality and high protein cereals such as wheat will contribute more to pellet quality than maize, oats or barley. Dietary fat is known to have an inverse relationship with pellet quality, hence the use of post pellet fat spraying for certain rations. When fat is incorporated into the feed the added fat coats starch granules, and prevents water uptake, which in turn impairs the heat trans-fer necessary for gelatinisation.
When high levels of dietary fat are used, or when maize is the primary cereal in the ration formulation, traditional binders such as thixotropic bentonite clays or lignosulpho-
nates (the waste product from the wood pulping process to man-ufacture paper) have been used to improve pellet quality. However, neither of these binders provides any substantial nutritional value to the diet. In fact, both these ingredients are incorporated at high inclusion rates and actually dilute the nutri-ent content of the feed resulting in more expen-sive raw material usage to com-pensate.
With cereal prices ever increasing in price the temptation to use more co-products such as DDGS from bioethanol pro-duction is much greater. However, DDGS inclusion
to ensure starch gelatinisation but this is not always achieved. Consequently the starch in the ration formulation is not able to con-tribute to pellet quality. By using gums in a pellet binder a much faster moisture uptake is achieved at lower temperatures to ensure higher viscosity in the conditioner and better heat transfer into the grist.
If the feed is very dry then not only is there insufficient water for gum hydrolysis but the feed is too dry for the heat transfer necessary to achieve starch gelatinisation. If this is the case it may be necessary to resort to spraying water directly in the mixer to add one to two percent water to the mix to increase pellet temperature in the condi-tioner and get better gum gelatinisation.
Moist feed is generally more palatable and digestible too. However, too much water increases the risk of moulding so it may be necessary to check that the pellets dry to 12 – 14 percent MC after the cooler to minimise the risk of moulding.
High pressure steam tends to be drier and does not achieve such high tempera-tures or moisture in the conditioner, there-fore different feed types will be more difficult to pellet than others if the pellet binders and starches do not activate
Recommended pressures for different products are:• Ruminant (fibrous) - 3.5 bar / 50 psi• Pig - 2.5 bar / 35 psi
Grain&feed millinG technoloGy18 | September - october 2012
FEATURE
Disrupting bacteria communication
Apart from the direct gut bacteria modi-fication and immune effect, new recent studies have demonstrated the effect of some bacteria belonging to Bacillus spp. to disrupt bacteria communication, a fact that can explain some of the effects of probiotics based on this bacterium.
It has been described that there is a communication between gut bacteria, called ‘quorum sensing’ that allows bacteria to get a consensus on whether the intestinal environ-ment has been effectively colonised before making the energetic investment required for the initiation of their metabolic response to colonize or infect the host (by producing toxins, adherence factors).
In particular, some gram-negative bac-teria typical from the gastrointestinal tract (Yersinia, E. Coli, Salmonella) produce spe-cific kinds of molecules (N-acyl-homoserine-lactones). These molecules are not only produced but also recognised by these bacteria, giving to them the possibility to know when the population has reached the optimal population level to start animal host infection. When this threshold level is reached, enteropathogens start inducing the expression of some specific genes that express for invasion and infective factors.
In this way, bacteria belonging to this group, guarantee the most suitable time to
start gut colonisation and invade host to succeed in host infection to cause damage. In particular, different in vitro trials run by Rubinum SA in collaboration with CRESA, have demonstrated that B. cereus var. toyoi has an effect against the gut colonisation by some potential gut enteropathogens, such as
Yersinia and Salmonella spp by destroying the chemical substances cited above.
It seems therefore that probiotics are not only able to directly modify gut specific bac-teria populations and profile host immune response, but also they can interrupt the way used by enteropathogens to communicate
between them. This new information opens a new concept in the probiotic´s mode of action studies.
Taking this in mind, the use of one probiotic with this ability may be helpful in some specific situations –in those situations in which we want not only to reduce the amount of these specific
enteropathogens in the gut, but also to avoid the potential of these bacteria to invade gut epithelium and therefore animal body.
More inforMation:Website: www.rubinum.es
Bredol ®for effective feed production and nutritional performance
Bredol® emulsifier technology opens up a multitude of technical opportunities bringing values in feed production as well as on the farm.www.bredol.com
"The use of one probiotic with this ability may be
helpful in some specific situations –in those situations
in which we want not only to reduce the amount of
these specific enteropathogens in the gut, but also
to avoid the potential of these bacteria to invade
gut epithelium and therefore animal body"
Grain&feed millinG technoloGy September - october 2012 | 21
WELCOME TO THE TWENTY FIRST EDITION OF THE INTERNATIONAL MILLING DIRECTORY
can result in reduced pellet quality which is because the main binding agent, starch, has been removed to produce ethanol. Whilst enzyme systems have been developed to improve the digestibility of the DDGS, a pellet binder is often required to achieve a suitable pellet quality from this high fibre ingredient.
One other important factor of pellet binders is that they help maintain pellet qual-ity during seasonal changes in raw material quality. The pelletability of freshly harvested cereals is often quite different to the last of the previous harvest grains. So it is likely that this year’s UK harvest, which has been subjected to an abnormal weather pattern, will be reflected in pellet quality.
Improving pellet qualityA low inclusion binder, like Kiotechagil’s
Mastercube, can really help overcome many of the problems associated with the feed for-mulation and can also help overcome some of the engineering shortfalls such as short conditioners or poor steam quality.
Mastercube is both a binder and a hard-ener and it uses only EU approved ingre-dients. The primary binder is a gum that gelatinises at much lower temperatures than traditional starches (Figure 1) and provides higher viscosity and improved lubrication at the die. The result is faster throughput and lower fines.
As the pellet cools the hardener in Mastercube, a high quality calcium sulphate, which is approved as a nutrient, has a dual function as a calcium source and a hardener. Pellet breakage during transport and storage due to soft or badly formed pellets is also wasteful. The hardener increases pellet dura-bility to enable pellets to be blown, augured and transported without being crushed.
The selection of a low inclusion binder has the advantage that it minimises the impact of nutrient density so feed costs can be maintained.
A feed mill operating efficiently and dust-free is a pleasant place to work. It is safe for the operators and easier to keep clean.
From a biosecurity viewpoint, fines, set-tling as dust on floors and equipment, will soon pick up moisture and will become a habitat for enteropathogens. The require-ment today must be for pellet binders that do not compromise nutrient density, throughput or biosecurity.
Genetic selection of meat producing animals that maximise feed intake ensures that the response to pelleted diets much more significant than was reported just twenty or thirty years ago.
Using an effective pellet binder is cost effective in so many ways and can be a real benefit in terms of digestibility, biose-curity and mill throughput thus making a quality pellet binder pay for itself many times over.
More inforMation:Website: www.kiotechagil.com
• Broiler – 1.5 bar / 20 psiRecommended conditioning temperatures
for different products are:• Ruminant (fibrous) – 50/60°C• Pig – 65/70°C• Pig creep (milk powder) – 45/50°C• Broiler – 80/85°C
Pelleting larger fibrous materials for rumi-nants requires a different approach to the smaller broiler pellets where biosecurity is paramount.
The thermal processing during pelleting is not the only cost consideration. It is gener-ally accepted that using a roller mill is less expensive that using a hammer mill mainly as a result of lower maintenance costs.
Feed formulation issuesFeed formulation plays a major part in
final pellet quality and high protein cereals such as wheat will contribute more to pellet quality than maize, oats or barley. Dietary fat is known to have an inverse relationship with pellet quality, hence the use of post pellet fat spraying for certain rations. When fat is incorporated into the feed the added fat coats starch granules, and prevents water uptake, which in turn impairs the heat trans-fer necessary for gelatinisation.
When high levels of dietary fat are used, or when maize is the primary cereal in the ration formulation, traditional binders such as thixotropic bentonite clays or lignosulpho-
nates (the waste product from the wood pulping process to man-ufacture paper) have been used to improve pellet quality. However, neither of these binders provides any substantial nutritional value to the diet. In fact, both these ingredients are incorporated at high inclusion rates and actually dilute the nutri-ent content of the feed resulting in more expen-sive raw material usage to com-pensate.
With cereal prices ever increasing in price the temptation to use more co-products such as DDGS from bioethanol pro-duction is much greater. However, DDGS inclusion
to ensure starch gelatinisation but this is not always achieved. Consequently the starch in the ration formulation is not able to con-tribute to pellet quality. By using gums in a pellet binder a much faster moisture uptake is achieved at lower temperatures to ensure higher viscosity in the conditioner and better heat transfer into the grist.
If the feed is very dry then not only is there insufficient water for gum hydrolysis but the feed is too dry for the heat transfer necessary to achieve starch gelatinisation. If this is the case it may be necessary to resort to spraying water directly in the mixer to add one to two percent water to the mix to increase pellet temperature in the condi-tioner and get better gum gelatinisation.
Moist feed is generally more palatable and digestible too. However, too much water increases the risk of moulding so it may be necessary to check that the pellets dry to 12 – 14 percent MC after the cooler to minimise the risk of moulding.
High pressure steam tends to be drier and does not achieve such high tempera-tures or moisture in the conditioner, there-fore different feed types will be more difficult to pellet than others if the pellet binders and starches do not activate
Recommended pressures for different products are:
• Ruminant (fibrous) - 3.5 bar / 50 psi• Pig - 2.5 bar / 35 psi
Grain&feed millinG technoloGy18 | September - october 2012
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