Steam Pelleting Research Articles

Effect of extrusion of corn and feed form on feed quality and growth performance of poultry in a tropical environment

Two experiments were conducted to study the effect of corn extrusion and feed form on feed quality and growth performance of broilers. In experiment 1, whole corn was extruded at a water flow rate of 16, 19, and 22 L/h. The experimental design was a completely randomized design with 3 replications for each treatment. The extrusion process significantly decreased (P < 0.01) ether extract, crude fiber, and moisture content of corn. Increased water flow significantly decreased enzyme susceptibility from 56 to 47% (P < 0.01), but increased the bulk density of extrudate from 134 to 224 g/L (P < 0.01). However, there was a trend for lower total energy consumption (P < 0.01) and extruding production rate (P < 0.05) when corn was processed at the water flow of 22 L/h. In Exp. 2, 1,600 broilers (initially BW of 41 g) were used to determine the effect of extrudate and feed form on the growth performance in poultry during a 42-d growth assay. There were 50 chicks per pen and 8 pens per treatment. Treatments were arranged in a 2 x 2 factorial arrangement with the main effect of feed form and the main effect of 25% processed corn inclusion. Treatments were 1) conventional corn mash, 2) conventional corn pelleted feed, 3) +25% extruded corn mash, and 4) +25% extruded corn pelleted feed. Chicks fed pelleted feed, regardless of processing of corn, had a greater BW and feed conversion than those fed mash feed diet (P < 0.001). Extruded corn mash decreased the growth performance. Results suggested that optimal growth rate and feed conversion of birds raised in a tropical environment given extruded corn might be achieved by steam pelleting.

Growth and Meat Yield Responses of Broilers Provided Feed Subjected to Extrusion Cooking

Rapid growth and breast meat accretion are genetic traits that are continually enhanced in modern commercial broiler strains. It is generally assumed that the nutrient content of the diet should be increased to meet this heightened genetic potential so that production time to market is reduced. In addition to increasing the nutrient utilization of the diet, the process by which feed is conditioned and its subsequent particle size can affect the feed intake and nutrient utilization of a bird. Two experiments were conducted to evaluate the effects of feed processing on early growth of broiler chicks.Cobb male broilers were placed in floor pens at 1 d of age and fed experimental diets to d 17 in experiment 1 and d 42 in experiment 2. Feed processing treatments represented feed fed as mash or crumble form after pelleting or extruding. Although results from extrusion cooking were inconsistent, extrusion cooking and conventional steam pelleting of feed resulted in improved broiler BW and carcass weights in comparison with birds fed the same diets in mash form.

Effects of steam pelleting or extrusion on digestibility and performance of silver perch Bidyanus bidyanus

The effects of different processing techniques on apparent digestibility coefficients (ADCs) and performance of silver perch Bidyanus bidyanus were evaluated. Results of a factorial digestibility trial, in which three diets (SP35, 95LC1 and 95LC2) and three processing methods (cold pelleted, steam pelleted and extruded) were evaluated, indicated that extrusion, but not steam conditioning, significantly improved ADCs of dry matter (DM) and energy. ADCs of DM and energy of cold-pelleted diets were statistically similar to steam-pelleted diets, and ADCs of nitrogen were unaffected by processing method. No interaction was found between diet type and processing method for DM, energy or nitrogen ADCs. A performance trial indicated that feed intake, weight gain and specific growth rate of fish fed steam-pelleted diets was greater than those of fish fed extruded diets. Feed conversion and digestible protein efficiency was better in fish fed extruded diets. The results indicated that extruded diets were better utilized than steam-pelleted diets; however, voluntary intake of extruded diets may have been limited. Fish fed cold-pelleted SP35 exhibited inferior performance compared with fish fed steam-pelleted or extruded SP35. Reduced performance of fish fed this diet may relate to poor utilization of digestible protein or reduced palatability. Diets for silver perch with similar formulations to SP35 and 95LC2 should be steam pelleted.

Effect of Extrusion Processing and Steam Pelleting Diets on Pellet Durability, Water Absorption and Physical Response of Macrobrachium rosenbergii

Two hundred and ten post-larvae (PL) of Macrobrachium rosenbergii (14.5-14.9 mg) were equally distributed in two experimental groups and fed with either steam cooked or extruded pellet for a period of 60 days. Physical evaluation and growth promoting effect of both the pellets were assessed. Significantly higher (p 0.05). Although insignificant (p>0.05) but higher amylase activity was recorded in steam pellet fed group. Survival was not affected by feeding either of the diets. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 9 : 1354- 1358)

Processing Procedures and Feeding Systems for Sorghum-based Diets Given to Lactating Sows

One hundred and twenty nine primiparous sows were used to determine the effects of alternative processing procedures and feeding systems on the nutritional value of sorghum grain-based diets for lactating sows. Treatments were a ground sorghum control, steam-flaked sorghum and extruded sorghum fed in meal form and the ground sorghum control given as pellets or gruel (1:1 ratio of water and feed on a volume:volume basis). Average daily feed intake was greater for sows fed pelleted and gruel diet forms than sow fed the diets with steam-flaked and extruded sorghum (p 0.14). Number of pigs weaned and livability rates were similar among treatments except that steam-flaked sorghum supported greater litter weight gains than extruded sorghum (p 0.35), but keratinization was greatest for sows fed extruded sorghum (p<0.01). In conclusion, the alternative processing methods (steam-flaking and extrusion) and feeding system (pellets and gruel) had little effect on sow and litter performance. However, nutrient digestibilities were improved for all treatments that involved heating (steam flaking, extrusion and pelleting) and, thus, these treatments resulted in less fecal excretion of DM and N. (Asian-Aust. J.

The response of broilers to the feeding of mash or pelleted diets containing maize of varying particle sizes

1. The effects of maize particle size and steam pelleting on growth and nutrient utilisation were studied with broiler chicks. 2. The presence or absence of 10 μg/kg of 1,25 dihydroxycholecalciferol in diets adequate or deficient in phosphorus was also investigated. Food efficiency was superior with the fine maize diets but calcium retention and phytate phosphorus retention were greatest with the coarse maize diets. Pelleting improved food efficiency and growth in both experiments while phytate phosphorus utilisation was decreased. 3. Addition of 1,25-dihydroxycholecalciferol to the diet increased 16-d body weight, bone ash, plasma dialysable phosphorus and retentions of total phosphorus and phytate phosphorus while decreasing phosphorus deficiency rickets and tibial dyschondroplasia. 4. There were significant interactions between maize particle size and food form. The improvement in calcium retention observed with the coarse maize diets was reduced when the diets were pelleted. When fed as a mash, coarse maize diets resulted in increased plasma dialysable phosphorus levels but when the diet was pelleted this response was eliminated. 5. There was also a significant interaction between particle size and phosphorus concentration in that chicks given diets deficient in phosphorus had improved bone ash when fed coarse maize as compared to fine maize. However, this response was eliminated when the diets were adequate in phosphorus. 6. In one experiment, fine maize diets had higher metabolisable energy values and there was a significant interaction between maize particle size and food form as pelleting improved the metabolisable energy value of coarse maize diets but not fine maize diets. In another experiment only pelleting of the factors studied improved the metabolisable energy value of the diets.

Effects of grinding, steam conditioning and extrusion of a practical diet on digestibility and weight gain of silver perch, Bidyanus bidyanus

As processing can affect the digestibility and utilisation of diets by fish, we examined the effects of grinding, steam conditioning and extrusion of a commercially available diet (SP35) on weight gain and performance of silver perch. SP35 (35% protein, 18 MJ/kg gross energy) with approximately 80% of particles between 710 and 1000 μm was either left (unground) or finely ground to 500 μm (ground). Both unground and ground fractions were made into sinking pellets in a commercial steam pelleting mill with or without the addition of steam (90°C) A fifth diet was processed by pelleting finely ground material in a single-screw extruder (after the addition of approximately 5% fish oil) at a temperature of 120°C. The extruded diet floated or sank slowly. Each diet was fed to 50 juvenile silver perch (mean initial weight 17.8 g) in each of three replicate 10 000-l tanks for 113 days. Fish gained between 55 and 71 g/fish during the experiment, and feed conversion ratio (FCR) ranged from 1.5:1 to 2.0:1. Steam conditioning significantly improved weight gain and FCRs while neither grinding nor the interaction between grinding and steam conditioning had any effect. Fish were reluctant to consume the extruded diet and grew less on this diet than on the steam-conditioned diets, although FCR was better than for all other diets. Ground diets, uncooked and steamed, and the extruded diet were subsequently reground and 1% chromic oxide was added as an inert indicator. Each of these three diets was fed to juvenile silver perch (mean initial weight 2.5 g) in 170-l cylindroconical tanks from which faeces were collected by settlement to determine digestibility coefficients for dry matter, energy and nitrogen. Digestibility coefficients for dry matter and energy were higher for the extruded diet but similar for the unsteamed and steamed diets. Protein digestibility was unaffected by processing. These results indicate that for silver perch fed diets similar to SP35, diets should be steam-conditioned, but the additional expense associated with fine grinding is unwarranted with respect to gains in either fish performance or improvements in pellet stability. Extrusion significantly improved digestibility and FCR but consumption of floating extruded pellets was reduced in our facility. Sinking, extruded diets deserve evaluation.

Optimum inclusion of field peas, faba beans, chick peas and sweet lupins in poultry diets. II. Broiler experiments

1.Three experiments were undertaken to determine the optimum inclusion rates of field peas, faba beans, chick peas and sweet lupins in broiler starter and finisher diets in amounts up to 360 g/kg. 2. In experiment A chickens in cages grown to 21 d on diets with field peas and faba beans gave better growth rate and feed efficiency than those with sweet lupins and chick peas. Growth rate and Food conversion ratio (FCR) improved with increasing amounts of faba beans in the diet while for chick peas growth rate and FCR declined. Digesta viscosity and excreta stickiness scores were much higher on diets with sweet lupins. Steam pelleting improved growth rate and FCR on all diets. 3. In experiment B birds were in cages and grown from 21 to 42 d. There were no differences between grain legumes (when combined for all inclusions) for growth rate, food intake or FCR. Viscosity was again much higher on the sweet lupin-based diets while the pancreas was significantly enlarged on the diets with chick peas, as observed previously in chickens grown to 21 d. Steam pelleting of diets gave a consistent and positive response for weight gain and FCR. 4. Experiment C was carried out in pens each holding 60 birds under semi-commercial conditions and grown to 42 d on starter and finisher diets with the same grain legumes as used previously but each at 2 rates of inclusion similar to those in commercial practice. Field peas at 200 to 300 g/kg and chick peas at 150 to 220 g/kg gave inferior growth to faba beans (150 to 180 g/kg) and sweet lupins (120 g/kg). 5. The results of these experiments allowed tentative recommendations to be made to industry for inclusion rates of these cultivars of the 4 grain legumes. These were: field peas 300 g/kg; faba beans 200 g/kg, chick peas 100 g/kg and sweet lupins <100 g/kg. Wet droppings and high gut viscosity were serious problems with sweet lupins although these were not so obvious in experiment C.

Stability of bacitracin methylene disalicylate and chlortetracyline in combination in a pelleted pig feed

A study was carried out to determine if the presence of bacitracin methylene disalicylate (BMD) interfered with the assay of chlortetracycline (CTC) and if the presence of CTC interfered with the assay of BMD when both are combined in a pig feed. In addition, the potential influence of steam pelleting on active concentrations of BMD and CTC was determined. Further, the stability of BMD in the presence of CTC and the stability of CTC in the presence of BMD was determined in pelleted pig feed. Finally, the homogeneity of BMD and CTC during normal mixing procedures and the extent of segregation during shipping were determined. The results of the study demonstrated that when present in pig feeds at levels anticipated for actual use, BMD and CTC can be assayed without interference, that each of these antibiotics remains within specifications for up to 13 weeks of storage and that standard feed mixing results in homogenous dispersion of the antibiotics which remain dispersed following transport.

Effects of steam pelleting and extrusion of feed on phytate phosphorus utilization in broiler chickens

Three experiments were conducted to determine the effects of pelleting and extrusion of feeds on the utilization of phytate P by broilers. The first experiment investigated the effects of pelleting the whole corn-soybean meal (SBM) diet, the corn, or SBM separately on phytate P utilization. The P-deficient basal diet contained 0.5% total P and 0.2% phytate P. Steam pelleting the whole diet, the corn, or SBM separately did not decrease the severity of the P deficiency obtained and there were no indications of increased phytate P utilization. In the second experiment, the whole corn-SBM P-deficient diet was extruded. Extrusion of the diet did not influence bone ash and P rickets, both sensitive criteria of P deficiency. Extrusion decreased Ca, P, and phytate P retention and decreased the ME value of the diet. In the third experiment, phytate P retention by chickens fed three commercial pelleted diets was compared to chicks fed the corn-SBM P-deficient diet. Phytate P retention by the chickens fed the commercial diets was much lower than retention by chickens fed the corn-SBM P-deficient diet. These studies gave no indication that pelleting or extrusion of corn-SBM diets would increase phytate P utilization by broiler chickens.

Effect of expander conditioning and/or pelleting of a diet on the ileal digestibility of nutrients and on feed intake after choice feeding of pigs

A pig diet, processed in three different ways, was evaluated in an ileal digestibility trial. The complete diet contained mainly pea, tapioca and soybean meal and was processed by steam-pelleting (SP), high-shear conditioning (expander treatment; E) and expander-pelleting (EP), respectively. Expander-pelleting clearly improved the physical quality of pellets in terms of hardness and durability as compared to steam-pelleting. The apparent ileal digestibility of dietary nitrogen, dry matter, organic matter and crude fat determined with piglets in the weight range of 20–25 kg was not affected by the technological treatments under investigation. Only the crude fibre digestibility was significantly improved by single expander conditioning (P<0·05); the absolute level of 7·6% however was of low significance. Under the conditions of the present study, high shear conditioning (expander treatment) prior to pelleting showed no favourable effects on the apparent ileal digestibility of nutrients. Feed intake of the diets, offered in a choice feeding design to piglets of about 27 kg liveweight showed a large variation between piglets but in favour of the SP and E diet. Since diet hardness is related directly to the animal feed intake, maximisation of diet durability of expanded or pelleted diets should be achieved in relation to an optimisation of diet hardness and nutrient utilisation in piglets. © 1998 SCI.

Effect of expander conditioning and/or pelleting of a diet containing tapioca, pea and soybean meal on the total tract digestibility in growing pigs

A study was carried out with piglets fed a complete diet containing mainly peas, soybean meal and tapioca. The diet had been processed in four different ways: by pelleting without steam addition (CP), steam pelleting (SP), expander treatment (E) and expander-pelleting (EP). Expander-pelleting clearly increased pellet durability and pellet hardness as compared with CP and SP treatment. The effect on the diet starch gelatinization degree (SGD) was small due to the high SGD of the unprocessed meal. A total tract digestibility experiment with piglets revealed no differences in the apparent digestibility coefficients for dietary protein, dry matter and nitrogen-free extract. The digestibility coefficient for fat was significantly ( P < 0.01) lower for the expandate compared with the SP diet. Both expander treatments decreased the digestibility of crude fibre ( P < 0.10). N-balance (g body N retained day −1) in pigs was similar for all diets but a trend was observed for a higher N-balance of pigs fed the CP diet. Under the conditions of the present study, the use of high-shear conditioning (expander treatment) prior to pelleting had no favourable effect on the apparent digestibility of nutrients in diets for growing pigs.

Effects of feed processing on the apparent ileal digestibility of amino acids in pig diets containing wheat bran or wheat middlings

The effects of feed processing on the apparent ileal digestibility of amino acid and the utilisation of nitrogen (N) in diets containing wheat by-products were studied in five castrated male pigs (live weight 40-109 kg). A T-cannula was surgically fitted into the caecum of the pigs at a live weight of 27 kg using the steered ileo-caecal valve technique. The experiment was conducted with a 6 x 5 cyclic change-over design in which six diets were arranged 2x3 factorially. The corresponding factors were type of wheat by-product in the diets: wheat bran (152 g/kg) or wheat middlings (328 g/kg), and method of feed processing: steam pelleting, expanding or extrusion. The other dietary feed ingredients were barley and soya bean meal. The feed-processing method or dietary wheat by-product had no effect on the apparent ileal digestibility of amino acids and crude protein. The pigs on diets containing wheat middlings tended to retain more N per intake (p

Die bedeutung extrudierter futtermittel für forellenernährung und gewässerschutz

Extruded feeds exhibit an improved starch digestibility and are more firmly bound due to the almost complete gelatinization of the starch. This results in fewer fines and longer water stability than pelleted feeds. Extruded pellets also have the advantage that they can soak up more oil than a conventional pellet. It is therefore possible to increase the maximum oil content to more than 20%. On the other hand extruding feeds is more expensive than steam pelleting. Gelatinized starch is a useful energy source in trout diets helping to reduce feed conversion ratios. Proportions up to 35-40% in the diet are tolerable. Using high dietary levels of both gelatinized starch and oil the non-protein energy of feed may be increased and thus a protein-sparing effect results. High-energy diets enable to reduce excretion of faeces and of nitrogen via gills. In addition a decrease of phosphorus level in feeds and thus of phosphorus excretion by fish is possible. Extruded high-energy diets therefore make a contribution to improve water quality.

The nutritive value for broiler chickens of pelleting and enzyme supplementation of a diet containing barley, wheat and rye

A diet based on barley (40%), wheat (25%), and rye (7%) was given as a mash diet or as dry or steam pelleted diets to a total of 384 broiler chickens. Diets were given with or without the addition of a fibre-degrading enzyme preparation. Pelleting increased the water solubility (at 38°C) of starch and crude protein. There were, however, no notable effects on the solubility of dietary fibre components following pelleting or enzyme supplementation. Buffer extracts from pelleted diets had a high relative viscosity, while mash diets gave the lowest relative viscosity. Enzyme supplementation diminished the high viscosity obtained for pelleted diets and reduced sticky droppings. Pelleting increased weight gain for chickens receiving the unsupplemented diets by ∼ 30% and for those fed on the enzyme-supplemented diets by ∼ 20%. This improvement, which was similar at both 14 and 20 days of age, was mainly due to a greater feed intake, particularly with the steam pelleting. Enzyme supplementation improved weight gain by 11–24%, and was more effective in the unpelleted diets and at Day 14. This improvement was due to both a higher feed intake and a better feed conversion efficiency. Pelleting tended to increase ileal digestibility of the unsupplemented diet while enzyme supplementation had a similar effect on the unpelleted diet. The latter treatment also increased whole-tract digestibility.

Effect of pelleting mixed feeds on phytase activity and the apparent absorbability of phosphorus and calcium in pigs

Six diets were used to determine the apparent absorbability of phosphorus (P), using total faeces collection, in pigs from 40 to 100 kg live weight. In diets containing a considerable phytase activity from feedstuffs such as wheat, wheat middlings or barley, steam pelleting at ∼ 80°C sometimes decreased the P and calcium (Ca) absorbability by 10 percentage units or more. This was mainly due to a considerable reduction of the phytase activity. Cold-pelleting such diets had no negative effect on the P absorbability or phytase activity. In diets without phytase activity, steam pelleting had no negative effect on P and Ca absorbability. The results indicate, that when the temperature of the pellets reaches ∼ 80°C, the concentration of absorbable P can be decreased substantially in feeds containing a high phytase activity. The type of diet and the conditions during pelleting are therefore decisive in determining P and Ca absorbability.

Research Note: Pellet Binder and Steam Pelleting as Nitrogen-Corrected True Metabolizable Energy Contributors: An Example of the Statistics Used to Evaluate a Component of a Mixture

A calcium lignosulfonate pellet binder included in diets at the 0 and 50% levels was assayed for TMEn using adult Single Comb White Leghorn cockerels. The effect of low level inclusion (.04 kg/kg diet) in a chick-grower diet, before and after steam pelleting, was also examined. The formulae for calculating the mean and standard error of the TMEn estimate of a component of a mixture are presented. The TMEn of the binder was 4.90 ± .52 MJ (1 MJ = .239 Mcal)/kg of dry matter compared with 14.34 ± .16 MJ/kg for the chick diet. Although diets containing practical levels of the binder (.04 kg/kg) had slightly reduced TMEn values, the differences were not significant (P>.05) because of the low inclusion level and the limited number of birds used. Steam pelleting had no effect on energy bioavailability.

Effect of pelleting and associations with maize or wheat on the nutritive value of smooth pea (Pisum sativum) seeds in adult cockerels.

Four types of diet were tested: 960 g maize/kg (M), 960 g wheat/kg (W), 463 g maize added to 497 g of smooth peas/kg (PM) and 463 g wheat added to 497 g smooth peas/kg (PW). Three treatments were applied to each of these 4 diets: grinding (OP), one steam pelleting (1 P) and two successive steam pelleting (2 P). The pelleted diets were ground before feeding. Adult cockerels received all the diets whereas rats received only W and PW diets. Apparent metabolisable energy values corrected for N-equilibrium (AMEn), protein and starch digestibilities were measured in adult cockerels. Digestible energy (DE) values were measured in rats. The AMEn values of cereals remained practically unchanged by pelleting, whereas that of smooth peas was increased by between 1.8-4.6% after pelleting. Pelleting also induced 3.5 and 5.4% increases respectively in the digestibilities of pea protein and starch. Pelleting did not change the DE values measured in rats. The AMEn values of smooth peas mixed with maize were 4.6% higher than those of smooth peas mixed with wheat. The true digestibility of pea protein was 8.4% higher in the former mixture, whereas the pea starch digestibility remained unchanged. Calculation showed that most of the pea AMEn variations could be explained in terms of variations in protein and starch digestibilities.

Utilization of steam pelleted wheat bran, with or without NaOH treatment, in broiler rations

An improvement in the nutritive value of wheat bran was attempted by steam-pelleting (SP) and treatment with NaOH (1·37% of material) prior to steam-pelleting (NaSP). Both samples were fed to two replicates of ten chicks each for 4 weeks at the 15, 20, 25 and 30% levels. The average body weights, in grams, for the respective levels were as follows: SP, 970, 989, 976 and 969; NaSP, 943, 938, 919 and 917, these being significantly different ( P < 0·01). Feed consumption ranged from 92 to 100 g per chick per day and was not significantly different. The feed efficiency of SP diets (1·69) was significantly better than that of NaSP (1·81). Average water consumption per chick per day was 252 ml for chicks on NaSP diets, which was much higher than for those on SP diets. NaOH treatment gives no advantage over simple steam-pelleting in the preparation of chick feeds.

Application of a Simple Radial Gel Diffusion Assay for Endo-β-Glucanase Activity in Dietary Enzyme Supplements

Abstract A radial gel diffusion assay for endo-β-glucanase activity was used to evaluate various materials as potential enzyme sources in diets containing detrimental amounts of β-glucan. Activity was detected in malt, two fungal sources (cellulase, pectinase), and two bacterial sources (alpha-amylase, a commercial enzyme supplement) but not in hog pancreatic alpha-amylase. Significant activity was detected throughout the gastrointestinal tract of 4-week-old broilers fed an enzyme supplemented diet. Further, in vitro tests to determine the stability of a bacterial endo-β-glucanase revealed the following effects on enzyme activity: 1) a 58% loss as a result of exposure to pif 1; 2) up to 36% decrease after steam pelleting; and 3) stable after 10-min exposure to a temperature less than 60 C. The results demonstrate the value of the gel diffusion assay in evaluating the endo-β-glucanase activity in dietary enzyme supplements.