Feed Processing Methods Research Articles

Full-Fat Soybean Meals as an Alternative Poultry Feed Ingredient-Feed Processing Methods and Utilization-Review and Perspective.

On a global scale, the poultry industry expands its wings in terms of meat and egg production to the masses. However, this industry itself requires a sustainable and permanent supply of different inputs, one of which is poultry feed and nutrition. Soybean is a versatile protein that is offered to poultry in different inclusion rates in commercial diets after being processed using various thermal and mechanical processing methods. Conventional commercial soybean meal is usually prepared by the extraction of oil from whole soybeans using solvents, producing a meal that has approximately 1% crude fat. Without oil extraction, full-fat soybean (FFSBM) is produced, and it is an excellent source of dietary energy and protein for poultry with a nutritional profile of 38-40% protein and 18-20% crude fat, on average. FFSBM has less crude protein (CP) than solvent-extracted soybean meal (SE SBM) but higher metabolizable energy due to higher fat content. Alternatively, extruded expeller processing produces defatted soybean meal containing approximately 6-7% crude fat. Studies have demonstrated that FFSBM can be used in poultry diets to improve poultry nutrition, performance, and quality of the poultry meat and eggs produced. This review aims to evaluate the nutrition and use of meals prepared from conventional and high-oleic soybeans using various feed processing methods.

Impacts of mycotoxin on cultured fish

Mycotoxins are secondary metabolites produced by filamentous fungi that could cause toxic responses when ingested by animals. The extent of production varies with geographic location, feed storage practices and processing methods. In the tropics, improper bagging, transport, storage and use of feeds with inferior quality of ingredients are ways in which mycotoxin is produced and is a great challenge that threatens life of culture fish. Mycotoxins in feeds are a problem of significant concern as farmers are taking steps to overcome the challenge of feed supply. The effects result in teratogenic, carcinogenic, oestrogenic or immune-suppressive effects, poor growth, low apparent digestibility, physiological disorders, histological change and death. The expression of mycotoxin impacts is influenced by factors such as age, nutrition, sex, species and the possibility of concurrent exposure to other toxins. The main target organ in animals is the liver; therefore, mycotoxin disease is primarily hepatic. Conditions increasing the likelihood of mycotoxin impacts in aquatic organisms include limited feed availability, environmental conditions that favour mould growth on feedstuffs, and lack of regulatory systems for aflatoxin monitoring and control. Mycotoxin's effect on these organisms is not only on health problems in exposed fish but also represents a high risk to consumers through residues in fish musculature. Therefore, control and prevention measures are needed to sustain the aquatic resources. However, several effective ways to prevent and control hazardous fungi and their dangerous mycotoxins have been presented.

Plant-based polymer as a thermoresistant carrier of phytase in Nile tilapia (Oreochromis niloticus) diets

A biodegradable soybean oil-based polymer produced following the Green Chemistry principles, was assessed as a thermoresistant vehicle of phytase aiming to improve the enzyme stability during fish diet processing. Juvenile Nile tilapia (70 ± 4.3 g) were submitted to a digestibility assay designed in a factorial model (3 ×2) to assess the polymer efficiency. The treatments comprised the combination of three phytase inclusion methods with two feed processing methods. The inclusion methods of phytase were: CPP- coating post processing, in which the enzyme was spread on top of pellets after processing, PAE- polymer associated to enzyme, which was adsorbed by the polymer and included in the ingredients mash prior feed processing and NE- no enzyme inclusion, playing a control role as phytase was not included. The feed processing methods were extrusion (120 °C) or pelleting (40 °C), exposing the polymer to different temperatures. Phytase was supplemented at 1500 units kg−1 using the CPP or PAE methods. There was a significant interaction for the apparent digestibility coefficient (ADC) values of phosphorus (P), calcium (Ca) and Ash (P < 0.05). CPP resulted in higher ADC values for P and Ca, compared to PAE and NE in extruded diets (P < 0.05). The PAE method resulted in higher ADC values of P, Ca, and Ash than NE in extruded diets (P < 0.05). In pelleted diets, PAE resulted in higher ADC values for P and Ca, and a similar ADCAsh in comparison to CPP (P < 0.05). As verified in extruded diets data, the polymer partially protected phytase from heat denaturation, resulting in higher ADC values in comparison to NE (P < 0.05). The polymer improved phytase effects in pelleted diets probably by reducing degradation in fish stomach. These results suggest that the polymer may be a potential protective carrier of phytase and other thermolabile additives in extruded and pelleted diets.

EFFECTIVENESS OF FEEDING CHEMICALLY TREATED PROTEIN FEED TO YOUNG BULLS

When rationing diets of young animals, special attention should be paid to the regulation of digestion and metabolism processes in the body of animals, as well as the choice of high-protein feed processing method to improve the efficiency of nutrient use. This article presents materials of scientific research, the purpose of which was to establish the effectiveness of feeding chemically treated protein feed to young bulls. It was found that the inclusion of lupine grain treated with organic acid in the diet of young bulls increased the average daily gain up to 917 g or 6.9% in relation to the control group, while reducing feed costs by 4.9%.

Effect of Cereals and Legumes Processing on In Situ Rumen Protein Degradability: A Review

The determination of the ruminal degradability rate of feeds, mainly starch and crude protein, is one of the most common methods to evaluate the nutritional value of ruminant feed. The protein requirements for ruminants are met from microbial protein and undegraded dietary protein digested in the small intestine. In order to reach maximum productivity, high-quality proteins are needed, and the requirement for undegraded dietary protein increases with the performance of the animal. This protein can be supplied by reducing the ruminal degradation to increase the amount of protein digested post-rumen, but the form in which a feed is administered influences degradability, and grain processing, especially, is a common practice to improve feed efficiency. Despite these aspects, studies on the effects of feed processing methods on protein degradability are limited, even though more and more ruminants are fed with processed feeds. For these reasons, this review investigated the protein degradability of different processed cereals and legumes in ruminants based on the analysis of available literature in order to take stock of the state of the art on this topic. Results showed that: First, the majority of the papers are focused on the energy aspects mainly due to carbohydrate-rich feeds; second, the majority of the studies in the literature are quite old, probably because the changes occurred in the animal testing legislation that made in vivo studies more and more difficult in the last 20 years; third, as a consequence, the few data available in recent years concern in vitro experiments; fourth, we found a high variability of the experimental conditions thus affecting protein degradability and making it quite difficult to compare the different results.

The Effect of Urea Level and Ripening Time on Nutrient Content on Ammoniation of Sugarcane Shoots Waste

Raising livestock on a large scale, especially ruminants, requires large amounts of green fodder, the availability of natural feed is not yet fully reliable, therefore breeders must provide extensive forage areas that require investment costs. the big one. To obtain nutritional value, as well as good crude fiber and easy to digest, it needs processing first. One of the effective animal feed processing methods which can increase the crude protein content, reduce the crude fiber content, increase the flavor and soften the structure of the feed ingredients so that it is preferred by livestock is the ammoniation method. The purpose of this study was to see the effect of ammonia on the nutritional content of feed waste, to increase the nutritional content of the waste, to find the best urea level, to obtain the best curing time for the ammoniation of sugarcane shoots on the ammonia content of sugarcane shoots waste. This study used a completely randomized design method, the factorial pattern consisted of 3 types of treatment with 3 replications with urea percentage A: 2%, B: 3%, C: 4%, with curing time of 7 days, 14 days and 21 days. Parameters measured, dry matter content, organic matter, crude protein content, crude fat (LK), crude fiber (SK). Keywords: Sugarcane Tops, Ammonia, Nutrient Content, Fiber Fraction.

Digestible nutrient and energy values of corn and wheat glutens fed to Atlantic salmon (Salmo salar) are affected by feed processing method

The impact of feed processing on the digestibility of two major grain proteins fed to post-smolt Atlantic salmon (Salmo salar) was examined using a simple factorial experimental design of two protein types (wheat and corn gluten) and two feed processing methods (hot [cooking] extrusion and cold extrusion). A series of diets were each prepared from the same basal mash, including two basal diets (each diet was prepared using the same processing methods as the test diets) were also included in the experiment. Triplicate tanks of salmon (286 ± 20.9 g) were fed each diet for one week and then stripped of faeces, which was repeated two more times. Faeces, diets and ingredients were assessed for protein, amino acid, and energy digestibilities and by derivation the ingredient digestibilities for these parameters were also determined. Ingredient protein digestibility was affected by both ingredient type and feed processing method, with an interaction effect between parameters also present. Protein digestibilities were highest in diets that were cold extruded, with corn gluten protein digestibility being significantly affected by feed processing method, but wheat gluten comparatively less affected. Energy digestibilities typically reflected the protein digestibilities, but the interaction effect was not evident. The digestibility of the sum of amino acids in corn gluten was negatively affected by hot extrusion but this processing method had limited impact on wheat gluten digestibility. The digestibility of individual amino acids was highly variable between ingredients and processing methods, though was typically consistent with the digestibility observations of crude protein and sum of amino acids. Wheat gluten had superior digestibility characteristics than that of corn gluten across most parameters. This study demonstrates that the feed processing method has a clear influence on the nutritional value of corn gluten but in contrast has negligible effect on the digestibilities of wheat gluten.

Effects of supplemental calcium gluconate embedded in a hydrogenated fat matrix on lactation, digestive, and metabolic variables in dairy cattle

There is growing evidence suggesting that by improving gut integrity and function, less energy is partitioned toward immune responses related to xenobiotic infiltration, sparing energy for productive purposes. Gluconic acid and its salts have previously shown prebiotic effects in the lower gut of nonruminant animals, where they serve as a precursor for butyrate, although evidence in ruminants is limited. Butyrate and its fermentative precursors have demonstrated multiple beneficial effects to gastrointestinal ecology, morphology, and function, such as the stimulation of epithelial cell proliferation and improvement of gut barrier function and ecology. The objective of this study was to evaluate changes in milk production, milk fatty acid composition, and fecal and blood parameters in lactating dairy cattle fed a hydrogenated fat-embedded calcium gluconate (HFCG) supplement designed to target the hindgut for calcium gluconate delivery. In addition, the effects of a compound feed processing method (i.e., incorporated into a mash or an extruded pellet) were tested to evaluate the effect of extrusion on product efficacy. Forty-five lactating Holstein cows at approximately 165 d in milk were used in a 3 × 3 Latin square consisting of three 28-d periods, during which animals were offered a basal ration mixed with 3 different compound feeds: a negative control in mash form containing no HFCG, or the HFCG supplement fed at a target rate of 16 g/d, delivered in either a mash or pelleted form. Supplementation of HFCG tended to increase yields of milk fat and fat- and energy-corrected milk. Total yields and concentrations of milk fatty acids ≥18 carbons in length tended to increase in response to HFCG. Plasma nonesterified fatty acids and milk urea increased in HFCG treatments. No differences were observed in fecal pH or fecal concentrations of volatile fatty acids, with the exception of isobutyrate, which decreased in HFCG-fed cows. Changes in milk fatty acid profile suggest that increased milk fat yield was driven by increased incorporation of preformed fatty acids, supported by increased circulating nonesterified fatty acid. Future research investigating the mode of action of HFCG at the level of the hindgut epithelium is warranted, as measured fecal parameters showed no response to treatment.

Processing Matters in Nutrient-Matched Laboratory Diets for Mice-Microbiome.

Simple SummaryFeed for laboratory mice is available in different physical forms. However, there is insufficient standardization in nutrient composition and physical forms. Results pertaining to energy and nutrient digestibility show that differentially processed feed (pelleted vs. extruded) and even batches from the same provider (pelleted vs. pelleted) differ in starch gelatinization. Here we show that feed processing impacts the mice’s gastrointestinal microbiome. Reproducibility and comparability between experiments with differently processed feeds in laboratory mice should not be taken for granted. Therefore, details on dietary ingredients and feed processing should be specified in studies that include animal experiments.The composition of the microbiome is subject to the host’s diet. In commercial laboratory mouse diets, different physical forms of the same diets are available, containing—according to their labels—identical ingredients and nutrient compositions. However, variations in nutrient composition and starch gelatinization due to production processes and their impact on digestibility have been described. In this study, a total of 48 C57BL/J6 mice were assigned to two equal groups and were fed diets (produced with different processes—extruded vs. pelleted) for eight weeks in two biological replicates. At the end of the experiment, samples were collected from five different gastrointestinal regions, including the stomach, small intestine, cecum, large intestine, and an extracorporeal region (feces), and the microbiome was analyzed with 16S rRNA gene amplicon sequencing. The replicates in both experiments differed significantly in their relative abundances of Muribaculaceae species. Furthermore, the gastrointestinal content of pellet-fed mice contained larger numbers of Lactobacillus species. These results indicate that starch gelatinization and ingredient composition significantly influence microbial makeup. In conclusion, different feed processing methods may affect fundamental digestive and metabolic processes, impacting animal experiments and biasing microbiome data.

Effect of feed form and heat processing on the growth performance of growing and finishing pigs

ABSTRACT The objective of this study was to evaluate the effect of different feed processing methods (pelleting and/or expansion) and feed physical form on the growth performance of growing-finishing pigs submitted to quantitative feed control. Commercial hybrid boars (n=200), with 22 kg initial body weight were distributed in a randomized complete block design with 5 treatments and 8 replicate pens of 5 pigs each. Treatments consisted of a mash feed, pelleted feed, expanded-pelleted feed, expanded-mash feed, and mash feed with previously expanded corn and soybean meal. Daily feed intake, average body weight, average daily gain, and feed conversion ratio were calculated at 63, 98, 128, 157, and 185 d. Data were submitted to analysis of variance, and when significant, treatment means were compared by orthogonal contrasts. No differences were detected for daily feed intake. However, from 63 to 128 d, the pigs fed processed diets showed improvements (P

Nutrition and Functions of Amino Acids in Fish.

Aquaculture is increasingly important for providing humans with high-quality animal protein to improve growth, development and health. Farm-raised fish and shellfish now exceed captured fisheries for foods. More than 70% of the production cost is dependent on the supply of compound feeds. A public debate or concern over aquaculture is its environmental sustainability as many fish species have high requirements for dietary protein and fishmeal. Protein or amino acids (AAs), which are the major component of tissue growth, are generally the most expensive nutrients in animal production and, therefore, are crucial for aquatic feed development. There is compelling evidence that an adequate supply of both traditionally classified nutritionally essential amino acids (EAAs) and non-essential amino acids (NEAAs) in diets improve thegrowth, development and production performance of aquatic animals (e.g., larval metamorphosis). The processes for the utilization of dietary AAs or protein utilization by animals include digestion, absorption and metabolism. The digestibility and bioavailability of AAs should be carefully evaluated because feed production processes and AA degradation in the gut affect the amounts of dietary AAs that enter the blood circulation. Absorbed AAs are utilized for the syntheses of protein, peptides, AAs, and other metabolites (including nucleotides); biological oxidation and ATP production; gluconeogenesis and lipogenesis; and the regulation of acid-base balance, anti-oxidative reactions, and immune responses. Fish producers usually focus on the content or digestibility of dietary crude protein without considering the supply of AAs in the diet. In experiments involving dietary supplementation with AAs, inappropriate AAs (e.g., glycine and glutamate) are often used as the isonitrogenous control. At present, limited knowledge is available about either the cell- and tissue-specific metabolism of AAs or the effects of feed processing methods on the digestion and utilization of AAs in different fish species. These issues should be addressed to develop environment-friendly aquafeeds and reduce feed costs to sustain the global aquaculture.

Productivity of pigs when feeding celluloseamylolytic additive

The use of different feed processing methods using exogenous feed additives to improve the digestibility of plant feed ingredients in pig feeding has been studied for decades. In the research laboratory of the Institute of Forage and Agriculture of Podillya NAAS, compositions of enzymes with cellulase and amylase activity were studied. They are able to effectively break down non-starch polysaccharides in cereals, increase digestibility and absorption of feed nutrients. The purpose of this work was to study the zootechnical efficiency of the use of biologically active in the composition of feed pigs for fattening. In the presented material, the influence of feeding cellulose amylolytic enzyme additive on the productive qualities of pigs for fattening is highlighted. The cellulose amylolytic additive contained α-amylase with an activity of 9342 IU/h and cellulase with an activity of 540 IU/h. Studies in pigs were performed in two stages: the equalization period (15 days) and the main (71 days). For feeding pigs, a feed mixture was used, consisting of feed grown directly on the farm – barley, wheat, soybeans. The diet of the control group consisted of 63 % barley grain, 27.5 % wheat grain, 9 % soybean meal 0.5 % mineral supplement. Pigs of the experimental group were fed cellulose amylolytic feed additive at the rate of 5 g of cellulase and 1 g of amylase per 1 kg of feed. Feeding supplements determines the intensity of the process of digestion of proteins, fats and carbohydrates. Cellulose-amylolytic additive affects the absorption of carbohydrates in the diet, providing an increase in the digestibility of the control and experimental groups, respectively, neutral-detergent fiber (38.2 and 46.7 %), acid-detergent fiber (18.7 and 36.5 %), the amount easily hydrolyzed carbohydrates (85.4 and 90.2 %), hemicellulose (65.7 and 61.5 %), cellulose (13.2 and 21.4 %). The decision on the feasibility of including cellulose-amylolytic additive in the diet can be confirmed on the basis of its use during the scientific and economic experiment. In the control group, the average daily increase in live weight was 725.07 g, and in the experimental group by 19.7 % more at the level of 902.53 g. It was also noted a positive effect on the formation of body biomass, development of individual organs and their systems.

Effects of pelleted and extruded feed of different ingredients particle sizes on feed quality and growth performance of gibel carp (Carassius gibelio var. CAS V)

Ten diets with different processing methods (PF: pelleted feed and EF: extruded feed) and different ingredients particle sizes (104, 115, 163, 199 and 260 μm) were examined for their physical characteristics and amino acid composition. This was followed by an 8-week feeding trial to gibel carp (Carassius gibelio var. CAS V) (mean initial weight: 7.11 ± 0.05 g) to evaluate the effects of ingredient particle size and feed processing methods on their growth, feed efficiency, intestinal enzymes/ultrastructure and some plasma biochemical parameters. The results showed that EF had higher expansion ratio, water absorption index, starch gelatinization degree and bigger size of pores inside the granules while lower bulk density, hardness, water solubility index, amino acid and reducing sugar content than PF (P < 0.05). Feed processing (pelleting or extrusion) significantly affected feed color and PF obtained higher lightness and redness than that of EF (P < 0.05). Gibel carp fed on EF had significantly lower feeding rate than those fed PF (P < 0.05). Specific growth rate, feed efficiency and protein retention efficiency in EF groups were significantly higher than PF groups (P < 0.05). Gibel carp fed EF showed significantly higher intestinal trypsin, chymotrypsin, amylase, plasma total free amino acid and plasma glucose than fish fed PF (P < 0.05). The smallest ingredients particle size (104 μm) resulted in significantly lower feed efficiency in gibel carp than other particle sizes groups (P < 0.05). Fish fed with the diets of 260 μm ingredient particles displayed damaged or deformed microvilli than 104 and 163 μm groups. In conclusion, extrusion processing improved feed quality and gibel carp growth performance. Large ingredient particle size negatively affected fish intestinal health. The optimal ingredients particle size for gibel carp was 163 μm.

Ruminal in situ disappearance and whole-tract digestion of starter feeds in calves before, during, and after weaning

Ten bull calves (n = 5/diet) were cannulated at 3 wk of age and used in a 2 × 2 factorial design with repeated measures over time to compare rumen and whole-tract degradability of 2 calf starter diets and to describe an in situ technique for estimating ruminal degradability of diets in calves at different ages. Calves received milk replacer and 1 of 2 starter diets through wk 7. Mean birth weight was 38.7 ± 1.3 kg. Weaning occurred in wk 8, and calves received only starter (up to 4,500 g/d) through wk 15. Starter diets were a complete pellet (PEL; 42% starch, 13% neutral detergent fiber, NDF) or texturized feed (TEX; 31% starch, 22% NDF). Portions of each diet were dried and ground through a 2-mm screen, and 1.25 g was inserted into concentrate in situ bags (5 cm × 10 cm, 50-µm porosity). Each calf received duplicate bags of each diet for a total of 8 bags/calf (2 diets × 2 time points). All bags were inserted at the time of starter feeding. Half of the bags were removed at 9 h, and the other half were removed at 24 h. After removal from the rumen, bags were rinsed, dried (55°C), and composited by diet and by calf within week for NDF, nitrogen (N), and starch analyses. This process was repeated over 3 d during wk 5, 7, 9, 11, 13, and 15. Daily starter intake and total fecal excretion were recorded during the same 3-d periods. Diets, refusals, and feces were subsampled, dried, ground, composited by calf by week, and analyzed for NDF, N, and starch content. Apparent digestibility coefficients, total intake, and fecal excretion were calculated and analyzed with a mixed models procedure. Intake and fecal excretion of all measured nutrients increased from wk 5 through wk 15 of age and were greater for calves fed TEX, whereas the proportion of dry matter (DM), N, and starch apparently digested through the total tract decreased from wk 5 to 15 and was greater in calves fed PEL. Ruminal disappearance of DM, N, and starch after 9-h incubations increased linearly with age. Likewise, DM, NDF, and N disappearance after 24-h incubations also increased. Ruminal disappearance of DM and NDF was greater for PEL than for TEX. Ruminal disappearance was estimable for DM, NDF, N, and starch. In addition, changes over time and changes due to rumen environment were clearly demonstrated. Based on these data, there is potential to design specific rations and feed processing methods for calves based on their ability to utilize nutrients.

Optimization of extruder cooking conditions for the manufacture of fish feeds using response surface methodology

AbstractA composite blend consisting of sunflower cake, maize germ, wheat bran, fresh water shrimps and cassava flour was extruded using a single‐screw extruder to produce expanded fish feed pellets. The effects of temperature (80–120 °C), die diameter (2–4 mm), and feed pre‐conditioning time (50–150 s; steam 400 kPa) on properties of the pellets (expansion ratio, bulk density, floatability, durability, water absorption, water solubility, water stability, and in‐vitro protein digestibility) were investigated using response surface methodology. Regression equations describing the effect of each variable on the product responses were obtained. The pellets extruded using a factor combination of 120 °C extruder barrel temperature, 2 mm die diameter, and 100 s of feed pre‐conditioning time gave most desirable pellet floatability (100%), durability index (99%), expansion ratio (2.64), water absorption index (4.12), water solubility index (9.31), water stability (87%), bulk density (479 g/L), and in vitro protein digestibility (69.97%) with a composite desirability of 0.88.Practical applicationsExtrusion is a modern feed processing method whose use is fast gaining popularity among small feed processors in developing countries. However, extrusion is a process that involves many parameters that need to be optimized for desirable end properties. These findings guide fish feed manufacturers on the optimum conditions for single screw extruders for production of feeds with desirable properties especially for the fish types that are top feeders. In addition, the results offer important insights on how temperature, die diameter, and feed pre‐conditioning, may be manipulated to influence properties of extruded aquafeed when using simple low‐cost small‐scale extruders.

PSII-17 Glucose and insulin response to feed processing method and meal time of day in horses.

PSII-17 Glucose and insulin response to feed processing method and meal time of day in horses.

Effects of feed processing method (extrusion and expansion-compression pelleting) on water quality and growth of rainbow trout in a commercial setting

ABSTRACTTo determine the effects of feed processing method (extrusion or expansion followed by compression pelleting) on feed physicochemical characteristics, fecal stability, water quality, and growth performance in rainbow trout, three types of feed pellets (expanded sinking [EpS], extruded sinking [ExS], extruded floating [ExF]) were prepared, analyzed, and fed to juvenile rainbow trout (initial weight = 285.8 ± 15.2 g) at three feeding rates based on feeding rate curves developed at Snake River Farm (Buhl, Idaho, USA) (median rates [%BW] for feeding rate 1: 0.85; feeding rate 2: 0.95; feeding rate 3: 1.05) for 124 days. Results showed that all feeds had similar chemical composition, but the degree of starch gelatinization (as % of starch) was significantly higher in ExS (90.01 ± 0.26) and ExF (84.82 ± 0.63) than in the EpS (9.09 ± 0.41) feed, which led to extruded feeds having much higher water stability, fecal durability, and lower phosphorus discharge. The ExF feed produced better growth (% increase; 154.4 ± 18.5) and feed conversion (1.06 ± 0.06) compared to EpS (126.3 ± 12.4 and 1.26 ± 0.14) and ExS (121.7 ± 7.8 and 1.22 ± 0.04) in rainbow trout. Growth (% increase) improved as feeding rate increased (feeding rate 1: 125.6 ± 10.3; feeding rate 2: 140.8 ± 16.0), but further improvements were not observed at the highest feeding rate (feeding rate 3: 135.9 ± 22.8). The present study is the first to show that the extrusion process not only produces pellets having better quality than the expansion-compressed pelleting method but also improves fecal size and durability in water, and therefore, use of extruded feeds has the potential to improve waste collection and removal and reduce contribution to pollution in effluent.

Effects of raw material extrusion and steam conditioning on feed pellet quality and nutrient digestibility of growing meat rabbits.

This study was conducted to investigate the effects of raw material extrusion and steam conditioning on feed pellet quality and nutrient digestibility of growing meat rabbits, in order to determine appropriate rabbit feed processing methods and processing parameters. In Exp. 1, an orthogonal design was adopted. Barrel temperature, material moisture content and feed rate were selected as test factors, and acid detergent fiber (ADF) content was selected as an evaluation index to research the optimum extrusion parameters. In Exp. 2, a two-factor design was adopted. Four kinds of rabbit feeds were processed and raw material extrusion adopted optimum extrusion parameters of Exp. 1. A total of 40 healthy and 42-day-old rabbits with similar weight were used in a randomized design, which consisted of 4 groups and 10 replicates in each group (1 rabbits in each replicate). The adaptation period lasted for 7 d, and the digestion trial lasted for 4 d. The results showed as follows: 1) ADF was significantly affected by barrel temperature (P < 0.05); the optimum extrusion parameters were barrel temperature 125 °C, moisture content 16% and feed rate 9 Hz. 2) Raw material extrusion and steam conditioning both significantly decreased powder percentage, pulverization ratio and protein solubility (P < 0.05), significantly improved hardness and starch gelatinization degree of rabbit feed (P < 0.05). They both had significant interaction effects on the processing quality of rabbit feed (P < 0.05). 3) Extrusion significantly improved the apparent digestibility of dry matter and total energy (P < 0.05). Extrusion and steam conditioning both significantly improved the apparent digestibility of crude fiber (CF), ADF and NDF (P < 0.05), but they had no interaction effects on the apparent digestibility of rabbit feed. Thus, using extrusion and steam conditioning technology at the same time in the weaning rabbits feed processing can improve the pellet quality and nutrient apparent digestibility of rabbit feed.

Effect of pelleting on survival of porcine epidemic diarrhea virus-contaminated feed.

Porcine epidemic diarrhea virus (PEDV) is a heat-sensitive virus that has devastated the U.S. swine industry. Because of its heat sensitivity, we hypothesized that a steam conditioner and pellet mill mimicking traditional commercial thermal processing may mitigate PEDV infectivity. Pelleting, a common feed processing method, includes the use of steam and shear forces, resulting in increased temperature of the processed feed. Two thermal processing experiments were designed to determine if different pellet mill conditioner retention times and temperatures would impact PEDV quantity and infectivity by analysis of quantitative reverse transcription PCR and bioassay. In Exp. 1, a 3 · 3 · 2 factorial design was used with 3 pelleting temperatures (68.3, 79.4, and 90.6°C), 3 conditioning times (45, 90, or 180 s), and 2 doses of viral inoculation (low, 1 · 102 tissue culture infectious dose50 (the concentration used to see cytopathic effect in 50% of the cells)/g, or high, 1 · 104 tissue culture infectious dose50/g). Noninoculated and PEDV-inoculated unprocessed mash were used as controls. The low-dose PEDV–infected mash had 6.8 ± 1.8 cycle threshold (Ct) greater (P < 0.05) PEDV than the high-dose mash. Regardless of time or temperature, pelleting reduced (P < 0.05) the quantity of detectable viral PEDV RNA compared with the PEDV-inoculated unprocessed mash. Fecal swabs from pigs inoculated with the PEDV-positive unprocessed mash, regardless of dose, were clinically PEDV positive from 2 to 7 d (end of the trial) after inoculation. However, if either PEDV dose of inoculated feed was pelleted at any of the 9 tested conditioning time · temperature combinations, no PEDV RNA was detected in fecal swabs or cecum content. Based on Exp. 1 results, a second experiment was developed to determine the impact of lower processing temperatures on PEDV quantity and infectivity. In Exp. 2, PEDV-inoculated feed was pelleted at 1 of 5 conditioning temperatures (37.8, 46.1, 54.4, 62.8, and 71.1°C) for 30 s. The 5 increasing processing temperatures led to feed with respective mean Ct values of 32.5, 34.6, 37.0, 36.5, and 36.7, respectively. All samples had detectable PEDV RNA. However, infectivity was detected by bioassay only in pigs from the 37.8 and 46.1°C conditioning temperatures. Experiment 2 results suggest conditioning and pelleting temperatures above 54.4°C could be effective in reducing the quantity and infectivity of PEDV in swine feed. However, additional research is needed to prevent subsequent recontamination after pelleting as it is a point-in-time mitigation step.

Microscopic Analysis of Extruded and Pelleted Barley and Sorghum Grains

Scanning Electron Microscopy (SEM) technique has been used in food and feed industry to characterize the final product with the main focus on changes that occur to starch material. This study demonstrates the use of SEM for examining the changes that occur to starch granules after exposing sorghum and barley grains to mild (pelleting) and intensive (extrusion) feed processing methods. In this study, SEM images analysis is proved to be a useful tool to recognize the changes that occur to grains after a different processing method. The present study showed that the swelling and melting of starch granules are influenced by the severity of the processing method. In case of pelleting process, oval shape appearance of starch granules remained intact after the pelleting process; however, absence of intact oval shape of starch granules occurred after the extrusion process.