Feed Particle Size Research Articles

Production Response of Athulya Layer Chicken to Dietary Energy Concentration and Feed Particle Size

Production Response of Athulya Layer Chicken to Dietary Energy Concentration and Feed Particle Size

Research Note: Beak morphology of infrared beak–treated laying hens and its impact on production and welfare

Despite previous research on the impacts of beak treatment on laying hens, little information exists regarding how variation in beak morphology that can occur following beak treatment affects production, behavior, and welfare. Following infrared beak treatment (IRBT), variations in beak shape, such as a shovel beak (bottom beak longer than top), cracks (Cr), or bubbles (B) may occur if the IRBT equipment is damaged or if a quality control program is not followed at the hatchery. This study aimed to determine if variations in beak morphology post-IRBT impacted laying hen production or welfare. Infrared beak-treated Lohmann LSL-Lite hens (n = 80) were selected from a 56-wk-old flock and randomly assigned into 1 of 8 treatments: flush beak (control), shovel beak extending 0–1 mm (SB0-1), 1–2 mm (SB1-2), 2–3 mm (SB2-3), 3–4 mm (SB3-4), or >4 mm (SB > 4), Cr, or B. Hens were housed in individual cages for 4 wk and production (body weight, feed intake, egg production, and egg quality), and welfare (behavior and histology) parameters were evaluated. Consumption of different particle sizes was assessed by measuring feed particle size of refused feed. Data were analyzed as a one-way ANOVA, in a completely randomized design using PROC GLM (SAS 9.4). The results indicated that the beak morphologies examined had minimal effects on the production or welfare of the hens. Histological assessment did not show the presence of neuromas in the beak tissue, suggesting that the hens were not experiencing chronic pain from the IRBT procedure.

Young Broiler Feeding Kinematic Analysis as A Function of the Feed Type.

Simple SummaryThe present study aims to compare the kinematic feeding variables of 3–4 days old broiler chickens using three different feed types: fine mash (F1), coarse mash (F2), and crumbled (F3); size was 476 µm, 638 µm, and 1243 µm, respectively. The head displacement and the maximum beak gape were automatically calculated by computational image analysis to find the feeding behavior of broilers. The results did not show strong correlations between birds’ weight, beak size (length and width), and the kinematic variables. The “catch-and-throw” movements in F1 (the smallest feed particle) generally occurred in the first mandibulation, while in F3 (the largest feed particle) occurred in the latest mandibulation. It can be suggested that the adoption of “catch-and-throw” in the latest mandibulations increases with larger particles.Past publications describe the various impact of feeding behavior of broilers on productivity and physiology. However, very few publications have considered the impact of biomechanics associated with the feeding process in birds. The present study aims at comparing the kinematic variables of young broiler chicks (3–4 days old; 19 specimens) while feeding them with three different feed types, such as fine mash (F1), coarse mash (F2), and crumbled feed (F3). The feeding behavior of the birds was recorded using a high-speed camera. Frames sequences of each mandibulation were selected manually and classified according to the temporal order that occurred (first, second, third, or fourth, and further). The head displacement and the maximum beak gape were automatically calculated by image analysis. The results did not indicate strong correlations between birds’ weight, beak size (length and width), and the kinematic variables of feeding. The differences between the tested feed were found mostly in the first and second mandibulations, probably explained by the higher incidence of “catch-and-throw” movements in F3 (33%) and F1 (26%) than F2 (20%). The “catch-and-throw” movements in F1 (the smallest feed particle) mostly occurred in the first mandibulation, as in F3 (the largest feed particle) also occurred in the latest mandibulations. It might be suggested that the adoption of “catch-and-throw” in the latest mandibulations increases with larger particles. The kinematic variables in the latest mandibulations (from the third one on) seem to be similar for all feed types, which represent the swallowing phase. It might be inferred that the temporal sequence of the mandibulations should be essential to describe the kinematics of a feeding scene of broiler chickens, and the first and second mandibulations are potentially the key factors for the differences accounted by the diverse feed particle sizes.

Effect of Temperature, Pressure, Feed Particle Size, and Feed Particle Density on Structural Characteristics and Reactivity of Chars Generated during Gasification of Pittsburgh No.8 Coal in a High-Pressure, High-Temperature Flow Reactor

The gasification behavior of coal under high-temperature and high-pressure conditions is important from the perspective of designing and optimizing high efficiency gasifiers and troubleshooting existing gasifiers. The effect of feed particle size, density, temperature, and pressure on char porous structure, morphology, reflectance, and reactivity under conditions relevant to entrained-flow gasification was investigated. The chars were generated over a range of temperatures (1100, 1300, and 1400 °C at 11.3 bar for the −150 + 106 µm fraction), pressures (3.4, 6.2, 11.3, 15.5, and 21.7 bar at 1300 °C for the −150 + 106 µm fraction), for various size fractions (−106 + 75, −150 + 106, −212 + 150, −420 + 212 µm at 1300 °C and 11.3 bar), and density fractions (<1.3, 1.3–1.6, >1.6g/cc for the −106 + 75 µm at 1300 °C and 11.3 bar) of Pittsburgh No.8 bituminous coal using a high-pressure, high-temperature flow reactor (HPHTFR) in a equimolar mixture of CO2 and N2. Chars were characterized for conversion, morphology, thermal swelling ratio, and reactivity using ash tracer technique, oil immersion microscopy, tap density technique, and a thermogravimetric analyzer, respectively, and the results were statistically analyzed to determine for effects by feed particle density, feed particle size, temperature, and pressure. The results showed that the conversion was most affected by temperature, followed by feed particle size, pressure, and feed particle density. In the case of structural characteristics (i.e., thermal swelling ratio and group-I char concentration), feed particle density affected group-I concentration, while both feed particle size and feed particle density affected thermal swelling ratio. Variation in vitrinite content and fragmentation affected the thermal swelling ratio and group-I char concentration. In the case of intrinsic reactivity, particle density showed the largest effect, followed by temperature, particle size, and pressure. An increase in reflectance and temperature was found to inversely affect intrinsic reactivity.

Constructive and regime parameters of horizontal impact crusher of grain materials

In order to ensure the best digestibility of feed, all the nutrients included in their composition should be given to animals in crushed form. Particle size of feed is different for all species and age categories of animals. The most common “shock” crushers give up to 30% of the dust fraction and up to 20% of the underground one. Nowadays, impact and centrifugal-rotor grain crushers that use a “slice-chipping” are the most effective ones. The small-sized horizontal impact crusher, which constructive and technological scheme of grinding is fixed in the patents of the Russian Federation, was made for carrying out experiments. The quality of the grinding process was assessed by three different indicators (the degree of grinding, the grinding module and the actual effectiveness of the process). Data on joint and separate grinding of wheat, barley, oats and corn were obtained. The conducted multifactorial experiment showed that the proposed design of the impact crusher allows obtaining up to 98% of the finished product balanced by the particle size at specific energy costs up to 2 WH/kg and productivity up to 260 kg/h. The most rational design and operating parameters of the horizontal impact crusher for various types of grinding were established on the basis of existing standards, zootechnical requirements and the latest scientific research. The developed horizontal impact crusher can be used instead of the widely used small-sized hammer mills, since, in comparison with them, its specific energy consumption is reduced to 50%.

Hydrocyclone classification control

An overview of the classification systems in hydrocyclones in the copper ore enrichment departments at KGHM Polska Miedź SA was presented. In recent years, IMN has been conducting an investment - replacing hydrocyclones with modern HC hydrocyclone solutions - manufactured by ZAM Kęty and IMN. The results of implementing modern hydrocyclones are presented. The important issue is to define relation between values of pressure and/or hydrocyclone feed density and cut point achieved in these conditions for chosen classification node By disposing this relation, implemented to classification monitoring system is possible to maintain cut point value within the range ± 5 % of assumed value by preserving acceptable feed variation in industrial conditions: - change of suspension density ± 20 % in ratio to assumed value, - change of feed particle size d80 ± 15 % in ratio to assumed value.

Impact of corn particle size on nutrient digestibility varies depending on bird type

The interaction between bird type (broilers and layers) and corn particle size (fine, medium, and coarse) on the coefficient of apparent ileal digestibility (CAID) of DM, nitrogen (N), starch, fat, gross energy (GE), calcium (Ca) and phosphorus (P), and AMEn was investigated in a 2 by 3 factorial study of 6 dietary treatments. Whole corn was ground in a hammer mill to pass through screen sizes of 2.0, 5.0, and 8.0mm for fine, medium, and coarse grades, respectively. A corn-soybean meal diet, mixed using the same batch of ingredients, was fed to both bird types. Titanium dioxide was included in all diets for digestibility measurements. 35-day-old Ross 308 male broilers and 59-wk-old Hy-Line Brown layers were used in this study. For each bird type, 108 birds of uniform body weights were accommodated in 18 replicates (6 replicates per particle size and 6 birds per replicate). The treatment diets were offered ad libitum for 7 d prior to the collection of ileal digesta. A bird type by particle size interaction was observed (P < 0.001) for the CAID of DM, starch and GE. In broilers, CAID of DM, starch and GE was unaffected by particle size, whilst in layers, increasing the corn particle size to medium and coarse resulted in a greater (P < 0.05) CAID for DM, starch and GE compared to fine particles. The CAID of N and fat was greater (P < 0.05) in broilers than layers and the opposite was observed (P < 0.05) for Ca and P. Regardless of bird type, coarse and medium-ground corn resulted in a greater (P < 0.05) Ca digestibility compared to finely-ground corn. Overall, broilers had a greater digestibility of nutrients than layers, except for Ca and P. Feeding medium and coarse corn particles benefited the CAID of DM, starch and GE in layers, suggesting that digestive system in these birds is probably more sensitive to feed particle size than broilers.

Effects of dietary particle size and fiber source on nutrient digestibility and short chain fatty acid production in cannulated growing pigs

The objective of this study was to evaluate the effects of different feed particle sizes and fiber sources on nutrient digestibility and short chain fatty acids (SCFA) concentration in different intestinal segments of pigs. Eighteen barrows with T-cannula in the distal ileum were randomly allotted to a 3 × 2 factorial arrangement with 3 different high-fiber diets including corn bran (CB), sugar beet pulp (SBP) and soybean hulls (SH), and 2 different feed particle sizes. The experiment contained 2 periods, and each period lasted for 15 days, including 10 days for diets adaptation, 3 days for fecal collection, and 2 days for ileal digesta collection. The results indicated that coarse diets decreased (P < 0.05) the apparent ileal digestibility (AID) of gross energy (GE), dry matter (DM), organic matter (OM), total dietary fiber (TDF) and insoluble dietary fiber (IDF), but tended to increase (P < 0.10) the hindgut disappearance of GE. Feed particle sizes did not affect the apparent total tract digestibility (ATTD) of dietary nutrients except for ether extract (EE), the AID of amino acid (AA) and SCFA concentrations in ileal digesta, but fiber sources had significant effects on (P < 0.05) the AID, ATTD and hindgut disappearance of most nutrients in diets and the fecal SCFA concentrations. Moreover, there were interactive effects (P < 0.05) between particle sizes and fiber sources on the hindgut disappearance of fiber fractions. Coarse CB diets increased (P < 0.05) the hindgut disappearance of TDF, soluble dietary fiber (SDF), IDF, neutral detergent fiber (aNDF), acid detergent fiber (ADF) and cellulose, but the different particle size of SBP and SH did not affect the hindgut disappearance of TDF, ADF and cellulose. In conclusion, particle size mainly affected the ileal digestibility of nutrients and fiber fractions in pigs, but had few effects on their whole gastrointestinal digestibility, and these influences varied among different dietary fiber sources.

High-pressure grinding rolls: model validation and function parameters dependency on process conditions

A model for High Pressure Grinding Rolls (HPGR) was developed in this work based on the widely used Population Balance Model (PBM). This approach uses a variety of different functions one of which is the breakage distribution function. The methodology to determine the function parameters is presented and using these values, the model was compared with real processed materials from an HPGR pilot plant, with tungsten ore as the test material. The results of the model parameter determination, and the product of the comminution in the HPGR, showed the dependency of material breakage on the material characteristics, and on the operative and process conditions. The model presented is reasonably robust, showing less error than the 3.0 Root Mean Square Error when compared with a heterogeneous feed particle size distribution material. The operational gap was also studied, and its dependency on the feed particle size, porosity, moisture, and specific pressing force was proven.

Examples of vibratory crushers applications in crushing technological lines

Abstract Very fine crushing of hard and very hard materials, to product of particle size less than 2-4 mm at feed particle size of 50-200 mm, requires a very large energy inputs. This is mainly because of the need for at least three or even four degrees of crushing, containing: jaw, cone or impact crushers. One of the methods of reducing the amount of energy expended on the crushing process is reducing the number of crushers in technological line. By replacing a large number of less effective crushers with fewer machines but characterized by higher crushing efficiency we can gain considerable savings in investment and operating costs. This is possible by using crushers capable of obtaining much greater degrees of fragmentation than the aforementioned, that is vibratory crushers. The paper includes the systematic of currently used vibratory crushers, their mechanical diagrams, descriptions of the construction and operation, and basic technical parameters as well as examples of crushing technological lines utilizing vibratory crushers.

Influence of feed particle size and feed form on productive performance, egg quality, gastrointestinal tract traits, digestive enzymes, intestinal morphology, and nutrient digestibility of laying hens reared in enriched cages.

A total of 640 Lohmann LSL hens were randomly allotted to 4 dietary treatments arranged in 2 × 2 factorial with 2 feed particle sizes (fine and coarse) and 2 feed forms (mash and crumble). The 2 particle sizes were achieved by grinding whole corn and wheat in the hammer mill to pass through 4- and 8-mm sieves. The laying hen diet was isonutritive, and each diet was fed to 8 enriched cages of 20 hens from 21 to 52 wk of age. Screen size and feed form did not affect feed intake, egg production, egg weight, egg mass, and quality traits of the eggs, except for yolk color score, which decreased with crumbling of the feed. Feed conversion ratio was greater (P < 0.01) in hens fed the coarsely ground diet than in hens fed the finely ground diet. Crumbling the feed increased (P < 0.01) feed intake and feed conversion ratio compared to those after mashing. The relative weight of the liver and length of the small intestines were greater (P < 0.05) in hens fed crumble than in hens fed mash. Finely grinding cereals decreased (P < 0.01) the pancreas and gizzard weight compared to those after coarse grinding. The pH of digestive organs showed significant responses to feed form. Crumbling resulted in increased (P < 0.01) pancreatic activities of amylase, while lipase secretion was not affected by the manipulations in screen size and feed form. Ileal villus measurements (villus height, villus height/crypt depth ratio, villus surface area) were greater (P < 0.01) in hens fed crumble than in hens fed mash, whereas particle size had no effect. Total tract digestibility coefficients of crude ash and ether extracts were improved narrowing screen size from 8 to 4mm. Data illustrated that grinding cereals to pass through a 4-mm screen could improve the efficiency of feed conversion. However, feeding crumbles provided no benefit to productive performance and egg quality, although the absorptive capacity of laying hens increased.

Influence of the particle size and form of feed on growth performance, digestive tract traits and nutrient digestibility of white egg-laying pullets from 1 to 112 D of age.

The influence of the grinding and physical form of diets on growth performance, gastrointestinal tract (GIT) development and nutrient digestibility was studied in layer pullets from hatch to 112 d of age. Diet formed a 2 × 2 factorial with 2 hammer mill screen sizes to grind cereals (4 and 8 mm) and 2 forms (mash and crumble). A total of 864 1-day-old layer chickens were randomly assigned to 1 of the 4 treatment groups with 8 replicates (27 birds per replicate). Cumulatively, pullets fed crumbles consumed less feed (P < 0.05) and had better feed conversion ratio (FCR; P < 0.01) than those fed mash. Coarse grinding cereals (CG) improved FCR (P < 0.05) without significant change in cumulative feed consumption compared to that of fine grinding (FG). With regard to body weight gain (BWG), pullets benefited from crumbles from 1 to 56 d of age (P < 0.01). There were interactions (P < 0.05) between screen size and feed form in relation to FCR (1 to 28 d) and overall BWG. At 112 d of age, the relative weight (RW, g/100g body weight) of the crop, gizzard, pancreas, and liver of crumble-fed birds were lower (P < 0.05) than those for birds fed mash. Pullets fed coarsely ground feed had higher RW of the crop, proventriculus, gizzard, liver, and caecum compared to those fed finely ground feed. Compared to mash feeding, pullets fed crumbles increased (P < 0.05) total tract digestibility of ether extract and crude protein and the activities of pancreatic amylase and lipase. Digestibility of ether extract (P < 0.05) and pancreatic amylase activity (P < 0.01) were higher in birds fed a CG diet than in birds fed the FG regimen. Regarding the nutrition of egg-laying pullets, crumbles might be preferred to mash feed when the main objective is to improve FCR. Data also suggested that cereals used for pullet feed can be ground more coarsely than is in current practice.

Case report

An important role of the dairy consultant is to increase the profitability of their clients. Current and comprehensive production, nutrition, and financial records that can be analyzed daily are essential to track the effect of management changes on production and profitability. This paper uses a case study to describe the effect of changes in ration formulation and feed particle size on feed intake, feed costs, milk production, and profitability.

Increasing Average Feed Particle Size During the Starter Period Maximizes Ross × Ross 708 Male Broiler Performance

SUMMARY Recent research in our laboratory demonstrated that average particle size of feed from 0 to 14 d influenced overall (0 to 46 d) performance. However, optimal starter average feed particle size has not been identified and represents an important void, as this is a critical stage in a broiler's lifecycle. Therefore, 2 experiments were conducted to evaluate the effects of average particle size on 0 to 14 d broiler performance in an effort to determine the optimal average particle size. Both experiments utilized Ross × Ross 708 male broiler chicks that were provided diets varying in average feed particle size from 1,202 to 2,172 μm (Experiment 1) or 1,174 to 3,736 μm (Experiment 2). Performance variables were analyzed with a randomized complete block design using one-way ANOVA. Improvements were most apparent for FCR with an associated 0.03 improvement in both experiments when broilers were provided feed of 1,760 or 2,172 μm (Experiment 1) or larger than 2,257 μm, compared to those receiving smaller average feed particle sizes (Experiment 2). Additionally, a 30 g improvement for ending BW and BW gain was demonstrated in Experiment 2 for broilers receiving ≥2,800 μm. However, linear relationships for 0 to 14 d FCR, ending BW, and BW gain for Experiments 1 and 2 demonstrate that the optimal particle size may not have been achieved during these experiments. Therefore, future research should focus on further expanding the range of particle sizes tested (beyond 3,700 μm) from 0 to 14 d to identify the optimal average feed particle size during this growth phase.

Effects of Feed Particle Size and Hydro-Thermal Processing Methods on Starch Modification, Nutrient Digestibility and the Performance and the Gastrointestinal Tract of Broilers.

Simple SummaryTechnological benefits of feed processing methods are well defined but not their benefits and disadvantages for broiler feeding. The current study tested the impact of feed particle size and various hydro-thermal processing methods (HTPM) on feed value, broiler performance and alterations of the digestive tract. It was shown that HTPM influences physico-chemical characteristics of the feed including starch modifications. The compaction process during pelleting contributes to the reduction of feed wastage and selection. However, the high daily feed intake caused by pellet feeding is also a main risk factor for proventricular dilatation.Influences of feed particle size (coarse, fine) and hydro-thermal processing methods (HTPM) (without–non-compacted feed, pelleting, expanding and pelleting) on feeding value and the performance and digestive tract of 624 broilers were studied. HTPM increased the starch disintegration of feed. Starch disintegration and electron microscopy indicated the highest degree of starch modification in expanded and pelleted feed. HTPM affected ether extract digestibility (p < 0.05). A grinding-by-HTPM interaction was found in case of crude protein digestibility (p = 0.008). Non-compacted feed reduced daily feed intake (DFI) and body weight gain and increased the feed to gain ratio compared to compacted feeds (p < 0.001). Compacted feeds increased proventricular size and the risk of Isthmus gastrici dilatation compared to coarsely ground non-compacted feed, except for finely ground expanded and pelleted feed. Finely ground feed reduced proventricular weights compared to coarsely ground feed and pelleted feed compared to other feeds. Non-compacted feed increased gizzard weights compared to compacted feeds. Relationships between proventricular size and Isthmus gastrici dilatation and the DFI were detected. Summarizing, the beneficial effects of pelleted feed were mainly based on the reduction of feed wastage and selection. However, the high DFI caused by pellet feeding is also a main risk factor for proventricular dilatation.

Effect of mineral particle size on froth stability

ABSTRACT Mineral particles offer an added stability to three phase froths, in addition to the stability imparted by frothers. The ability of particles to influence froth stability is particle size dependent. Knowledge of the quantitative effect of particle size on froth stability is essential for froth flotation model development and prediction. This study investigated the extent to which discrete particle size fractions, as well as mixtures of particle size classes, affect the stability of three phase froths in a synthetic pyrite-quartz ore. A novel bench-scale continuous column flotation cell was used to assess froth stability and metallurgical performance. Results obtained show that froth stability decreases as a function of increasing feed particle size. When particle size is transformed to surface area, a linear relationship between froth stability and particle specific surface area is obtained. The effect on flotation performance is reflected by an increase in valuable mineral recovery as froth stability increases.

Effects of exogenous fibrolytic and amylolytic enzymes on ruminal fermentation and performance of mid-lactation dairy cows

Lactation diets are composed mostly of carbohydrates that are not fully fermented by rumen microbes. The aim of this study was to evaluate exogenous fibrolytic (Fibrozyme, Alltech Inc., Nicholasville, KY) and amylolytic (Amaize, Alltech Inc.) enzymes on nutrient intake, sorting index, total-tract apparent digestibility, ruminal fermentation, nitrogen utilization, milk yield, and composition of dairy cows in mid-lactation. Thirty-two multiparous Holstein cows (181 ± 35 d in milk, 571 ± 72.7 kg of body weight, and 29.6 ± 5.24 kg/d of milk yield at the start of experiment) were blocked according to milk yield and randomly allocated to treatments in a 4 × 4 Latin square design. Treatments were (1) control, basal diet without exogenous enzymes; (2) fibrolytic enzyme (FIB), dietary supplementation of Fibrozyme at 12 g/d (51 IU of xylanase activity/kg of diet dry matter); (3) amylolytic enzyme (AMY), dietary supplementation of Amaize at 8 g/d (203 fungal amylase units/kg of diet dry matter); and (4) both fibrolytic and amylolytic enzymes (FIB+AMY) added at the same dose of the individual treatments. Enzyme products were added to the concentrate during its preparation (once a week). The supply of FIB and AMY had no effect on nutrient intake and digestibility. However, an interaction effect was observed on sorting index of feed particle size between 8 and 19 mm. Amylolytic enzyme increased the sorting for feed particles between 8 and 19 mm, only when fed without FIB. In addition, AMY decreased the sorting for feed with particle size greater than 19 mm. An interaction effect was observed between FIB and AMY for ruminal butyrate concentration and N excretion. Amylolytic enzyme increased ruminal butyrate concentration in cows treated with FIB. Further, FIB decreased milk protein production and feed efficiency only in cows not fed AMY. Amylolytic enzyme reduced urinary N excretion. Exogenous enzymes had no effect on milk production and composition of dairy cows. This study lacks evidence that fibrolytic and amylolytic enzymes can affect nutrient digestibility, ruminal fermentation, and performance of mid-lactation cows.

Effects of feed form and particle size, and pellet binder on performance, digestive tract parameters, intestinal morphology, and cecal microflora populations in broilers

This study was conducted to assess the effects of feed form (FF), particle size (PS), and pellet binder (PB) on performance, digestive tract parameters, intestinal morphology, and cecal microflora populations in broiler chicks. Two FF (mash and pellet), two feed PS (fine and coarse), and two levels of PB (0 and 3%) were evaluated in a completely randomized design with a 2 × 2 × 2 factorial arrangement of treatments. A total of 256 one-day-old male Ross 308 chicks were allocated into 8 treatments consisting of 8 replicates (4 birds/cage) with equal weight from 25 to 42 d of age. The results showed a three-way interaction among FF, PS, and PB for growth performance in broilers. The growth performance parameters were significantly improved by feeding the pellet-coarse PS-3% PB diet in comparison to the other treatments (P < 0.05). Birds fed pelleted diets had lower relative weight of the gizzard and pancreas, goblet cell (GC) number of the duodenum, crypt depth (CD) of the jejunum, higher villus height (VH) of the duodenum, and cecal spore-forming bacteria population (P < 0.05). Coarse PS resulted in lower jejunum CD and higher cecal count of lactic acid bacteria (LAB) and spore-forming bacteria (P < 0.05). Adding PB significantly improved pellet durability index (PDI) (P < 0.05). In addition, coarse PS-3% PB diets had higher pellet hardness. Also, adding PB to diets significantly (P < 0.05) decreased cecal spore-forming bacteria population. Pellet-coarse PS-3% PB diets fed broilers had a lower (P < 0.05) cecal Clostridium spp. bacterial population. The main factors had no significant effect (P > 0.05) on cecal Coliform spp. levels. Birds fed pellet-3% PB diets had higher VH:CD ratio both in the duodenum and jejunum, and those fed mash-3% PB diets had significantly (P < 0.05) lower VH in the jejunum than other treatments. Overall, pellet-coarse PS-3% PB diets improved growth performance through the positive changes on intestinal morphology of broilers under short-term conditioning (STC).

Role of Feed Processing on Gut Health and Function in Pigs and Poultry: Conundrum of Optimal Particle Size and Hydrothermal Regimens.

The aim is to give an overview of available literature data on the role of feed processing on gut health and function with specific focus on particle size and hydrothermal processing. In addition, influence of feed processing on efficacy of exogenous feed enzymes will be discussed. The current feed processing technologies are such that ingredient choices and diet form are refined to improve feed intake and nutrient utilization efficiency. Finer feed particle size enables optimal nutrient utilization and enhances animal performance due to increased surface area allowing better contact with digestive enzymes. Moreover, adequate diminution of feed ingredients is beneficial to feed manufacturing processes such as mixing and hydrothermal treatments including pelleting, extrusion, and expansion. However, emerging trends in consumer and regulatory demands for restriction or cessation of animal production practices such as use of antimicrobial growth promoters are challenging current approaches to feed processing. There is limit as to the fineness of the particle size, as very fine particles negatively affect gut health due to higher incidences of stomach ulceration in pigs and gizzard dysfunction in poultry. Coarse particle size increases stomach and hindgut acidification which may be beneficial in controlling proliferation of enteric pathogens such as salmonella and E. coli. Optimal particle size could be designed in the grinding process using roller or hammer mill. However, since most commercial pigs and poultry diets are subjected to hydrothermal processes, additional reduction of feed particle size is inevitable. The need to achieve high physical quality and to reduce potential levels of feed-borne pathogens such as Salmonella has led to the application of relatively high conditioning temperatures during conventional hydrothermal processes, a practice that does not favor high nutrient utilization and stability of heat sensitive feed additives such as feed enzymes. Therefore, with evolving pig and poultry production practices, the regimens for feed processing will no longer be appreciated only in terms of optimizing nutrients utilization, but also in terms of impact on feed hygienic status, efficacy of feed additives, animal health, and food safety.

Avian Liver: The Forgotten Organ.

Simple SummaryThe liver is a multi-purpose organ, with involvement in bile secretion, and lipid, carbohydrate and protein metabolism, as well as a number of other metabolic functions. This organ can adapt easily to changes in feed and the environment. Being at the centre of a number of digestive, metabolic and productive activities, it is essential to have a better understanding of this organ and the factors affecting liver functionality.Despite having huge responsibilities in avian species, published reports on the influence of dietary factors and other possible constraints on the size, development and function of liver are limited. Consideration of the factors that could influence and alter liver function is therefore of critical relevance. In the current review, aspects of liver structure and function, and the influence of feed restriction, anti-nutritional factors, structural components and feed additives on liver are discussed. Effects of feed technology techniques such as thermal treatment and pelleting, feed particle size and whole grain feeding on the liver are also reviewed. A discussion of lipogenesis and lipid storage in poultry is presented to provide a better understanding and to differentiate the normal pathways of lipid metabolism from abnormal (i.e., disordered) pathways. The liver is the main site of fat synthesis in poultry, but under certain conditions, excessive fat can accumulate in the liver and cause problems. Factors contributing to the fatty liver syndrome are also examined.