Maize Particle Research Articles

Impact of maize particle size on egg production and egg quality of White Leghorns in early stage of production

The aim of the present study was to determine the effect of the maize particle size on the performance of layers. Five maize-soybean based diets were formulated with maize particle size of 4.0, 6.0, 8.0, 10.0 and 12.0 mm sieve size with five treatments (T1: 4.0 mm mash diet; T2: 6.0 mm mash diet; T3: 8.0 mm mash diet; T4: 10.0 mm mash diet; T5: 12.0 mm mash diet) fed from 20 to 28 weeks of age. Each treatment was replicated three times, with 10 birds in each replicate. The results showed no significant difference in average daily feed intake, live weight, hen day egg production percentage, egg mass and egg indices except for haugh unit, which was highest for the 4 mm screen size and lowest for the 12 mm screen size in layers from 20 to 28 weeks of age. FCR (g/g egg mass) was highest for T3 as compared to the average of other treatments not affected by either of the feeds. In conclusion, the size of the screen used to mill the grain had no impact on hen production within the range of the study. Furthermore, the decision to grind grains more coarsely than is already customary would be favourable for the environment and the economy because it would reduce the amount of energy, labour, and time utilised in feed mills.

Behavior of maize particle penetrating a sieve hole based on the particle centroid in an air-screen cleaning unit

Screening is an indispensable process for a combine harvester. To improve screening performance, the behavior of screened particles needs to be investigated. In this paper, kinetics models for a particle on a sieve were founded based on the particle centroid. Effects of buoyancy and the sieve movement on the motion of the irregularly shaped particle were quantified by MATLAB. Models for a particle penetrating a sieve hole after impacting the sieve hole were founded based on the particle centroid. It was beneficial for a particle to penetrate the sieve hole when the particle centroid was on the left of the impact point. CFD-DEM (Computational Fluid Dynamics and Discrete Element Method) was used to investigate the motion of particles at different stages of screening and the effect of airflow velocity above the sieve on the dispersion degree of particles. The results provide a theoretical basis to improve cleaning performance.

Maize particle size with the addition of wheat on zootechnical parameters in chickens

T. An experiment was performed to compare in the meal diets different particle sizes of corn, with and without the addition of whole wheat, on the performance of chicken broilers. 2 800 broilers, four particle sizes was compared; T1) 1175 µm, T2) 740 µm, T3) 541 µm, and T4) 398 µm, with and without the addition of whole wheat (5, 10 and 15%). Body weight (kg), feed consumption (kg), feed conversion ratio (kg/kg), and mortality percentage were evaluated at 7, 14, 21, 28, 35, 42 and 45 days. The gizzard total weight and relative weight was recorded at end of the study. The data recorded in each variable was analyzed by general lineal model for factorial design 4 x 2. At 45 days of age, T2 showed the highest body weight (p < 0.01), maintaining a similar conversion feed rate than T3 and T4, without effects (p > 0.05) in mortality rate; while the size of the gizzard was lower (p < 0.01) as the particle size decreased. The diets with the addition of whole wheat, showed higher body weights (p < 0.01), in relation to diets without addition, non significative effect (p > 0.05), was observed in the other parameters evaluated. A significative effect (p < 0.01) of the interaction of particle size 740 µm with the addition of the whole wheat was observed on the body weight at the end of the study, suggesting that this can be alternative for obtain best performance and save money by feed.

Influence of maize particle size on kibble quality, palatability and metabolizability of diets for the Blue-fronted Amazon parrot (<i>Amazona aestiva</i>)

Influence of maize particle size on kibble quality, palatability and metabolizability of diets for the Blue-fronted Amazon parrot (<i>Amazona aestiva</i>)

Broilers’ behavioural adjustments when submitted to natural heat stress and fed different maize particle sizes in the diet

AbstractSince behavioural adjustments are an important line of defence against thermal stress, either due to their energy efficiency or to efficiency at preventing overheating, we aimed to evaluate whether broilers fed different maize particle sizes adjusted their behaviour to deal with heat stress challenges. At several times a day, the behaviour of 220 naked neck broilers was evaluated. These broilers were fed with isonutritive diets containing maize with different geometric mean diameters (GMD): 605 and 2280 μm. The thermal environment was monitored during the experiment. Panting and open wings were the only behaviours that showed differences between the times of day (P < 0.05). However, GMD showed a significant effect on feed intake and panting (P < 0.05). The interaction between GMD and time of day was significant only on panting (P < 0.05). Although no daily variation was observed, the highest feed intake was observed in broilers fed the diet containing maize with a GMD of 2280 μm. Less than 5% of the broilers were observed drinking water during the day. Open wings was the behavioural adjustment most used by broilers from 10:00 h, and remained elevated until 14:00 h for both GMDs. The birds panted more when fed the diet containing maize with a GMD of 2280 μm. In conclusion, broilers adjust their behaviour to dissipate excess body heat from the environment and as a result of feed intake. Coarse particles of maize in the diet increase the thermal challenge of broilers since the environment also provides stressful thermal conditions.

Effects of alternative feed additives and flint maize grain particle size on growth performance, carcass traits and nutrient digestibility of finishing beef cattle

AbstractThe current study evaluated growth performance and digestion responses of finishing bulls fed diets containing 825 g/kg flint maize [dry matter (DM) basis] ground to medium (1.66 mm; MG) or coarse particle sizes (2.12 mm; CG), with added monensin (26 mg/kg; DM basis; MON) or a blend of essential oils (BEO) + exogenousα-amylase (AM; 90 mg/kg + 560 mg/kg commercial product, respectively, DM basis). In Expt 1, 256 Nellore bulls were blocked by initial body weight (BW) (360 ± 11.7 kg) and assigned to 48 pens in a 2 × 2 factorial arrangement of treatments. Effect of a maize particle size × feed additive interaction was not detected for final BW, DM intake (DMI), average daily gain (ADG) and feed efficiency. The DMI was greater for bulls fed BEO + AMv.MON. Final BW and ADG tended to be greater for bulls fed CG than MG maize. An interaction was detected for hot carcass weight which was 11 kg heavier for bulls fed BEO + AMv.MON in diets containing CG, but not MG particle size. In Expt 2, four ruminally cannulated Nellore steers were offered the same treatments as Expt 1, in a 4 × 4 Latin Square design. Intake of most nutrients was greater for steers fed CG than steers fed MG maize. In summary, feeding bulls CG maize increased growth performance and carcass characteristics compared with MG. The combination of BEO + AM resulted in heavier carcass weights compared with MON supplementation when included in diets containing CG maize.

Determination of the coefficient of rolling friction of an irregularly shaped maize particle group using physical experiment and simulations

The coefficient of rolling friction is an important physical property of a maize particle. It is difficult to obtain the value of this coefficient because of the irregular shape of maize particles. This paper describes an approach that combines the discrete-element method (DEM) and a physical test to determine the coefficient of rolling friction of irregularly shaped maize particles. A novel test platform was used to obtain the maize particle’s coefficient of restitution and the coefficient of static friction. EDEM software (DEM-Solutions, United Kingdom) was used to simulate the accumulation of maize particles on particles and on a zincified plate. The golden-section method was used to determine the range of the maize particle’s coefficient of rolling friction. A single-factor test was used to determine the relationship between the maize particle’s coefficient of rolling friction and their angle of repose. The results obtained from the EDEM simulation were compared with physical test results to determine the intergranular coefficient of rolling friction and the coefficient of rolling friction between maize particles and the zincified plate. Our study demonstrates that the angle of repose increases linearly with the coefficient of rolling friction of maize particles. The effect of the coefficient of rolling friction on the particle movement is studied. The physical verification test indicates that the obtained rolling friction of the maize particles is accurate. The findings of this paper provide a theoretical basis for maize-processing machine design and a discrete-element study of the motion of maize particles inside such machines.

Influence of maize particle size on the kinetics of starch digestion in the small intestine of growing pigs

The kinetics of starch digestion in the small intestine, nutrient utilisation and the performance of growing pigs that were fed diets containing maize of different particle sizes were evaluated. For the performance evaluation, 42 barrows and females (initial weight: 30.5 ± 1.78 kg) were used in a randomised block design with three treatments [maize with different geometric mean diameters (GMD) of 550, 700 and 850 μm] and seven replications. To evaluate the kinetics of starch digestion, one animal from each experimental trial was sacrificed. The small intestine was removed and separated into five equal parts. The starch digestibility in each segment was determined. To determine the total digestibility and nitrogen balance, 24 barrows (initial weight: 41.3 ± 4.72 kg) were housed in metabolism cages in a randomised block design with three treatments and eight repetitions. The animals that were fed diets containing maize of 550-μm GMD exhibited better (P = 0.008) feed conversion. However, the digestion of starch was gradual and variable among the degrees of grinding that were tested. There were higher (P = 0.008; 0.005 and 0.009) digestible energy, dry matter digestibility and nitrogen uptake in diets containing the maize ground to 550 and 700 μm in GMD. Thus, the smallest GMD of maize (550 μm) that was used in diets for growing pigs improves feed conversion. GMD of 550, 700 and 850 μm of maize were associated with rapid, intermediate and slow starch digestion, respectively.

Effect of feeding fine maize particles on the reticular pH, milk yield and composition of dairy cows

The particle size of cereal grains has been found to modulate the rate of passage from the rumen and the digestibility of starch and neutral detergent fibre (NDF), but few studies have examined its impact on reticular pH. The study aimed to evaluate the effect of feeding finely ground maize on the risk of ruminal acidosis, milk yield and composition. Twelve Holstein-Friesian cows were assigned to one of two experimental groups and fed according to a cross-over design. Diets were isoenergetic and isonitrogenous and were characterised by the same NDF and ADF, differing only in maize particle size. In the control diet (Ct), the maize meal was ground to 1.0 mm, whereas in the experimental diet, it was finely ground (Fg) to 0.5 mm. The pH and temperature of the reticulum were continuously measured in eight cows throughout the trial using indwelling sensors. Dry matter intake was higher in cows offered Fg diet than in Ct (19.0 vs. 20.3 kg/day; p = 0.067). However, milk yield (p = 0.855) and the 3.5% fat-corrected milk (FCM) (p = 0.724) did not show any differences between the diets. Casein (2.48 vs. 2.57%; p = 0.035) and crude protein (CP) (3.18 vs. 3.31%; p = 0.021) resulted higher in Fg. Similarly, starch digestibility increased in animals offered Fg diet versus Ct (0.94 vs. 0.98; p = 0.078). Among the reticular parameters, the Fg-fed cows spent a significantly higher time below the 5.5 pH threshold (15 vs. 61 min/day; p = 0.047) and had an average daily variation in reticular pH characterised by a lower nadir pH (5.95 vs. 5.72; p < 0.001) and a higher pH range (0.79 vs. 0.94; p = 0.003). In this study, grain particle size affected the risk of the onset of ruminal acidosis. Therefore, it should be carefully considered when formulating rations.

Different fibrous ingredients and coarsely ground maize affect hindgut fermentation in the pig in vitro but not Salmonella Typhimurium survival

The fermentation kinetics of both fibre choice and maize particle size were studied in vitro from the ileal contents of cannulated pigs given five different experimental diets. Additionally, in vitro batch systems were used to study the quantitative effect of fibre choice and maize particle size on Salmonella Typhimurium growth. Freeze-dried ileal effluents obtained from five cannulated pigs given the five experimental diets in a latin square were used as incubation substrates. The experimental diets consisted of: (1) a standard maize-based diet (ST) where all the ingredients were milled to pass through a 2.5-ml screen, (2) the same diet with the maize ground using a 4.0-ml screen (CG), (3 and 4) two diets in which the maize was partially replaced by (3) sugar beet pulp (80 g/kg; BP) or (4) wheat bran (100 g/kg; WB), or (5) a combination of 80 g sugar beet pulp and 100 g wheat bran/kg (diet HF). Results showed that substrate from BP and HF generated more gas than substrate from ST (P<0.001). In addition, short chain fatty acids production during the entire incubation period was higher (P=0.001) for all the substrates compared to ST substrate (P<0.001) where lower acetate and higher propionate, valerate and branched-chain fatty acids molar ratios were measured. The molar ratio of acetate was highest and the branched-chain fatty acids was lowest for substrates from diets that included sugar beet pulp. The butyrate molar ratio was lower for all substrates compared to the ST diet except for the WB diet. After 12 h of incubation, HF substrate presented the lowest ammonia (91.7 mg/l vs. 125.3 mg/l, P=0.014) and the highest purine bases concentration (0.28 μmol/ml vs. 0.22 μmol/ml, P=0.009). None of the substrates showed any inhibitory effect on Salmonella growth when the batch systems were inoculated with S. Typhimurium. In summary, under the in vitro conditions used, the changes in hindgut fermentation promoted by the inclusion of different fibrous ingredients or by different maize particle size did not produce an inhibitory effect on the growth of S. Typhimurium.

Influence of particle size and microbial phytase supplementation on the performance, nutrient utilisation and digestive tract parameters of broiler starters

The aim of the present experiment was to examine the interaction between particle size and microbial phytase supplementation on the performance, nutrient utilisation and digestive tract development of broiler starters fed maize-based diets. The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two maize particle sizes (medium and coarse) and two levels of phytase supplementation (without or with 500 phytase units/kg diet). The two particle sizes were achieved by grinding the whole maize in a hammer mill to pass through 3- and 7-mm screens, respectively. Broiler starter diets, based on maize and soybean meal, were formulated to meet recommended requirements for major nutrients, except phosphorus. Each of the four diets was fed ad libitum to six pens of eight male broilers each, from day 1 to day 21 post-hatching. Phytase supplementation increased (P &lt; 0.001) the feed intake and weight gain, and lowered (P &lt; 0.05) feed per gain in both medium and coarse particle size diets. Coarse grinding improved (P &lt; 0.05) weight gain, but had no effect (P &gt; 0.05) on feed intake and feed per gain. No interactions (P &gt; 0.05) between phytase supplementation and particle size were observed for any of the performance parameters. Phytase supplementation increased (P &lt; 0.001) ileal phosphorus digestibility and toe ash content of birds fed the medium particle size diet, but had no effect in those fed the coarse particle size diet. Apparent metabolisable energy and ileal digestibility of calcium and nitrogen were not influenced by particle size or phytase supplementation. The present findings suggest that the effectiveness of supplemental phytase on broiler performance is not influenced by the particle size of maize.

Effects of maize and lucerne particle size on ruminal passage rate, chewing activity of cows in midlactation

Effects of maize and lucerne particle size on ruminal passage rate, chewing activity of cows in midlactation

The effect of grinding and pelleting of wheat and maize on amino acids true ileal digestibility and endogenous losses in growing pigs

Abstract Two experiments were performed in order to test the effects of grinding and pelleting wheat (experiment 1) or maize (experiment 2) on amino acids (AA) standardized (SID) and true (TID) ileal digestibility. Basal ileal endogenous losses (IEL), used to calculate SID from apparent digestibility, were determined by feeding a protein-free diet. Total IEL required to calculate TID were estimated as the difference between total and dietary losses determined according to the isotope dilution technique using 15N-labeled crops. Wheat and maize were ground to compare two different mean particle sizes (d50 500 μm and 1000 μm). Then, a fraction of the 500-μm mash was further pelleted through two dies of different thicknesses (16 vs. 20 mm for wheat and 16 vs. 24 mm for maize), holes diameter 4 mm in both cases. Cereals were incorporated in 4 isoproteic diets either in mash form (fine vs. coarse mash) or in pelleted form (thin vs. thick die). In experiment 1, wheat was associated with rapeseed meal diets, while in experiment 2, maize was associated with soybean meal. The reduction of wheat particle size affected neither AA SID nor TID. In contrast, the pelleting treatment significantly improved protein and most AA SID and TID. In addition, total IEL of protein and several AA were significantly reduced when the thicker die was used. Numeric improvements of protein and AA SID were observed with reduction of maize particle size and this was associated with a significant decrease in total IEL so that TID was not modified. Further improvements of AA SID and TID occurred with pelleting of maize, without significant effect on IEL regardless of die thickness.

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.

Effect of sources of maize and maize particle sizes on the utilization of phytate phosphorus in broiler chicks

Two experiments were conducted to test the effects of sources of maize and maize particle sizes on the utilization of phytate P in broiler chicks fed on maize–soyabean meal diets deficient in P. In Experiment 1, maize from four consignments was ground separately using the same milling facility. Four maize–soyabean diets representing each maize source, and two control diets made of maize-starch–soyabean meal (maize starch control diet) and maize–soyabean meal-casein (casein control diet) were tested. The maize starch control diet was used to evaluate the ability of chicks to utilize phytate P when they were provided solely by soyabean meal. The casein control diet had similar amounts of total P as the diets containing the four maize sources, but part of the maize and soyabean meal was substituted with casein so that the diet contained greater amounts of available P and less phytate P. Experiment 2 was conducted on a 3×2 factorial arrangement, consisting of three diets each containing maize differing in geometric mean diameter (GMD), and two levels of dietary phytase at 0 and 600FTU/kg. Sources of maize significantly (p<0.05) influenced Ca, total P, and phytate P utilization, and the amount of ME derived from the diets. Only 0.248 of soyabean meal phytate P was utilized by the chicks fed on the maize starch control diet. Substituting part of the maize and soyabean meal with casein did not affect the total P utilization but reduced Ca utilization, possibly due to the binding of Ca in the gut with phytate P not utilized by the chicks. Maize particle sizes significantly (p<0.05) affected utilization of Ca, total P, and phytate P. The coarser the GMD (894 vs 573 and 484μm), the greater the utilization of these nutrients. There were no two-way interaction effects of particle sizes and phytase.