Effect Of Dietary Particle Size Research Articles

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.

Assessment of the effect of dietary particle size on gastrointestinal permeability

Assessment of the effect of dietary particle size on gastrointestinal permeability

Evaluation of the effect of dietary particle size on gastric ulceration

Evaluation of the effect of dietary particle size on gastric ulceration

An investigation into the effect of dietary particle size and pelleting of diets for finishing pigs

The aim of the study was to investigate the effects of feed form (meal or pellets) and dietary particle size profile (fine or coarse) in a 2×2 factorial design on finishing pig performance and nutrient digestibility. A simple cereal soya-based finishing pig diet was formulated to provide 13.6MJ/kg digestible energy (DE) and 167g/kg crude protein (CP). The coarsely ground diets were made using 2×14mm+4×10mm screens and 6×4mm screens were used to produce the finely ground diets. Diets were then pelleted or not. The effect of feed form and particle size was tested on pig performance (20 pigs per pen, 8 replicates per treatment) and nutrient digestibility (8 pigs/replicates per treatment) in two separate trials. Data were analysed by Analysis of Variance (ANOVA) using Genstat Version 14.0 according to the 2×2 factorial design. There was no significant interaction (P>0.05) between particle size and feed form. However, the ADG and feed conversion ratio (FCR) of pigs between 18 weeks of age and finish was significantly improved (P<0.05 and<0.001, respectively) when diets were in pellet form (990g/day and 2.79, respectively) compared with when diets were in meal form (940g/day and 3.01, respectively). Pigs offered the finely ground diets also had a higher ADG (989g/day, P<0.05) (between 18 weeks and finish) and a better FCR (2.82, P<0.01) than pigs offered coarsely ground diets (941g/day and 2.98, respectively). Overall FCR between 12 weeks of age and finish was improved by 5.5% when diets were pelleted (P<0.001) and by 3% when diets were finely ground (P<0.05). Pelleting of the diet significantly improved dry matter (DM) digestibility and DE content (both P<0.05) and tended (P<0.1) to improve energy digestibility and ash digestibility. Reducing the particle size of the diet significantly improved CP digestibility (P<0.05) and tended (P<0.1) to improve DM, energy digestibility and digestible energy content. Nitrogen excretion was reduced (P<0.05) by 10% when pigs were offered diets in pellet form compared to meal form. There was no effect of feed form or particle size (P>0.05) on stomach ulceration. Overall, the results suggest a cumulative effect of feed form and particle size on FCR, nutrient digestibility and DE content of the diet since these parameters were optimized when pigs were offered a pelleted diet with a fine particle size profile but were poorest when meal diets with a coarse particle size profile were offered.

Effects of alfalfa hay particle size in high-concentrate diets supplemented with unsaturated fat: Chewing behavior, total-tract digestibility, and milk production of dairy cows

This study evaluated the effects of increasing the physically effective neutral detergent fiber (peNDF) intake of lactating dairy cows fed high-concentrate diets supplemented with unsaturated fat on intake, eating behavior, diet sorting, chewing activity, total-tract digestibility, and milk production and composition. Diets contained 24% alfalfa hay (AH), 16% corn silage, 58% concentrate, and 2% yellow grease [dry matter (DM) basis], and dietary peNDF content was increased by varying the particle size (PS) of the AH. Nine multiparous cows averaging 87.8±14.8d in milk and weighing 653±53kg were randomly assigned to a triplicate 3×3 Latin square. During each 21-d period, cows were offered 1 of 3 total mixed rations that varied in PS of AH: fine, medium, and long, with a geometric mean particle length of 3.00, 3.57 and 3.87mm, respectively. Increasing PS quadratically affected DM intake (DMI; 24.7, 25.4, and 23.7kg/d, for fine, medium, and long, respectively), but cumulative DMI at 2, 4, and 6h after feeding was similar across treatments, averaging 23.4, 35.6 and 46.4% of total DMI for the 3 time points, respectively. Increased peNDF intake did not affect feed sorting, but increased daily eating time, and eating and total chewing time per kilogram of DMI. Daily rumination time exhibited a quadratic response, with highest rumination time for the medium diet. Dietary PS had no effects on digestibility in the total tract, but we observed, for fine, medium, and long diets, quadratic responses in milk production (41.5, 43.3, and 40.4kg/d), 4% fat-corrected milk production, and milk protein yield. Milk fat content decreased linearly with increasing PS, but milk fat content and fat:protein ratio were low for all treatments, likely due to adding unsaturated fat to a diet containing a high level of nonfiber carbohydrates (42.2% of DM). The composition, degree of saturation, and total conjugated linoleic acid content of fatty acids in milk fat were not affected by the change in peNDF content of the diet. The study indicates that a moderate increase in the PS of AH in diets containing unsaturated fat elevates peNDF intake and increases chewing activity, DMI, milk yield and milk fat production. However, the effects of dietary PS were quadratic, with maximum DMI and milk production observed with diets supplying 24% dietary peNDF (measured as the proportion of the ration retained on sieves >1.18mm multiplied by dietary neutral detergent fiber content; DM basis).

Effect of dietary particle size and carbohydrase and/or phytase supplementation on nitrogen and phosphorus excretion of grower pigs

The effect of dietary particle size and enzyme supplementation on N and P excretion were investigated in a 3 × 2 × 2 factorial arrangement, with three particle sizes (400, 700, or 850 μm), two levels of a carbohydrase cocktail [0 or 444 added units (U) β-glucanase plus 1385 added U xylanase kg-1 diet], and two levels of phytase (0 or 374 added U phytase kg-1 diet), for a total of 12 dietary treatments. Diets (70% barley, 25% peas) were formulated to contain 3.25 Mcal digestible energy (DE) kg-1, 1.6 g digestible lysine Mcal-1 DE, and 1.2 g kg-1 available P. Sixty pigs (25.3 ± 1.4 kg) had restricted access (3 × maintenance DE) to feed, and five individual pig observations for each of the 12 mash diets were obtained. Reducing particle size from 700 to 400 µm reduced total P excretion 12% and increased P digestibility and retention 15% (P &lt; 0.05), while phytase reduced total P excretion 28% and increased P digestibility and retention 42% (P &lt; 0.01). Reducing particle size from 850 and 700 to 400 µ m decreased total N excretion 4 and 7%, respectively (P &lt; 0.05). Carbohydrase did not affect P digestibility or excretion (P &gt; 0.10), but increased digestibility of N and energy (P &lt; 0.05). Carbohydrase interacted with particle size for energy digestibility (P &lt; 0.01) and with phytase for N and energy digestibility (P &lt; 0.05). Particle size affected N excretion and energy digestibility more than enzyme supplementation, while phytase affected P excretion more than particle size, suggesting that particle size reduction and phytase supplementation are effective to reduce nutrient excretion of grower pigs. Key words: Particle size, carbohydrase, phytase, pig, nitrogen, phosphorus

Effect of dietary particle size and nutrient supply on energy digestibility and nitrogen excretion in ileal cannulated grower pigs

Diets with two particle sizes (600 and 900 µm) and two nutrient supply levels [digestible energy (DE)-limiting and amino acid (AA)-limiting; 2.8 and 1.8 g digestible lysine Mcal-1 DE, 3.15 and 3.40 Mcal DE kg-1, respectively] were used. Eight ileal cannulated pigs (25 ± 2 kg) had restricted access to feed (3 × maintenance DE) for three periods (N = 6 per diet). Reducing particle size from 900 to 600 µm did not alter urinary or total N excretion (P &gt; 0.10), reduced faecal N excretion 11%, increased total-tract digestibility of N and energy 3%, and increased ileal digestibility of N 9% and energy 11% (P &lt; 0.05). Reducing particle size increased energy digestibility but did not reduce total N excretion. Key words: Particle size, pig, nitrogen, excretion, energy, digestibility

Particle size and heat treatment of barley in diets for early-weaned piglets

One hundred and twenty male piglets weaned at 20 days and weighing 5.7±1.0 kg were used in a 28-day trial to evaluate the effect of dietary particle size and heat treatment of barley on performance and total tract apparent digestibility. There were four dietary treatments: coarsely ground barley (4.5 mm screen); finely ground barley (2.5 mm screen); micronized and then finely ground barley (2.5 mm screen); and finely ground (2.5 mm screen) and then expanded barley. All the diets contained 500 g of barley issued from the same batch/kg. There were six replicates of five piglets per treatment. Total tract apparent digestibility of organic matter (OMD), energy (ED) and crude protein (CPD) were assessed from samples taken at 14 and 28 days from each replicate using chromic oxide as indigestible marker. No differences were found between results associated with screen sizes in the raw barley-based diets. Processing of barley caused an increase in starch gelatinization, a decrease in the proportion of large particles (>1.25 mm) and an increase in the proportion of fine particles (<0.16 mm; p<0.05), as compared with unprocessed barley. Piglets fed processed barley-based diets grew faster than piglets fed raw barley-based diets only in the first 14 days of experiment (232 vs. 204 g per day; p=0.04). Feed conversion was not modified by barley processing. Processed barley-based diets showed higher values for OMD, ED and CPD than raw barley-based diets, but only the difference for OMD approached significance (0.817 vs. 0.784; p=0.07). It is concluded that processing of barley improved piglet performance in the first 14 days post-weaning, and that no differences exist between processing techniques or grinding size of barley for any of the traits studied.

Use of tritiated water to assess, in vivo, the effect of dietary particle size on the mixing of stomach contents of swine.

Use of tritiated water to assess, in vivo, the effect of dietary particle size on the mixing of stomach contents of swine.

Effect of dietary particle size on lesion development and on the contents of various regions of the swine stomach.

Effect of dietary particle size on lesion development and on the contents of various regions of the swine stomach.

Gastric ulcers in swine. 4. Effects of dietary particle size and crude fiber contents on ulceration.

The effects of various nutritional factors on the development of gastric ulcers were studied in 3 experiments including 92 pigs. Coarsely ground soybean meal (10%) in the diet gave better protection than did finely ground soybean meal. Isolated soybean protein had no protective action. A watery extract of soybean meal offered some protection in 1 experiment, but had no effect in another. Coarsely ground barley straw included in the diet at 5 or 10% gave almost full protection against ulceration, whereas 2.5% gave only partial protection. Finely ground straw as 2.5% of the diet gave no protection. With increasing severity of the gastric lesions the gastric content became significantly more fluid.