جستجوی مقالات مرتبط با کلیدواژه « اندازه ذرات » در نشریات گروه « علوم دام »

The aim of this study was to evaluate the effect of limestone particle size and phytase enzyme supplementation on production performance, egg quality traits, and coefficient of apparent digestibility of calcium of commercial laying hens. A total of 216 laying hens were randomly distributed in six treatments, and six replicates per each. The design consisted of a factorial arrangement of three particle sizes of limestone from the same source (fine (<0.5 mm), medium (0.5-2 mm) and coarse (2-4 mm)) and two phytase levels (0 and 300 (FTU)/kg) in a completely randomized design. Egg production and egg mass were not influenced by experimental diets. Phytase inclusion numerically increased egg weight in second (P=0.06) and whole trial period (20-26 wk, P=0.1). Fine and coarse particles of limestone increased shell thickness (P < 0.01), compared to medium particles, also phytase supplementation improved shell percent (P < 0.01). Fine and medium sizes of limestone resulted in a higher apparent digestibility coefficient of Ca compared to coarse size ((P < 0.0001),0.43, and 0.45 vs. 0.33). Diets containing medium limestone size showed lighter yolk color than those containing fine and coarse particles (P˂0.05). Medium size of limestone significantly increased digestibility of DM compared to fine and coarse particles. In conclusion, productive performance of laying hens did not respond to limestone particle size, however, fine and medium sizes of limestone through enhancing effect on Ca digestibility, is more suitable than coarse particles for practical applications in young layers.

This experiment was conducted in order to investigate the effect of dietary enzyme supplementation (DES) and wheat particle size (WPZ) on growth, microbial population and intestinal acidity and litter characteristics of Japanese quails using a 3×3 factorial arrangement in a completely randomized design with nine treatments each replicated 4 times with 20 quails per replicate. The experimental factors included three WPZ [2, 3 and 3/5 mm] and three levels of DES [Rovabio enzyme at 0, 200 and 400 ppm]. Through the whole experimental period, groups of birds received diets with 2 and 3 mm WPZ+400 ppm of DES showed significantly reduced feed intake compared to the groups with 3.5 mm WPZ without and with 200 ppm DES (p<0.01). Birds received diets with 2 and 3 mm WPZ+400 ppm of DES also showed better feed conversion ratio than those fed with 3.5 mm WPZ without enzyme supplementation (p<0.01). Lactobacillus counts increased significantly in quails fed diets with 2 mm WPZ and 400 ppm of DES in comparison to 3.5 WPZ without enzyme supplementation group (p<0.01). Birds fed diets with 2, 3 and 3.5 mm WPZ+400 ppm of DES had lower litter pH than those fed wheat-based diets without enzyme supplementation (p<0.01). Treatment of 2 mm WPZ+400 ppm of DES showed less litter moisture than those with 3 and 3.5 mm WPZ without enzyme supplementation (p<0.01). In conclusion, dietary inclusion of wheat grain at 2 mm diameter particle size supplemented by 400 ppm enzyme is recommended.

An experiment was conducted to evaluate the effect of particle size and feed form on growth performance, digestibility, and intestinal morphology of growing Japanese quails from 21 to 35 days of age. A total of 480 mixed Japanese quails were used in a completely randomized design with a 2×3 factorial arrangement, three feed forms (mash, crumble, and pellet) and two levels of particle size (fine, and coarse), with 6 experimental treatments, 4 replicates and 20 birds per each replicate. Birds consumed pelleted and crumbled feeds with coarse particle size showed significantly higher body weight gain, compared to the birds fed with mash feed with both coarse and fine grinding particle size(p<0.05). A significant increase in feed intake were detected in birds fed with pelleted form (p<0.01). Feed conversion ratio was significantly higher in quails fed with pelleted diets than mash and crumbled diets and also in fine particle size than coarse particles (p<0.01). Birds fed with pellets with higher particle size had significantly heavier gizzards (p<0.05). The length of villi was significantly higher in birds fed with pelleted and crumbled feeds (p<0.01). The highest percentage of dry matter and nitrogen digestibility were observed in birds fed with the mash form diet and also in coarse particle size diets (p<0.05). Based on the results, the use of crumbled diets with coarse particle size are recommended due to more weight gain compared to the mash diets and also better feed efficiency in compare to the pelleted diets.

This study was performed to assess the effects of offering wheat straw as free choice with different particle sizes on ruminal fermentation, blood metabolites and nutrients digestibility of Holstein dairy calves. Individually housed calves (n = 40, BW = 43.8 ±3.2 kg) were used in a completely randomized design and divided to four different treatments consisting of: 1) starter feed without wheat straw supplementation (control; CON), 2) starter feed + wheat straw with 1mm geometrical mean particle length (GMPL, Fine), 3) starter feed + wheat straw with 4mm GMPL (Medium), and 4) starter feed + wheat straw with 7mm GMPL (Long). Calves entered the trial on d 15, weaned on d 56 and the study ended on d 90 of age. After morning feeding, the ruminal pH were increased by offering forage only at 8 h on d 35 and 4 and 8 h on d 90 (P = 0.05). The total short chain fatty acids concentration (SCFAs), molar proportion of acetate and propionate were similar across treatments, however, the molar proportion of butyrate increased (P = 0.04) in forage supplemented calves compared with CON calves. Regardless of forage particle size, dry matter and crude protein digestibilities were increased in forage supplemented calves compared with CON calves (P = 0.05). Moreover, no differences were found for different geometrical mean particle length of WS. Overall, free-choice provision of wheat straw enhanced ruminal pH, apparent nutrient digestibility, and rumen development indicators (BHBA) in Holstein dairy calves.

This experiment was conducted to investigate the effect of wheat particle size and different levels of enzyme on performance, carcass traits, and small intestine morphologyof Japanese quails. A 3 × 3 factorial arrangement in a completely randomized design was used in nine experimental treatments replicated four times with 20 birds per replicate. The investigated factors were three wheat grain particle sizes (2, 3, and 3.5 mm) and three levels of dietary enzyme supplement (0, 200, and 400 ppm). The measured traits included: performance, carcass traits, and small intestine morphology. The results showed that the dietary enzyme significantly reduced feed intake and feed conversion ratio (P<0.01). The effect of wheat particle size on feed intake, body weight, and feed conversion ratio were also significant (P<0.01). The interaction effect of wheat particle size and enzyme affected significantly feed intake and feed conversion ratio through the experimental period from 7-35 days of age (P<0.01).Relative weights of proventriculus, gizzard, and liver were significantly reduced by enzyme supplementation (P<0.05). The relative weight of the breast significantly increased by dietary enzyme addition (P<0.01). Enzyme supplementation also significantly increased the villi length of the jejunum (P<0.01). In conclusion, dietary inclusion of wheat grain at 2 mm diameter particle size supplemented by 400 ppm enzyme is recommended.

Introduction:

 Barley is one of the cereal grains that used to supply energy in broiler diets, but high content of non-starch polysaccharides (NSP) such as β-glucans, has limited the application of it in poultry diets. It has been shown that NSP can increase intestinal viscosity, reduce litter quality, compromising the access of digestive enzymes to dietary components by protecting lipids, starch, and protein, and cause poor productive performance. Recent studies have shown the inclusion of moderate amounts of insoluble fiber or coarse particles in the diet increases the retention time of the digesta in the upper part of the gastrointestinal tract (GIT) (i.e., from crop to gizzard), improves the development and function of the gizzard, and increase the secretion of HCl in the proventriculus in broilers. The objective of this study was to determine the influence of supplementing insoluble fiber sources in different particle sizes on energy and protein efficiency ratios, intestinal morphology and welfare indicesin broiler chickens fed barley based-diets.

Materials and Methods:

 Ross 308 (n=308) were used in a completely randomized design with 7 treatments, 4 replicates and 11 chickens per replicate for 42 days. The dietary treatments included: a barley based- diet (control, CTL) or Sunflower hulls (SFH), Sugarcane bagasse (SB), and Wheat bran (WB) ground through a 1.0 (fine) or 3.0 mm (coarse) screen that were added to the control diet at 3.0%. The CTL diet included 3.0% fine silica sand as filler that was replaced by the same amount of insoluble fiber sources in the corresponding diets. The dry sieving method was used to determine the particle size distribution of diets. Body weight gain (BWG) and feed intake (FI) of each pen were recorded. Feed conversion ratio (FCR) adjusted for mortality and it was calculated by dividing FI with BWG for each period of the experiment (1-21 d and 22-42 d) in total period (1-42 d). The welfare indices were examined at 42 days of age. Litter moisture was measured on days 35 and 42 of the rearing period. For the purpose of small intestinal morphological studies, the digestive tract of slaughtered birds (two birds of each replicate) was removed at 42 days of age and from two small intestine sections including duodenum and Jejunum, two centimeter-long Isolated.

Results and Discussion:

 The results showed that different sources of insoluble fiber showed significant effect (p < 0.05) on energy and protein efficiency ratios during growth period (22-42 days of age) and whole experimental period (1-42 days of age). During the entire experimental period (1-42 d), dietary inclusion of SFH (coarse and fine) and WB (fine particle size) improved BWG as compared to the CTL diet (P < 0.05). Dietary inclusion of WB and SFH in both particle sizes (coarse and fine) and SB (coarse particle size) improved FCR as compared to the CTL diet from 1-42 d (P < 0.05). The villus height and villus height to crypt depth ratio in duodenum of treatments fed insoluble fiber with the exception of sugarcane bagasse with particle size of 1 mm showed significant increase (p < 0.05) in comparison to control diet. The number of goblet cells in jejunum of treatments fed insoluble fiber significantly decreased (p < 0.05) when compared to control group. The relative frequency of score two welfare indices was higher in control treatment. Reports have indicated that soluble and insoluble non-starch polysaccharides (NSp < /strong>) affect digestive organs and intestinal morphology of broilers. Coarse fiber and large particles may increase villi length in gastrointestinal tract. Therefore, increased villi length resulted in increased surface area for more absorption of nutrients. Currently, the control of litter moisture is a priority in the broiler industry to reduce productivity losses and minimize bird welfare issues due to footpad dermatitis (FPD), hock burn (HB), and ammonia production. Wet litter was found to increase FDP, HB, and breast irritations and reduce broiler performance. The inclusion of 3% fiber in the diet resulted in lower litter moisture content.

Conclusion:

 Overall, the results showed that dietary inclusion of three percent of different insoluble fiber sources improved energy and protein efficiency ratios, intestinal morphology, litter moisture and welfare parameters of broilers fed barley-based diet.

This study was conducted to evaluate the effect of corn particle size and different insoluble fiber sources on performance and carcass and gastrointestinal tract characteristics of broilers from 1 to 21 days of age. A total of 660 male broilers were used in a 2×3 factorial arrangement with 6 treatments and five replicates per treatment. The factors of interest were two corn particle sizes (2 and 6 mm) and three insoluble fiber sources (lignocellulose, rice hull, RH and sunflower hull, SFH). The main effect of fiber source was significant for the body weight gain (P<0.01) and feed conversion ratio, with SFH inclusion improved BWG (P<0.01) and FCR (P<0.01) compared to OH and lignocellulose. The supplementation of lignocellulose (P<0.05) and fine particles (P<0.01) resulted in higher carcass weight compared to other fiber sources and coarse particles, respectively. Feeding lignocellulose increased (P<0.01) the weight of the small intestine than the other two fiber sources. The Experimental treatments had no significant effect on the relative length of small intestinal segments. Coarse grinding of corn and SFH inclusion reduced gizzard pH when compared to fine grinding and lignocellulose inclusion, respectively (P<0.05). The Gizzard weight of birds fed a diet containing lignocellulose and SFH was significantly higher (P<0.01) those fed RH. Generally, the dietary inclusion of 3% SFH improves growth performance through improved weight and reduced pH of gizzard and can be practically used in the broiler industry.

To evaluate the effect of type (Rice Hull (RH) and Oat Hull (OH)), level (3 and 6 percent) and particle size (0.5 and 2 mm) of insoluble fiber on performance, carcass characteristics and intestinal morphology of chickens, 360 day-old male broilers (Ross 308), were use in a completely randomized design with 9 treatment and 4 replicate with 10 birds each, for 42 days. In the 29-42 days, broilers fed 6 percent with 0.5 mm RH had higher (P≤0.05) average daily gain, daily feed intake and lower feed: gain than control group. In fact, the 6 percent with 0.5 mm OH inclusion reduced (P≤0.01) abdominal fat and carcass performance as compared to control (P≤0.0`5). Results showed that broilers fed OH and RH had higher relative weight of gizzard and gallbladder than broilers fed the control diet (P≤0.05). Broilers fed RH had higher villus length than other treatment in the jejnum at 21 and 42 days of age and duodenum at 21 days of age (P≤0.01). In this experiment, the broiler fed 3 percent RH with 2 mm particle size had the highest epithelium width (P≤0.01) in the ileum section at 21 day of age. Therefore the results showed inclusion of 3 percent RH with 0.5 mm particle size to broiler diets may improve the growth performance and intestine morphology.

Inorder to evaluate the effects of four sources of fiber (soy hulls, barley hull, rice husk and corn husks) each with two particle size (with 1 and 2- mm of geometric mean) on performance, nutrient digestibility, some blood parameters, small intestine morphology and secum bacteria in broiler chicken, 540 Ross308 broiler male chicks from 1 to 42 days were used in a completely randomized design with a factorial arrangement 2×4, with nine treatments (one control treatment), four replications and 15 broilers in each replicate.Weight gain in the starter and finisher periods, feed intake during the finisher and the whole period, and feed conversion ratio in the growr, finisher and the whole period of breeding were affected the entire fiber source. The treatment with coarse barley hull had more weight gain, lower feed intake, and less conversion ratio (P<0.05). The most unfavorable feed conversion ratio observed in treatment containing rice husk. Crude protein (P<0.0493) and ether extract (P<0.0004) digestibility in corn husks fed diets was higher than other treatments. In duodenum, jejunum and ileum, the highest and lowest villus height were observed in barley hull treatment and control group, respectively (P <0.05). The depth of crypt was affected only in the jejunum and crypt diameter in all three parts of the intestine (P<0.05). The number of intestinal Lactobacilos in the chiks fed diets containing corn and barley hulls was significantly more than those fed with diets containing soya and rice hull. The fibers particle size had significant effect on E.Coli and coliform bacteria (P<0/007). However, with adding a fiber source such as barley or corn hull, to broiler diets would have beneficial effects in yield, health and welfare of the bird.

In order to design, manufactur and use chewing activity automatical recorder and more accurate assessment of livestock nutrition from 8 Holstein dairy cattle were used with similar production, weight, age, breed and health in change over design 2×2 in two 21-day periods (2 weeks to adapt to the diet and 7 days for sampling). Treatments were 2 diets with the same chemical composition and different alfalfa hay particle size. The geometric mean of coarse and fine alfalfa hay, and geometric mean of two experimental rations were 3.09, 4.65, 2.91, and 3.6 mm, respectively. Animal chewing activity was recorded with visual observation and chewing activity automatically recorder. Rumination time in cows fed fine particle size was lower (P= 0.0159). Eating time was not significant different by visual observation and chewing activity automatical recorder. The jaw displacement during each a rumination meal was 334.34 and 295.47 cm for fine and coarse diet, respectively (P= 0.0001). The each rumination time In this study was ranged from 68.93 to 55.33 seconds for diets containing fine and coarse particles (P= 0.0001). The chewing of a rumination meal was reduced by increasing of particle size. The movement of jaw in one second of rumination was 4.86 and 5.34 for diets containing fine and coarse particles, respectively (P= 0.1706). The degree of displacement in a jaw movement of one minute of rumination did not change with increasing feed particles size (P= 0.1706). The jaw movements in resting time between each meal of rumination were 4.61 and 4.46 seconds for fine and coarse diets. In current experiment, In addition to evaluating the chewing activity automatical recorder was confirmed accuracy and the precision of its operation.

In order to determine the effects of hydraulic press pressure in the complete feed blocks (CFBs) machinery, with the pressure dwell time and forage particle size on durability, particles abscissionand storage of blocks using a completely randomized design (12 treatments and 10 replications)with factorial arrangement current experiment was conducted. The factors were: two levels of 200 and 220 bar hydraulic pressures in CFB machinery, three levels of 5, 17 and 30 sec dwell time along with two particle sizes (alfalfa hay and wheat straw) of short (average 10 mm) and long (average 30 mm) using forage to concentrate ratio of 45:55. Complete feed blocks with long or short particles with press pressure of 220 bar and dwell time of 30 sec had higher durability andCFBs with long or short particles with press pressure of 220 bar and dwell time of 17 sec had minimum and maximum of particles abscission, respectively (P

The experiment was carried out using 200 Ross 308 broiler chickens in a completely randomized design with 5 treatment and 4 replicates. The experimental diets were consisted of a control free hulls diet and four diets containing 0.75 or 1.5 percent rice hulls with particle sizes of less than 1 mm or between 1-2 mm. The performance traits were determined through 42 d experimental period and carcass traits were expressed as a ratio of live weight. The digestibility coefficients of nutrients of the experimental diets were also determined. At grower phase, the diets contained 1.5% rice hulls regardless of their particle size, improved weight gain compared to the group fed the diets with 0.75% rice hulls (P

Introduction Today, the citrus industry supplies the large quantities of diversed by-products such as whole citrus fruits, fresh or dried citrus pulp, citrus molasses, and silage as feed for animals. In 2000-2003, global production of citrus was 4.69 MT. Iran has produced 3.5 MT citrus fruits (3.5 % of the world's production) and is known as the world's sixth-largest citrus producing country. Citrus by-product feedstuff can be used as a high energy feed in ruminant rations to support rumen microflora, growth and lactation, with fewer negative effects on rumen fermentation than starch rich feeds (Leiva et al., 2000), andimproves dietary fiber digestion, rumen fermentation and microbial protein synthesis. To increase the usefulness of citrus pulp it can be preserved by drying, but direct drying is difficult because of the slimy consistency of the waste. Citrus pulp may be ensiled alone or in combination with high dry matter cereal crop residues, such as wheat straw to control effluent outputs from silages. Application of wheat straw in silage as an absorbent additive decreases ensiling losses but also decreases quality of silage (. However, using wheat straw and urea in silage citrus pulp silage and their effects on feedlotting lambs has not evaluated. Therefore, this experiment conducted to test the effect of citrus pulp silage on fattening performance of Zel male lambs.
Materials and Methods Sixteen Zel male lambs (BW=25±0.5kg) in 4 treatments with 4 replications over 90 days fed with 4 experimental diets including: 1) basal diet with 14.61% of the citrus pulp silage withowt additives, 2) basal diet with 24.46% of the citrus pulp silage with 40% wheat straw, 3) basal diet with 24.22% of the citrus pulp silage with 38.5% wheat straw and 1.5% urea, and 4) basal diet with 23.76% of the citrus pulp silage with 37% wheat straw and 3% urea when forage to concentrate ratio was 40: 60%. Rations formulated using SRNS® (version 1.9.4208), mixed and fed twice daily at 700 and 1900. The daily gain, feed intake, feed conversion ratios were determined each 15d. Particle size distribution of ration was determined with dry sieving. Digestive kinetics were measured using Cr-mordanted NDF wheat straw a single dose. At 53 th d, rumination and chewing activity animal was measured visually with five-minute intervals over 24 h for all animals.
There were no significant difference in daily weight gain, dry matter intake and feed conversion ratio among treatments. Gado et al (2011) showed that the intake of nutrients was not changed with orange pulp silage without additives or orange pulp silage treated with the enzyme lambs except the fiber fractions (i.e., NDF and ADF) were consistent with the results. Treatment 1 had highest apparent digestibility of nutrients than other experimental treatments therefore, additives significantly decreased digestibility in comparasion to treatment control. Increase dry matter digestibility with orange pulp is two reasons: (1) a large amount of pectin as a major component of orange pulp. 2- highly digestible NDF (Aregheore, 2000). Citrus pulp pectin and increase the surface area of the particle size reduction in treatment 1 increased digestibility (Mertens, 1997). Wheat straw, urea, increasing the diet particles size and physical effective fiber, increased chewing and rumination times in comparasion to treatment control and decreased the resting time. Krause and Combs (2003) reported consuming diets with equal cell wall, with reduce the particle size of corn silage in the ration, dry matter intake increased, rumen fluid pH and chewing activity decreased. Treatment 1 had the highest ruminall particulate passage rate and lowest ruminal mean retention time, but treatment 4 had the lowest ruminall particulate passage rate and the highest ruminal mean retention time. Particle size reduction and fresh citrus pulp in the low quality diet by increasing the digestibility and passage rate improve voluntary feed intake, in treatment 1 This research was observed (Teimouri et al., 2004; Scerra et al., 2001). Addition of urea in treatments 3 and 4 significantly increased ruminal pH and NH3N. Iow pH of fresh orange pulp silage and decreased rumination and chewing activity lead to lower rumen pH treatment 1 (Krause and Combs, 2003).
The results experiment showed that the citrus pulp silage treated with urea, produced suitable alternative from protein source for fattening lambs and reduced costs, also partly resolved the problem of disposal of byproducts in the factories. So that 15% citrus pulp in diet improvements digestibility of nutrients, daily weight gain, feed conversion ratio and fattening lambs performance without negative effect.

This experiment was carried out using 200 Ross 308 broiler chickens in a completely randomized design with 5 treatments and 4 replicates. The true metabolisable energy of the barley hulls were determined using cecectomized roosters.The dry matter, true metabolisable energy, ash, ether extracts, crude protein, crude fiber, NDF, ADF, Ca and total P content of barely hulls were: 92%, 978 kcal/kg, 3.53%, 4.26%, 12.26%, 12.6%, 52.1%, 23.5%, 0.9% and 0.6%, respectively. The experimental diets were consisted of a control hulls free diet and four diets containing 0.75 or 1.5 percent barley hulls with particle sizes of less than 1 mm or between 1-2 mm. The barley hulls improved weight gain and feed conversion ratio and particularly the diet contained 1.5 percent barley hulls with particle size of 1-2 mm was more effective in this respect (P

In this experiment for the first time in Iran, designing, manufactureing and use of a new automated chewing activity recorder was evaluated to assay feed intake activity in lactating dairy cattle fed diets with different particle size. 8 Holstein cows are similar production, weight, age, breed and health, were used in a changover design 2×2 with two 21-day periods. The chewing activity that record visually and automatic recorder was not significant different that indicates the accuracy and performance of the new device. During of intake, jaw movements decreased when particle size of alfalfa hay increased. The number of jaw movements per minute when feed intake was not significant between the two treatment (P=0.1302). The jaw movement per a second was reduced when particle size of alfalfa hay increased. The jaw in each opening and closing movement were reduced when dietary forage particle size increased. The number of chewing per second was 1.36 time for ration containing shorter particles alfalfa hay and 1.33 time for larger particles alfalfa hay that were not statistically significant difference (P=0.1491).

Forage particle sizes has two opposite effects on animal performance, on the one hand fed with long particle increases ruminant activity and rumen buffer and reduce the risk of subacute acidosis, on the other hand decreases the flow rate of digestion and subsequently feed intake and milk production. Therefore this experiment was done to determine the functional response of lactating cows when fed diets containing alfalfa hay forage whit 3.09 and 4.65 mm geometric mean.
In this study was used of 8 Holstein cows similarly, with regard to the production stage, weight, age, breed and health, in rotate design 2×2 and the two period 21-day (2 weeks to adaptation with the diet and 7 days for samples) with four replicates for each treatment. During the 7 days of sampling, was measured feed intake, indicators blood and milk.
The cows DMI increased with reduced forage particle size (25 versus 22.5 kg per day). Non-fiber carbohydrates, organic matter, neutral detergent fiber, ash, and acid detergent fiber intake was reduced by increasing the particle size alfalfa hay. Physically effective fiber greater than 8 mm intanke in the experiment was statistically significant between the two treatments, that diet smaller particle size had lower levels compared to the larger particle size diet (0.41 to 0.52 kg) . With increase geometric mean particle size alfalfa hay of diet from 3.09 to 4.65 mm did production increase from 3.26 to 3.65 percent. In this experiment protein content, lactose, urea, solid nonfat, total solids, somatic cell counts of milk were not significantly different between the two treatments. By increasing the particle size of alfalfa hay increased blood glucose and triglyceride levels. Blood insulin levels was more in cows fed diets greater geometric mean alfalfa hay (16.29 and 12.86 mg per deciliter). Cholesterol levels, antioxidants, urea and beta-hydroxy butyric acid were not significantly different between two treatments of alfalfa hay particle size in diet. According to the results of this experiment, the particle size reduction of alfalfa hay and diet was decreased in the rumen fluid pH. The rumen fluid pH for diets containing alfalfa hay with geometric mean 3.09 and 4.65 was 6.09 and 6.39 respectively.
With increasing the forage particle size increased pH of the rumen fluid, dry matter intake and milk fat.

Two independent experiments were carried out to investigate the effects of natural aluminosilicates and glauconite in sheep nutrition. At 1st experiment, dry matter disappearance of these minerals by two particle sizes (0.85-1 mm and <0.5 mm), was determined. For this, 3 fistulated Dalagh rams in a completely randomized design with factorial arrangement 2×4 by nylon bag technique were used. 2nd experiment conducted to investigate dietary effect of zeolite and perlite on feed intake, nutrients digestibility, fecal moisture and blood parameters. 2nd experiment carried out in a change-over design by 4 treatments, 4 periods and 4 non pregnant Dalagh ewes. Each experimental period was 15 days, including 10 days as adaptation and 5 days for total feces collection. Dietary treatments were: 1) control 2) control diet + two percent zeolite, 3) control diet + two percent perlite and 4) control diet + one percent zeolite + one percent perlite. Analysis of variance and separation of means by Duncan's multiple range tests were conducted by SAS software. 1st experiment showed that between two particle sizes of bentonite, there was no significant difference in dry matter disappearance (P>0.05), While, in other minerals these amount having certain trend for larger size, in any time, that was lesser than smaller size significantly (P<0.05) whereas maximum difference shown in zeolite supplemented treatment that in 48 h. were 6.71 and 52.03% in coarse and fine particle size respectively. The 2nd experiment indicated that 2% zeolite supplemented treatment had significantly higher apparent digestibility of CP, Ca and P in comparison to other groups (P<0.05). Supplementation of ewe diet by two percent zeolite and perlite can be lead to better performance.

To study the effects of barley silage particle size and concentration levels on feed intake, nutrient digestibility and ruminal parameters, four 14 months Kermani male lamb with an average weight of 35 ± 2 kg were used in change over design in 2×2 factorial arrangement with the four periods of 21 days. For the preparation of silage, 1200 kg of whole plant of barley was chopped with coarse and fine particle size and ensiled for 45 days in nylon bags. Experimental diets were: 1) 40% coarse barley silage and 60% concentrate, 2) 60% coarse barley silage and 40% concentrate 3) 40% fine barley silage and 60% concentrate and 4) 60% fine barley silage and 40% concentrate. Geometric mean of coarse and fine barley silage particle size were 13.95 and 10.83 mm, and pH was lower in fine barley silages (P=0.03). The results showed that DM feed intake was higher in 40% concentrate and diets (P<0.001), but the highest DM and OM digestibility were in 60% fine barley silage and 40% concentrate diet (p<0.05). Rumen pH value was higher in coarse silage diets four hours after feeding (p=0.005), but rumen ammonia nitrogen concentration was not affected by experimental diets. Microbial protein synthesis was the greatest in 60% fine barley silage and 40% concentrate diet (p<0.044). Reducing the level of concentrate and barley silage particles size, was caused the highest DM and OM digestibility, because of improved rumen conditions and increased surface area of silage particles.

Four ruminally cannulated sheep were used in order to investigate the effects of alfalfa particle size (long vs fine) and canola meal treatment with hydrochloric acid solution (untreated vs treated) on feed physical characteristics, distribution of ruminal content particle size and the effect of initial chewing on decrease of particle size. Data documented from experiment analyzed at Latin square design. The method of wet sieve was used in order to determine distribution of rumen content and mild flow of water on sieves was used for dissociation of particles. Using two methods of BD100 and BD50, determination of bulk density were done. The effect of initial chewing on the amount of decrease of particle size determined by measurement of ruminal content distribution of particle size emptied at the time of measurement of saliva secretion rate. The results of this experiment showed that decrease of particle size caused increase of bulk density and insoluble ash (P = 0.0001) and in the other hand increase of particle size caused increase of water holding capacity and insoluble dry matter (P= 0.0001). Treatment with acid caused no change in physical characteristics (P> 0.05). Comparison to alfalfa, Canola meal had higher insoluble dry matter. Trend of particle size distribution for all hours showed that increase of time after feeding caused decrease of long particles percent and increase of remained particles on the end sieves (P< 0.05). Investigate the results related to escapable phase particles percent from rumen showed that Increase of time post-feeding caused increase of escapable phase particles percent from rumen and decreased of nonescapable phase particles percent from rumen (P< 0.05)