digestibility

Generally, most feeds used in livestock nutrition are deficient in some nutrients and require nutritional supplements. Among the supplements, micro and macro minerals are of particular importance. Selenium is a scarce and essential mineral in animal nutrition, and its importance has been well confirmed in the health and productivity of animals. Selenium plays a role in enzyme activity and acts as an antioxidant to prevent oxidative damage to body tissues. The use of selenium supplements in the diet of sheep can stimulate rumen microbial activity, digestive microorganisms, and their enzyme activity and improve rumen fermentation. It is believed that the low selenium absorption in ruminants is due to the deficiency of selenium in the ration and its conversion into an insoluble form. The reasons for improving the digestibility of feed nutrients in response to selenium supplementation include an increase in protozoan activity and an increase in the activity of cellulolytic bacteria. The use of different organic and inorganic forms of selenium affects its absorption in the digestive system. The use of organic selenium supplements, such as selenium chelates, with organic acids and amino acids increases the ability to absorb this element in the digestive system. There is a direct relationship between the amount of selenium in the soil and plants, and based on the published reports, the soil of our country is deficient in terms of the condition of this element, which shows the necessity of using selenium supplements in the ration of livestock in many regions of Iran. As a result, this study aimed to investigate the effects of organic and inorganic selenium supplements on digestibility, rumen parameters, microbial protein production, rumen protozoa populations, and carcass characteristics of crossbred Zel fattening male lambs.

Twenty-five male lambs aged 4-5 months and with an average body weight of 32.4 ± 1.5 kg were assigned to five treatments with five replications as a completely randomized design for 84 days. The experimental treatments were:1) basal diet without selenium supplement (control), 2) basal diet + 0.5 mg Se/kg DM as selenium glycine, 3) basal diet + 0.5 mg Se/kg DM as selenium methionine, 4) basal diet + 0.5 mg Se/kg DM as selenium cysteine, and 5) basal diet + 0.5 mg Se/kg DM as sodium selenite. The apparent digestibility of feed nutrients was determined using the acid-insoluble ash internal indicator method. Ruminal fluid was collected 3 hours after consuming the morning feed on the 84th day of the experiment to determine the protozoa population and the pattern of volatile fatty acids in the rumen fluid. In the last week of the experiment, urine was collected to estimate the production of microbial protein by measuring the excretion of purine derivatives from urine. After completing the experiment, 15 lambs were weighed and slaughtered to evaluate the carcass and meat characteristics. Data were analyzed as a completely randomized design using the General Linear Model (GLM) procedure of SAS.

In treatments containing selenium methionine and selenium cysteine supplements, the digestibility of dry matter and insoluble fibers in neutral detergent increased significantly compared to the inorganic selenium and control groups (P < 0.05). The digestibility of organic matter in treatments supplemented with selenium methionine and selenium cysteine increased significantly compared to that in the control group (P < 0.05). In addition, crude protein digestibility improved significantly in all treatments supplemented with selenium compared to that in the control group (P < 0.05). No statistically significant difference was observed in the digestibility of ether extract and acid detergent insoluble fibers (ADF) among experimental treatments (P < 0.05). The rumen fluid pH was significantly lower in all lambs receiving selenium supplements than in the control group (P < 0.05). In treatments containing selenium methionine and selenium cysteine, the concentration of propionic acid increased compared to the treatment containing sodium selenite and the control group (P < 0.05), and the acetic acid/propionic acid ratio decreased significantly compared to the treatment containing inorganic selenium and the control group (P < 0.05). The concentration of butyric acid in all treatments supplemented with organic selenium was significantly lower than that in the control group (P < 0.05). Moreover, the experimental treatments did not affect the concentrations of ammonia nitrogen, other volatile fatty acids, and total fatty acids in the rumen liquid of lambs (P < 0.05). In the present study, the use of organic and inorganic selenium supplements did not significantly affect microbial protein production, rumen fluid protozoa population, carcass characteristics, and the chemical composition of lamb meat (P > 0.05).

In general, it can be concluded that adding 0.5 mg Se/kg DM to the basic diet (containing 0.07 mg Se/kg DM of feed) from organic sources of selenium supplements (especially selenium methionine and selenium cysteine supplements) compared to the inorganic source of selenium has a better effect on the digestibility of feed nutrients and rumen parameters of fattening lambs.

 Wheat grain is normally used for animal feed in some regions, but is seldom used in others. Its nutritional composition is very similar to that of the barley grain commonly used, but there are concerns about its effects on the performance and health of the animals. Wheat seed is one of the grain varieties with the highest amount of protein available for animal feed, exceeding corn. Furthermore, it has a high energy value of 3.0 to 3.5 Mcal of ME (metabolizable energy), which is an important source of energy for animal feed. The most abundant carbohydrate in wheat is starch, a digestible polysaccharide. On the other hand, it is recommended that wheat has a moisture content of less than 14% to avoid problems with digestibility and contamination by mycotoxigenic fungi. Barley is an important grain which is widely used as a source of feed for ruminants. Feed deliveries during the fattening period are the physical processing of the feed. It has been demonstrated that barley starch ferments rapidly in the rumen. The high digestibility of barley has raised concerns regarding acidosis, lameness, liver abscesses, and gastrointestinal abnormalities in ruminants. It is generally considered that the processing of barley grain may be used in the feed industry to adjust the rate of digestion of its nutrients to avoid acidosis. Consequently, the distribution of particle sizes after processing is one of the main factors influencing the rate and extent of digestion of barley (feeding of livestock accounts for 65-70% of the cost of raising livestock). Wheat and barley are used as the predominant source of energy for animal nutrition in most parts of the world. Wheat seed has been used for a long time because of the extensive cultivation and livestock rearing in Iran. The most common way of processing barley and wheat grain in the country is by grinding. Farmers prefer to use whole grains in the production of concentrates, as the concentrate involves the use of crushed grains, but the farmer's wish to use whole grains in the concentrate requires a study and field investigation. The purpose of this study is therefore to examine the effects of the grain size of barley and wheat on the diet of lambs fattening and to compare their effects on growth performance, digestibility, rumination and blood parameters.

 This experiment was carried out in the form of a completely randomized design with a factorial arrangement of 3×2 with six treatments including 1. Finely milled barley grain with sieve number two, 2. Coarsely milled barley grain with sieve number eight, 3. Unmilled barley grain, 4. Finely milled wheat grain with sieve number two, 5. Coarsely milled wheat grain with sieve number eight, and 6. Unmilled wheat grain. Five fattening lambs aged 4-5 months with almost the same starting weight were allocated to each treatment and a total of 30 male lambs were individually tested for 98 days, including two weeks for acclimatization and 84 days for the remainder of the main test period. The performance of lambs was assessed in this experiment, including average daily feed consumption, daily weight gain, final weight, and feed conversion ratio. Nutrient digestibility was measured by the acid-insoluble ash (AIA) method from day 80 for four days. The digestibility of dry matter organic matter, crude protein, ether extract, and neutral detergent fiber was evaluated. Blood parameters were measured including blood glucose, blood cholesterol (LDL-c, HDL-c), and blood urea nitrogen (BUN).

 The results showed that daily weight gain was significant throughout the treatment period and daily weight gain was greater in the treatment group that consumed barley than in the treatment group that consumed wheat (P<0.05). The impact of the grain, the type of processing, and their interaction on feed consumption in all three experimental periods was not significant. Total feed consumption was not significant, but it was significant during the last month of fattening (P<0.05). Lambs consuming barley and wheat milled with sieve number eight had the highest feed consumption compared with the treatment of wheat and barley with sieve number two and whole grains (P<0.05). The feed conversion ratio in treatments receiving wheat was higher than that in those receiving barley (P<0.05). The type of processing had no significant impact on the feed conversion rate (P>0.05). In the study of nutritional behavior, the results showed that the parameters of eating and rumination were higher in the treatments receiving wheat compared to barley (P<0.05). Also, the treatments receiving unmilled barley and wheat (whole grain) showed the highest levels of eating and rumination (P<0.05). The treatments receiving barley and wheat grains with sieve number two also showed the lowest levels of eating and rumination. There were no significant differences in nutrient digestibility, rumination parameters, and blood parameters (P>0.05). Contrary to the view of the farmers that whole grains are better than milled grains, the results showed that overall the use of ground or whole grains did not show a significant difference.

 Overall, the results showed that there was no significant difference between whole grain and milled grain, and even from the point of view of palatability, milled grain with a sieve number 8 had a higher consumption rate than the other treatments. These findings indicate that milled barley grain with a sieve number 8 may be used as a substitute for whole barley grain in the feeding of lambs.

Dietary protein plays an important role in ruminant nutrition, because in addition to providing amino acids, it’s a nitrogen source for microbial protein synthesis. Providing protein, especially for high-producing livestock, is one of the most important concerns of livestock farmers. Soybean meal has been used for a long time as an excellent source of CP for ruminants, but with the increase in its price, has challenge due to the limitation of production and direct consumption by humans. Due to the ability of ruminants to use NPN (urea), nitrogen unit density and its low price, it has been used as an alternative in ruminant diets. Urea is converted into ammonia in the rumen, on the other hand, fiber-digesting bacteria in the rumen need ammonia to growth. Hydrolysis of common urea is faster than the growth of microbes and the digestion of structural carbohydrates in the rumen, so it will reduce the efficiency of nitrogen use and even nitrogen poisoning in livestock. Slow-release urea (SRU) is a type of urea that slows release of nitrogen in the rumen. Substitution of SRU instead of common urea in the diet of ruminants that have a limit with protein sources can reduce the competition between humans and animals. Also, it will not have the dangers of common urea for livestock. This article review the effects of using SRU instead of common urea and plant protein sources in ruminants diet on feed intake, digestibility, fermentation parameters, growth and production, blood parameters and carcass characteristics.

In today's society, where we are facing an increase in the price of grains, the use of agricultural by-products in animal husbandry is very important. Corn is widely used in industry. The nutritional value of corn industrial products is very important and it is one of the cheapest and purest sources of production of organic materials for industrial consumption. Starch, animal feed, sugar syrup and oil are extracted from this plant in starch factories. Residues from food industries are among the industrial wastes that can be consumed by animals. In extracting starch and preparing glucose from corn, by-products are obtained which are suitable for animal feeding. Among these products, we can mention the corn steep liquor. Corn steep liquor, which is produced during the wet milling process of corn kernels to extract corn starch and oil, is a relatively cheap, tasty and easily available product for animals and it has potential to be used as a feed material in ruminants due to its relatively high energy and protein content and low fiber concentration.

This research was conducted in order to investigate the effect of different levels of corn steep liquor on performance, milk composition, digestibility of nutrients, rumen and blood parameters and rumination behavior of Dalagh ewes. In order to perform this experiment, 21 dairy ewes with three bellies of the Dalagh breed with an average weight of 36±3.7 kg were used in 3 treatments and 7 repetitions in the form of a completely randomized design. The treatments included: control treatment (diet without adding corn steep liquor), second treatment (ration containing 100 grams of corn steep liquor per kilogram of dry matter consumed), third treatment (ration containing 200 grams of corn steep liquor per kilogram of dry matter consumed). The duration of the experiment was 42 days of main course. The rations used in this experiment were prepared and adjusted according to the tables of the National Sheep Research Society and were given to the ewes at two times in the morning (8 o'clock) and in the evening (16 o'clock).The daily feed was thoroughly mixed with livestock. During the whole experiment, the animals had free access to clean drinking water. On the 38th day of milk test all ewes were milked and samples were taken to measure milk composition. The ewes were weighed weekly before feeding in the morning. Feed was also given, and feed was then recorded daily to calculate the dry matter consumed. Stool and feed samples were collected from days 41 to 45 for 5 days to perform digestibility tests. Blood sampling were performed on days 42, respectively. In order to perform this experiment, 21 dairy ewes with three bellies of the Dalagh breed with an average weight of 36±3.7 kg were used in 3 treatments and 7 repetitions in the form of a completely randomized design. The treatments included: control treatment (diet without adding corn steep liquor), second treatment (ration containing 100 grams of corn steep liquor per kilogram of dry matter consumed), third treatment (ration containing 200 grams of corn steep liquor per kilogram of dry matter consumed). The duration of the experiment was 42 days of main course. The rations used in this experiment were prepared and adjusted according to the tables of the National Sheep Research Society and were given to the ewes at two times in the morning (8 o'clock) and in the evening (16 o'clock).The daily feed was thoroughly mixed with livestock. During the whole experiment, the animals had free access to clean drinking water. On the 38th day of milk test all ewes were milked and samples were taken to measure milk composition. The ewes were weighed weekly before feeding in the morning. Feed was also given, and feed was then recorded daily to calculate the dry matter consumed. Stool and feed samples were collected from days 41 to 45 for 5 days to perform digestibility tests. Blood sampling were performed on days 42, respectively. During the 39th and 40th days of the experiment, feed intake behavior was recorded as activity record for 24 h.

The results showed that there was no significant difference in the final weight of ewes, daily weight gain and food conversion ratio in receiving different amounts of corn steep liquor (P<0.05), but the dry matter consumption increased with the increase in the level of corn steep liquor in the diet. Among the different treatments, no significant difference was observed in terms of the amount of milk produced, milk fat, total solids and milk lactose, but the percentage of protein and milk ash was affected by the experimental treatments, so that with the increase in the levels of corn steep liquor, this Milk compounds also increased (P<0.05). There was no significant difference between the treatments for dry nutrients, organic matter, crude protein, acid detergent fiber, neutral detergent fiber and ether extract. By increasing the level of corn steep liquor in the diet, the rumination behavior including eating, ruminating, chewing increases and naturally the resting behavior decreases (P<0.05). There is no significant difference in albumin, globulin and the ratio of albumin to blood globulin among the treatments receiving different amounts of corn steep liquor. However, total protein was affected by the experimental treatments, so that the concentration of these parameters increased with the increase in the level of corn steep liquor (P<0.05).

According to the results, it can be recommended to add corn steep liquor to animal rations up to the level of 200 grams per kilogram of dry matter consumed.

 Total mixed ration silage (TMRS) is a new technology that has been considered by animal nutritionist in recent years. The TMRS is balance feed prepared from fodder components (mainly silage), concentrate and mineral-vitamin supplements that provides the nutritional requirements of livestocks due to the presence of these components, its use has been expanded in livestock breeding units, where the fermentation process improved the nutrients digastibility. This study, with the aim of preparing complete feed silage based on triticale and wheat plants and determining their nutritional value (optional feed consumption, digestibility and rumen parameters) in comparison to daily complete feed with the same food ingredients (daily mixing the desired fodder silage with dry ration) was done.

Four experimental diets were prepared including: 1) diet containing wheat silage, 2) complete feed silage based on wheat, 3) diet containing triticale silage, 4) complete feed silage based on triticale. The digestibility and voluntary consumption of the experimental rations were determined by the in vivo method on adult male sheep of Zel breed. The amount of feed consumed, the remaining feed, total feces and daily urine for each sheep were collected separately. Stool samples were dried in an oven at a temperature of 60 degrees Celsius and then the percentage of dry matter was calculated. In the dried samples of feces and feed, the amount of ash and insoluble fibers in neutral detergent was measured

The amount of dry matter in terticale silage was the highest (47.30%) and the diets containing silage, wheat silage and complete wheat silage were the lowest (46.50%), but there was no significant difference between the treatments (p>0.05). The average digestibility of dry matter and insoluble fibers in neutral detergent fiber in the silage treatment of terticale complete feed was the highest compared to other treatments (p < 0.05). The treatment 2 had the highest, but the treatment 1 had the lowest digestible nutrients intake (p<0.05), whereas no significantly differences were obtained among the other treatments. Metabolizable energy in whole wheat silage treatment had the highest (11.42 megacalories per kilogram of dry matter) compared to other three treatments (p < 0.05). The production of rumen microbial protein was highest when feeding on whole grain wheat silage and the lowest when feeding on ration containing triticale silage (p < 0.05).Conclution: In general, ensiling the food ration in the form of complete feed based on wheat fodder improved its nutritional value, but no such improvement was achieved in the case of triticale fodder.

The aim of this study was to examine the effect of Bufferman as a biological regulator on the disappearance of nutrients by bacterial and fungi in anaerobic culture in diets containing different ratios of concentrate to Forage. The experimental diets consisted of different forage to concentrate ratios (respectively 20-80, 30-70, 40-60, 60-40) with treatments included control (zero percent), Bufferman 1% and 2%, and sodium bicarbonate 1 %. This research was conducted in vitro, using a completely randomized design. The experiment results indicated that the disappearance rates of DM , NDF , ADF and rumen pH were influenced by the test diets (P<0.05). Different forage to concentrate ratios (20:80, 30:70, 40:60, 60:40 F:C) were influenced by buffering, resulting in the highest disappearance of DM, disappearance of NDF, and disappearance of ADF in treatments with 1% Bufferman inclusion (P<0.05). According to the present experiment, it can be inclusion of 1% Bufferman led to a significant increase in nutrient disappearance and rumen pH by creating favorable conditions for bacterial and fungal activity throughout the evaluation period.The aim of this study was to examine the effect of Bufferman as a biological regulator on the disappearance of nutrients by bacterial and fungi in anaerobic culture in diets containing different ratios of concentrate to Forage. The experimental diets consisted of different forage to concentrate ratios (respectively 20-80, 30-70, 40-60, 60-40) with treatments included control (zero percent), Bufferman 1% and 2%, and sodium bicarbonate 1 %. This research was conducted in vitro, using a completely randomized design. The experiment results indicated that the disappearance rates of DM , NDF , ADF and rumen pH were influenced by the test diets (P<0.05). Different forage to concentrate ratios (20:80, 30:70, 40:60, 60:40 F:C) were influenced by buffering, resulting in the highest disappearance of DM, disappearance of NDF, and disappearance of ADF in treatments with 1% Bufferman inclusion (P<0.05). According to the present experiment, it can be inclusion of 1% Bufferman led to a significant increase in nutrient disappearance and rumen pH by creating favorable conditions for bacterial and fungal activity throughout the evaluation period.The aim of this study was to examine the effect of Bufferman as a biological regulator on the disappearance of nutrients by bacterial and fungi in anaerobic culture in diets containing different ratios of concentrate to Forage. The experimental diets consisted of different forage to concentrate ratios (respectively 20-80, 30-70, 40-60, 60-40) with treatments included control (zero percent), Bufferman 1% and 2%, and sodium bicarbonate 1 %. This research was conducted in vitro, using a completely randomized design. The experiment results indicated that the disappearance rates of DM , NDF , ADF and rumen pH were influenced by the test diets (P<0.05). Different forage to concentrate ratios (20:80, 30:70, 40:60, 60:40 F:C) were influenced by buffering, resulting in the highest disappearance of DM, disappearance of NDF, and disappearance of ADF in treatments with 1% Bufferman inclusion (P<0.05). According to the present experiment, it can be inclusion of 1% Bufferman led to a significant increase in nutrient disappearance and rumen pH by creating favorable conditions for bacterial and fungal activity throughout the evaluation period.

Ruminants and their products play an important role in providing food for many people. They are able to convert plants that cannot be digested by humans into usable protein for humans. New animal feed has been commonly developed for long years. To improve food production from ruminants, it is important to explore new feed sources. New or less exploited types of feed can replace or supplement traditional feeds in ruminant diets. Sesbania is a multipurpose plant that is cultivated for consumption as fodder and green manure. As a fast-growing plant, Sesbania has been mentioned as a food source to reduce feed costs. The food value of some of its species is equal to alfalfa and several other valuable plants. Due to proper digestibility, low fiber, and relatively high protein, it is possible to replace it with hay for livestock, especially small ruminants. In addition, as a tropical legume, Sesbania can easily withstand temperatures above 35°C, which are limiting for most legume plants, and grow well under salinity stress conditions if there is sufficient moisture in the soil. Therefore, this research aimed to investigate the nutritional value of Sesbania sp. L. for ruminants.

The present research was carried out in the laboratories and teaching-research station of animal husbandry at the Agricultural Sciences and Natural Resources University of Khuzestan. The experimental treatments included a control diet (without the Sesbania plant), 25, 50, 75, and 100% replacements of the Sesbania plant with alfalfa. The chemical compositions of the Sesbania plant, alfalfa hay, treatments, and other experimental samples, including crude protein, dry matter, ash, acid detergent fiber, and total tannin, were measured by standard methods. The neutral detergent fiber was quantified with the usual method without using the alpha-amylase enzyme and sodium sulfite by removing ash. The amount of gas produced by the samples was recorded at 2, 4, 6, 8, 10, 12, 24, 48, 72, and 96 hours after incubation, and gas production parameters, digestibility of organic matter, their metabolizable energy, ammonia nitrogen concentration, pH, and protozoa population of culture medium were estimated in the treatments. In the gas production experiment, rumen fluid was taken from the rumen of three male sheep fed with a forage-based diet at the maintenance level and before morning feeding using a stomach tube. Ruminal fluid was filtered with a four-layer cheesecloth, mixed, and transferred to the laboratory in a flask containing hot water at 39 °C. To count protozoa at the end of 24 hours, a sample was prepared from the gas culture medium and mixed with 10 ml of 10% formaldehyde, and protozoa were counted using a hemocytometer slide. The resulting data were analyzed with a completely randomized design. In the present experiment, the chemical composition, digestion, and fermentation of the Sesbania plant were also compared with alfalfa hay.

Compared to the control, Sesbania-containing diets replaced with alfalfa had significantly the lowest potential and gas production rate at all levels (P < 0.05). The comparison of the Sesbania plant and alfalfa hay showed that the potential and gas production rate of alfalfa were higher than that of the Sesbania plant. In the experimental diets, the partitioning factor, microbial biomass production, and microbial biomass production efficiency were higher at all levels of Sesbania replaced with alfalfa than the control diet, and the levels of 75% and 100% of Sesbania replaced with alfalfa had a significantly higher partitioning factor than the control and other treatments (P < 0.05). However, the truly degradable organic matter was not affected by the experimental treatments. The results of the comparison of the Sesbania plant and alfalfa hay showed that the partitioning factor, microbial biomass production, and microbial biomass production efficiency of the Sesbania plant were significantly higher than alfalfa (P < 0.05). The results of fermentation parameters after 24 hours of incubation showed that the pH of the rumen culture medium was not affected by the experimental treatments, but the ammonia nitrogen concentration was affected by the experimental treatments (P < 0.05), and the control treatment contained the highest ammonia nitrogen concentration. In the comparison of the Sesbania plant with alfalfa hay, the pH of the rumen culture medium was not affected by the experimental treatments, and the ammonia nitrogen concentration of the Sesbania plant was significantly lower than that of alfalfa hay (P < 0.05). The helotrich, entodinomorph, and cellulolytic protozoa population, and the total rumen protozoa population were the highest in the control treatment (29.33) and the lowest in the 100% replacement of the Sesbania plant with alfalfa hay (9.66). The results of the comparison of the Sesbania plant with alfalfa hay showed an increase in the population of Helotrich, Entodinomorph, and Cellulolytic protozoa and the total population of rumen protozoa in alfalfa hay, with a decrease in the population of the Sesbania plant. The results of in vitro digestibility indicated the highest digestibility of dry matter, NDF, and, ADF in the control treatment. The comparison of the Sesbania plant with alfalfa hay revealed that the digestibility of dry matter, NDF, and ADF of alfalfa was higher than that of the Sesbania plant.

In general, the results of the present experiment demonstrate that the chemical composition and digestibility of the Sesbania plant are similar to alfalfa hay. Therefore, the Sesbania plant can be considered a suitable substitute for alfalfa hay.

The limitation of animal feed resources has increased the tendency to use agricultural residues such as straws in feeding ruminants. It has been reported that livestock production decreases when using low-quality crop residues due to the low palatability, energy level and protein of these feed materials. In other hand, high consumption of straws decreases ruminant's performance because of feed intake restriction, low digestibility and the presence of anti-nutritional factors such as silica, tannin and lignin in straws. The use of fibrolytic enzymes of foreign origin increases the usability of forage, which results in increased production. One of the most important methods of processing wooden materials is the use of chemicals, especially alkaline materials, especially urea. Adding molasses as an energy-generating part and urea as a non-protein nitrogen source simultaneously provides the rumen microorganisms with a source of energy and protein. In general, the addition of enzymes to the diet is used for the purpose of supplementing and compensating the defects of the enzyme system of the ruminant’s digestive system, removing anti-nutritional substances and increasing the availability of nutrients in the animal body. The purpose of this research was to investigate the effect of processing chickpea straw with urea, molasses and enzymes on chemical composition, ruminal and intestinal digestibility, gas production and disappearance under laboratory conditions. So that the results of this research can be optimally used in animal nutrition.

This research was conducted on processed chickpea straw with urea, molasses and, enzyme source of fungal cellulase and rumen liquid. The tested feed material was chickpea straw, which was processed with urea, molasses and enzymes. Enzymes included fungal cellulase and rumen liquid. The tested feed ingredients were ground using a special mill with a sieve with 2 ml pores and then sieved using a 50 micrometer sieve to remove particles smaller than 50 micrometers.To perform the gas test, first, the sample of the tested feed (chickpea straw enriched with urea, molasses and enzyme) was ground with a 1 mm grid. Measurements of chemical composition and gas production were carried out by standard methods and the determination of the digestibility of samples was done with Daisy ǁ device and Gargalo's three-step method. After performing the initial calculations and collecting all the data, statistical analysis of the data was done using the SAS statistical software in the form of a completely random design and a 4x4 factorial experiment with the GLM procedure.

According to the results, processing chickpea straw with urea, molasses, and enzymes increased the percentage of dry matter and the amount of crude protein in the treatments. However, it decreased the percentage of cell wall and cell wall without hemicellulose. The processing of chickpea straw with urea, rumen liquid and a mixture of two enzymes and the combination of all three enzymes with a level of 4% molasses increases the digestibility of dry matter in the total digestive system, and the addition of molasses and the combination of rumen liquid and a mixture of two enzymes with different levels of molasses were increased the digestibility of crude protein in the rumen (P<0.05). Adding all three enzymes to chickpea straw at 2, 4, 6, and 8 hours, but with rumen juice from 12 to 96 hours, has led to an increase in gas production. The combination of molasses levels of 2 and 4% with a mixture of two enzymes increased gas production in all hours of incubation (P<0.05). The average constant rate of disappearance and gas production potential of chickpea straw was significantly different among all treatments (P < 0.05). The results showed that molasses and enzyme increased the constant rate of disappearance and 4% molasses and enzyme increased the gas production potential. The combination of molasses with fungal cellulase and the mixture of two enzymes decreased the constant rate of disappearance and gas production potential. The average laboratory digestibility of organic matter, metabolizable energy, lactation energy and short chain fatty acids were significant in all chickpea straw treatments (P < 0.05).

In general, based on the obtained results, the use of urea, molasses, and enzyme sources including fungal cellulase and rumen liquid has successfully increased the nutritional value, gas production parameters, and digestibility of chickpea straw. Among the experimental treatments, processing chickpea straw with 3.5% urea, 4% molasses, and fungal cellulase enzyme improved the nutritional value the most. Further animal experiments are needed to confirm these results. More research is required in the field of using agricultural waste in animal nutrition.

The particle size and physical form of fat supplements are effective factors in the digestibility of nutrients, fatty acids, and some blood parameters in dairy cows. This research aims to investigate the effect of a feeding fat supplement containing an additive (lecithin or bile powder) with the physical form of flake or granule on the apparent digestibility of nutrients and some blood parameters in Holstein dairy cows. 48 lactating cows were used during two experimental periods in a 2x3x2 completely randomized factorial design and randomly grouped into 6 experimental treatments: 1. Control diet + 2.5% granulated fat supplement, 2. Control diet + 2.5% granulated fat supplement containing 5% lecithin 3. Control diet + 2.5% granulated fat supplement containing 5% bile powder 4. Control diet + 2.5% Flaked fat supplement 5. Control diet + 2.5% Flaked fat supplement containing 5% lecithin and 6. Control diet + 2.5% Flaked fat supplement containing 5% bile powder. All the experimental diets were balanced according to the recommendations of the National Research Association. All data were analyzed by statistical software. The digestibility of the ether extract, total fatty acids, 16 and 18-carbon fatty acids, as well as the plasma concentration of NEFA, triglycerides, cholesterol, HDL, and VLDL were increased in the treatments containing the additives (P ≥ 0.05). The addition of emulsifying ingredients to the fat supplement of the high-production dairy cow diet may have positive effects on the digestibility of some nutrients and lipid metabolism.

This study was conducted in order to investigate the effect of different levels of a type of mineral ‎biochar obtained from Kohbanan mine in Kerman on the performance, digestibility, blood ‎parameters and ruminal fermentation of suckling Holstein calves in an industrial cattle farm. For this ‎purpose, 35 Holstein calves with an average weight of 48.88 ± 4.87 were used in a completely ‎random design in five treatments and seven replications.The experimental rations include: 1) milk ‎and ‎starter feed (basal ration), 2) basal diet with 10 g of mineral biochar mixed in the starter feed, 3) ‎‎basal diet with 10 g of mineral biochar dissolved in milk, 4) basal diet with 20 g of ‎mineral biochar ‎mixed in the initial feed, 5) basal diet with 20 g of mineral biochar ‎dissolved in milk. Consumption ‎of 20 grams of biochar in the initial feed increased the daily weight and improved the average feed ‎conversion coefficient . The highest amount of blood glucose and albumin concentrations ‎was related to calves fed with 20 g of biochar in ‎the initial feed. Calves consuming 10 and ‎‎20 g of biochar in the starter feed had the ‎highest apparent digestibility of nutrients. ‎Calves fed with 20 g of biochar in the initial ‎feed had higher rumen pH than the other calves. Therefore, the addition of 20 g mineral biochar to the starter diet of Holstein calves is ‎recommended because of its positive effects on performance, digestibility blood parameters and ‎rumen fermentation.‎

The aim of this experiment was to investigate the effects of dietary artichoke level on growth performance, nutrients digestibility and plasma parameters in fattening male lambs. Twenty-four Kurdish lambs (30.18 ± 2.35 kg BW and 7 months age) were used in a completely randomized design. Experimental diets were diet containing 0% artichoke (control), diets containing 10 and 20% artichoke respectively. The experiment was lasted for 100 days including 20 days for adaptation period and 80 days for data recording and samples collection. Results showed that lambs fed diet containing artichoke had greater average daily gain and feed efficiency compared to the control group (P<0.05). Digestibility of dry matter (P=0.09), organic matter (P=0.09) and crude protein (P=0.10) tended to increase linearly with increasing artichoke level in the diet, whereas digestibility of neutral detergent fiber was not affected by artichoke level in the diet. Lambs fed diets containing artichoke had lower blood urea concentration compared to those fed control diet (P<0.05), but plasma glucose, total protein, albumin, globulin, cholesterol and triglyceride concentrations were not affected by the experimental diets. It is concluded that feeding artichoke up to 20% of total mixed ration not only had no negative effect on feed intake and nutrients digestibility but also improved growth performance of fattening lambs.

The dry climate and water scarcity in most areas of Iran caused to serious restriction in planting fodder. Therefore, it is very important to find new fodder sources to feed ruminants in order to reduce the ration costs. One of the new sources of fodder that may have a favorable nutritional value are plants of the Paulowniaceae family in China, East Asia and some parts of Iran. Several types of Paulownia are known in the world. These plants are known for their high growth rate and intense photosynthesis, which are specific to C4 plants, and with wide leaves with a diameter of about 90 cm. The commercial production of Paulownia wood generates a large quantity of leaves, which are typically used as natural fertilizers.At the age of about 6 to 8 years, the production leaf of each Paulownia tree reaches about 100 kg. When the leaves have a favorable nutritional value, they can be used as fodder in feeding ruminants. In Iran, there has been no study on the nutritional value of Paulownia leaves for use in animal feed. Therefore, the aim of this research was to investigate the chemical composition of Paulownia leaves and the chemical composition, gas production parameters, digestion and fermentation characteristics of the silages from the mixture of different levels of Paulownia leaves (Tebjoo hybrid variety) and fodder corn in vitro. The corn forage and Paulownia leaves (Tebjoo hybrid variety) were prepared. At first, the chemical composition of corn forage and Paulonia leaf samples was determined based on the conventional methods. Then, both forages were chopped into 2-4 cm sizes using a hand chopper for silage preparation. Experimental treatments included silages containing different ratios of fodder corn and Paulownia leaves (0:100, 75:25, 50:50, 25:75 and 0:100). The materials were compacted in the plastic containers and the silage period lasted 60 days. Determining the chemical composition of fresh fodders and the nutritional value of experimental silages including chemical composition, in vitro gas production and fermentation parameters, digestibility and enzyme activity were carried out based on a completely random design. Results indicated that dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), ether extract (EE), lignin, non-fibrer carbohydrates (NFC) and water soluble carbohydrates content of fresh Paulownia leaves were 266, 911, 173, 402, 201, 35.5, 86.4, 404 and 91.2 g/kg DM, respectively. The mentioned chemical composition in Paulownia silage were 273, 902, 164, 393, 191, 38.8, 74.5, 386 and 25.4 g/kg DM, respectively. With increasing the proportion of Paulownia leaf in silage, DM, CP, lignin, EE, ammonia nitrogen concentration increased linearly (P<0.05). However, OM, NDF and ADF decreased linearly (P<0.05). By increasing the ratio of Paulownia leaf to corn in th silage, in vitro gas production (GP) in 24, 36 and 48 h, GP potential (coefficient b) and short-chain volatile fatty acids concentration decreased linearly (P<0.05), although it linearly increased ammonia nitrogen concentration and microbial protein synthesis (P<0.05). The carboxymethyl cellulase and filter paper degrading activities decreased linearly with increasing the inclusion level of Paulownia leaf in silage (P<0.05). However, ruminal alpha-amylase and protease activity showed a linear increase (P<0.05). The present study showed that the Paulownia leaf of Tebjoo hybrid variety has a favorable nutritional value as a new forage source in animal nutrition. Also, the preparation of silages including different ratio of Paulownia leaves and corn is recommended for animal feeding in the conditions of significant shortage of protein resources in the country. Future research is warranted to investigate how Paulownia leaf affect ruminant performance.

Phosphorus (P) and calcium (Ca) are macro-minerals for normal growth and development. Phosphorus plays a vital role in muscle function, enzyme activity, lipid metabolism, bone mineralization, maintaining osmotic and acid-base balance, energy metabolism, amino acid metabolism, and protein synthesis. In addition, in layers, P is required to replace tissue metabolites such as nucleotides and phospholipids, maintain skeletal integrity, and produce the egg. Also, Ca is essential for eggshell formation, coagulation, muscle, and nerve function. Bone is a rich source of P and Ca, which can be converted into bone ash (BA) as an organic source to supply P and Ca. Today, BA has been introduced as a suitable alternative for mineral sources of P and Ca in the poultry industry. Barshan et al reported in 2019 that the use of BA compared to dicalcium phosphate caused a significant increase in weight in broilers. The purpose of this study was to use bone ash as a dietary P source and to investigate the P bioavailability in it compared to monocalcium phosphate (MCP) as a standard source. 350 one-day-old broilers were used in a completely randomized design with 7 treatments and 5 repetitions. The dietary treatments were: 1) basic diet containing 0.11% of available P; 2, 4, 3) supplementing the basic diet with 0.05, 0.1, and 0.15% P from MCP source; 5, 6, 7) supplementing the basic diet with 0.05, 0.1, and 0.15% P from BA source. All experimental diets contained 0.78% Ca. At the end of the experiment, the P bioavailability in the BA was obtained based on the P consumed in relation to the daily weight gain and tibia bone ash by the slope-ratio method. Also, the investigated parameters such as digestibility and antibody titer against sheep red blood cells (SRBC) were analyzed in a factorial design. The results showed that based on the weight gain in the grower (10 to 25 days) and finisher (26 to 35 days) periods, the bioavailability of P in BA was 82.37% and 93.24%, respectively. Therefore, it can be concluded that with the increase in the consumption time of BA, its P bioavailability has also increased and it has been able to compensate for the lack of growth well and almost similar to monocalcium phosphate. Also, based on the percentage of ash and P of tibia bone, the P bioavailability was 92.86% and 96.39%, respectively.The factorial analysis of digestibility results also showed that by increasing the level of P in diet and using MCP, the percentage of dry matter digestibility increases significantly (P<0.05). Also, the percentage of P digestibility increased numerically with the increase in diet P and the use of BA. Also, factorial analysis of the data related to the production of antibody titer against sheep red blood cells, we observed that the only significant difference in the main effects was for the total antibody titer and IgG in the secondary response; So that the antibody titer produced in the secondary response was significantly higher in chickens fed with monocalcium phosphate than in chickens fed with bone ash (P<0.05). The results of the bone quality test showed that the shear and tensile stress for the tibia was significantly higher in chickens fed with 0.26% P (P<0.05); but there was no significant difference between chickens fed with MCP and BA. An increase in tensile and shear stress means that more force is required to break these bones, which indicates the greater strength of these bones. Measuring the percentage of ash and phosphorus (P) in tibia bones showed that as the dietary phosphorus level increased, the percentage of ash and phosphorus in the tibia also increased significantly (P<0.05). Additionally, using monocalcium phosphate (MCP) in the diet resulted in a significant increase in tibia phosphorus (P<0.05); however, there was no significant difference in the percentage of tibia bone ash. Given the limited availability and high cost of phosphorus and calcium mineral resources, it is essential to find suitable alternatives. Bone ash (BA) is a rich source of phosphorus and calcium, which can be used as an organic source to supply these minerals in industrial poultry diets. Consistent with our results, Van Haren et al. reported that BA can compensate for growth deficits in broiler chickens, similar to diets supplemented with dicalcium phosphate (DCP) and MCP, compared to diets without a phosphorus source. In general, according to the results, it can be concluded that the bioavailability of P in BA is 92 to 96% compared to MCP. This result shows the good ability of BA to replace mineral sources of P. Also, since the absorbability of MCP is higher than dicalcium phosphate (DCP), it can be concluded that BA can have the same efficiency as DCP and be introduced as a substitute in the poultry industry.

The domestic rabbit Oryctolagus cuniculus from the Leporidae family is a herbivorous mammal and their usual diet is plant sources. Rabbits can tolerate temperatures between 4 and 27 degrees; Of course, the recommended average temperature for them is between 16 and 22 degrees. The average pregnancy period for rabbits is 28 to 31 days. Different forages in rabbit diets affect its optimal growth performance. Rabbits need energy, fiber and protein in their diet. It is recommended to use fodder plants as well as tropical plants to feed rabbits, currently dry fodder such as alfalfa constitutes 40 to 80% of the rabbit's diet. Corn, wheat, barley, and alfalfa are plants with high energy levels, and therefore, the consumption of these plants in diets is very high. Due to the high price of alfalfa and barley, the cost of preparing feed increases, as a result of which the economic efficiency decreases. Tropical plants have a significant amount of protein, fat, minerals and carbohydrates that can affect growth and production. Among the tropical plants are Conocarpus erectus and myrtle. Cenocarpus erectus is a common ornamental plant in tropical and semi-tropical regions, which usually has a height of 1.5 to 4 meters. This plant contains bioactive compounds such as alkaloids, saponin, tannin, phenolic compounds, resin, terpenes, glycosides and antibacterial activity. Myrtle plant is a small shrub with evergreen leaves. Among the effective substances found in the plant, we can mention phenolic acids such as gallic acid, vanillic acid and ferulic acid, tannins, catechin and quercetin. Therefore, the purpose of this experiment was the effect of the use of myrtle and conocarpus plants in the diet of first-generation rabbits on digestibility, antioxidant capacity, blood parameters and microbial population of the digestive tract.

In this project, 12 breeding rabbits of New Zealand breed (10 females and 2 males) were tested, for this purpose, after 28 days of rabbit pregnancy period and 30 days of lactation period of born rabbits, the considered treatments were applied to the born rabbits (each treatment consisted of five repetitions). The treatments include: 1 control treatment, 2 treatments receiving 25% of myrtle plant and 3 treatments receiving 25% of conocarpus plant in the form of completely randomized design. The experiment was conducted on born rabbits for 30 days, and the average weight of the tested rabbits was 250 grams. At the end of the experiment, the digestibility of dry matter, crude protein, insoluble fibers in neutral detergent, insoluble fibers in acidic and organic detergents, antioxidant activity of meat during storage in the refrigerator and in the freezer, microbial population of the digestive tract (population of Lactobacillus, E. coli and coliform bacteria) ) and blood parameters including cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein, glucose, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase concentrations were measured.

The effect of the use of myrtle and conocarpus on the digestibility of tested rabbits, the test results showed that Myrtle and conocarpus plants result in decreasing of the digestibility of dry matter, crude protein, neutral detergent fiber and acid detergent fiber (P<0.05). he results of the treatments on the microbial population showed that the populations of Lactobacillus, E. coli and coliforms in the cecum of rabbits were placed on Mord and Cenocarpus treatments (p > 0.05). The effect of myrtle and conocarpus plant on the antioxidant level of meat during storage in the refrigerator showed that the meat of rabbits fed with myrtle plant had a lower concentration of malondialdehyde and more antioxidant properties than the meat of rabbits fed with conocarpus plant (p< 0.05). The results of the experiment on the effect of treatments on blood parameters showed that the concentration of cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein, and glucose in the treatment using myrtle leaves and the treatment using conocarpus plant were significantly higher than the control treatment. decreased (p<0.05), but regarding the effect of treatments on liver enzymes, the test results showed that there was no significant difference in the concentration of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase between the treatments using myrtle and conocarpus compared to the control treatment (p> 0/05).

The results of the experiment showed that using myrtle plant and conocarpus plant as a substitute for part of alfalfa in the diet of newborn rabbits had an effect on digestibility, malondialdehyde concentration and blood parameters, and according to the positive effects of mord plant and conocarpus plant on the antioxidant concentration of rabbit meat. Whether during storage in the refrigerator or during the storage of rabbit meat in the freezer and blood biochemical parameters, and also considering the cheapness and availability of these plants in some areas, especially in Khuzestan, it can be concluded that the use of 25% of Sometimes myrtle and conocarpus have a positive effect as an effective antioxidant and a herbal supplement in the diet.

Investigating the performance of quinoa (Chenopodium quinoa willd.) forage and determining its digestibility in dried and ensiled formABSTRACT

Quinoa (Chenopodium quinoa willd.) is a dual-purpose crop for grain and forage production. Quinoa has excellent properties such as low water requirement for growth, resistance to drought, salinity and nutritional good quality, which are the reason for the great interest in Iran. The objective of this study was to investigate the performance of quinoa forage and determine its digestibility in dried and ensiled forms.

Three genotypes of quinoa forage (Sejama, Titicaca and Q12) were used in a completely randomized design in dry in the shade and silage forms. All genotypes were sown at the same time and harvested at the time dough of seeds and then were calculated performance of quinoa forage. The harvested forages were chopped and one part was dried in the shade and the other part was ensiled during 60 days in experimental silos. The silages were appearance characteristics evaluated after opening the silos. The samples were ground to pass a 1-mm screen, and then were used for evaluation of rumen degradability and rumen disappearance of dry matter (via incubating the samples inside the bag (pores 50 micrometers) in the rumen of steers) and post-ruminal disappearance of dry matter (via incubating the samples inside the bag in the DAISYII incubator). The samples were incubated in the rumen using polyester bags. All variables were statistically analyzed in a completely randomized design by the Statistical Analysis Systems (SAS).

The results show that, the duration of sowing to the dough stage of seeds was 60 days in Kerman condition, and wet plant yield for Sejama, Titicaca and Q12 genotypes were 34500, 30400 and 36610 kg/ha respectively. The appearance characteristics of silages were in an acceptable condition and were scored 16.75, 17.50 and 18.13 for Sejama, Titicaca and Q12 genotypes respectively in a 0 to 20 scoring system (P<0.01). The average of ruminal and gastro intestinal tract DM disappearance varied between 64.64 to 69.86 % and 69.64 to 75.19 % respectively (P<0.01). Furthermore, rapidly degradable DM fraction (a), in dried forage was lower (39.65 vs. 45.23 %) than in ensiled forage, and slowly degradable DM fraction (b) and rate constant of degradation of the b fraction (c) in dried forage was higher (41.46 vs. 36.39 % and 0.079 vs. 0.063 per hour respectively) than ensiled forage (P<0.01).

In general, the results have shown that quinoa forage had an acceptable digestibility and can be used as a substitution feedstuff with low water requirement in ruminant nutrition.

Various methods have been used to evaluate the digestibility coefficients of nutrients. The total fecal collection (TFC) method is a reliable approach for determining the digestibility of rations in live animals. In this method, animal are kept in a metabolic cage in to collect all the feces, making it the most accurate method for measuring feed digestibility. Total fecal collection (TCF) is one of the most accurate direct procedures to determine apparent digestibility. Despite its accuracy, TFC is labor-intensive and time-consuming when evaluating a wide range of feed samples and requiring a large number of animals. Moreover, animals should be confined in stalls, considering that being surrounded will be accepted by camels for a short period and training is necessary for camels fed with ration containing high amounts of energy. Other disadvantage of keeping the animal trapped includes the potential impact on animal metabolism. These problems led to separation from the animal's normal behavior. Accurate measurement of food intake and fecal collection is a tough work. Digestibility coefficients can be measured indirectly by markers. Various indigestible markers include polyethylene Various indigestible markers include polyethylene, chromium oxide (Cr2O3), acid detergent lignin (ADL) and acid-insoluble ash (AIA) have been used to determine the digestibility of nutrients in different parts of gastrointestinal tract. By the end of 19th century, lignin was considered as a potential internal marker for the estimation of digestibility. Because no specific enzymes exist for degradation of lignin in mammals or in anaerobic bacteria, different results have been re-ported by researchers when using ADL for the estimation of digestibility. Digestibility was reported to be underestimated when using AIA as a natural marker. However, it is difficult to apply this method to grazing animals. AIA is one of the most common internal indicators for determining apparent digestion coefficients. One of the advantages AIA compared to other markers is simplicity of analysis and it does not need special equipment. This study aims to evaluate the nutrient apparent digestibility of different diets in camels using AIA, ADL and TFC.

The field phase of the research was conducted at Asrar Sabzevar Agricultural Research Station, and the laboratory phase was conducted at the Animal and Poultry Nutrition Laboratory of Gorgan University of Agricultural Sciences and Natural Resources. Four male camels (age=1 year, BW= 116.3±9.35 kg) were used in a completely random design to measure the apparent digestibility of nutrients in wheat straw and wheat straw with rice hull using AIA, ADL, and TFC. The experimental period was 42 days (2 periods of 21 days) with 14 days of adaptation to experimental diets and 7 days of data collection. Camels had free access to water, and feeding was done once a day at 8 A.M.

The results showed no significant difference between TFC and AIA for measuring the digestibility of dry matter, organic matter, crude fat, crude protein, neutral detergent insoluble fibers, and acid detergent insoluble fibers in wheat straw and wheat straw with rice hull (P>0.05). However, digestibility was significantly higher in TFC than in ADL (P<0.05).

The recovery percentage of AIA marker was 92.8±92.38 in the diet of 75% wheat straw with 25% rice hull. Based on the study's results, AIA can be used as a suitable internal indicator to measure digestibility in camels if the recovery percentage is more than 90%. The amount of digestibility measured using AIA was close to the amount of digestibility measured using TFC.

With the increase of the population in the last century, the need for protein sources, especially protein with animal origin, has increased. One of the important and inexpensive sources of animal proteins is poultry products. However, many food-borne diseases that are among the most obvious problems related to human health are transmitted to humans through poultry products. Generally, poultry are sensitive to pathogenic bacteria such as Clostridium, Salmonella, and Campylobacter. Campylobacter jejuni and Campylobacter coli are the main causes of bacterial enteritis in humans and account for about 90% and less than 10% of deaths in people with campylobacteriosis, respectively. Poultry farmers use antibiotic growth promoters to prevent the colonization of pathogenic bacteria, but their use has been banned in European Union since 2006 due to antibiotic resistance. However, in order to prevent the reduction of growth performance and mortality caused by the colonization of pathogenic bacteria in the gastrointestinal tract, it is necessary to introduce suitable alternatives. The antimicrobial potential of several medicinal plants, some plant-derived bioactive compoundsas well as some organic acids against a suspension of two Campylobacter serotypes (including 8 strains of C. jejuni and 3 strains of C. coli) has been investigated, under in vitro study. It has been revealed that oregano, rosemary, and cinnamon have a higher potential in reducing campylobacter colonization, among other phytobiotic compounds. Considering that under in vivo conditions, no research has been conducted on these medicinal plants with broiler chickens exposed to Campylobacter colonization. Therefore, this research was conducted with the aim of investigating the growth performance, excreta microbiota, intestinal morphology, and nutrient digestibility of broiler chickens challenged with C. jejuni and evaluating the potential of oregano, rosemary, and cinnamon in reducing the negative effects of this pathogen.

A total of 192 one-day-old chicks were randomly allocated to 6 dietary treatments in a completely randomized design with 4 replicates of 8 birds. The dietary treatments were as follows: 1-negative control (NC; basal diet without additive and without of C. jejuni); 2-positive control (PC; basal diet without additives but challenged with C. jejuni); 3-basal diet + Erythromycin (55 mg/kg); 4-basal diet + oregano powder (3 g/kg); 5- basal diet + rosemary powder (3 g/kg) and 6-basal diet+cinnamon powder (3 g/kg). All chickens were orally gavaged once a day with a suspension of C. jejuni live culture (2×108 cfu/mL, 1 mL/bird) on days 21 to 25, with the exception of those fed the NC. Throughout the experimental period, the birds were fed ad libitum and had free access to water.

The results showed that the C. jejuni, while weakening performance during the growth period, caused an increase in campylobacter colonization and a decrease in lactobacilli counts of the excreta (P<0.05). The reason for the improvement of the microflora can be due to the presence of antibacterial compounds such as thymol, carvacrol, verbenone, and cinnamaldehyde in the composition of the mentioned medicinal plants. Campylobacter jejuni also decreased the digestibility of organic matter and led to a decrease in villous height, villous height to crypt depth ratio, and villi surface area in the jejunum (P<0.05). The reason for the improvement of the intestinal morphology by herbal additives can be due to the improvement of the microflora of the digestive tract. All the negative effects arising from C. jejuni were alleviated by dietary treatments containing feed additives (P<0.05).

In general, it can be concluded that oregano and rosemary have the potential to reduce the pathogenic effects of Campylobacter jejuni and can be used as suitable alternatives to antibiotics in feeding broilers.

To optimize livestock production and health, sufficient amounts of minerals are necessary in the diet. Zinc (Zn) is a trace element and an essential mineral in animal nutrition, and is found in many enzyme systems. The presence of Zn is necessary to ensure the physiological activities of several hormones. In addition, zinc plays an essential role in the metabolism of carbohydrates, proteins, lipids, and nucleic acids, and its deficiency can disrupt several vital cellular reactions. Organic sources of Zn are more biologically active than inorganic sources, and their high accessibility has led to the use of more organic Zn compounds for feeding animals. However, results comparing the bioavailability of organic and inorganic sources of zinc in ruminant nutrition differ. According to the National Research Council (2007), the recommended requirement for Zn in growing lambs is approximately 33 mg Zn/kg DM. The amount of zinc in surface soils of Iran is usually less than 0.8 mg/kg and the plants grown in these soils and used as animal feed are deficient in this element. However, a few studies have been conducted to identify the best source of zinc for growing local lambs; therefore, the present study aimed to compare the effects of supplementing 30 mg Zn/kg DM from common organic sources of zinc (zinc methionine and zinc glycine) with inorganic sources of zinc (zinc sulfate and zinc oxide) on performance, digestibility, blood and rumen parameters in crossbred Zel fattening male lambs.  

This study was conducted at the research station of the Department of Animal Sciences, Sari University of Agricultural Sciences and Natural Resources, Iran. Twenty-five male lambs aged 3-4 months and with average body weight (25.5 ± 1.4 kg) were assigned to five treatments with five repetitions, as a completely randomized design for 70 days, including 2 weeks of adaptation to basal diet and 8 weeks of data collection. The experimental treatments were as follows: 1) basal diet without zinc supplement (containing 19.39 mg Zn/kg DM) as the control group, 2) basal diet + 30 mg Zn/kg DM as zinc methionine, 3) basal diet + 30 mg Zn/kg DM as zinc glycine, 4) basal diet + 30 mg Zn/kg DM as zinc oxide, and 5) basal diet + 30 mg Zn/kg DM as zinc sulfate. Dry matter intake, daily weight gain, and feed conversion ratio were determined. The acid-insoluble ash (AIA) internal indicator method was used to determine the apparent digestibility of feed nutrients. Blood samples were collected on the 70th day prior to the morning meal. To determine rumen parameters, rumen fluid was collected 3h after morning feed consumption. The chemical compositions of the experimental samples, including (dry matter, organic matter, crude protein, ether extract, NDF, and ADF) were measured according to standard methods.

The results showed that total weight gain, daily weight gain, and feed conversion ratio were significantly improved in lambs received organic zinc supplements (zinc methionine and zinc glycine) compared to the control group (P<0.05). The apparent digestibility of organic matter in the diets supplemented with zinc methionine and zinc glycine was significantly higher than that of the other treatments (P<0.05). The digestibility of NDF and ADF in lambs receiving zinc methionine, zinc glycine and zinc oxide was improved compared to the treatment containing zinc sulfate and the control group (P<0.05). Serum glucose and zinc concentrations were significantly higher in all lambs receiving zinc supplements than the control group (P<0.05), but there was no significant difference in serum albumin, cholesterol, urea nitrogen, copper and iron concentrations between experimental treatments. Feeding zinc supplements had no effect on pH, ammonia nitrogen and the concentration of volatile fatty acids in the rumen fluid.

The results of this study show that the addition of 30 mg Zn/kg DM from organic zinc supplements (zinc glycine and zinc methionine) and inorganic zinc supplements (zinc sulfate and zinc oxide) meets the needs of growing lambs fed a basal diet containing 19.39 mg Zn/kg DM. The use of zinc supplements in the diet of fattening lambs improved growth performance, serum zinc and glucose concentrations, and crude fiber digestibility. There were no differences among the treatments supplemented with organic sources of zinc.