بره پرواری

Every day, large amounts of rumen contents are produced as waste in slaughterhouses and are left unused in the environment, which causes environmental problems. Compared to other processing methods, bioconversion is a new and desirable method for managing agricultural waste and residues. As a rich source of enzymes, ruminal liquid can be used in the bioconversion of agricultural wastes. About 35% of all potatoes are thrown away as waste during different stages. Potato waste is a suitable raw material that can be used as a valuable protein by-product during the simple fermentation process by using rumen liquid obtained from slaughterhouse waste and adding various non-protein nitrogen (NPN) sources. For this purpose, the effect of using processed potato waste with rumen contents was evaluated in the diet of fattening lambs.

The slow-release NPN source used in this experiment, with the brand name Nitrosa, contained a 40% nitrogen equivalent to 250% of crude protein. The best level of NPN for processing potato waste using the potential of rumen liquid microorganisms based on the results of the crude protein content of the solid part produced during incubation for use in the farm sector was determined at 3 g of nitrogen from a Nitrosa source. A constant ratio of rumen liquid to waste potatoes (2:1) was chosen for the ratio of 400 ml of rumen liquid + 200 g of damaged potatoes. The solid part of the fermented product of the semi-industrial production of potato waste processing with rumen liquid and urea was included in the diet of 24 heads of 5-month-old Romanov-Moghani crossbreed lambs with four diets and six replications (lambs) at three replacement levels of 2.5, 5, and 7.5%of the basic diet of the 78-day fattening period of the lambs. The average weight of the lambs in the groups was 31.1 kg at the beginning of the period. The experimental groups were 1) basic diet (without processed potato waste), 2) basic diet with 2.5% processed potato waste (the dried solid phase), 3) basic diet with 5% processed potato waste (the dried solid phase), and 4) basic diet with 7.5% processed potato waste (the dried solid phase). To determine the concentration of blood metabolites in all lambs, blood was drawn from the jugular vein 3 hours after consuming feed on the 60th day of the fattening period. Then, the blood parameters, including glucose, blood urea nitrogen, cholesterol, triglyceride, total protein, albumin, high-density lipoprotein, alanine aminotransferase, aspartate aminotransferase, and BHBA, were determined with Pars Azmoun kits using a spectrophotometer. Total antioxidant capacity, glutathione peroxidase, and superoxide dismutase were measured using RANDOX kits. The concentration of malondialdehyde was measured using the reaction of thiobarbituric acid with malondialdehyde, with the Ransod RANDOX kit by an autoanalyzer.To measure the carcass characteristics, the lambs were weighed at the end of the fattening period. The measured traits included hot and cold carcass weights, tail weight, heart, liver, kidney, and lung of the slaughtered lambs. Carcass yield was calculated by dividing the carcass weight by the final live weight. All the carcasses were separated from the area between the last back vertebra and the first tail vertebra between the slip joint, and the carcass without the tail was weighed by a digital scale to obtain the carcass weight without the tail. The tails of all the carcasses were separated from the part between the last vertebra of the back and the first vertebra of the tail between the slip joint and weighed with a digital scale. The tail percentage was calculated by dividing the tail weight by the carcass weight.

There was no significant difference between the groups in the dry matter intake, FCR, daily weight gain, and final weight of lambs during the fattening period. The average daily weight gain levels of the lambs of the 5% level were 228.6, 218.0, and 231.0 g for the second, third, and whole periods, respectively. The results showed that the lambs of this level gained the lightest body weight with a final weight of 49.18 kg. The lambs of the 2.5% level showed the highest amount in line with the data of the FCR in the whole period with an average daily weight gain of 241.6 g. Therefore, the final weight of Moghani lambs of this level at the time of slaughter was 49.99 kg, that is, the heaviest lambs for this group. The results of blood analysis showed no significant differences between the experimental groups, and blood factors were not influenced by different substitution levels of the experimental substance. The antioxidant activity index and the concentration of malondialdehyde in the blood serum of lambs were not affected by the diets. From the results and data analysis, no significant differences were observed in the weight factors of the hot carcass, heart, liver, kidney, lung, back fat thickness, tail, and finally cold carcass.

The results show that it is possible to improve the nutritional value of potato waste by using rumen contents to process potato waste while supplementing it with urea and use the produced experimental material in feeding ruminants. In this research, the semi-industrial production of the experimental material of potato waste processed with rumen contents and its replacement at three levels of 2.5, 5, and 7.5% in the diet of fattening lambs showed no significant differences between the groups in dry matter consumption, FCR, daily weight gain, and final weight. Moreover, no significant differences were observed between the experimental groups in carcass characteristics and meat yield. The experimental material of potato waste processed with rumen contents, without significant differences and yield reduction, could meet the requirements of fattening lambs.

 Animals need vitamins A, D3, and E to improve their performance and health. Vitamin A has an active role in maintaining all epithelial cells in the body and plays an important role in bone growth. Vitamin D3 plays an important role in increasing the absorption of calcium and phosphorus, in addition to the formation and calcification of the bones in animals. Vitamin E is a fat soluble vitamin which is both a growth-promoting vitamin and is considered an antioxidant. These vitamins also play an important role in improving the immune system in ruminants. Ruminants cannot produce vitamins A, D3, and E in their body; therefore, to meet physiological requirements and maintain high production performance, they need to be provided with an exogenous regular intake of vitamins A, D3, and E in their diet. Several studies have been carried out on the effects of dietary or injectable vitamin AD3E supplements on fattening lambs. This study aimed to determine the effects of various forms of AD3E supplementation on growth performance, rumen fermentation, protozoa population, and blood parameters in Mehraban lambs by in vivo and in vitro experiments.

 The project comprised two in vitro and in vivo experiments. In this experiment, the in vivo growth parameters such as final body weight, total weight gain, average daily gain, average daily gain, dry matter intake, feed conversion ratio, the ruminal fermentation parameters such as pH, ammonia nitrogen, total volatile fatty acids, blood biochemical metabolites [blood urea nitrogen (BUN), cholesterol, triglyceride, glucose, albumin, HDL, LDL, and malondialdehyde (MAD)], protozoa count, and in vitro gas production, organic matter digestibility, methane gas production, metabolizable energy, and short-chain fatty acids were studied. This experiment consisted of a 14-day adaptation period and a 60-day experiment. Twenty Mehraban lambs (body weight of 41.3±0.5 kg) were divided into four groups with five replicates in each group using a completely randomized design. The treatments included 1) the control group received a base diet without vitamin supplements, 2) injectable vitamin AD3E, 3) rumen-protected vitamin AD3E as a part of concentrate, and 4) AD3E vitamin in drinking water. Feed intake and body weight of lambs were recorded weekly during the fattening period. The samples of blood and rumen liquid were collected from the lambs on the 30th and 60th days of the experiment.

 The results indicated that the gas production, digestible organic matter, metabolizable energy, and short-chain fatty acids were reduced due to vitamin AD3E supplementation compared with the control group (P<0.05). Growth performance was not different when supplemented with AD3E, but for the rumen-protected vitamin, the average daily increase was 48 g more than that in the control group. The feed conversion ratio showed a significant decrease in AD3E water-soluble vitamins compared with the control group (P<0.05). The pH was not influenced by experimental treatments. The ammonia concentration was higher in treatments 3 and 4 (P<0.05), and the protozoa count was reduced due to vitamin AD3E supplementation (P<0.05). The BUN serum concentration was lower in treatments 2 and 3 compared with other treatments (P=0.008). Vitamin supplementation with AD3E administered in water or its injection made a significant increase in cholesterol concentration (P=0.002). Blood concentration of triglyceride showed a significant increase in treatment 4 (P=0.007). Plasma concentration of HDL was lower in lambs who received rumen-protected AD3E compared to the control group (P<0.05). Experimental treatments did not affect plasma glucose, total protein, albumin, LDL, and MAD concentrations of fattening lambs (P>0.05). Plasma concentration of BUN on day 60 was higher compared to the 30th day in all treatments (P<0.05). However, plasma concentrations of triglyceride and glucose were lower on day 60 compared to the 30th day of the experiment in all groups.

 Results showed that vitamin AD3E had no significant effect on growth performance; however, it was greater in the vitamin group treated with rumen protection than in the control group. Gas production, protozoa population, and ammonia nitrogen decreased compared to control. Higher doses of vitamins, especially the rumen-protected vitamin AD3E, are recommended in larger sample sizes and for longer periods.

 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.

Cottonseed is a valuable feed ingredient due to its high fiber and energy content, which can enhance the energy and protein levels in animal diets. In the irradiation or micronization method, using infrared rays and without damaging the fat cells, while maintaining the profile of fatty acids, the seed is heated, and its anti-nutritional factors are destroyed. Sodium hydroxide treatment can affect ruminal degradability and nutrient digestibility, ultimately influencing performance. This study aimed to assess the impact of feeding processed cottonseed on the performance, blood parameters, nutrient digestibility, and feeding behavior of fattening male lambs.

The study was conducted at the animal husbandry facility in Ghala Khan village, North Khorasan province. For this purpose, 40 Afshari male lambs (4-6 months old) with an average weight of 27.6±4 kg were randomly allocated to four treatments with ten replications for 84 days. The experimental treatments included: 1) diet containing whole cottonseed, 2) diet containing ground cottonseed, 3) diet containing micronized cottonseed, and 4) diet containing sodium hydroxide-treated cottonseed. For irradiation, 5% of drinking water was added to the cottonseed and it was rotated inside a cylinder for 10 minutes at a speed of 20 revolutions per minute until the water was completely absorbed by the seed. Then, the seeds were exposed to infrared radiation with an irradiation distance of 12 cm for 60 seconds in a gas flicker micronizer and immediately after leaving the micronizer, they were placed between two metal rollers. They were pressed and filled at a distance of 1 mm. The chemical processing of the foam samples was done in such a way that first a 4% solution of sodium hydroxide (40 grams of sodium hydroxide in 100 milliliters of distilled water) was prepared. This solution was mixed with cottonseed samples to obtain four grams of sodium hydroxide per 100 grams of dry matter of cotton seeds, and then it was kept and dried in open air for 48 hours. Lambs were kept in individual stalls during the experiment and had free access to water during the period. Fecal and feed samples were collected during the last week of the experimental period for determining digestibility. Insoluble fiber levels were determined using Van Soest's method, and nutrient digestibility was assessed using acid-insoluble ash as an internal marker. Blood samples were collected on the last day and before morning feeding. Feeding behavior (resting, rumination, chewing, eating) of the lambs was measured continuously for 24 hours on the last two days of experiment.

The micronized cottonseed increased final weight as well as dry matter digestibility (P<0.05), and improved feed conversion ratio. There was no significant difference in feeding behavior in lambs fed with different treatments of cottonseed. Blood cholesterol, triglyceride and urea levels were highest in lambs fed micronized cottonseed and lowest in those fed whole or ground cottonseed (P<0.05).

Our findings indicated that micronized cottonseed and processing of cottonseed by sodium hydroxide could increase daily weight gain and improved the feed conversion ratio in fattening lambs, suggesting their potential inclusion in feedlot diets.

Recently, nanoparticles have been produced and marketed using nanotechnology. Reducing the size of particles to nanoparticles (size less than 100 nm) increases the surface-to-volume ratio and changes other material properties. Increasing the contact surface in nanoparticles causes their interaction with organic and inorganic molecules to be done differently. Among the minerals, copper is an essential, scarce element that performs various functions in living organisms. It has been reported that copper nanoparticles have beneficial effects on animal performance and can replace copper sulfate. Also, nano copper oxide has several advantages over copper sulfate, including improved effectiveness, lower dosage with better results, no interference with other materials, and less disposal in the environment, and can replace copper sulfate. High copper in the diet has benefits such as antibacterial activity, increasing growth hormone secretion, increasing feed intake and production performance. However, environmental pollution and subsequent accumulation in feed and water can affect vital organs such as the liver and kidney.The objective of this study was to investigate the effect of different copper forms and levels (copper nano oxide and copper sulfate) on performance, blood parameters and immunity in Romanov-Moghani crossbred lambs.

This research was conducted using 30 lambs in the form of a completely randomized design with 5 experimental groups and 6 replications (lambs) in each group. The duration of the experiment was 56 days. The experimental diets of this research include: 1) basal or control diet (CON; without copper supplementation), 2) basal diet + 10 mg of copper per kg of dry matter in the form of copper sulfate (CuS10), 3) basal diet + 20 mg of copper per kg of dry matter in the form of copper sulfate (CuS20), 4) basal diet + 10 mg of copper per kg of dry matter in the form of copper nano oxide (CuN10), 5) basal diet + 20 mg of copper per kg of dry matter in the form of copper nano oxide (CuN20). Lambs were randomly grouped based on body weight and each group was fed with one of 5 experimental diets. On the 30th and 56th days of the experimental period, blood samples were collected from the jugular vein 3 hours after the morning meal. Next, after separating serum and plasma, the samples were kept at -20◦C until the analysis. The determined blood parameters include the concentration of copper, zinc, selenium, malondialdehyde, glucose, cholesterol, triglyceride, total protein, albumin, urea, beta-hydroxybutyrate, liver enzymes (ALT and AST). Total antioxidant capacity, activity of glutathione peroxidase, superoxide dismutase and catalase enzymes were also determined.After killing the animals, meat samples were taken from the 12-13 intercostal eye muscle to determine the concentration of copper, zinc and selenium elements, and liver samples were also taken. Liver, meat and blood samples were digested by the method of Kechoui et al. (2013). For the analysis of blood and tissue samples, ICP-OES (model: Optimum 7300 DV) was used at Isfahan University. At the time of animal slaughter, the quantitative and qualitative characteristics of the carcass, including the weight of the heart, kidney, lungs, liver, and tail, along with the cold carcass and the hot carcass, were recorded. The resulting data were analyzed in the form of a completely randomized design using SAS software (2003). Means were shown as Least Squares (LSMEAN) along with standard error and mean comparisons at a significance level of five percent.

The results of this study showed that the use of copper sulfate and copper nano oxide at the levels of 10 or 20 mg/kg dry matter of the diet had no significant effect on the performance parameters of fattening lambs, in terms of body weight, live weight gain, dry matter intake and feed conversion ratio (P>0.05). Also, the findings of this research showed that the concentration of blood urea in 30 days increased significantly with CuS10 and CuN10 treatments (P<0.05). Other blood parameters such as glucose, cholesterol, triglyceride, albumin, protein, BHBA, AST, ALT enzymes and antioxidant indices superoxide dismutase, glutathione peroxidase and total antioxidant capacity were not affected by the experimental treatments (P>0.05). The supplemental feeding of nano copper oxide increased catalase enzyme activity in blood samples (P<0.05). Copper concentration was increased in the liver significantly as a result of feeding 20 mg of copper in the form of copper nano oxide(P<0.05). Supplemental feeding of copper sulfate decreased the concentration of selenium in meat compared to the control group (P<0.05). Carcass characteristics including the percentage of hot carcass and cold along with the percentage of internal organs (tail, heart, liver, kidney and lungs) were not significantly different among the treatment groups (P>0.05).

According to the present results, the use of mineral and nano forms of copper at levels of 10 or 20 mg/kg dry matter of the diet had a significant effect on parameters such as blood urea, malondialdehyde, catalase enzyme activity, percentage of copper in blood and selenium in meat. However, no significant difference was observed in performance and most blood parameters, antioxidant indices, total antioxidant capacity, activity of superoxide dismutase, glutathione peroxidase enzymes, carcass characteristics of fattening lambs and clinical signs of poisoning in lambs of treatment groups. This shows that the levels used in this study did not have the potential of poisoning and health risks for the tested lambs. Considering the improvement of liver concentrations of copper in the treatment receiving copper nano oxide source; it seems that the use of 20 mg/kg of dry matter of copper nano oxide can be a useful strategy in reducing the disposal of this element and reducing environmental pollution.

Whole plant barley and triticale were chopped and ensiled separately. After three months, half of each silage was mixed with the roughage and concentrated and prepared in 30 kg packed silages. Four rations including: 1) TMR based on barley silage, 2) TMR base on triticale silage, 3) TMR silage based on barley silage 4) TMR silage based on triticale silage were prepared. In a completely randomized experiment 64 male Zel lambs of about four months age and 20.8 kg average body weight, using in a completely randomised experiment with four treatments and for replicates. During 84 days experimental period, daily feed intake was recorded and body wieht changes was recorded three weeks interwals. Daily weight gain of lambs fed ration 3 was significantly (P<0.05) higher (147 grams), than those fed ration 1 and 2 (147g vs. 108 and 130 g). The highest amount of daily dry matter intake was observed in lambs fed ration 3 (1213 grams) but the lowest amount in lambs fed ration 1 (1213 vs. 937 g) (P=0.03). Feed conversion ratio was improved in lambs received diet comparing to the other treatments (P=0.03). The average carcass wieght was increased (15.3 vs 13.6 and 12.7 kg) in lambs fed diet 3 comparing to the diet 1 and 2 (P<0.05). Lambs fed diet 4 had more abdominal fat than those fed diet 2 (P<0.05). It can be concluded that the use of total mixed silge based on the barley and triticale may improved the fattening performance of lambs.

The effects of non-protein nitrogen (NPN) source and feeding level on growth performance, digestibility of nutrients, blood metabolites and nutritional behavior of fattening lambs have been studied. 28 male lambs (age: 4-5 month; BW: 36.1±3) were used in a 2×2 factorial design with four experimental treatments for 60 days. Two type of NPN (urea and biuret) were used twice and three times a day. The results showed that lambs consuming biuret had a higher ADG and lower FCR (P<0.05) than those fed urea. The effect of NPN source on ADF digestibility was significant (P>0.05). There was no significant difference in blood glucose concentration between experimental treatments (P>0.05). The concentration of urea and blood urea nitrogen before and six hours after morning feeding was higher in lambs consuming urea than biuret (p<0.0.5). The concentration of total protein was significantly higher six hours after feeding in lambs consuming urea than biuret (P<0.0.5). The type of NPN source was not significant on the nutritional behavior of lambs (P>0.05) however, feeding level had a significant effect on eating behavior, chewing, eating dry matter and eating NDF consumption (P<0.05). In general, it can be concluded that the use of biuret improves growth performance and nitrogen metabolism as compared to urea in fattening lambs.

Today, the increase in the world's population, especially in third-world countries, has caused an increase in the demand for livestock products, which will subsequently require more livestock products and more food resources to meet these needs. The use of waste from factories of agricultural transformation industries in feeding livestock helps to make the cost of breeding more economical. Since cotton by-product is considered a product of cotton ginning factories, it can be said that due to its nutritional value, its use in animal diets is to avoid wasting this huge source of feed. Cotton by-product contains 86.9% dry matter, 12.3% crude protein, 57.7% NDF, 12.2% ash, 1.7% calcium, 0.31% phosphorus, and 1.06% net energy. The results of the studies showed that cotton waste can be used as a source of protein in the diet of fattening animals. This study aimed to assess the effect of feeding different levels of cotton by-products on performance, degradability, rumen fermentation parameters, microbial protein, and microbial population in fattening lambs.
In this study, 24 male Afshari lambs with a mean weight of 30±0.7 kg and a mean age of four months were used in a completely randomized design with four treatments and six replications for 90 days. The experimental treatments included: 1) a diet without cotton by-product (control), 2) a diet containing 33.33% cotton by-product instead of alfalfa, 3) a diet containing 66.66% cotton by-product instead of alfalfa, and 4) a diet containing 100% cotton by-product instead. Hay was based on dry matter. The cotton by-product used in this study was obtained from Mahosh cotton ginning factory located in Razavi Khorasan province, Neyshabur city, Iran. After entering the test site, it was chopped and then mixed with alfalfa in certain percentages; it was consumed by experimental lambs. Growth performance traits including daily feed intake, daily weight gain, and feed conversion ratio were measured during the experiment period. To measure ruminal fermentation parameters and bacteria and protozoa populations, the rumen fluid of the experimental lambs was taken from the rumen on the 90th day of the experiment, three hours after morning feeding using an esophageal tube. To determine urine purine derivatives, the total 24-hour urine production of each animal was collected in a special container under the metabolic cage on five sampling days. The number of three fistulaized Afshari sheep with a mean weight of about 50±2 kg and a mean age of approximately 11 months was used to estimate the parameters of degradability of dry matter, crude protein, and NDF.
The growth performance results showed that replacing 100% cotton by-products instead of dry alfalfa increased feed intake, increased daily weight, and decreased feed conversion ratio (P<0.05). The results of ruminal parameters showed that the treatment containing 66.66 and 100% replacement of cotton by-products instead of dry alfalfa had the highest concentration of total volatile fatty acids, acetic acid, and acetate to propionate ratio (P<0.05). There was no significant difference between the experimental treatments in the amounts of purine excretion derivatives and microbial protein production. The use of 66.66% of the substitute cotton by-product instead of dry alfalfa in the diet increased the total population of rumen fluid bacteria (P<0.05) but had no significant effect on the protozoan population. The results of meta-measures of dry matter degradability, crude protein, and NDF showed that there was no significant difference between experimental treatments.
The general results of the study showed that replacing cotton by-products by 66.66 or 100% instead of dry alfalfa in the diet improved the performance, increased the bacterial population, and concentration of total volatile fatty acids in the rumen fluid of fattening lambs. The use of cotton by-products can be a suitable substitute for alfalfa in the diet of fattening lambs without negative effects on growth performance and rumen fermentation indices.

Approximately 80 to 85 percent of the costs of raising fattening lambs are related to the cost of feed. Therefore, conducting research in order to determine the functionally and economically optimal ration for fattening lambs will help to improve the country's animal husbandry situation. On the other hand, with the advancement of technology and the use of new methods for converting and processing food, many sources of animal feed have become competitive with human food sources, including corn, wheat and barley. In order to compensate for this deficiency, exploitation and optimal use of agricultural wastes and by-products as feed in feeding ruminants to improve livestock production is inevitable. One of these agricultural wastes is the by-product of corn called corn germ meal, which is produced during the process of extracting corn germ with dry or wet milling process to produce corn germ to produce corn oil for human consumption. Therefore, based on this, this research was conducted to investigate the effect of replacing soybean meal (SBM) with corn germ meal (CGM) in the diet on performance, digestibility, chewing behavior, and blood parameters of fattening lambs.

In this research, 30 breeding lambs (with an average weight of 32.1±2.7 kg) were randomly divided into 3 groups with 10 repetitions. The lambs of the control group were fed with diet without corn germ meal. Other groups were fed by replacing 50% and 100% soybean meal with sprout meal in the diet for 84 days. At the beginning of the research, in order to ensure the complete health of the lambs and being free from parasites, parasite control (disinfecting the place and eating albendazole tablets) was carried out, and enterotoxemia vaccine was injected subcutaneously. Finally, the animals were randomly assigned to each of the experimental treatments and placed in individual cages. During all stages of the research, animals had free access to rock salt and clean drinking water. Lambs were weighed every 14 days. The amount of food consumed and post-feeding was recorded on a daily basis. The diet of fattening lambs was adjusted according to the recommended requirements of the tables of the National Sheep Research Association, and the experimental treatments were the same in terms of protein and energy content. In order to calculate the weight changes, the animals were weighed weekly after 16 hours of starvation using a digital scale. The daily feed was completely mixed to the animals and the remaining feed for each animal was weighed and recorded every day. The feed consumption of each animal was also calculated from the difference and then the remaining manger of each animal was calculated. For samples related to digestibility, firstly, feed, waste and feces samples collected from each animal on day 77 to 82 were collected for five days. In order to measure blood metabolites, blood samples were taken from the jugular vein of lambs using heparinized tubes and syringes on the 60th day. Chemical kits of Pars Azmoun company and autoanalyzer were used to measure blood glucose, urea and triglyceride levels. Finally, during the 82nd and 83rd days of the test period, chewing activity was measured for a duration of 48 hours. The time spent for the activities of eating, resting and ruminating was recorded visually every 5 minutes and assuming that the activity continued for the last 5 minutes for all the animals during the day and night hours. Finally, the results of the experiment were analyzed with SAS statistical program.

According to the results obtained in the present study, replacing soybean meal with corn germ meal in fattening lambs did not show any difference in body weight gain on days 28, 56 and 84. In addition, total body weight and daily weight gain during the entire experimental period were not affected by the replacement of soybean meal with corn germ meal in the diet of fattening lambs. Also, weekly feed consumption, daily dry matter consumption and feed conversion ratio were not affected by the consumption of corn germ meal in the diet of fattening lambs. Also, the results of the apparent digestibility of the nutrients of the experimental diets showed that the digestibility of dry matter, organic matter, crude protein, insoluble fibers in neutral detergent, insoluble fibers in acidic detergent and ether extract of fattening lambs was not affected by corn sprout meal feeding. The results of the chewing behavior of the lambs showed that there was no significant difference between the different treatments in terms of time of eating, rumination, chewing, resting and standing. The results of some blood serum parameters showed that the concentrations of triglyceride (P=0.031) and urea (P=0.014) in lambs fed with corn germ meal showed a significant increase compared to the control group; Anyway, replacing soybean meal with corn sprout meal in this study had no effect on blood glucose concentration.

According to the results obtained from the present research, corn germ meal can be used in the diet of fattening lambs without reducing performance, feed consumption, nutrient digestibility, chewing behavior and blood serum parameters, and this product can be completely replace soybean meal.

Nowadays, excessive exploitation of natural resources and excessive grazing of pastures has led to a sharp decrease in feed sources for ruminant animals. Considering the fact that today most of the feed materials needed by livestock are expensive, replacing them with cheaper feed materials, in a way that does not result in a decrease in livestock productivity is of great importance. Oak fruit is one of the cheap feed that can be used in animal feed. Livestock feeding with oak fruit is particularly important due to high production per unit area, non-competition with human nutrition and easy access. The Alborz Mountains in the northern part of the country are covered by oak forests, from Talash forests to Naharkhoran forests in Gorgan, according to the climatic conditions and altitude, there are several species of oak trees. Therefore, considering the abundance of oak fruit in the forests of the central part of Mazandaran province and also the lack of scientific studies on the effects of consumption of oak fruit processed with sodium hydroxide and urea on degradability indicators and microbial protein production, the present study is to investigate the effect different levels of oak fruit processed with sodium hydroxide and urea on  ruminal fermentation, morphology, ruminal degradability and  microbial protein synthesis in crossed Zell and Atabai fattening male lambs.

In the first study, from the number of 20 fattening male lambs mixed with Zel and Atabai with an mean age of 5.5±0.38 months and an initial weight of 27±0.4 kg in a completely randomized design with 4 treatments and 5 repetitions for 90 The day was used. The experimental treatments included the control group (no oak fruit + polyethylene glycol) and treatments containing levels of 10, 20 and 40% in the dry matter of oak fruit processed with sodium hydroxide and urea in the diet. In the second study, the number of 3 fistulaized Zell sheep with mean weight of about 40 kg and an average age of approximately 10 months were used to estimate the parameters of degradability. The oak fruit used in this study was randomly collected from oak trees of the Bolandmazo species (Quercus castaneifolia C. A. Mey) in different forest areas of Mazandaran province from late summer to early autumn. Data obtained were analyzed by statistical software SAS (version 1.9).

The results of rumen fermentation parameters showed that there was a significant difference between experimental treatments in ammonia nitrogen, total volatile fatty acids, bacterial population and protozoa of rumen fluid (P<0.05). The highest and lowest concentrations of ammonia nitrogen were observed in the control group and the 20% processed oak fruit treatment, respectively. In the concentration of total volatile fatty acids, the treatment of 20% of processed oak fruit had the highest concentration and the treatment of 40% of processed oak fruit had the lowest concentration. There was no significant difference between the experimental treatments in the results of the morphological characteristics of the rumen villi. Degradability parameters of dry matter and crude protein were determined under the influence of experimental treatments (P<0.05). In the parameters of degradability of dry matter and crude protein, rapidly degraded fraction, constant rate of degradation and effective degradability with different passage rate had significant differences between experimental treatments (P<0.05). In dry matter degradability parameters, the control group and the treatment group of 40% processed oak fruit had the highest and lowest value of rapidly degraded fraction and constant rate of degradation, respectively. The results of gas production parameters showed that there was a significant difference between experimental treatments in gas production potential, short chain acids, digestibility of organic matter and metabolizable energy (P<0.05). The results of excretion of purine derivatives and microbial protein production showed that there was a significant difference between the experimental treatments in the amounts of excreted allantoin, xanthine+hypoxanthine, excreted purine derivatives, absorbed purine derivatives and microbial protein (P<0.05).

The general results of the current research showed that an increase in the concentration of volatile fatty acids, degradability of dry matter and crude protein, as well as the production of microbial protein was observed with consumption of 40% processed oak fruit. Also, an increase in the population of ruminal fluid bacteria and protozoa was observed in the treatment of 20% processed oak fruit. In general, it is recommended to use the level of 40% of processed oak fruit in feeding fattening lambs.

This study was aimed to optimize the suitable slaughter weight of Afshari fattening male lambs by using the feed conversion ratio curve and carcass tissue composition. Thirty-two Afshari male lambs, averaging 105±15.0 (SD) days of age and initial body weight of 30.2±3.6 (SD) kg, from the commercial herd in the Animal Science Research Institute of Iran were used. Metabolizable energy (ME) contents were, 2.79, 2.78, 2.72 and 2.69 Mcal/kg dry matter (DM) and crude protein (CP) contents were 146, 128, 109, and 103 g/kg for the 1, 2, 3, and 4 diets, respectively. The results showed, DMI and feed conversion ratio (FCR) had an increasing trend, with the increasing length of fattening period. The daily weight gains, had an upward trend from the beginning of the experiment to the 56th day, and then it decreased with a relatively small slope. Dressing percentage increased, with increasing length of the trail, so that it was significantly higher in the last stage of slaughter (55.3%) than the previous (52%). Weight percent of digestive tract (stomach and intestine), liver and, lung decreased but weight percent of internal fat increased, with a significantly difference, when experimental period increased. The highest percent of fat-tail weight, was observed in the last stage of slaughter (19.8) and the lowest was observed in the first stage of slaughter (14.2). Back fat thickness increased with increasing length of the experiment, so that a significant difference observed between the last stage of slaughter and the previous stages.

The aim of this research was to evaluate the effects of different levels of camelina sativa meal (CSM) (native variety of Soheil) on nutrients intake, growth performance and apparent nutrient digestibility of Lori-Bakhtiari fattening lambs. A total of 30 fattening lambs with average age of 4 to 5 month (average live weight of 34.5 ± 5.0 kg) were used in a completely randomized design with 3 treatments and 10 replications for 56 days. Experimental diets were replacing soybean meal with CSM at levels 0 (control), 5 and 10% diet of dry mater (DM). The results showed that by increasing the level of the CSM in the diet up to 10%, except fot ether extract consumption which increased linearly (P <0.05), intake of other nutrients including DM, organic matter (OM), crude protein (CP), neurtal detergent fiber (NDF) and acid detergent fiber (ADF) were similar among experimental diets (P >0.05). In term of performance traits, final body weight, total weight gain, average daily gain and feed conversion ratio were unchanged during the entire fattening period and once every two weeks by feeding experimental diets (P >0.05). Also, experimental diets did not affect nutrients digestibility of DM, OM, CP, NDF and ADF (P >0.05). In general, the results of the present study showed that the use of native variety of camelina meal instead of soybean meal as a new protein source is recommended up to 10% in fattening lambs diet.

This study was conducted to evaluate the effect of different levels of probiotic yeast supplement (Saccharomyces servicii) in the diet on growth performance, carcass traits, and some blood and rumen parameters in Zell cross-breed fattening lambs. For this purpose, a total of 24 crossbred of Zell-Atabai lambs with a mean weight of 26±2 kg and a mean age of 5.5 months were used in a completely randomized design with 4 treatments and 6 replications for 90 days. The results of growth performance showed that the treatment with 8 grams of probiotic supplement significantly had the highest final fattening weight, daily weight gain and the lowest feed conversion ratio (P<0.05). In apparent digestibility of nutrients, treatment with 8 grams of probiotic supplement had the highest digestibility of crude protein and NDF (P<0.05). In the results of blood parameters, there was a significant difference in the concentration of glucose, cholesterol and HDL between experimental treatments (P<0.05). The results of carcass traits showed that in live weight, thigh percentage and shoulder percentage, treatment with 8 grams of probiotic supplement significantly had the highest values (P<0.05). The highest value of pH, VFA, acetic acid, propionic acid, total population of bacteria and ruminal fluid protozoa was observed respectively in the treatment of 8 grams of probiotic supplement (P<0.05). The general result of the research showed that the consumption of 8 grams of yeast probiotic supplement improved growth performance, valuable carcass parts, apparent digestibility and morphological characteristics of rumen villi in fattening lambs.

The lack of animal feed resources and the increase in animal feed costs relative to the total production costs have created challenges in supplying society with animal protein. Therefore, correctly estimating the nutritional value of feed, especially protein sources, can be an important step in meeting the needs of livestock and reducing production costs. Protein is the most important and expensive nutrient used in ruminant diets. Using non-protein nitrogen (NPN) sources such as urea or its products can be considered a cheap alternative source in animal feeding. Iran is one of the most important urea-producing countries in the world; therefore, using urea or its slow-release products as a feed additive in animal nutrition can be beneficial. In the past years, various sources of slow-release urea have been produced and used in animal feeding. Biuret (heated urea) is one of the slow-release urea compounds, and its production cost is lower than other slow-release urea sources. Compared to urea, it has less solubility in water and is converted to ammonia in the rumen at a much slower rate. It is also less toxic than urea and has a lower negative effect on feed palatability, so it can be used to a greater extent than urea in the diet of ruminants. Biuret is very safe and it can be included in the diet of animals in an amount of 20 times higher than the toxic dose of urea. Biuret usually contains 248.5% crude protein (39.8% nitrogen content), which is a little less than urea. On the other hand, increasing the daily feeding frequency is one of the management methods that may improve the productive performance of livestock, as well as the quantity and quality of the carcass. Increasing the feed frequency may improve nitrogen retention and reduce body fat. It is believed that increasing the frequency of daily feeding will keep the feed fresh, reduce the amount of feed waste, and improve livestock performance. Therefore, this study aimed to investigate the effect of NPN source, in high-protein diets, and feeding frequency on growth performance, rumen parameters, and the activity of rumen microbial enzymes of fattening lambs.
Twenty-eight male Lori-Bakhtiari fattening lambs (age: four to five months; live weight: 36.1±3 kg) were assessed for 60 days using a 2×2 factorial experiment in a completely randomized design with four treatments and seven replications. The experimental high-protein diets (16% of DM) contained urea or biuret, which were given to the lambs in the form of a total mixed ration two or three times a day. The lambs were kept in 1×1.5 m2 individual stalls. Nutrient intake, growth performance, and ruminal parameters [on day 45 of the experiment at fasting (before morning feeding), three, and six h after feeding] including pH, ammonia and volatile fatty acid concentrations, and microbial enzyme activity were measured.
Results showed that intakes of dry matter, organic matter, crude protein, neutral detergent fiber and ether extract, final weight, and total weight gain were not affected by NPN type or feeding frequency (P<0.05). Compared to urea, lambs consuming biuret had higher average daily gain and better feed conversion ratio (P<0.05). The ruminal pH was not affected by the NPN source, feeding frequency, and their interaction (P<0.05). Rumen ammonia nitrogen concentration at three and six hours after morning feeding was significantly higher in lambs fed the diet containing urea than in biuret (P<0.05). The effect of NPN source, feeding frequency, and their interaction was not significant at 0 and six h after feeding on the ruminal concentration of total volatile fatty acids (VFA), acetate, propionate, butyrate, valerate, iso-valerate, and acetate to propionate ratio (P<0.05). However, feeding a diet containing biuret and given three times a day increased total VFA and acetate concentration at three hours post-feeding (P<0.05). The ruminal activity of carboxymethyl cellulase at 0, three, and six hours after feeding increased in animals fed biuret-containing diet compared to urea (P<0.05). However, rumen protease activity significantly increased in lambs fed a urea-containing diet than biuret-containing diet (P<0.05). Feeding three times a day increased the activity of carboxymethyl cellulase at three hours post-feeding (P<0.05). Filter paper degrading activity at three and six hours after feeding in lambs fed biuret was significantly higher than those fed urea (P<0.05). The activity of microcrystalline cellulase and α-amylase was not affected by the NPN source, feeding frequency, and their interaction (P<0.05).
Using biuret compared to the urea, in high-protein diets, and feeding diets three times a day, compared to two times a day, improved rumen fermentation parameters and performance of fattening lambs.

Based on current knowledge, it has been proven that many edible ingredients in addition to meeting the needs of creatures, in terms of energy and protein, contain compounds that affect cellular actions and intracellular signaling pathways and can temporarily or permanently change the function of the cell. The use of molecular biology tools and genetic research defines the mechanisms through which gene expression is affected by food, and conversely, these genes also affect the absorption of food, metabolism, and excretion. From the point of view of nutrigenomics, dietary nutrients are signals that are received by sensitive cell systems and can affect the expression of genes and proteins and the production of metabolites. Nutritional manipulations and strategies are key tools to influence ruminant production. Fatty acids act on the nucleus by binding to and regulating the activity of specific nuclear receptors or transcription factors, thus playing a central role in regulating the expression of genes involved in fatty acid uptake by muscle cells. Interactions between diet nutrients and the expression of genes involved in lipid metabolism have many possibilities regarding the deposition of fatty acids in the tissue. The study of gene expression has enabled clarification of the mode of fatty acid metabolism in muscle and the accumulation of intramuscular fat or marbling and the role of the genes that promote fatty acid oxidation and mitochondrial respiration in the liver muscle and adipose tissue. Polyunsaturated fatty acids with multiple double bonds (PUFA) and monounsaturated fatty acids with one double bond (MUFA) have received much attention in the last decade, and their health benefits are increasingly evident. Therefore, this study investigated the effect of using calcium salts of fish oil, olive oil, and saturated fat on the expression of some genes related to fat metabolism in Lori Bakhtiari×Romanov fattening lambs.
This study was carried out at the educational research station of the Department of Animal Science of the College of Agriculture and Natural Resources, University of Tehran. 49 male lambs aged four to five months with an average initial weight of 29.97 ± 0.88 kg were divided into seven groups of seven lambs in a completely randomized design. The experiment consisted of seven treatments with a basic diet as follows: 1) Basic diet without fat powder (control), 2 and 3) Basic diet with calcium salt of fish oil (rich in omega-3 fatty acids) in the amount of 2% dry matter of the diet for 90 and 45 days, respectively, 4 and 5) Basic diet with calcium salt of olive oil (rich in omega-9 fatty acids) at the rate of 2% dry matter of the diet for 90 and 45 days, respectively, 6 and 7) Basic diet with saturated fat powder in the amount of 2% dry matter of the diet for 90 and 45 days, respectively. Rations were adjusted based on the NRC Sheep and Goat and using the fifth version of CNCPS (The Cornell Net Carbohydrate and Protein System) software so that they are the same in terms of energy and protein. Twenty-eight lambs were slaughtered and a liver sample was taken for nutrigenomics studies. Total RNA was extracted from liver tissue samples using the RNA extraction kit produced by Dena Bio Asia Company (Mashhad) and according to the protocol provided with the kit. The expression of four main genes involved in lipid metabolism in liver tissue was investigated to provide comprehensive information on the effects of omega-3, omega-9 fatty acids, and saturated fat at the molecular level.
The results showed that feeding with calcium salts of fish oil, olive oil, and saturated fat, both in the whole 90 days or the last 45 days of the fattening period, had no significant effect on the expression of FADS1 and FADS2 genes in liver tissue compared to the control group. However, the use of calcium salts of fish and olive oils in periods of 90 and 45 days significantly increased the hepatic mRNA expression of the CPT1 gene (P=0.001) and ACOX1 gene mRNA expression in liver tissue compared to control and saturated fat treatments (P=0.002). The CPT1 enzyme is responsible for a mitochondrial transport system and plays a key role in controlling the oxidation of long-chain fatty acids and stimulating mitochondrial β-oxidation.
The results of this study showed that diet supplementation with calcium salts of fish and olive unsaturated fatty acids, regardless of the period of consumption, increased the expression of genes involved in the lipolysis of liver tissue fats of lambs.

One of the important by-products is the pomegranate pulps which is pulp left after pomegranate juice. The presence of significant amounts of biologically active compounds such as phenolic acid, flavonoids, and tannins in pomegranate fruit ensures its high nutritional value. Pomegranate peel is a part of the fruit that has very high antioxidant properties and contains high amounts of polyphenols such as tannins. There have been numerous reports of the negative effects of tannins on consumer animals. One of the compounds that can bind to tannins and reduce their harmful effects is the tannase enzyme. So, this study aimed to investigate the effects of using different levels of pomegranate pulp without or in combination with tannase enzyme in the diet of fattening lambs on performance, nutrient digestibility, and some blood parameters. After preparing pomegranate pulp, drying it, and preparing tannase enzyme, 25 male Moghani lambs with an average weight of 30±2 kg and the average age is about 7 months, were used in four treatments in a completely randomized design. experimental treatments include 1- control, 2- 2.5% pomegranate pulp powder, 3- 5% pomegranate pulp powder, 4- 2.5% pomegranate pulp powder + 0.05 % dry matter of tannase enzyme 5- 5% pomegranate pulp powder + 0.05 % dry matter of tannase enzyme. During the experimental period, the performance parameters including feed intake, weight gain, and feed conversion ratio were measured. The concentration of blood parameters and the activity of liver enzymes containing ALP, ALT, and AST in the blood of lambs were determined. The Data obtained were analyzed using SAS (9/1) statistical software. The experimental treatments demonstrated no significant impact on the weight gain and feed intake of the lambs. However, when examining the amount of feed consumption and daily feed consumption, higher values were observed during the second 30 days of the rearing period in comparison to the initial 30 days.While nutrient digestibility remained largely unaffected, a notable trend in the digestibility of dry matter was observed. Further comparisons between treatments revealed a higher digestibility of organic matter, neutral detergent fiber (NDF), acid detergent fiber (ADF), and ash in the group receiving 2.5% pomegranate pomace. These findings provide insights into the potential influence of pomegranate pomace supplementation on specific aspects of nutrient utilization in lamb diets. Fat in the treatment of 2.5% pomace with enzyme and digestibility of crude protein was higher in the treatment of 5% pomace with the enzyme. The comparison of different pomace levels showed that the use of high levels of pomegranate pomace (5%) increased blood glucose and the lowest blood urea concentration was obtained by feeding 5% pomace. The lowest concentrations of HDL and LDL in the blood also belonged to the control treatment. The use of tannase enzymes in the diet also increased the concentration of glucose parameters and decreased blood urea. The highest amount of glucose of the studied lambs were observed in the first thirty days of sampling. In the present study, the use of pomegranate pomace increased glucose in both rearing periods and decreased blood triglyceride levels in the second rearing period. Alanine phosphatase (ALP) enzyme activity was significant in the second period, the breeding period (P<0.05). The highest level of activity of this enzyme was observed in the blood of lambs fed with 2.5% of dung. The activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was not significant between sampling periods (P<0.05). Feeding different levels of pomegranate pomace powder with or without tannase enzyme had no significant effect on blood malondialdehyde concentration as an antioxidant index of the blood of fattening lambs. However, the comparison between the experimental treatments showed that the highest level of this index was found in the blood samples obtained from lambs fed with a diet containing 5% of pomegranate pomace powder + 0.05% of the dry matter of the tannase enzyme diet. The inclusion of different levels of pomegranate pomace in the diet led to a significant difference in the activity of the alanine phosphatase enzyme among the experimental treatments (P<0.05) and increased blood glucose (P<0.05). None of the functional parameters, including weight gain, and feed consumption, were affected by the use of pomegranate pulp with or without tannase enzyme during the entire experimental period. However, the food conversion coefficient improved in the treatments containing pomegranate pomace with tannin enzyme. The highest amount of antioxidant index related to the diet containing 5% of pomegranate pomace powder + 0.05% of the diet's dry matter was tannase enzyme. Therefore, the level of 5% of pomegranate pomace along with the tannase enzyme increases animal health and improves animal growth performance.

In order to investigate the chemical and nutritional characteristics of pea pod silage (PPS) and its effect on the performance of fattening lambs, 24 Zandi male lambs (initial BW, 33.5 ±1.5 kg) were used in a completely randomized design over 75 days. Experimental treatments were: 1) control; (basal diet) 2- pea pod silage (PPS replaced wheat straw and alfalfa in the basal diet). The amount of dry matter (DM), crude protein, ether extract, ash, neutral detergent fiber and acid detergent fiber of PPS were determined 20, 11.8, 1.8, 8, 62 and 20.2 percent, respectively, and pH was 6.02. The rumen degradability potential of DM and in vitro gas production potential of PPS after 96 h of incubation were estimated 83 and 58.6 percent, respectively. The use of PPS in fattening lambs rations improved the final body weight and increased the daily weight gain (P<0.05). The amount of DM digestibility was affected by the treatment (P<0.05), but digestibility of other nutrients was not affected by the experimental treatment. Blood parameters (cholesterol, triglyceride, HDL and LDL) were not affected by the experimental treatments, except for the glucose, which significantly decreased by feeding PPS (P<0.05). The experimental treatments had no significant effect on carcass traits. Based on the results of this study, the use of pea pod silage as a cost-effective alternative forage in replacement with common forages such as wheat straw and alfalfa can improve the performance of fattening lambs.

The use of agricultural by-products instead of grain seeds in livestock diets has been an important issue for scientific study. One of these products is potato waste that, if properly processed by methods such as ensiling, can replace cereal seeds such as barley in the diet, due to the proper nutritional value of this product, improving animal growth performance, reducing feed costsand prevent food from being wasting. Therefore, the purpose of this study was to investigate the effect of replacing different levels of potato waste silage with barley on growth performance, digestibility, and rumen and blood parameters of fattening lambs.

In this study, 30 Zell and Afshar mixed male lambs with a mean weight of 26±2 kg and mean age of 5.5±0.4 months were used in a completely randomized design (CRD) with 5 treatments and 6 replications for 90 days. The experimental treatments included the control treatment (without potato waste silage) and the treatments containing 25, 50, 75 and 100 potato waste silage replacement of barley seeds (based on dry matter).

The results of performance traits showed that there was a significant difference in fattening weight, daily weight gain, dry matter intake and feed conversion ratio between experimental treatments (p<0.05). The highest and lowest final weight, daily weight gain and dry matter intake were observed in the treatment containing 50% of potato waste silage and the control treatment, respectively. The results of the apparent digestibility of nutrients of experimental diets showed that there was a significant difference in the apparent digestibility of raw protein and neutral detergent fiber (NDF) between experimental treatments (p<0.05). The highest and lowest apparent digestibility of crude protein (CP) was observed in the treatment containing 50% of potato waste silage and the control treatment, respectively. The results of some blood serum parameters showed that there was a significant difference in the concentration of glucose, triglyceride, Low density Lipoprotein (LDL) and blood urea nitrogen (BUN) between the experimental treatments (p<0.05). The results of rumen fermentation parameters showed that there was a significant difference in the population of lactic acid bacteria, coliforms, protozoa, rumen liquid ammonia nitrogen, total volatile fatty acids (VFAs), acetic acid, propionic acid, butyric acid, valeric acid and isovaleric acid between experimental treatments (p<0.05). The highest population of lactic acid bacteria 100%, the lowest coli form population, the highest population of protozoa and the highest concentration of VFAs were observed in the treatment containing 100%, 70%, 100% and 50% of potato waste silage, respectively.

The overall results of the present study showed that growth performance, the appearance of crude protein digestion, the total concentration of rumen fluid fatty acids and the population of bacteria and protozoa improved by consuming 50 % of potato waste silage

The use of dairy by-products as a new feed source in order to reduce the costs of raising livestock is very important. Whey powder is a residual cheese or casein, which is one of the animal proteins used in the human food chain. It is also a feed source of protein and contains some useful minerals. Whey can be used in the diet of livestock due to its proper nutrient balance. Also, the fact that whey can reduce the consumption of concentrate without any negative effect on daily weight gain and feed conversion ratio, so the purpose of this study was performed to investigate the effect of using different levels of whey powder in diet on growth performances traits, apparent digestibility of nutrients and some blood parameters in fattening male crossed Zell lambs.

To perform this study, 24 mixed fattening Zell lambs were examined with a means age of 4.5±0.52 months and a means initial weight of 24±2 kg in a completely randomized design for 90 days. Experimental treatments included control treatment (without adding whey powder in the diet) and treatments containing 1.5, 3 and 4.5% whey powder in the diet. Chemical analysis of whey powder used included pH, 6.8 to 5.8, protein 12.5%, lactose 64%, fat 1.5%, moisture 4.5%. Whey powder used in the study was given to the experimental animals at different levels after mixing with the diet. The daily diet was given as a TMR to the animal twice and the amount consumed was recorded. Live weight measurement was performed every 14 days with 12 hours of feed and water deprivation. Measurement of the apparent digestibility of nutrients in the last days of the experiment as well as the study of carcass traits and blood parameters were performed on day 90 of the experiment.

The growth performance results of experimental lambs showed that there was a significant difference in end weight, DMI and daily weight gain between experimental treatments (P <0.05); So that the highest final weight and daily weight gain was observed in the treatment containing 4.5% whey and the highest dry matter intake was observed in the treatment containing 3% whey. The results of apparent digestibility of nutrients showed that there was a significant difference in apparent digestibility of dry matter, crude protein and NDF between experimental treatments (P<0.05). The highest apparent digestibility of dry matter and crude protein was observed in the treatment containing 4.5% whey and the highest apparent digestibility of NDF was observed in the treatment containing 3% whey. The results of some blood parameters showed that there was a significant difference in the concentration of glucose, triglyceride, HDL and BUN between experimental treatments (P<0.05). The results of quantitative traits of carcasses of fattening lambs showed that there was a significant difference in hot carcass weight, hot carcass percentage, cold carcass weight, cold carcass percentage, thigh percentage and shoulder percentage between experimental treatments (P<0.05). The results of qualitative traits of carcasses of fattening lambs showed that there was a significant difference in the rate of TBARS of the straight muscle 48 hours after slaughter between experimental treatments (P <0.05).

The overall result of the present study showed that the weight at the end of the fattening period, dry matter intake and also the apparent digestibility of nutrients were significantly improved by consuming 3 and 4.5% levels of whey powder. There was a higher carcass percentage and improvement in valuable carcass parts in the treatment containing 3% whey powder.