مجله پژوهش در نشخوار کنندگان
سال دهم شماره 3 (پاییز 1401)

In mixed breeds or high-yielding breeds that require the use of lipid resources in the diet to provide the required energy level for livestock, in order to increase fat consumption and increase its digestibility, the use of lysophospholipids has advantages. Also, the possibility of using fat in the diet while maintaining other conditions of gastrointestinal physiology, reduces the consumption of grains and prevents metabolic disorders such as acidosis. This study was performed to investigate the effects of consumption of different levels of lysophospholipids on performance, quantitative and qualitative traits of carcass, apparent digestibility, some blood parameters and liver enzymes in male fattening lambs of Afshari breeds.

In this study, 24 male lambs of Zell mixed with Afshari with an average weight of 29.85 ± 1.9 kg and an average age of 4 months were used. Experimental lambs were tested in 4 treatments and 6 replications in each treatment for 90 days. Experimental treatments include: 1) control treatment without adding lysophospholipid in the diet and with diets containing lipid source 2) diet treatment containing lipid source plus 0.25% lysophospholipid in the diet 3) diet treatment containing lipid source plus adding 0.5 % lysophospholipid in diet 4) Diet treatment contained lipid source plus addition of 0.75% lysophospholipid in diet.

The results showed that the addition of lysophospholipid supplement to the diet of fattening lambs had a significant effect on daily feed intake (P <0.05). The use of 0.75% lysophospholipid supplement increased feed intake. In the present study, the use of 0.75% of lysophospholipid supplement diet reduced the numerical value of feed conversion ratio, but this reduction was not numerically significant (P <0.05). The final live weight was higher in the lysophospholipid supplementation treatments than in the control group. Also, the group that received 0.75% of lysophospholipid supplement had a higher final weight than the control group and other groups (P <0.05). Dry matter and crude protein digestibility were not significantly different in the experimental groups and the control group. However, the apparent digestibility of crude fat increased in all groups that received lysophospholipid supplementation compared to the control group. NDF digestibility increased in the groups that received 0.5 and 0.75% of lysophospholipid supplement diet. However, ADF digestibility increased significantly only in the group that received 0.75% lysophospholipid supplementation. Experimental treatments had no effect on the serum glucose concentration of crude protein in experimental animals. Also, serum urea, cholesterol, triglyceride, LDL and VLDL concentrations increased with lysophospholipid supplementation. But the serum HDL concentration decreased. Also, experimental treatments had no effect on the concentration of liver enzymes in blood serum. Although the concentrations of alkaline phosphatase (ALP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were numerically higher on day 90 in the groups receiving lysophospholipid supplementation, but this increase was statistically significant. Was not significant (P <0.05).

Due to the positive effects of lysophospholipid supplement on fat digestibility, functional traits and without creating unfavorable conditions on fiber digestibility (NDF and ADF), liver enzymes can be used in the diet of Afshari mixed breeding male lambs.

Considering that the significant numbers of eggs are broken during transport, storage and sale and are not consumable by humans, so it can be used as a high quality feed in livestock diet. Egg is an important alternative feed ingredient that contains high quality crude protein and crude fat. It is estimated that 8% of produced commercial eggs had not a good quality which has good nutritional value for animal consumption. It has been thought that, as a high quality nutrient, unmarketable cracked eggs could be used in animal nutrition and a few studies have been carried out on that respect. Therefore, the purpose of this experiment was to investigate of the effect of feeding different levels of wasted egg as the main source of dietary protein on sheep rumen fermentation, nutrient digestibility and blood parameters.

Whole waste egg were prepared from a commercial laying hen farm during 10 consecutive days. The collected eggs were air-dried away from direct sunlight then grounded. After determining the chemical composition of wasted eggs, levels of 0, 2.5, 5 and 7.5% were used in experimental diets. For determine the effects of wasted egg on sheep, four mature ram (with 44±0.5 live weight) were used in a change-over design with four periods of 21 days. Nutrients digestibility determined by fecal total collection method. In the 5 days at the end of each period at 0, 3 and 6 h after morning feeding, rumen fluid was sampled from sheep by esophagus tube and were filtered through three layers of cheesecloth. Blood samples were collected at the end of each period and 3 h after morning feeding in 10-mL. To determine the amount of allantoin and microbial protein synthesis, the daily urine produced during 24 hours was collected.

In the present study, dry matter intake and digestibility in sheep fed experimental diet were not significantly altered. Ruminal pH was not affected by waste egg. But, ammonia nitrogen and total protozoa population (13.54 and 9.94 respectively) in rumen fluid at three hours after morning feeding increased (P<0.05) by adding of waste egg in sheep’s diet. Total purine derivatives and microbial protein synthesis did not change. Blood cholesterol levels in sheep fed wasted egg were significantly higher (58.75 in control diet vs 69 in 7.5 % whole waste egg diet) than other groups (P<0.05).

In conclusion, waste egg has suitable nutrients for using livestock feed. Whereas, feeding 7.5% of wasted egg increased of total protozoa population and ammonia nitrogen, and improved fermentation condition. Because alter in ruminal fermentation characteristics, this waste can be used as part of a concentrate in the diet of sheep.

To achieve maximum microbial protein production and efficiency of feed protein utilization, the simultaneous availability of rumen degradability carbohydrate and nitrogen sources for ruminal microorganisms is essential. When using urea, due to its very high ruminal degradability rate, highly fermentable carbohydrate sources such as soluble sugars should be used to achieve maximum efficiency of nutrients utilization, microbial protein production and fermentation. On the other hand, considering the rate of nitrogen release in slow-release urea compared to urea, it seems that the type of carbohydrate source and its degradation rate should be considered when using this product in the diet of lactating cows, because it can affect the efficiency of nitrogen utilization in the rumen. Therefore, the aim of this study was to investigate the effect of carbohydrate source type on the performance of Holstein lactating cows fed a diet containing slow-release urea.

This experiment was performed in the 3 periods in a completely randomized design as repeated measurement using 9 Holstein lactating cows (average weight: 650± 50 kg, milk production: 33± 0.5 kg and DIM: 100± 25 days) in three 21-day periods. Experimental treatments were; 1. basal diet include Nitroza® (a source for slow- release urea, as control); 2. basal diet plus 2.7 % molasses as a replacement for corn grain and 3. basal diet plus 2.7% barley grain as a replacement for corn grain. To measure ruminal fermentation parameters, on the day 21 of each period, four hours after the morning meal, ruminal fluid was collected. Apparent digestibility of nutrients were measured by acid insoluble ash as internal marker. The milk production was recorded daily and on the day 20 of each period, milk produced from each animal was sampled at each meal to measure the milk composition. To determine the concentration of serum albumin, glucose, total protein, cholesterol, triglyceride and urea nitrogen concentration on day 21 of each period, 4 hours after the morning meal, blood samples were taken from the tail vein of each animal.

The results of the present study showed that the addition of molasses and or barley grain as a replacement for a part of corn grain had no significant effect on feed and nutrient intake (except for organic matter). Compared to the control group, replacing corn with molasses in a diet containing slow-release urea increased the amount of organic matter intake (P< 0.01). The results of independent comparisons showed that the addition of molasses compared with control and barley treatment reduced ADF intake, but increasing the amount of barley in the diet resulted an increase in the ADF intake (P< 0.02). Treatments had no significant effect on apparent digestibility of nutrients, ruminal fluid pH, total concentration of volatile fatty acids, molar ratio of propionate, butyrate, acetate, valerate, isovalerate, and acetate: propionate ratio and glycogenic:non-glycogenic fatty acids. Treatments had no significant effect on milk production and composition. Although, milk production in the cows fed diet containing molasses and barley grain was higher than that of control group. The serum concentration of albumin, glucose and urea nitrogen in was not significantly affected by the type of carbohydrate source. Compared to the control group, the addition of molasses caused a significant increase in serum total protein concentration (P <0.05). Economic calculations showed that the addition of molasses or barley grain to diets containing slow release urea increased net income.

The results of the present study demonstrated that the addition of carbohydrate sources with degradability higher than corn grain in dairy cow diets include slow release urea (Nitroza®) can improve nutrients utilization efficiency and increase farmer income.

Due to the recent drought condition and rising cost of production, the productivity of any feedstuff that can be used to feed livestock has become inevitable. The use of agricultural residues, while estimating some of the needs of low-cost livestock, often faces problems such as the presence of anti-nutritional compounds such as tannins and saponins. This experiment was designed and performed to investigate the effect of saponin on fermentation, functional and metabolic parameters of Baluchi sheep.

This experiment was performed using 3 Baloch male sheep with an average live weight of 40±2 kg, which were about 9 months old, in the form of a change over design in three 21-day periods including 14 days of adaptation and 7 days of sampling period. Experimental treatments including; Different level of pure saponin in proportions of 0, 60 and 120 mg / kg dry matter were added to the feed. The ration used was adjusted based on the nutritional needs of Baluchi male sheep using SRNS software version 2007, which included a mixture of forage and concentrate in 50:50 ratios. The rations were thoroughly mixed and provided to the animals in two meals in the morning (08:00) and in the evening (20:00). The animals had free access to water and feed during the experimental period. The obtained statistical data were evaluated in the form of a change over design using SAS 9.1 software. Blood sample were harvested from jugular vein for serum blood metabolites. To collect plasma, blood samples were transferred test tubes and after 15 minutes at room temperature, centrifuged (for 15 minutes at 1509 xg) and their plasma was collected, then transferred to sterile microtubes. Serum was stored in -20 centigrade until further analysis.

The results of the above experiment showed that the addition of saponin had no significant effect on the apparent digestibility of dry matter, organic matter, crude protein, insoluble fibers in neutral detergent (NDF) and insoluble fibers in acidic detergent (ADF). Data indicated that experimental treatments could not have a significant effect on the urea, triglyceride and blood glucose levels. The amount of cholesterol in the blood was affected by saponin so animals received 60 or 120 mg saponin had a significantly lower cholesterol than control group (p>0/05). Although ammonia nitrogen during pre-feeding and 2 or 4 h after feeding was not affected by treatments but in overall the mean ammonia was affected by saponin level, so by increasing saponin in diet trend was to decrease of ammonia nitrogen compare to control group. Accumulation of saponin in rumen cause to alter rumen environment and decrease its pH in Baluchi sheep.

The results of the present experiment showed that increasing the amount of saponin in the diet reduced the nitrogen level of ruminal urea and some blood parameters, which can have destructive effects on animal growth. Increasing saponin to levels above 60 mg / kg of dry matter in the diet has led to a significant reduction in blood cholesterol. Based on the data of this experiment and the results reported in different experiments, it is recommended that the using feed contained saponin be targeted and limited as a feed, to reduce the side effects on the animal performance and health.

Iodine is an essential element for the production of thyroid hormones that control the body's metabolism. Subclinical iodine deficiency, which is related to the deficiency of this element in the soil, is likely in most livestock in different parts of the country, especially grazing livestock, and was reported in sheep with plasma inorganic iodine less than 5 Micrograms per deciliter in some areas of Markazi province about 10 years ago. The objective of this study was to re-evaluate the iodine status of sheep in Shazand areas and evaluate the effects of using an injectable iodinated oil supplement on thyroid hormone concentrations, blood serum and milk inorganic iodine content, and the production performance of ewes and their lambs.

Seven sheep breeding farms in this region randomly selected and ewe’s serum inorganic iodine analyzed. To evaluate the effects of iodine supplementation, the herd with the lowest amount of serum inorganic iodine in which the experiment could be performed was considered as the experimental herd. In this herd,80 Farahani ewes with an average weight of 48.53±7.8 was divided into two groups of 40 as control and experimental groups. The experimental group, were supplemented with 1.5 ml iodised oil (Depodine®) intramusculary three weeks before mating and nine weeks later. Concentrations of thyroid hormones including triiodothyronine and thyroxine on days 60 and 120 from start of the test, inorganic iodine in blood serum every month until day 180,inorganic milk iodine after lambing and production and reproductive parameters were measured and compared in the two groups.

The iodine status of the studied herds indicated that iodine deficiency continued in the study area, and this problem was not resolved. The lowest and highest serum mineral iodine levels of the studied herds were 2.0±0.22 and 4.38±2.08 μg/dl, respectively. Thyroid hormone concentrations were significantly (P< 0.05) elevated in the iodine-supplemented ewes after treatment. Serum inorganic iodine and milk inorganic iodine of ewes also increased from 2.39 and 1.22 μg/dl in the control group to 11.2 and 21.44 μg/dl in the experimental group, respectively (P<0.01). The mean birth weight of lambs in the experimental and control groups was 4.33±0.62 and 3.91±0.77 kg, respectively, which had a significant difference (P<0.05). Also, the mean weaning weight of lambs in the experimental group increased compared to the control group (17.08±1.16 and 16.6±1.83 kg, respectively) and lamb survival rate up to day 120 increased significantly (P<0.05) while lambing rate and litter size of ewes didn’t affect.

The results indicate that sheep continue to be impacted by the effects of iodine deficiency in the study area based on low serum mineral iodine concentration, and the effectiveness of the iodine supplement in preventing the effects of iodine deficiency in sheep and improving their production and reproduction performance.

Despite the central importance of ruminants in providing the human nutritional requirements, their relatively low production efficiency leads often to increased production costs and pollut the environment. In this connection, using supplements and feed additives have considered as efficient strategies for improving the efficiency of livestock production. The plant-based feed additives, including essential oils and plant extracts, are the products that improve the efficiency of the ruminant production, through ameliorating the rumen digestion and fermentation. On the other hand, using the supplements, such as the different fat sources as the energetic supplement in animal diet, has had several positive impacts such as reducing ruminal acidosis, reducing methane production and and consequently declining environmental pollution, and improving feed energy efficiency and the performance of animals. Regarding the growing importance of high-quality products and special interest of consumers for the safety and quality of animal products in recent years, the feed additives of natural and green origin have been of great interest for animal nutritionists in recent decades. In this context, the current research aimed at investigating in vitro the savory essential oil effects on rumen fermentation, microbial protein synthesis and protozoal population in two diets supplemented with fish and soybean oils.

The essential oil was extracted by steam distillation using a clevenger apparatus, and was subsequently analysed qualitatively and quantitatively by Gas Chromatography-Mass Spectrometry (GC-MS). The essential oil effects on fermentation parameters were tested in vitro at 0, 150, 300, 450, and 600 mg/ in two diets supplemented with fish and soybean oils using the incubations of 24 h.

None of the rumen fermentation parameters was affected by the diet type. The gas produced over 24 h of incubation, in vitro true dry matter and organic matter degradability decreased linearly with increasing doses of the essential oil (P < 0.01) in both experimental diets. However, the partitioning factor as well as the microbial protein, and the efficiency of microbial protein synthesis increased none-linearly (linearly and quadratically) and linearly, respectively, with the essential oil dosage (P < 0.01). The ruminal ammonia concentration decreased none-linearly with the essential oil dosage (P < 0.01). Total protozoa numbers as well as most of the rumen common protozoal genera were reduced by increasing doses of the essential oil (P < 0.01). Total VFA concentration increased at the doses up to 450 and 300 mg/L of the essential oil in the fish oil and soybean oil containing diets, respectively (P < 0.05), and decreased thereafter at higher doses. The acetate molar proportions decreased none-linearly and that of propionate increased quadratically in both diets with essential oil dosage (P < 0.05).

In total, these findings indicated that using the savory essential oil, especially at low and medium doses, improved rumen fermentation through enhancing microbial protein synthesis, reducing ammonia and protozoa population, and increasing TVFA. Hence, the above-mentioned doses of the this essential oil can improve rumen fermtaion thereby enhancing the farm animals productivity. However, the savory essential oil seems to have negative impact on some rumen microorganisms at 450 mg/L and higher doses.

Quality of wool has a major impact on its consumption and ultimate use and therefore, evaluation and genetic analysis of wool characteristics is one of the most important research fields for native sheep. Considering that Iran-black sheep is a result of Baluchi and Chios crossbreeding, the present study was conducted to compare and genetic analysis of fleece characteristics of Baluchi and Iran-black sheep.

In this study, wool samples were collected from 176 Baluchi and 105 Iran-black sheep in Abbas-Abad sheep breeding center located near to Mashhad, Khorasan-Razavi province, in October 2017. Fleece characteristics, including greasy fleece weight, average fiber diameter, average staple length, hetero-type fibers (%), modulated fibers (%), and true wool fibers (%) were measured. To determine the fixed effects (breed, year of birth, type of birth and sex) affecting wool characteristics of the breeds, the GLM procedure of SAS software was used. Least square means comparisons of different fixed effects subclasses was carried out by Tukey-Kramer test at 5 percent probability levels. The components of (co) variances and genetic parameters of the studied traits were estimated using the multi-trait animal model and restricted maximum likelihood using WOMBAT software.

Results showed that the differences between the breeds were significant for average fiber diameter, hetero-type fiber percentage and true wool percentage. None of the studied traits were affected by sex of lamb except for hetero-type and true fiber percentages (P<0.05). Year and type of birth could only affect the greasy fleece weigh (P<0.05). Coefficient of variation for greasy fleece weigh (26.28 percent), hetero-type fiber (76.77 percent) and modulated fiber (99.59 percent) showed that considerable variations are there for these traits in the two studied breeds. Average fiber diameter in Baluchi (26.28 micron) was significantly lower than Iran-black breed (29.26 micron) (P<0.05). True wool percent in Baluchi (94.81 percent) was significantly higher than Iran-black breed (92.65 percent) (P<0.05). Heritability of wool traits in Baluchi breed ranged from 0.26 (modulated fiber percent) to 0.45 (hetero-type percent) and in Iran-black breed ranged from 0.28 (modulated fiber percent) to 0.34 (true fiber percent).

In general, Baluchi breed had finer wool than Iran-black and Iran-black fleece characteristics were worse than the native Baluchi parent. Moreover, moderate heritability for the studied traits in both of the breeds indicated that selection programs for improving these traits in these populations would be effective.Keywords: Baluchi Sheep, Crossbreeding, Wool, Genetic parameters

Zinc (Zn) is an essential mineral that involved in many vital functions such as growth, DNA synthesis and hormones and enzymes’ structure. So the presence of Zn is necessary in diet of animals. Deficiency of Zn in diet reduces appetite and impairs ruminal fermentation. This study was performed to investigate the effect of different levels of Zn on digestibility and ruminal parameters in Mehraban male lambs.

18 Mehraban male lambs 3-4 months old with an initial body weight of 33.62 ± 2.67 kg were used in a completely randomized design. The basal diet (containing 26.10 mg Zn/kg DM without supplementary Zn) was offered in a total mixed ration twice daily at morning (08:00) and evening (16:00) for 60 days. Experimental treatments included 1) basal diet without adding Zn supplementary (control), 2) basal diet plus 40 mg Zn/kg DM in the form of zinc sulfate and 3) basal diet plus 80 mg Zn/kg DM in the form of zinc sulfate. During the experimental period, feed intake and body weight gain were measured daily and every 15 days, respectively. The rumen fluid was collected from the lambs using the esophagus tube, on the end of the experiment at 3 hours after feeding morning. After determination of pH, rumen fluid was filtered through four layers of cheese cloth, acidificated and then stored at -20 ° C. These samples were used for measurement of total volatile fatty acid and ammonia concentration. Another part of the ruminal fluids (without filtration) was mixed with 18.5% formaldehyde in a ratio of 1: 1 and kept at room temperature away from light for determination of rumen protozoa population. At the end of day 60, 4 lambs from each treatment were randomly transferred to the metabolic cages for 10 days (5 days for adaptation and 5 days for sampling period) for digestibility and nitrogen retention trial. During the sampling period, feed intake, ort, urine and feces excreted for 24 hours were recorded and sampled daily.

The results showed that using different levels of zinc had no significant effect on dry matter, organic matter and crude protein intakes. The digestibility of dry matter and diet ingredients were not affected by zinc supplementation. Nutritive value of the diets (digestible crude protein and total digestible nutrients) did not show significant differences between the treatments. Also, the supplementation of zinc to the basal diet had no significant effect on ruminal parameters (pH, total volatile fatty acids and ammonia concentration), total numbers and observed genus of ruminal protozoa. The highest and lowest numbers of observed protozoa were related to Entodinium and Dasytricha genus, respectively. Supplementation of zinc to the basal diet had no significant effect on retained nitrogen. The amount of nitrogen retention in control and treatments 2 and 3 were 8.95, 8.55 and 8.61 g/day, respectively, which was not affected by zinc supplementation.

Generally, the results of this study showed that the adding 40 and 80 mg Zn/kg DM to the diet of fattening lambs (containing 26.10 mg Zn/kg DM) had no significant effect on measured traits such as feed intake, nutrients digestibility, ruminal parameters and retained nitrogen. It seems that the amount of zinc in the basal diet has provided the animal's needs in this regard and there is no need to adding zinc.