فصلنامه پژوهشهای علوم دامی ایران
سال شانزدهم شماره 3 (پاییز 1403)

Introduction : 

Diarrhea is the main cause of calf mortality in the first two weeks after birth. Even when calves recover from diarrhea, they may subsequently show impaired growth. Considering this fact and especially following the ban of antibiotics in many countries, it is very important to identify effective anti-diarrheal supplements for use in suckling calves. Zinc is an effective anti-inflammatory and anti-diarrheal substance that improves the function of the immune system, reduces the number of pathogenic bacteria and increases the relative abundance of beneficial microbes in the digestive system. It is thought that the mechanisms of anti-diarrheal effect of zinc element are due to regulation of intestinal fluid transfer and mucosal integrity, strengthening of immunity and modulation of oxidative stress. The purpose of this experiment is to investigate the use of different proportions of organic (methionine-zinc) and inorganic (zinc oxide) sources of zinc to prevent diarrhea, improve the condition of the immune system and performance indicators of suckling calves. 

A total of 50 suckling Holstein calves were used over 70 days in a completely randomized design with 5 treatments and 10 replications. The experimental treatments were different proportions of organic and inorganic zinc supplements, including 1) zinc supplementation, 100% Methionine-zinc 2) combination of 75% methionine-zinc and 25% zinc oxide, 3) combination of 50% methionine-zinc and 50% zinc oxide, 4) combination of 25% methionine-zinc and 75% zinc oxide, and 5) 100% zinc oxide. All treatments received 1.96 mg of zinc supplementation per kilogram of body weight. Zinc supplements mixed with milk were fed to the calves from day one to day 14, and performance monitoring continued for 70 days. The stool score was evaluated on a scale of 1 to 4. Diarrhea was defined as the presence of grade 3 or 4 stools for 2 consecutive days. Data were analyzed in a completely randomized design using the GLM procedure of SAS. For variables measured over time (average daily gain, dry matter intake, and feed conversion ratio), time was added to the model as a repeated factor. 

The results showed that experimental treatments did not significantly effect the average daily gain, dry matter intake, and feed conversion ratio of the calves fed with Different ratios of mineral (zinc oxide) and organic (methionine-zinc) sources of zinc. In addition, the average of fecal consistency score did not differ significantly among the treatments. The results blood analysis demonstrated that treatment 100% methionine-zinc had higher level of concentration alkaline phosphatase. However, among the treatments contained methionine-zinc, a decrease in the ratio of methionine-zinc resulted in a decrease in Alkaline phosphatase concentration. Higher ratios of zinc oxide caused a significant decrease in the concentration of superoxide dismutase in the blood on the 14th and 70th day of the experiment. Also, on the 70th day of the test, the antioxidant capacity of whole blood was significantly higher in treatments containing methionine-zinc than in treatment %100 zinc oxide. The results showed that other blood parameters were not significantly influenced by the treatments in this study. In general, production performance did not change in different ratios of organic and mineral sources, the lack of effect of replacing zinc oxide with methionine-zinc on the performance of the present calves may be due to the provision of sufficient levels of zinc for all calves. So that the zinc supplement, taking into account its purity percentage, reached the same amount (1.96 mg of zinc supplement per kilogram of body weight) in all treatments. 

In the present study, overall production performance and blood parameter concentrations did not change with different ratios of organic and mineral sources. However, the activity of antioxidant enzymes was higher with higher ratios of the organic supplement (methionine-zinc) compared to the mineral source (zinc oxide). The lack of positive effect of replacing zinc oxide with methionine-zinc on the performance of the present calves may be due to the provision of sufficient levels of zinc for all calves. And it can be said that when a mineral is supplied at a sufficient level, the chemical form and bioavailability of resources are less important on performance.

Currently, trace elements are provided to livestock with the aim of achieving optimal growth and enhancing performance in the majority of farm animals. Zinc (Zn) is one of these elements. It has been found that Zn is present within the structure of numerous enzymes and plays a crucial role in various essential physiological functions within the body. Regarding a low concentration of Zn in surface soils in Iran (less than 0.8 mg/kg), resulting in Zn deficiency in plants grown in these soils. Consequently, the consumption of these plants as animal feed can lead to Zn deficiency in the animals' bodies. Therefore, it is imperative to include Zn in the diet of all animals. However, one of the basic problems regarding for addition of Zn to the livestock diets in Iran is the lack of accurate knowledge of the livestock requirement for Zn (according to the country's geographical conditions). The present study was carried out to determine the optimal requirement of Zn in Holstein suckling calves using some models. 

In this experiment, a total of 30 Holstein suckling calves (5 treatments, n=6 calves/treatment) aged from 4 (42.75 ± 3.26 kg mean body weight) to 70 days (93.52 ± 3.97 kg mean body weight) were used in a completely random design. The experimental treatments consisted of zero (control), 15, 30, 45 and 60 mg Zn/kg DM of diet (in the form of zinc sulfate). The calves were fed with whole milk (approximately 10% of birth weight) in two equal meals daily at 08:00 and 19:00 and each calf's specific Zn requirement was supplemented to the evening meal milk in the form of zinc sulphate solution. Starter and fresh water were freely available for the calves throughout the experiment. The starter feed, provided in pellet form, consisted of a blend of corn grain, soybean meal, corn gluten, barley grain, wheat bran, sodium bicarbonate, and mineral and vitamin supplements. Additionally, chopped wheat straw (5%) and alfalfa hay (5%) incorporated into the starter feed from the 15th day of age until the weaning stage. During the experimental period, the calves' performance (including dry matter intake, average daily weight gain, feed conversion ratio and weaning weight) was systematically assessed. lood samples were taken from the jugular vein at the end of the trial (day 70) before the morning feeding for measurement of blood zinc and some parameters (glucose, urea, albumin and total protein) concentration.The performance of calves was assessed using simple broken line, quadratic broken line, and quadratic regression models. Subsequently, the Zn requirements for calves were estimated based on the optimal performance of calves as determined by these models. 

Results showed that the including Zn to the diet of calves had no significant effect on dry matter intake and feed conversion ratio. Also, no significant differences were observed among treatments for the concentration of glucose, urea, albumin and total protein in blood serum. But it significantly increased the average daily weight, blood zinc concentration and weaning weight of the calves (p<0.05). According to the analysis using a simple linear model, there was no statistically significant correlation between the Zn requirement and dry matter intake or daily weight gain. However, a significant correlation (p<0.05) was observed between the Zn requirement and weaning weight, as well as feed conversion ratio. Consequently, the Zn requirement for calves to achieve weaning weight and feed conversion ratio was determined to be 76.43 and 74.87 mg Zn/ kg DM in the diet, respectively. Based on the quadratic broken line model fitting, there was no statistically significant association between the Zn requirement for calves and their dry matter intake. However, a significant correlation was observed between the Zn requirement and other measured attributes (p<0.05). Consequently, the Zn requirement for daily weight gain, weaning weight, and feed conversion ratio was determined to be 83.96, 89.18, and 89.53 mg Zn/kg DM in the diet, respectively. Based on the quadratic regression model analysis, it was found that there was no statistically significant relationship between the Zn requirement and dry matter intake. However, a significant correlation was observed between the Zn requirement and other measured variables (p<0.05). Specifically, the Zn requirement for daily weight gain, weaning weight, and feed conversion ratio was determined to be 86.99, 79.50, and 86.99 mg Zn/kg DM in the diet, respectively. Fulfilling the Zn needs of calves resulted in optimal performance in terms of daily weight gain, weaning weight, and feed conversion ratio, with values of 759.2 g/d, 97.25 kg, and 2.21, respectively. 

Overall, these results showed that the optimal dietary Zn requirement for Holstein suckling calves falls within the range of 74.89-89.53 mg Zn/kg DM of diet. Furthermore, providing this level of Zn in the diet resulted in the highest performance in calves.​

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

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

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

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

Introduction : 

Corn grain is one of the main sources of energy in the dairy cow diets; about 70% of corn's weight is due to starch. The starch granule is the basic unit of starch in corn endosperm and is a part of the starch–protein matrix. Its digestibility is influenced by the starch-protein matrix, granule morphology and size, as well as the degree of granule crystallinity and extent of granule damage. Cereal starch digestibility in ruminants is improved by an average of 10% by the application of heat, moisture and pressure during the steam flaking process. Depending on the processing method, the digestion site shifts from the rumen to the intestine, which is a significant factor in determining the rate of nutrient absorption that influences animal performance. Surface-active, foam-forming properties can increase water penetration and, consequently, the digestibility of processed grain. The most significant physicochemical property of surfactants is their ability to reduce surface tension, which is known as their interface activity. Low surface tension in rumen fluid may expedite food absorption and digestion. The main aim of this study was to evaluate the effect of various surfactants on nutrients content and appearance specification of steam-flacked corn grain.    

In the present study, a steamed-flaked (SF) method was applied to processed corn grains. During the steaming, grains did not treated with the surfactants (CON) or treated with 1% Tween 80 (TW80),1% sodium dodecyl sulfate (SD), 1% Alum (AL), and 1% extract of Laurus nobilis (LN) as surfactants. The ethanolic extract of Laurus nobilis (Ln) was provided by dissolving 100 g of dried and ground Ln in 500 mL of 96% v/v ethanol/water and shaking for 72 hours, then, the plant extract was prepared using evaporating method. Non-treated or treated corn grains were then steamed for approximately 35 minutes at 96 °C. Scanning electron microscopy (SEM) to achieve the best scanning quality of starch granule structure and surface in processed corn grain with the surfactants through steam-flaked were taken. The samples were assayed at 25 kV accelerating voltage and 2500x magnification. Physical properties (Giger-Reverdin, 2000) and chemical composition (AOAC, 2012) were then examined. The Robertson and Eastwood, (1998) method was used to calculate water holding capacity. According to Aghajani et al. (2012), the grain density was calculated as the ratio of the grain's mass to the sample's particle volume. Crude protein and carbohydrate fractionations were carried out (Higgs et al., 2015). Protein fractions reported as NH3 (A1), soluble protein (A2), insoluble true protein (B1), fiber-bound protein (B2) and indigestible protein (C). Carbohydrates were divided into five fractions including A4 (water soluble carbohydrates or sugar), B1 (starch), B2 (soluble fiber), B3 (digestible fiber), and CC (ingestible fiber). 

Scanning electron microscopy (SEM) analysis displayed that the processed corn grain using surfactants had larger surface starch granules than the SFC. All physical properties of the processed corn grain were significantly influenced by the chemically and physically procedures applied (P< 0.05). The highest bulk density was shown in LN (P< 0.05). Flaked corn grain treated with Tween 80 (TW80) had significantly (P< 0.05) higher volume compared with those of the others. The CP content of LN was higher than those of SD, TW80 and AL. Furthermore, the NDF content in SD was higher than that of LN and AL (P< 0.05). The total carbohydrates, non-fiber carbohydrates, digestible fiber and Indigestible fiber fractions of the processed corn grain were affected by the surfactant (P<0.05). The total carbohydrates and non-fiber carbohydrates fractions in LN were lower than that of the TW80, SD and AL. Digestible fiber and Indigestible fiber fractions were greater (P< 0.05) in AL than SD. 

All processed grains showed a different starch granule structure and surface compared with that of CON. Our findings illustrated that treating corn grain with the surfactants, applied in the present study during the steaming, improved the physically and chemically properties of the grain. Various alterations in carbohydrate fractions were traced in processed corn grain with the surfactants through steam-flaked procedure. The grain treated with extract of Laurus nobilis showed a reduction in both non fiber carbohydrates and soluble fiber concentration.

Exposure of poultry to various environmental stressors, such as vaccination, heat stress, high stocking density, and direct contact with excrement in the litter, can stimulate the stress response, disrupt the body's immunity, and external pathogenic factors introduce to a healthy animal. Therefore, they affect natural growth and production. High stocking density can be stressful and have harmful effects on the performance and safety of broiler chickens. Among the environmental factors, stocking density is an important factor in the production of broiler chickens due to its effects on health, well-being, and performance. Stocking density is defined based on the number of birds per surface unit or the amount of surface for each bird and based on the kilogram of poultry weight per surface unit. Yeasts and yeast products can act as an alternative to antibiotics to promote growth and disease resistance in poultry. Autolyzed yeast consists of ruptured or lysed cells and includes both intracellular and cell wall parts. Autolyzed yeast is usually concentrated or dried by liquid fermentation of Saccharomyces cerevisiae, and after autolysis or hydrolysis catalyzed by exogenous enzymes. In broiler chickens, the effects of prebiotics are partially dependent on the blocking of pathogen-adherent receptor sites, regulation of the immune system, production of antimicrobial molecules by the intestinal microbial community, and changes in the intestinal microbial structure. 

This experiment was carried for 37 days in 3 periods including starter (1-10 days old), grower (11-24 days old) and finisher (37-25 days old) using 520 one-day-old broiler chickens of Ross 308 commercial strain in a completely randomized design based on factorial arrangement 4 x 2 with 5 replicates. Experimental treatments included different levels of autolyzed yeast (0, 0.1, 0.2 and 0.3%) and 2 density levels (10 (normal density) and 16 (high density) bird per square meter). The basal diet used was adjusted based on the requirements of broiler chickens (Ross, 2019). Food and water were provided ad-libitum. Feed intake (FI) and body weight gain (BWG) of birds were recorded and feed conversion ratio (FCR) was calculated. On the 37th day of the experiment, two birds from each replicate were randomly selected and the weight of different parts of the carcass including the weight of gastrointestinal tract, breast, thigh, gizzard, liver, pancreas, and spleen (as a percentage of live body weight) were recorded. Also, at this time, caecal digesta (1 g) from each bird were aseptically transferred into 9 ml of sterile saline solution and serially diluted. Lactobacilli, Coliforms, and E.Coli were grown on Rogosa–Sharpe agar, MacConkey Agar, and Eosin Methylene Blue Agar, respectively. Plates for Lactobacillus were incubated anaerobically for 48 h at 37 °C. Microbial populations for E. coli and Coliforms were counted after aerobic incubation at 37°C for 24 hours. All samples were plated in duplicate. The obtained data were statistically analyzed using SAS statistical software, GLM procedure. Also, comparison of averages was done by Duncan's multi-range test at 5% probability level. 

The results of the experiment showed that feed intake, body weight gain and feed conversion ratio were not affected by the interaction of yeast and density (P>0.05). However, the use of autolyzed yeast significantly reduced the feed intake in the finisher period as well as the whole period of the experiment (P<0.05). Also, birds reared in high density showed significantly less feed intake and weight gain compared to birds reared in normal density in the finisher period and the whole period of the experiment (P<0.05). The feed conversion ratio in birds fed with autolyzed yeast improved significantly compared to the control treatment in the starter period as well as the entire experimental period (P<0.05). Carcass components and cecum microbial population of broilers were not affected by the interaction of yeast and density (P>0.05). Also, birds reared in high density showed less Lactobacillus population in cecum compared to birds reared in normal density (P<0.05). Using levels of 0.2 and 0.3% of autolyzed yeast in the diet caused a significant decrease in the cecum E. coli population compared to the control treatment. 

The results of the present study showed that although the use of autolyzed yeast in high density conditions could not affect the functional and physiological parameters of the animal, the use of autolyzed yeast improved the feed conversion ratio and reduced the population of E. coli of cecum.

Manganese is an essential trace element that acts as an activating component of many crucial enzymes such as alginase and pyruvate carboxylase. It is involved in carbohydrate, lipid, and protein metabolism, as well as in vital biochemical reactions (Hassan et al., 2020). Additionally, manganese serves as a cofactor in the synthesis of chondroitin sulfate and plays a significant role in bone formation in broiler chickens (Mwangi et al., 2019). Moreover, manganese is vital for the antioxidant and immune systems of animals (Patra and Lalhriatpuii, 2020; Wang et al., 2018). In the production of broiler chickens, manganese sources commonly used include inorganic Mn (Mn sulfate, Mn carbonate and Mn oxide) and organic Mn (Mn chelated with amino acid and protein). Inorganic sources of manganese are cheaper, although they have low digestibility (Tufarelli and Laudadio, 2017; Yenice et al., 2015). Organic sources have excellent chemical stability and high absorption efficiency. They have not been widely used in poultry diet due to different quality levels of manufactured products, unpredictable effects and high cost (Tufarelli and Laudadio, 2017; Brooks et al., 2012). Therefore, it is important to assess new sources of manganese that have higher digestibility and lower cost. Manganese hydroxychloride is a group of minerals which solubility in water is minimal, but it becomes more soluble in acidic conditions in intestine (Wang et al., 2011). The purpose of this experiment was to investigate the different levels and sources of manganese in the diet of broiler chickens by investigating their effects on growth performance, immunity, the digestibility of different sources in different solvents, and the digestibility using the technique of Everted Gut Sacs. Manganese sulfate, organic manganese, and manganese Hydroxychloride were obtained from Ariana company. In order to measurement of the amount of dry matter and ash, one gram in four repetitions was sampled from each of the sources. They were dried at 105°C for 12 hours and dry matter was calculated through subtraction. Then samples were transferred to the oven at 550°C for 16 hours and their ash content was determined. Finally, they were digested in hydrochloric acid and passed through Whatman filter paper No. 42. After making up to volume with mili-Q water, they were read by an atomic absorption device at a wavelength of 520 to 560 nm (AOAC, 1995; Williams, 1972). In order to evaluate the solubility, three samples (0.1 g) were prepared and dissolved in 100 ml of 2% citric acid, 0.4% hydrochloric acid and deionized water (Watson et al., 1970). For assessment ability to absorb minerals by the technique of Everted Gut Sacs, 180 one-day-old broilers of the Ross 308 commercial strain were fed from one to twenty-one days old with corn and soybean based (2018). On the 22nd day to the 28th day, they were fed with a diet free of manganese and on 29th day, they were starved for one day and night. Chickens were grouped into three treatments with Hydroxychloride, organic and manganese sulfate sources with 6 replications and 10 pieces per replication. Three parts were selected from each replication for the test steps (Feng et al., 2006). Samples prepared from jejunum and ileum in two buffers, Mis-Krebs and Tris-Krebs. In order to determine the relative bioavailability of different manganese sources, an experiment was conducted with 12 treatments included four different levels of manganese (35, 70, 105 and 140 mg/kg) with three different sources including Hydroxychloride, organic and sulfate. The highest amount of dry matter of manganese was related to manganese sulfate (99.23%). The lowest was manganese hydroxychloride (92.58%). The highest ash percentage was related to manganese hydroxychloride with 86.14% and the lowest was related to organic manganese with 21.56%. The amount of manganese calculated after testing organic sources, hydroxychloride and sulfate was 5.64, 34.64 and 34.47% respectively. The organic form of manganese had the highest solubility in 2% citric acid and the lowest in deionized water with 96.12 and 34.14%, respectively. Manganese hydroxychloride also had the highest solubility in 2% citric acid solution. Manganese sulfate had the highest solubility in hydrochloric acid and the lowest solubility in deionized water. In general, manganese sulfate had the highest solubility in deionized water compared to the other two sources. Also, the highest solubility of organic manganese in 2% citric acid was 96.12% in the whole experiment. It has been reported in studies that binding minerals with proteins will be a weak chelate and when they are placed in solvents, their chelate breaks easily and dissolve (Cao et al., 2000). The results related to performance traits and primary and secondary response of antibody titer against sheep red blood cells (SRBC) showed that experimental treatments had no significant effect on them.  The results showed that the highest solubility of the organic form of manganese was in citric acid (96.12%) and the lowest was in deionized water (34.13%). Manganese hydroxychloride had the highest solubility in 2% citric acid, while manganese sulfate had the highest solubility in 0.4% hydrochloric acid. Overall, manganese exhibited the highest solubility in hydrochloric acid and the lowest in deionized water. The results of the technique of inverted intestinal segments showed that the most absorption of manganese occurs in the ileum, and these results were in line with the results of other researchers who had performed this experiment in vitro and in vivo Among the experimental treatments, the highest absorption in the technique of inverted intestinal segments was related to the organic source of manganese, and the lowest was related to the form of sulfate, 3.25% and 1.99%, respectively. At the end, the use of organic manganese in broiler diet is recommended due to its high absorption level.

Today, livestock and poultry health in the advanced production system is the main challenge affecting human health and the global economy. For years, antibiotics have been widely used as growth promoters to stabilize the microbial population of the digestive tract and improve performance. However, scientific evidence suggests that the massive use of these compounds has led to increased problem of antibiotic resistance and presence of antibiotics residues in feed and compromises human and animal health. Hence, there is a growing need to find effective alternatives to control infectious diseases and limit the spread of resistant bacteria.Organic acids are an alternative to antibiotics in poultry diets. These are improving the immune system of broilers by acidifying the gastrointestinal tract and improving the intestinal microflora. Coating of organic acids prevents their dissociation and digestion in the stomach so that the biological effect of organic acids reaches the distal parts of the gastrointestinal tract and is effective in intestinal microflora and mucosal morphology. Also, Essential oils are volatile oil compounds that are produced as secondary metabolites by plants. Essential oils extracted from plants have anti-bacterial, anti-viral, anti-fungal, antioxidant activities as well as immune-modulating effects, reducing blood fat and stimulating the digestive system of poultry. Organic acids can complete the effect of essential oils through synergism antibacterial and bactericidal activities. Therefore, the present study was designed to investigate the effect of different levels of butyric acid glycerides and clove oil on growth performance, blood parameters and tibia bone characteristics of broiler chickens.  A total of 300 male and female broilers (Ross 308) with a completely randomized design with a 2 × 3 factorial arrangement, two levels of butyric acid glycerides (0 and 0.2 %) and three levels of clove oil (0, 500 and 1000 mg/kg) were used. Each of the six dietary treatments was fed to five replicate pens of 10 birds each from 0 to 42 days of age. Body weight gain, feed intake, feed conversion ratio, weights of immune organs, plasma lipids and physical and mineral characteristics of the tibia were recorded. The collected data were analyzed using SAS software (2003) and using the general linear model (GLM) procedure. The equation of the statistical model of the experiment was according to the relation Yijk = µ + Ai + Bj + (AB)ij + eijk, where Yijk represents the numerical value of each observation, µ is the population mean, Ai is the effect of butyric acid glycerides (0 and 0.2%), Bj was the effect of clove oil (0, 500 and 1000 mg/kg), ij (AB) was the interaction effect of butyric acid glycerides and clove oil, and eijk was the experimental error. The results showed that the addition of 0.2% butyric acid glycerides in the diet of broiler chickens reduced feed intake, body weight and daily weight gain compared to the control group (P<0.05). Addition of 1000 mg/kg of clove oil in the diet reduced feed intake, body weight, daily weight gain and european production index compared to the control group (P<0.05). Body weight, feed efecioncy, european efficiency factor and feed conversion ratio of broiler chickens were affected by the interaction effect of butyric acid glycerides and clove oil (P<0.05). The addition of different levels of clove oil with and without butyric acid glycerides in the broiler diet reduced cholesterol and LDL concentration compared to the control group (P<0.05). But the concentration of triglyceride, HDL and VLDL were not affected by the experimental treatments. The interaction effect of clove oil and butyric acid glycerides did not affect the weight of bursa of fabricius, thymus and spleen of broiler chickens. The amount of calcium, phosphorus and ash of tibia bone was significantly affected by butyric acid glycerides. Also, the length of the tibia of broiler chickens was affected by the clove oil and the interaction effect of butyric acid glycerides and clove oil (p<0.05). In general, no synergistic effect was observed between butyric acid glycerides and clove oil on growth performance of chickens. Although the use of 0.2% butyric acid glycerides and 1000 mg/kg clove oil led to a decrease in the weight gain of chickens by reducing feed intake, but the addition of butyric acid glycerides caused an increase in the concentration of phosphorus, calcium and ash in the tibia bone of broiler chickens.

Ascites is one of the most common metabolic syndromes in today's fast-growing broilers and is associated with rapidly growing and characterized by accumulation of fluid in the abdominal spaces. Effective factors in the occurrence of ascites syndrome, can mention free radicals in the body such as superoxide, hydroxide and hydrogen peroxide. By reducing the capacity of the body's antioxidant systems, free radicals make the bird susceptible to various diseases. Free radicals produced in the body by damaging the cell membrane lead to cell death and ultimately tissue damage. Therefore, by increasing cell protection from such injuries, one of the common causes of ascites and heart failure abnormalities can be prevented. In addition, free radicals from oxygen derivatives reduce the half-life of nitric oxide (vasodilating agent), causing a decrease in the ability of vasodilation and providing the basis for the occurrence of ascites. Therefore, it is suggested that antioxidants can prevent ascites and improve performance in broilers. Medicinal plants are among the rich sources of natural antioxidants that do not have the harmful effects of antibiotics and synthetic antioxidants. For this reason, the use of medicinal plant extracts is an important step in animal nutrition to increase the immunity of poultry. The mentioned extracts have strong antioxidant, antibacterial and digestive properties. Probably, the positive effects of medicinal plants are due to the active compounds found in plant extracts such as menthol, thymol, carvacrol. In order to investigate the effects of aqueous ethanol extract of Vinifera Vitis (V.V) on the performance, antioxidant status and blood parameters of broiler chickens under induced ascites. 

A total 300 one-day-old chickens (Ross, 308) were done in the form of a completely randomized design with 4 treatments and 5 replications (15 chickens in each replication). Experimental treatments include: 1- positive control group (without inducing ascites and fed with basal diet), 2- negative control group (inducing ascites and fed with basal diet), 3 and 4- Vinifera Vitis groups (ascites induction with 1000 and 2000 ppm of Vinifera Vitis extract). To induce ascites, water containing 1200 mg of sodium (3 grams per liter of salt) was provided to the chickens from the 15th day of the experiment. Growth performance parameters including feed intake, weight gain and feed conversion ratio were calculated for the total period. On the last day of the experiment (42 d), two birds were randomly selected from each cage and after sampling from the wing vein, killed and the ascites index was calculated as the ratio of the weight of the right ventricle to the total ventricles. The mortalities were collected as soon as they were observed and after weighing to correct the feed conversion ratio, were necropsied to investigate the cause of death. Serum triglyceride and cholesterol levels, as well as serum antioxidant parameters including the level of malondialdehyde and the activity of antioxidant enzymes including glutathione peroxidase, superoxide dismutase and catalase. In addition, liver enzymes present in the serum including alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT), and alkaline phosphatase (ALP) were also measured. 

The results showed that induction of ascites increased the ratio of right ventricle to total ventricles, mortalities due to ascites, feed intake, feed conversion ratio and body weight (P <0.05). The administration of Vinifera Vitis extract improved the growth performance index and reduced the ratio of the right ventricle to the total ventricles and mortalities (P <0.05). Vinifera Vitis extract moderated the increasing effects of ascites induction on triglyceride and cholesterol compared to the negative control treatment (P <0.05). In addition, the induction of ascites caused a decrease in the activity of glutathione peroxidase, superoxide dismutase and catalase enzymes and an increase in serum malondialdehyde, the experimental treatments improved the antioxidant status compared to the negative control treatment (P <0.05). Also, induction of ascites increased the serum levels of aspartate aminotransferase, alanine aminotransferase, gammaglutaryl transferase and alkaline phosphatase enzymes. The supplementation of the experimental supplements decreased the serum level of the mentioned enzymes (P <0.05). The results of this research showed that the use of ethanolic extract of Vinifera Vitis has positive results on the performance and stress reduction of broiler chickens affected by ascites and it can be effectively used from the level of 2000 ppm of the ethanol extract Vinifera Vitis was used in the diet of broiler chickens to reduce stress and improve performance.

Commercial silkworm hybrids result from the controlled crossing of the Japanese-shaped parent with the Chinese-shaped parent (direct cross) and vice versa (reverse cross). Suppose the silkworm hybrids resulting from direct and reverse crossing have a large difference in the performance of the important productive, reproductive, and viability characteristics. In that case, they are not suitable for supply to the farmers. In this research, to identify the hybrid pairs with the least differences, the traits of 72 reciprocal hybrids (36 mating pairs) were tested by statistical methods. These results will be used for the final selection of commercial hybrids. Also, the genetic analysis of reciprocal hybrids and the estimation of genetic parameters in each of the mating programs were done separately using line × tester analysis. 

The current research was done at the Iran Silk Research Center by carrying out two mating programs in the form of line-tester crosses between six Chinese lines (IRA2, IRA4, IRA6, IRA8, IRA10, and IRA12) with six Japanese lines (IRA1, IRA3, IRA5, IRA7, IRA9, and IRA11). Six lines with dumbbell-shaped cocoons (Japanese) and six lines with oval-shaped cocoons (Chinese) were crossed bilaterally. All lines (12 genotypes) and 72 hybrids (36+36) were reared in a completely randomized design with 4 replications. All stages of hatching and rearing of silkworm lines and hybrids in this project were done in the same way based on standard methods. The studied traits including the number of cocoons per liter, cocoon weight per liter, best cocoons percentage, middle cocoons percentage, cocoon weight per 10,000 larvae, hatchability percentage, cocoon weight, cocoon shell weight, cocoon shell percentage, and pupation rate were recorded and analyzed by applying of GLM procedure of SAS software. Line×tester analysis was applied to study the reciprocal crossing effect and estimate genetic parameters. Gene effects, heritability, σ2gca/σ2sca, and Baker’s ratio were investigated by applying of IML procedure of SAS software. 

The results of the comparison of reciprocal hybrids based on the total difference (∑D) showed that this parameter was more than the total average in 14 pairs of hybrids. Therefore they could not be selected for commercial level. In the other 22 pairs, either none of the traits or at most one trait had a significant difference (P<0.05). The results showed that the characteristics of cocoon weight and cocoon shell weight were more affected by reciprocal crossing. On the other hand, the number of cocoons per liter, the hatchability percentage and the middle cocoon percentage were higher in Chinese mother hybrids than in Japanese mothers. For other traits (weight per liter, cocoon weight per 10,000 larvae, pupation percentage, good cocoon percentage and pupation percentage), Japanese mother hybrids were almost superior. The comparison of crosses effect in Japanese-shape lines and Chinese-shape testers with Chinese-shape lines and Japanese-shape testers showed that four traits (cocoon weight, cocoon shell weight, cocoon shell percentage and cocoon weight per 10 thousand larvae) and for the interaction effect (line × tester), three Traits (cocoon weight, cocoon shell percentage and pupation rate) were most affected by the substitution of parents. The values of additive genetic variance, Baker's coefficient, ratio σ2gca/σ2sca and heritability in four studied traits including cocoon weight, cocoon shell weight, cocoon shell percentage and number of cocoons per liter showed that these traits are under additive genetic effect. Moreover, they had a higher value in Chinese mothers than the Japanese mother crosses. The trait of cocoon weight per 10,000 larvae was also controlled by non-additive genetic effects, and the substitution of parents did not affect their genetic parameters. The pupation rate in the direct crosses was due to additive genetic effects, but in the reverse crosses was affected by non-additive genetic effects. In general, the narrow sense heritability for all traits was higher in Chinese-shape than in Japanese-shape mothers. 

In the present study, similar and close performances of the Chinese mother and Japanese mother hybrids were determined except for cocoon weight and cocoon shell weight which was different in almost 33% of reciprocal hybrids. The crosses effect in the line × tester ANOVA supported the result of mean comparison for reciprocal hybrids evaluation. Further field investigations can be carried out to select the hybrids suitable for different geographical conditions.