zinc

Goat as a multipurpose animal is crucial for the economy and food supply for urban and rural communities. Zinc is one of the most restricted trace minerals, which should be included in the diet of ruminants on daily. Research has shown that the use of organic or zinc nanoparticle supplements compared to inorganic supplements causes the stability of the sperm membrane and reduces oxidative damage, as well as improves the preservation of the integrity of the sperm membrane. Studies conducted in humans, mice, dogs, cows and goats showed that zinc chelates are more effective in maintenance, stability, motility and attachment of head to tail of spermatozoa. Also, since different sources of zinc have different bioavailability and there are few studies about the effects of different sources of zinc on the reproductive attributes in bucks, the present experiment is to investigate the effect of different sources of zinc on reproductive performance and some blood parameters in Murciana bucks.

Forty mature Murciana bucks (with an average age of approximately 1.5 years and an average body weight of 43±1.54 kg) were applied for a 60-day experiment in a completely randomized design model. The animals were randomly assigned into 4 experimental treatments with 10 replications, which included: control (containing 19.95 mg kg-1 Zn without supplementation), 32 mgkg-1 ZnSO4, 32 mg kg-1 ZnMet, and 32 mg kg-1 nano-Zn. Blood samples were collected by jugular vein puncture containing an anti-coagulant agent before morning meal on days 30 and 60 days of the experiment. Chemical analysis of feed samples was adjusted through international instructions for dry matter, ash, crude protein, ether extract, and neutral detergent fiber. Ejaculate volume was evaluated in a graduated glass tube that was adjusted to the artificial vagina. Moreover, the concentration of sperm to each ejaculation was carry out by a hemocytometer chamber through an optical microscope. The Eosin-Nigrosin stain was utilized to calculate the proportions of live, dead and abnormalities including head, mid-piece and tail. The CASA computer software was used to evaluate sperm motility characteristics according to reference guidelines. The ELISA method measured plasma testosterone concentration using a commercial kit. Plasma samples were digested with hydrochloric acid and then the concentrations of Fe, Zn and Cu were determined by a flame atomic absorption spectrometry. Semen quality and quantity traits were analyzed by completely randomized design (CRD) using the Proc GLM. Blood testosterone concentrations were analyzed as repeated measures in a completely randomized design using the Proc MIXED.

In this research, Zn supplementation caused an increase in ejaculate volume, sperm concentration, viability, sperm membrane integrity, sperm morphology and some sperm velocity characteristics (P ≤ 0.05). Also, no significant difference was observed between the quantitative, qualitative, motility and morphological characteristics of sperm among the source of Zn supplements (ZnSO4, Zn-Met, nano-Zn) (P > 0.05). The Zn plasma concentration and testosterone were improved in the treatments fed Zn supplements compared to the control group (P ≤ 0.05), but no significant difference was observed between the plasma concentrations of Cu and Fe (P > 0.05).

Feeding various types of Zn supplements (organic, inorganic and nanoparticles) improved the reproductive performance of Murciana bucks, which seems to be probably due to the lack of sufficient amounts of Zn in the diets. Considering the amount of zinc in the basal diet and the conditions of this experiment, it is suggested to use zinc sulfate in rations to improve reproductive performance and feed cost management.

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.​

In this research, the effect of zinc and selenium synthesized from nano-mineralized probiotics was investigated on yield characteristics, egg quality characteristics, antioxidant status, and immune response of laying hens. A number of 576 high-line laying hens at the peak of production (from 25 to 37 weeks of age in three four-week periods) were used as a completely randomized design with a 3x3 factorial experiment with eight replications and eight birds per replication. Experimental treatments are 1. The control diet (without selenium and zinc), 2. Control diet + selenium chelate, 3. Control diet + zinc chelate, 4. Control diet + zinc synthesized from probiotics, 5. Control diet + selenium synthesized from probiotics, 6. Control diet + zinc chelate + selenium chelate, 7. Diet Control + zinc chelate + selenium synthesized from probiotic, 8. Control diet + zinc synthesized from probiotic + selenium chelate, 9. Control diet + zinc synthesized from probiotic + selenium synthesized from probiotic. The results showed that using zinc and selenium synthesized from probiotics increased production percentage, average egg weight, and improved feed conversion ratio (P<0.05). The serum concentration of cholesterol, triglyceride and malondialdehyde in chickens receiving probiotic zinc and selenium was the lowest. The serum HDL concentration and total antioxidant index were the highest compared to other treatments (P<0.05). In general conclusion, zinc and selenium synthesized from nano-mineralized probiotics have a better performance in laying hens.

Efficient management methods should be used to achieve optimal production of livestock products in breeding, reproduction and feeding stages. If proper nutritional management is not performed correctly at the end of pregnancy, it will have adverse effects on the amount of dry matter intake and the metabolic condition of the animal during early lactation. In all animal tissues, there are variable proportions of mineral elements and vitamins; the concentration of these elements must be within the specified range in order to protect the functional and structural activity of the tissues and to keep the growth, health and productivity of the animal without reduction or damage.

In order to evaluate the effects of selenium and vitamin E supplements administered orally or by injection in late pregnancy on the concentration of selenium, copper, zinc and iron in the blood and milk of ewes and the blood of their lambs this experiment were conducted using 18 pregnant ewes of the first lambing in a completely randomize design with three treatments and six replications. Experimental treatments included: 1) Control (receiving a dose of 10 ml of selenium and vitamin E supplement by injection two weeks before delivery; each ml contains 0.5 mg of sodium selenite and 50 mg of vitamin E). 2) selenium and vitamin E (receiving 0.3 mg of selenium and 50 mg of vitamin E mixed with diet daily per kilogram of dry matter intake) orally from four weeks before delivery and, 3) Injection of 10 ml selenium and vitamin E supplement in two stages including four weeks before calving (five ml) and two weeks before calving (five ml).The Blood samples were collected from the ewes before the administration of supplements and at the time of delivery. Blood was collected from newborn lambs before consuming colostrum and 14 days after birth. Selenium, copper, zinc and iron concentrations were measured in colostrum and milk.

The results of the experiment indicated that the average weight of the ewes two weeks after lambing for ewes that received selenium and vitamin E orally was higher than the control (P<0.05). No significant difference was observed in the concentration of iron, copper and zinc in the blood serum of ewes or lambs. The concentration of selenium in the serum of ewes and their lambs and the colostrum of ewes that received selenium and vitamin E orally was higher than other ewes. No significant difference was observed between the experimental treatments in terms of the average body condition score (BCS) until the time of delivery, but two weeks after delivery, BCS in the orally supplement of selenium and vitamin E treatment was higher than that of control group.

The results of the present study showed that in order to improve the status of selenium in livestock and the convenience of supplement administration, the use of orally selenium and vitamin E supplements is preferred by its injection method.

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.

Zinc (Zn) is required for many enzymatic and metabolic functions in the animal’s body (Prasad and Kucuk 2002). Also, it affects the antioxidant defence system, where deficiency of Zn increases oxidative damage to cell membranes (Prasad and Kucuk 2002). Zn was assumed to improve the antioxidant capacity (Liu et al., 2011) since Zn is necessary for the structure and function of superoxide dismutase, which protecting the brain, lungs, and other tissues from oxidation (Noor et al., 2002). However, it has been suggested that Zn increases the synthesis of metallothionein, a cystine-rich protein that acts as a free radical scavenger (Oteiza et al. 1996). Nys et al. (1999) reported that the deficiency of Zn decreased egg production and eggshell quality linked to its role as a cofactor in the enzyme carbonic anhydrase, which is essential for shell deposition. The NRC (1994) recommends a level of 40–75 mg/kg of Zn in various poultry diets. Due to the high amount of phytate, Zn can be less bioavailable, despite the high level of Zn available in pulses and cereals. Therefore, this micronutrient can be supplemented to diets of livestock and poultry (Sahin et al. 2009). ZnO and ZnSO4 are the two most common inorganic Zn supplements used for poultry diets (Batal et al. 2001). The present study has examined the effects of Zn supplementation of laying hens on performance, egg quality traits and immune response under high stock density.

This experiment was conducted to evaluate the effects of dietary inclusion of different levels of zinc on performance, egg quality traits and immune response of laying hens under high stock density with 160 Hy-Line W-36 leghorn hens for 10 weeks. Treatments consisted of different levels of zinc (40, 80, 120 and 160 ppm) and 2 cage densities [3 hens/cage (recommended) or 5 hens/cage (high density) (38 × 38 × 40 cm)], that was performed in completely randomized design with 2×4 factorial arrangement with 5 replicates. The basal diet was formulated to meet all of the nutrient specifications according to the Hy- Line W-36 recommendations (Hy-Line International, 2007). The first 2-wk (61–62 wk of age) was considered as the adaptation period. The main trial period commenced from 63 wk of age and lasted for 8 weeks. Lighting program was set on 16 light: 8 dark using an artificial light in a windowless house. The hens had free access to feed and water at all times.The temperature was maintained at 20±2 °C throughout the study. Egg production and egg weight were recorded daily and feed intake (FI), feed conversion ratio (FCR) and egg quality were recorded weekly. Egg quality traits were evaluated every35-d period. All eggs produced during thelast2-d of each period were collected and egg quality indices including Haugh unit (HU), yolk color, egg shell thickness, andshell breaking strength were measured as followings: Each egg was weighed and the eggshell breaking strength (kg/cm2) was measured by a quasi-static compression device. The broken eggs were put onto a glass surface. The height of the albumen, midway between the yolk and the agde of the thick albumen, was measured with micrometer. Haugh units were calculated using the formula: HU=100log (H+7.57– 1.7×W0.37), where H is the mean height (mm) of the albumen and W is the weight (g) of egg (Haugh, 1937).Yolk color was visually scored by the Roche yolk colorfan. Eggshell thickness was determined on 3 points (air cell, equator, and sharpend) by using a micrometer screw gauge. In order to study immune responses, suspension of SRBC were injected into the breast muscle of two birds of each replicate at the first of 6 and 7th weeks of experiment and blood parameters were analyzed 7 days after each injection. Also reproductive parameters, blood lipid parameters were analyzed at the end of the experiment.

The results of this experiment showed that dietary supplementation of zinc in different stock density could not affect performance of layers (P > 0.05). Although, dietary increasing levels of zinc caused significant decrease in egg production percentage and egg weight during the whole period of experiment. Sorosh et al (2019) showed hens receiving 130 mg Zn/kg of diet, laid more eggs than the birds which receiving 40 and 70 mg Zn/kg of diet. Also, they reported hens receiving 130 mg Zn/kg of diet had lower feed consumption compared with the other treatments. FCR was influenced by supplemental Zn in which dietary inclusion of 70, 100, and 130 mg Zn/kg of diet improved FCR compared with that of the 40-mg inclusion level. Mirfendereski and Jahanian (2015) showed that hens in cages with higher stocking density had lower hen-day egg production, egg mass, and feed intake compared with those in normal density cages. Also they reported plasma concentrations of triglycerides and high-density lipoproteins were not influenced by dietary treatments. Sarica et al. (2008) observed that hen-housed egg production, egg mass, viability, and live weights were decreased by the higher stocking densities. In addition, the same authors reported that hens housed at the lower stocking densities reached sexual maturity significantly earlier than those in higher stocking densities. In the current experiment haugh unit was significantly lower in birds with high stock density compared with those in normal density cages. Jahanian and Mirfendereski (2015) showed that eggshell thickness was greater in hens under high stocking density challenge during the second 35-dperiod. Ovary weight was lower in hens under high stocking density challenge (P <0.05). Dietary supplementation of zinc (160 ppm) increased plasma LDL level and high stocking density increased plasma glucose level (P <0.05). The present findings indicated that dietary zinc supplementation in high stock density could not affected performance or egg quality of birds, although, levels of 120 and 160 mg Zn/kg of diet increased eggshell strength.

Zinc is one of the most important and essential trace elements that plays a vital role in many biological processes such as the activity of enzymes and hormones, cell membrane stability, gene expression, cell division and antioxidant defense. Therefore, this experiment was performed to compare the effects of supplementation of nano (zinc nano oxide), organic (zinc polysaccharide) and inorganic (zinc sulfate) forms of the trace element zinc on performance, antioxidant status and some blood parameters of growing Sanjabi lambs.

This study was performed on 20 male Sanjabi lambs (approximate age 4.5 months and mean weight 29.55 ± 1.1 kg). Treatments include 1) control group (basic diet without zinc supplement), 2) zinc sulfate group, 3) zinc-polysaccharide group 4) zinc nano oxide group. The amount of zinc added in each experimental group was 20 mg / kg dry matter. The diet was given to the lambs freely for 60 days in the morning and evening. In order to evaluate the growth performance, weight loss was performed at the beginning of the experiment and then at 15-day intervals. To determine the amount of dry matter consumed, the amount of feed and its residue were measured daily for each animal. To measure blood parameters and antioxidant status, blood samples were taken in the first days, 30 and 60. Data were analyzed using SAS statistical software version 9.2 using Mixed procedure and Duncan test was used to compare the means at the probability level of 0.05.

The use of zinc supplement in different forms had no effect on the growth performance of lambs (P >0.05). The use of 20 mg zinc per kg of dietary dry matter in different forms caused a significant increase in plasma compared to the control group (P <0.05), but had no significant effect on plasma copper and iron concentrations and serum calcium and phosphorus(P >0.05). The activity of superoxide dismutase increased in the groups supplemented with zinc (P <0.05). Despite the decrease in serum malondialdehyde index in the zinc supplemented groups compared to the control treatment, this difference was significant only in the zinc nano oxide group (P <0.05). The use of different forms of zinc had no effect on the total antioxidant capacity (P >0.05).

The results of this experiment showed that the use of zinc supplement in different forms (inorganic, organic and nano) increases the concentration of zinc in plasma. In addition, it reduces the malondialdehyde index and increases the activity of superoxide dismutase enzyme.

Zinc is involved in the regulation of many metabolic processes and zinc deficiency resulting in low appetite, consequently decreased feed intake. Also, zinc deficiency decreases the growth and weight gain of the animal. It has been reported that the daily requirement of zinc for suckling calves is 33 mg/kg DM. While, the amount of this element in cow’s milk is 3-5 mg/kg. Therefore, zinc supplementation may improve the performance of suckling calves. So, this study was performed to investigate the effect of different levels of zinc on performance and some blood and ruminal parameters in Holstein suckling calves.

This study was conducted using 18 newborn Holstein calves from 4 days of age to weaning (70 days) in a completely randomized design. Experimental treatments were treatment 1 (control, basal diet), treatment 2 (basal diet plus 30 mg / kg DM as zinc sulfate) and treatment 3 (basal diet plus 60 mg/ kg DM as zinc sulfate). The calves were housed in individual pens with cement floors and were offered with whole milk (approximately at 10% of weight) in two equal meals daily at 8:00 and 19:00 during the experimental period. They had free access to the pelleted starter and fresh-water. After 15 days, chopped wheat straw (5 %) and alfalfa (5%) were added to their starter. Daily feed and ort were measured to estimate daily dry matter intake and animals were weighed fortnightly to obtain average daily gain. Blood samples were taken from the jugular vein at the end of the trial (day 70) before the morning feeding for measurement of blood mineral (Zn, Ca, P, Fe, and Cu) status and the hematological parameters (hemoglobin concentration, red blood cell count, white blood cell count and hematocrit %). Also, the ruminal fluid samples were collected on day 70, 3 h after the morning feeding, by stomach tube and a vacuum pump for determination of ruminal volatile fatty acids concentrations.

The results showed that the use of different levels of zinc had no significant effect on feed conversion ratio in weaning calves. However, average daily gain in treatments 2 and 3 (724.29 and 765.00 g / day, respectively) and dry matter intake in treatment 3 (1692.41 g / day), were significantly (P<0.05) higher than the control treatment (628.29 and 1532.83 g / day, respectively). Supplementation of zinc significantly increased (P<0.05) serum zinc concentration in treatments 2 and 3 (1.184 and 1.168 mg / l, respectively). However, no significant differences were observed among treatments for the concentration of other minerals in blood serum (calcium, phosphorus, iron and copper). Also, supplementation of zinc had no significant effect on blood hematological parameters. Ruminal total volatile fatty acids, acetic acid, propionic acid, and butyric acid concentrations, and acetic acid: propionic acid ratio were not affected by zinc supplementation.

Generally, the results showed that a basal diet containing 29.68 mg Zn/kg DM can supply the zinc requirement of Holstein suckling calves. But, zinc supplementation improved the performance of these animals.

This experiment was conducted to evaluate the effects of supplementation of zinc and inorganic selenium in diets containing oxidized oil on performance, antioxidant enzymes activity, and meat quality of broiler chickens. A total of 480 day-old Ross 308 broiler chickens were randomly attributed into 12 treatments with four replicates each with 10 chickens in 2×3×2 factorial arrangement, includes: The thigh was dissected and muscles were removed to assess the malondialdehyde (MDA) content. The results showed that the birds’ average daily FI and FCR were not significantly influenced by dietary treatments. Inversely, the average daily BWG showed a significant difference among treatments over the experimental period (P <0.05). The birds received dietary Zinc at the level of 100 mg showed a higher activity of SOD enzyme (P <0.05). The lowest amounts of GPX was observed in birds fed diets containing oxidized oils, no dietary zinc and selenium at the level of 3.0 mg/kg. The highest and lowest levels of thigh meat MDA levels were noted in birds received diets containing oxidized oil with no dietary zinc and those had given fresh oil diets with supplementary zinc at 100 mg kg zinc and supplementary Se at 0.3 mg/kg, respectively. The results of this study revealed no synergistic effects between zinc and selenium on oxidative enzymes and MDA levels. It is recommended to supplement 100 mg / kg of zinc and 0.3 mg / kg of selenium to reduce the peroxidation effects of dietary oxidized oil.

In order to study the effect of different levels of zinc and selenium in diets containing oxidized oil on humoral and cellular immunity and relative weight of lymphoid organs in broilers, an experiment performed in a 2×3×2factorial arrangement in a completely randomized design(two Zero and 2% oxidized oil levels, three levels of 0, 40 and 100 mg / kg zinc sulfate, two levels of zero and 0.3 mg / kg selenium) using 480 one-day-old Ross 308 chicks with 12 treatments and 4 replicate per treatment  and 10 chicks per each treatment. To evaluate the immune system, changes in antibody titers were performed by injection of Sheep red blood cell (SRBC) at two times (21 and 28 days) and blood sampling at two times (28 and 35 days). The relative weights of bursa, spleen and thymus were measured at 42 days after slaughter. Cutaneous basophil hypersensitivity (CBH) test was used to evaluate cellular immune system. The results of total antibody titer in first and second times showed significant difference (P <0.05). Maximum grade of primary and secondary total antibodies in chicks fed with 100 mg / kg zinc and 0.3 mg / kg selenium and chicks oil). Containing 100 mg / kg zinc and 0.3 mg / kg selenium and the effect of zinc, Selenium, and their combined supplementation on the initial total antibody grade response was also significant, with 100 mg / kg zinc and 0.3 mg / kg. Selenium significantly increased the initial total antibody titer response. The effect of different experimental groups on IgM antibody response was significant at the first and second time (P <0.05). The cellular immune response of CBH test was not affected by different experimental diets. The effect of treatments on the relative weight of different lymph nodes was not significantly different. The results demonstrated that supplementation of zinc sulfate and sodium selenite improved the immune system of broilers.

Zinc is an essential trace mineral for all forms of life because it plays an important role in ‎DNA and RNA synthesis by increasing replication and cell proliferation. Zn deficiency in grazing and ‎forage feed is widespread in Iran and other countries, so Zn supplements are generally required for ‎ruminants. Several kinds of Zn sources have been used in diet ruminants. Supplemental Zn is usually ‎added to animal diets in the form of inorganic Zn (Zno and Znso4), However,. Many studies reported ‎that organic Zn is absorbed more readily by ruminants than inorganic Zn. Recently, a novel elemental ‎Zn source used in animal diets. The development of nano technology holds unique properties for nano ‎Zn, because nanometer particulates exhibit novel characteristics, such as great specific surface area, high ‎surface activity, high catalytic efficiency and strong absorbing ability. The objectives of this study were to evaluate the effects different forms of zn on feed digestibility, rumen fermentation of diatery dairy ‎cows with high production using gas production and nylon bags techniques.‎

The Zno naoparticles were prepared by chemical co-precipitation method. The ‎basal diet for sheep and dairy cows were provided according to NRC (2007) and NRC (2001) ‎respectivelely, to meet requirements, except of Zn. The four various tretments in the current experiment ‎were as: (1) the basal without Zn supplementation. (2) the basal diet plus 40 mg Zn/kg DM as zinc ‎oxide (Zno), (3) the basal diet plus 40 mg Zn/kg DM as zinc glycine (ZnGly, ZnGly, B-TRA MIX R ‎‎2C, 18.5% Zn) and (4) the basal diet plus 40 mg Zn/kg DM as Zn nano (zn>99%, 15-20 nm). Four ‎ruminal fistuled male sheep were used in a replicated 4×4 Latin square, experiment with four 28-day ‎periods (21 day adaptation and 7 day sampling collection each period). Nylon bags methods 5g of ‎samples were incubated in the rumen of fistulated sheep for 0, 2, 4, 8, 12, 16, 24, 36, 48, 72 and 96 h ‎for determination degradability of dry matter (DM) and crude protein (CP). The gas production was ‎recorded after 2, 4, 6, 8, 12, 16, 24, 36, 48,72 and 96 h of incubation. Ruminal fluid were used for pH, ‎ammomia-N, voliate fatty acids (VFA). ‎

In present study, the highest amount of gas production was obtained in ‎organic, nano and in organic zin supplemented treatments respectively. Zinc supplementation ‎significantly increased the OMD, SCFA and ME concentrations (p < 0.05). The results of this study ‎showed that Zinc supplementation significantly (p < 0.05) decreased the N-NH3 concentration in ‎different experimental groups. There was no effect on molar proportion of acetate and butyrate ‎‎(p < 0.05), whereas that of propionate was linearly (p < 0.05) increased with increasing nano-zn and ‎glycine-zn supplementation. As a result, ratio of acetate to propionate was decreased. Total ruminal ‎VFA concentration was increased (p < 0.05) as Zinc Supplementation. Increasing the concentration of ‎total volatile fatty acids in the rumen can be due to improved microbial fermentation in the rumen. In ‎situ trial, adding zn in forms nano and organic increased the DM disappearance (p < 0.05). Also zn ‎supplementation significantly increased ;b; fraction of DM of diatery cows with high production in ‎different experimental groups. The present results suggested zn functions to maintain the production of ‎proteolytic digestive enzymes and activity of protein decomposing bacteria could be improved by zn. In ‎‎24 to 96 hours incubations crude protein degradability zn-glycine and nano-zn was significantly ‎‎(p < 0.05) lower than zn oxide and control treatments. Also zinc Supplementation in forms nano and ‎organic decreased (p < 0.05) ;b; fraction and ;ED; of crude protein of diatery cows with high production ‎compared to control and zinc oxide treatments. The reason for this can be because of the low solubility ‎of proteins dietary due to bonding with the zinc element in the rumen or the change in the activity of ‎the proteolytic microbes.‎

The results suggested that the addition of zinc in the forms of organic and nano increased ‎the fermentation and degradability of the dietary high production dairy cows compared with inorganic ‎form. Also, there was no difference in digestibility and fermentation between organic and nano forms; ‎hence, in order to select the nanoparticulate or organic form of zinc element in the diet of animals, it ‎was necessary to pay attention to their price and price in the market.‎

Thirty multiparous Holstein dairy cows used to aim the investigation of the effects of zinc from different sources on bioavailability, production performance, and digestibility. Dairy cows in a complete randomized design randomly allocated to one of five dietary treatments that consist of 1) control (no supplement Zn), 2) Zn glycine complex (ZnGly), 3) Zn Hydroxychloride (ZnHcl), 4) Zn oxide (ZnO), 5) Zn sulfate (ZnSO4). The result indicated that different sources of zinc had not affected glucose, cholesterol and triglyceride (P>0.10). The used of different sources of zinc significantly increased of serum zinc to compare control (P<0.010).  Results showed that, BCS, milk, energy-corrected milk, fat-corrected milk yield and milk yield composition in dairy cows were not significantly affected by Zn source (P>0.10). Somatic cell count tended to decrease in ZnGly (P=0.096) and ZnHcl (P=0.073) in compare of control group. Dry matter intake was not different between treatment (P>0.10). Daily zinc intake, fecal zinc, the zinc concentration in milk per liter/or day, the zinc concentration in milk per liter/or day, apparent absorption and retention of zinc significantly were higher in zinc supplemented group in compare of control (P<0.010). Also, the used of different sources of zinc had not significantly affected on digestibility of dry matter, organic matter, and Ash (P>0.10). Therefore, the results of this study suggested that used of zinc sources in dairy cows diet ZnGly and ZnHcl have higher bioavailability than inorganic sources of zinc and also might improve milk quality throw decrease of somatic cell count.

The aim of this trail was to evaluate the effects of the use of Mn, Zn and Cu from different sources (inorganic, organic and hydroxy) in the diet on egg and eggshell quality of aged laying hens. A total of 240 Hy-Line w36 Leghorn, from 55 to 65 weeks of age, were used. The experiment carried out in a completely randomized design, with four treatments, four replicates, each containing 15 hens. The experimental treatments included: 1. The control diet, consisted of sulphate source of Mn, Zn and Cu, 2. The diet consisted of Mn, Zn or Cu-Methionine chelate, 3. The diet consisted of Mn, Zn or Cu Hydroxy, and 4. The diet consisted of Mn, Zn and Cu Hydroxy, only 70% level relative to treatment 3. In the most of experimental weeks, the Mn, Zn and Cu hydroxy and chelate forms increased egg weight and improved significantly feed conversion ratio in the 62, 64 and 65 weeks of age, compared with the sulphate group of these elements (P<0.05). But there was no difference between 70% hydroxy and sulphate groups. Also, there were no differences in feed intake, eggshell thickness, strength and weight, yolk index, Haugh unit, yolk color and shape index of egg and blood alkaline phosphatase, cereluplasmin, Zn, Cu and Ca levels among the treatments. The chelate source only increased blood Mn level significantly (P<0.05). There was the significant increase in eggshell and yolk Mn and yolk Zn levels and also significant decrease in the levels of Mn, Zn, Fe and Cu of excreta using hydroxy and chelate forms compared with the sulphate and 70% hydroxy forms (P<0.05). These results indicated that the Mn, Zn and Cu hydroxy and chelate forms in the diet improved the performance of aged laying hens.

This experiment was conducted to evaluate dietary supplementation of different levels of sulfate, chelate and nano sources of zinc on growth performance, tissue zinc reserves and meat quality of male growing Japanese quails. The experiment was carried out using 400 Japanese quails in a completely randomized design with 10 experimental treatments and four replicates. The experimental treatments consisted of: basal diet (control group, without zinc supplement) containing 41.25 mg/kg zinc and basal diet supplemented with different sources of zinc (sulfate, chelate and nano zinc) each at three levels of 15, 25 and 35 mg/kg of diet. Birds fed basal diet + 25 mg chelate zinc/kg of diet showed lower feed intake, higher weight gain and improved feed conversion ratio compared to the control group (P< 0.05). Zinc content in serum, liver, breast meat and tibia of birds fed basal diet + 35 mg nano zinc/kg of diet were higher than the control group (P< 0.05). Malondialdehyde levels and drip losses in meat of birds fed diets supplemented with different sources of zinc were lower than the control (P<0.05). According to the results of the current study, supplementation of corn–soybean meal-based diet of Japanese quails with 25 mg zinc chelate/kg improved growth rate and feed conversion ratio compared to the control group.

A study was conducted to investigate the effect of various levels of organic and inorganic trace minerals (zinc, copper and manganese) on performance, carcass and tibia characteristics and blood parameters of broiler chickens. 224 one-day old Ross 308 male broilers in a completely randomized design were raised until 42 days. 4 experimental treatments were: T1) Inorganic form of Zn, Cu and Mn to 110, 16 and 120 mg, T2) Organic form of Zn, Cu and Mn to 110, 16 and 120 mg, T3) Inorganic form of Zn, Cu and Mn to 55, 8 and 60 mg, T4) Organic form of Zn, Cu and Mn to 55, 8 and 60 mg. Results indicated that organic zinc, copper and manganese supplementation improved (P< 0.05) body weight gain and feed conversion ratio compare to inorganic form of the trace minerals. Moisture content and pH of the litter were not affected by the treatments. However, the incidence and severity of FPD were lower in broilers received organic trace minerals (T2 and T4). Highest Zn and Manganez content in tibia was found for treatments 2 and 4. Moreover, highest blood alkaline phosphatase enzyme and lowest blood cholesterol were also obtained for treatments 2 and 4. . The results showed that organic trace minerals, as alternative to inorganic forms, are useful to improve performance and health of broilers.

During the semen storage, oxidative damage is one of the major causes of reduced motility and fertility of spermatozoa. Therefore, antioxidants such as zinc and vitamin C in seminal plasma may be have the important effects on reduce the lipid peroxidation of spermatozoa by prevent the destroy effect of ROS. The aim of this study was to evaluate the effect of different levels of vitamin C and zinc in tris extender on spermatozoa characteristics of Arabi ram in liquid condition by 3×3×4 factorial arrangement with the use of completely randomized design. Treatments were included the levels of vitamin C (0, 150 and 300 μg/ml), zinc (0, 90 and 180 μg/ml) and storage periods of diluted semen (0, 2, 4 and 8 hours) in refrigerator temperature. Semen was collected weekly from 8 Arabic rams with 2-3 years old in breeding season and mixed together. The mixed semen was divided in to 9 parts and after dilution with tris, vitamin C and zinc levels were added. Spermatozoa characteristics include the progressive motility, viability and morphological defect rates were evaluated in various times of semen storage period. The effects of vitamin C, zinc and storage periods of semen on spermatozoa progressive motility, viability and morphological defect rates were significant (P<0.05). Also, comparison the means by Duncan test revealed that the highest motility and viability rates and lowest morphological defect rates were observed in zero levels of vitamin C and zinc (P<0.05). Therefore, vitamin C and zinc have no improved effects on motility, viability and morphological defect rates of spermatozoa in liquid storage condition of Arabian ram.

The present study was conducted to determine the zinc (Zn) requirement in broiler chickens fed wheat-soy based diet. Two hundred fifty day-old broiler chicks (Ross 308), were randomly assigned to a completely randomised design (CRD) experiment with 5 treatments, and 5 replicates of 10b each. The experimental treatments included five dietary Zn levels (30, 70, 110, 150, and 190 mg/kg) provided by the addition of reagent grade “ZnSO4.7H2O”. The experiment lasted from 1-42d of age. Increasing dietary Zn level to 70mg/kg significantly increased 10, 24 and 42d live body weight (LBW), feed intake (FI) and weight gain (WG) during 1-10, 25-42 and 1-42d of age and feed efficiency (FE) during 1-10d of age. The linear broken-line (LBL), quadratic-broken line (QBL) and the quadratic polynomial (QP) regression models were used to estimate the Zn requirement. The Zn requirement for optimal final LBW and FI, WG, and FE during 1-42d of ages by LBL model were 68.77, 83.12, 66.99 and 62.75 mg/kg of diet, and by QBL model 70.00, 79.93, 69.63 and 58.01 mg/kg of diet, respectively. In conclusion, Zn requirement varied between 58-83 mg/kg, which is higher than NRC and is lower than strain recommendation in the broiler chickens fed wheat-based diet.

The aim of this study was to investigate the effect of zinc and copper adding to diet of late-pregnant Mehraban breed ewes, on blood and milk minerals profile, lambs growth performance and some blood parameters. Seventeen ewes with 3-4 years old, 45 days before delivery were divided into 3 groups. Treatments includes: treat1) basal diet without supplement (containing 18.98 ppm Zn and 7.51 ppm Cu); 2) basal diet+30 ppm Zn as zinc sulfate, and 3) basal diet+30 ppm zinc as zinc sulfate and 8 ppm Cu as copper sulfate.Lambs were weighed at birth and at 10, 20 and 30 days of age. Lambs were raised with their dams during the experimental period. Blood samples of ewes were collected at -45, 0 and +30 days of delivery and lambs at 10 and 20 days of age. Milk sample was collected at 0, 15, 30 days after delivery. Dietary supplementation of zinc and copper significantly increased plasma (ewes and lambs) and milk zinc and copper concentrations (P<0.05), however, milkiron and also serum Calcium and Phosphorus concentrations were not affected (P>0.05). In treat-2 and 3, lambs body weight, daily gain, red blood cells count, hemoglobin concentration, plasma T3, zinc and ALP concentrations were significantly higher than control group (P<0.05). The concentrations of glucose, creatinine, total protein, albumin, globulin, lactate dehydrogenase, triglycerides, cholesterol were not affected by treatments (P>0.05). The results showed that adding 30 ppm zinc to pregnant ewes' diet result in increase plasma and milk zinc concentrations and finally lambs growth performance.

This research was conducted to evaluate the effect of some feed additives compare to Flavomycin growth promoter antibiotic. Experiment was conducted in completely randomized design manner consisting 3 treatments, 5 replicates and 20 hens per each replicate using 300 White Leghorn, Hy-Line W-36 strain. The experimental treatments included: control, Flavomycin growth promoter antibiotic at 0.05% dietary level and feed additive mixture consisting of thyme and oregano plant extracts and propionic acid and zinc supplement at 0.1% dietary level which fed to laying hens for 42 days (3 periods of two weeks each). The results of this study showed that the utilization of feed additive mixture significantly (P