جستجوی مقالات مرتبط با کلیدواژه "هورمون های تیروئیدی" در نشریات گروه "علوم دام"

Soybean meal (SBM) is the main protein source in diets for poultry due to its high protein and excellent amino acid quality and profile, in addition to its high availability of amino acids. However, in some countries, other protein sources are available at lower prices and can be included in least-cost formulations instead of SBM. Rapeseed meal (RM) is the second most important oil-producing crop after soybean. Recently, there has been increasing interest in rapeseed production in countries around the world including Iran. Although RM has a good amino acid profile, its crude protein content (36% to 39%) is lower than that of SBM (44% to 48%). Despite higher levels of methionine and cysteine in RM, its lysine content is lower than SBM. The use of RM has been limited by its low available protein and energy contents relative to SBM. The main factor affecting the levels of available crude protein and energy content is the fibrous hull of RM. RM also contains non-starch polysaccharides and glucosinolates. Excessive levels of RM and thus high dietary glucosinolate content could lead to abnormalities in thyroid function activities and consequently a retardation in growth performance. Therefore, the objectives of the current study were to determine the effects of dietary selenium (Se) and levothyroxine (LT) supplementation on performance, carcass characteristics, and thyroid hormone concentration in broiler chickens fed diets containing RM.
This experiment was performed to evaluate the effect of dietary Se and LT supplementation on performance, carcass characteristics, weight of internal organs, and thyroid hormone concentration in broiler chickens of commercial strain Ross 308. The experimental treatments were: 1) diet based on SBM and corn grain (positive control), 2) diet with 10% RM (negative control 1, NG1), 3) diet with 20% RM (negative control 2, NG2), 4) NG1+ 0.3 mg Se/kg diet, 5) NG2+ 0.3 mg Se/kg diet, 6) NG1+ 80 µg LT/kg diet, 7) NG2+ 80 µg LT/kg diet, 8) NG1+ 0.3 mg Se and 80 µg LT/kg diet, and 9) NG2+ 0.3 mg Se and 80 µg LT/kg diet. Nine dietary treatments with four replications and 15 chickens in each replication were allocated to the experimental pens in a completely randomized design. During the experimental period (1 to 42 days), average feed intake, body weight gain, and feed conversion ratio were measured. At day 38, two birds from each pen were selected and blood was taken from their axillary vein for measuring thyroid hormones. At the end of the experiment (day 42), two birds from each replicate were selected, weighed, and slaughtered for carcass and internal organs weight determination.
The results showed that there were no significant differences between the treatments receiving RM and the positive control treatment in terms of growth performance. The percentage of abdominal fat and the relative weight of the internal organs, except the gizzard, were not significant between the dietary treatments. The treatment of 10% RM supplemented with Se and LT had the highest relative weight of the thymus. The treatment with 20% RM had the highest and the treatment with 10% RM + LT and 10% RM + LT and SE had the lowest relative weight of bursa Fabricius. The relative weight of the spleen was not affected by the experimental treatments. The treatment containing 20% RM showed the lowest carcass weight and the positive control treatment had the highest percentage of breast muscle. The use of RM at 20% caused a significant increase in thyroid weight compared to the positive control group (group without RM). The thyroid weight was reduced by SE and LT supplementation to diets containing RM. Rapeseed meal had no significant effect on T4 hormone levels, but treatments supplemented with SE increased and treatments supplemented with LT decreased T3 hormone levels. Also, the level of TSH hormone in the treatments receiving RM was lower than that in the treatments without RM. Chickens receiving RM with SE and LT had the highest levels of antioxidant enzymes of glutathione peroxidase and superoxide dismutase.
According to the results of the present experiment, supplementing RM with SE and LT decreased the weight of the thyroid gland and increased the level of antioxidant enzymes, which suggests the positive effects of the use of these compounds in the diet based on RM on the function of the thyroid gland.

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.

In this study, the effect of black cumin and the black seed was evaluated on the growth, blood metabolites, thyroid hormones, and liver enzymes activity of lambs under pasture grazing conditions.  Twenty-four Sanjabi male lambs in their four to five months of age (live weight of 30 ±0.9 kg) were used in four treatments and six replicates in a completely randomized design for 70 days. Treatments included group 1: Control (rangeland forage), group 2: Rangeland forage plus 0.3 g of black seed per kg body weight (BW), group 3: Rangeland forage plus 0.3 g of black cumin per kg BW, and group 4: Rangeland grass plus 0.15 g of black seed + 0.15 g of black cumin per kg BW. The lambs were weighed every two weeks. Blood samples were collected from the jugular vein on days one, 35, and 70 of the experiment. Adding black seed and cumin had no significant effect on growth performance, but significantly increased total blood protein in treated groups (P<0.05). The blood urea level of lambs in treated lambs was lower than in the control group. Thyroxine concentration in lambs fed on black seed was higher than that of other groups (P<0.05). The activity of aspartate aminotransferase and alanine aminotransferase was lower in the herbal supplemented groups than in the control group (P<0.05). Overall, the results of this experiment showed that incorporation of these amounts of black seed and black cumin to the diet as herbal supplements improved some blood parameters, but had no significant effect on growth performance.

To compare the effects of injection different levels of selenium and vitamin E in late pregnancy on thyroid hormone metabolism and biochemical parameters of Holstein cows and their calf performance, 28 pregnant Holstein cows were selected in 8 weeks before calving and randomly assigned to 4 treatments and 7 replications. Cows were then injected with selenium and vitamin E four and two weeks before the expected time for calving. Treatments included: injection of 0 (contro), 15, 30 and 45 ml of selenium and vitamin E supplements. Each ml of supplement contained 0.5 mg of selenium in the form of sodium selenite salt and 50 international units of vitamin E in the form of DL alpha tocopherol acetate. Cows were balanced in terms of age, weight and calving time. The results showed that injection of selenium and vitamin E in pregnant cows affected the weight performance of their calves (P<0.05) so that the daily weight gain and weight of calves at 30 and 45 days of age in Selenium and vitamin E treatments increased, compared to the control group (P<0.05). Receiving of selenium and vitamin E makes pregnant cows resistant to low blood glucose and triglycerides in the postpartum period. At one week after delivery. The concentration of glucose and blood triglycerides in the injected cows increased compare to the control treatment (P<0.05). Also, one week before and after delivery, with increasing the dose of selenium and vitamin E, the activity of glutathione peroxidase and the concentration of tetrahydrotyronine and triiodothyronine increased (P<0.05). In general, according to the present results, at least 30 ml of selenium and vitamin E at the end period of pregnancy for Holstein cows, could be recommended.

This experiment was performed to evaluate the different ratios of organic and inorganic Iodine (0:100, 25:100, 50:50, 75:25, 100:0) on the performance, blood parameters and serum thyroid hormones in broiler chickens in a completely randomized design with 5 treatments were tested in 5 replicate pens. The results showed that there was no significant difference between treatments in weight gain, feed intake and feed conversion ratio. The highest concentrations of T3, TSH and TRH were detected in 75% organic Iodine treatment (p < 0.05). The diet contained 100% organic Iodine was highest concentrations of tetraiodothyronine (T4) among treatments (p < 0.05). In blood serum, chicks fed with a diet containing 75% organic Iodine treatment were found to have the highest levels of glucose, total protein, nitrogen urea and superoxide dismutase, glutathione peroxidase enzymes (p < 0.05). However, there was no significant difference in the concentration of creatinine and uric acid blood. Generally, according to the results of this experiment, the replacement of mineral supplement with organic supplementation of iodine without negative effects, affected on blood parameters and concentration of thyroid hormones, so that the highest concentration in treatment of 75%organic iodine + 25% inorganic iodide was observed.

The aim of this study was to evaluate the effect of Tribulus terrestris powder on thyroid hormones (T3 &T4) and IGF-I concentrations in blood serum of Arabi male lambs. For this purpose, 18 Arabi male lambs with an average age of 3 months and average weight of 16.14 ± 2 kg were used in a completely randomized design with 3 treatments and 6 replications per treatment for 5 months. Experimental treatments included the zero (control), 15 and 30 gr/kg of Tribulus Terrestris powder in diet. The weights of lambs were measured monthly. At the age of 4-8 months, 5 consecutive samples were collected monthly to measure serum T3, T4 and IGF-I concentrations. The results showed thatTribulus terrestris powder had no significant effect on body weight. The concentrations of T3 and T4 were higher in lambs treated with Tribulus terrestris powder compared to control group (p<0.05). Concentrations of T3 at the age of 7 months and T4 at 8 months of age in lambs fed 30g/kg of Tribulus terrestris were significantly higher than control group (p<0.05). IGF-I concentration in lambs feed with 15g/kg of Tribulus terrestris at the age of 6 months was higher than control group (p<0.05). In general, the results of this study showed that feeding of 15 g/kg of Tribulus terrestris powder in Arabi male lamb diet by modulating thyroid hormones and IGF-1 and improving the reproductive system, prevents the reduction of sexual behavior and failure of reproductive activity.

The replacement of inorganic mineral with organic sources can impose benefical effects on broiler chickens. The replacement of 25 and 50% inorganic iodine with organic source had beneficial effects on the determined indices of current experiment (Angelovicova et al., 2012). Higher replacement levels (100% organic iodine) detrimentally affected the blood and tissue indices of broiler chickens (Opalinski et al., 2012; Saki et al., 2012; Peyvastegan et al., 2017). The aim of this study was to investigate the replacement of inorganic mineral with organic sources iodine effects on performance, carcass characteristics, meat iodine, thyroid hormones, and some blood indices in broiler chickens. This experiement was performed to investiage the effects of different levels of inorganic iodine (potassium iodiate) replaced with organic source (yeast iodine) on performance, carcass characteristics, iodine content of meat, and thyroid hormone concentrations and blood indices (hematocrit, RBC, WBC, Hb, ALP, ALT, AST, cholesterol, triglyceride, HDL, LDL) in broiler chcikens. The experiment was done based on a completely randomized design using 250 male broiler chickens (Ross strain) with 5 treatments and 5 replicates per each treatment (10 birds per each replicate) during a 42 days period. The experimental treatments included different replacement levels of 0.0 (5 mg/kg inorganic iodine without any organic source), 0.25 (3.75 mg/kg inorganic iodine along with 1.25 mg/kg organic source), 0.50 (2.5 mg/kg inorganic iodine along with 2.5 mg/kg organic source), 0.75 (1.25 mg/kg inorganic iodine along with 3.75 mg/kg organic source) and 100% (5 mg/kg organic iodine without any inorganic source) inorganic iodine (potassium iodiate) with organic source (yeast iodine). None of the repleacement levels of inorganic with organic source had effects on feed intake, weight gain and feed conversion ratio (P>0.05). Inceasing the inorganic replacement with organic form of iodine linearly increased the carcass and thigh relative weight (P<0.05). The birds fed 5 mg/kg inorganic iodine had the highest carcass weight (P<0.05). The birds fed the diets including 75 and 100% of organic iodine replacement had the highest breast and thigh weights (P<0.05). The abdominal fat trended to be lower in birds fed 5 mg/kg organic iodine (100% replamecment) as compared to control diet (100% inorganic iodine), (P=0.065). Moreover, increasing the replacement amount of organic iodine to 100% increased the breast meat iodine content linearly (P<0.05), while breast meat of birds fed 5 mg/kg organic iodine had the highest iodine content (P<0.05). Moreover, the breast iodine content of birds fed the diets with 75% replacement of inorganic iodine (3.75 mg yeats iodine and 1.25 mg potasium iodate per kg) was higher than those of diets with lower inorganic iodine replacements (P<0.05). No effects of inorganic iodine replacement were detected on relative weights of liver, heart, spleen, small intestine, deudenum and ileum (P>0.05), but incressing replacement of organic iodine caused an increase in the relative weights of pancreas, gizzard, jujenum, and thyroid gland (P<0.05). Birds which received the highest replacement level of organic iodine showed the highest pancrease,
gizzard, jejunem and thyroid gland weights wherease the control birds had the lowest weights of these organs at day 42 of experiment. There were no effects of inorganic iodine replacement with organic source on white blood cells, lymphocytes, monocytes, basophils, eosinophils and hetrophils at day 42 of experiment (P>0.05). Moreover, increasing the organic iodine replacement to inorganic form increased red blood cells and hematocrit (P<0.05). Blood hematocrit was increased by increasing the organic replacement until 50% (P<0.05). No effects of replacement level were observed for blood triglyceride and cholesterol (P>0.05). Both the blood LDL and HDL contents were affected by the replacement levels (P<0.05). Blood LDL concentration was increased by increasing the inorgainic level replacements but there were no significant difference between the replacement levels of 50, 75 and 100% inorganic iodine. The highest blood HDL concentration was related to the birds fed the 50% replacement of inorganic iodine with organic iodine source (2.5 mg yeast iodine and 2.5 mg potassium iodate). Moreover, the lowest blood HDL content was observed for the birds fed 75% replacement of inorganic iodine with organic iodine source. The blood enzyme activities of alanine amino transferase, aspartate amino transferase and alkaline phosphatase along with T3 and T4 contents were increased by increasing the replacement level of inorganic iodine with organic source (P<0.05). The birds fed the control diet (5 mg/kg potassium iodate) had the lowest enzyme activities and thyroid hormone contents while the highest activity of the mentioned enzymes and thyroid hormones were observed for the higest replacement rate (100% inorganic iodine replacement). It is concluded that higher than 50% inorganic replacement with yeast iodine caused functional impairment of vital organs. Hence, replacement of 25 and 50% inorganic iodine with organic form had the benefical effects in broiler chickens by increasing the carcass and thigh weights, the breast iodine content and relative weights of internal organs.

The aim of this experiment was to study the effects of long-term induced hyperthyroidism on the body weight and egg production. In addition the relationships between hyperthyroidism and some reproductive parameters were studied. A total of seventy 47-week-old Cobb 500 breeder hens were randomly allotted to two treatment groups (5 replicates of 7 hens each). Thyroxine was orally administered to the hyperthyroid group (0.3 mg/bird/day) for 100 consecutive days during which the body weight and egg production were recorded on a weekly basis. Effect of hyperthyroidism on plasma T4 levels was significant; but, the T3 level was not affected. Results indicated a significant decreasing effect of thyroid hormones on body weight. Thyroid hormones had no effect on egg production; however, the treatment × time (wk) interaction effect was significant on egg production. Ovarian and oviductal weight were not different between the control and hyperthyroid hens. Administration of thyroxine to breeder hens decreased the diameter of F1 follicles.

The effect of dietary olive leaf in diet at different periods of breeding was studied on growth performance and ascites incidence in broiler chickens. A total of 336 one day-old male broiler chickens (Arian) used in complete randomize design with 6 treatments, 4 replications and 14 birds in each replication. The period of experiment was 42 days. The rations were supplied base on recommendation of Arian broiler management guide in three phase of feeding. In each phase, tow diets were provided with 0 (control) and 1 percent of olive leaves dried in diet. The treatments were diets:1) control, 2) from 1 to 14 days olive leaf, 3) from 1 to 21 days olive leaf, 4) from 1 to 28 days olive leaf, 5) from 1 to 35 days olive leaf, 6) from 1 to 42 days olive leaf. The effects of treatments were not significant on final body weight, daily feed intake and feed conversion ratio. The mortality due to ascites syndrome was reduced in treatments of olive leaf 1 to 14 and olive 1 to 42 (P

BAKGROUND: Age and season may affect the thyroid gland, which regulates the metabolism of the body.
The experiment was conducted to study the effects of age and season on the concentration of thyroid hormones T3, T4, T3uptake, T3/T4 and free thyroxin index (FTI).
Blood samples were collected from jugular vein of 21 healthy purebred Arabian male horse in summer (July) and winter (January). The male horses were under the same management and feeding program in three age groups 2-6, 6-10 and 10-14 years. After centrifugation of blood samples and isolation of serum, the concentration of thyroid hormones were measured in serum by standard radio immunoassay (RIA) method.
Results showed that there is significant differences in mean values of serum T4, T3uptake and T4/T3 ratio between summer and winter seasons (P>0.05). The concentration of T3 and free thyroxin index (FTI) did not show a statistically significant differences between summer and winter (P>0.05). In summer, the concentration of T4 and FTI value in 2 to 6 years and the ratio of T4 to T3 in 10 to 14 years old males had significantly differences than other ages (P>0.05). In winter, there were not significantly differences for thyroid parameters among various ages of males (P>0.05).
The results of this study showed that under constant conditions, thyroid gland performance may be affected by season and ages in Arabic male horses.

The aim of this study was to investigate the effects seaweeds Gracilariopsis persica in diets on performance and TSH، T3 and T4 hormones in serum of laying quail. A total of 112 laying quails were randomly allocated into four dietary treatments (diets containing 0، 1، 3 and 5% seaweed) with 4 replicates of 7 birds each. The birds were fed on experimental diets for 12 weeks. Eggs were collected daily and weighed. Then egg yield (based on hen day)، egg mass، feed conversion ratio and the percent of abnormal eggs were calculated during the 7-10، 11-14، 15-18 and 7-18 weeks of age. At the end of the experiment، the blood samples were taken from two birds per each replicate and analyzed for T3، T4، TSH hormones. There were no significant differences in egg production، feed intake، feed conversion ratio، egg weight، egg mass and percentage of abnormal eggs between treatments. However، the highest egg production was belonged to birds fed 3% of seaweed in diets and had significant difference with birds fed on diets containing 5% seaweed (P<0. 05). There were no significant differences in T3، T4، TSH of serum between treatments. As conclusion، Gracilariopsis persica can be include up to 3% in laying quail diets.

This experiment was performed to evaluate the different ratios of organic and inorganic selenium (0:100، 30:70، 50:50، 70:30، 100:0) on the performance and blood parameters of broiler breeders. In a completely randomized design 6 dietary groups were tested in 4 replicate pens of broiler breeders. The results showed that fertility، settable egg production، hatchability and chick percent were significantly increased among the organic selenium diets compare to the inorganic selenium diet and control. Egg quality was improved for the hens received organic selenium rich diets than that of the inorganic selenium diet and the control (p<0. 05). At the 4th week، WBC was significantly lower in 30% organic selenium diet than the other groups (p<0. 05). At the 8th week، the serum T4 to T3 ratio had significant difference among the 100% organic selenium diet، 100% inorganic and control diets (p<0. 05). The results showed that the organic selenium supplement، improved productive and reproductive performance and egg quality in broiler breeders at the end of the trial.

The objective of this study was to investigate the effect of age، sex on thyroid’s hormones levels and rhythmicity of these hormones in turkey chickens. 20 turkey chickens were randomly assigned to two groups (male=10&female=10). Blood samples were collected at 10 d intervals during 80 days. Data were analyzed with Proc Mixed of SAS. In second experiment، circadian rhythmicity of thyroid hormone in male and female was studied. 16 turkey chickens (male=8&female=8) were randomly selected and blood samples were collected at 2 hours intervals for 24 hours. Then، the plasma concentration of thyroid’s hormones were measured. Results showed that the effect of age on plasma concentration of thyroxin was significant but there was not significant different between male and female birds. By aging the birds، concentration of thyroxin enhanced. Plasma concentration of thyroxin in female and male was 20. 63±1. 6 vs. 20. 58±1. 7 µg/dl، respectively. Effect of genus and age on plasma concentration of triiodothyronine was significant. Overall mean plasma concentration of triiodothyronine in female chicken (209. 72±0. 34 ng/ml) was higher than male chicken (187. 74±0. 30 ng/ml). Possitive correlation was indicated between age and triiodothyronine level in male birds، while negative correlation was detected in female birds. Results of second experiment showed thyroxin increased during the night and decreased during the daytime، while the mean plasma concentration of triiodothyronine increased during the daytime and decreased during the night.