Effect Add Different Concentrations of Organic, Inorganic, and Nano-Selenium to Diet of Broiler Chickens (Ross 308) that Exposed to Heat Stress on Certain Productive Traits

This study was conducted at Al-Anwar Poultry Station in Babil Governorate Iraq for 35 days, from July 10, 2022 to August 17, 2022, in order to demonstrate the effects of supplementing broiler diets with varying concentrations of organic, inorganic and nano-selenium (Se) on certain production traits and under conditions of heat stress, 560 chicks of one day old (Ross 308) were used without identifying their sex and divided randomly into 7 transactions with 4 replicates for each transaction, and each replicate included 20 chicks. The first transaction, T1, was the control transaction without addition, and organic selenium was added in the second and third transactions (T2 and T3) at a concentration of 1 and 1.5 mg / kg, respectively, while the fourth and fifth transaction (T4 and T5) inorganic selenium was added at a concentration of 1 and 1. 5 mg / kg, respectively, while the sixth and seventh transaction (T6 and T7) included the addition of nano-Se at a concentration of 1 and 1.5 mg / kg, respectively. The results of the study showed the following: (1) Highly significant (P≤0.01) superiority of T2 transaction over all studied transactions in live body weight and overweight. (2) There was a significant (P≤0.01) superiority of the rate of feed consumption for the transactions T2, T5 over the T1, T3, T4, T6, T7. As for the food conversion coefficient, the transaction T4, T6 was more “significant” improvement at a level of (P≤0.01) than the rest of the transactions. The control transaction was the least improved transaction. (3)The data recorded a “significant” decrease for all addition transactions in the percentage of total deaths compared to the control transaction. T5 was similar to T1, but with a lower rate.


Introduction
Bird breeding is directly affected by environmental conditions, especially temperature and humidity.The climate in Iraq is characterized by high temperatures for most of the year, which negatively impacts poultry performance as ambient temperatures exceed normal limits, leading to a drop in feed consumption and consequent deficiencies in essential nutrients [1].Which negatively affects the rate of growth, the efficiency of feed conversion, the quality of meat and eggs, fertility, the weakening of the immune system of birds, and the high mortality rate, and it is the cause of large economic losses [2].Due to the increased demand for chicken and eggs, the development of the poultry industry around the world requires the production of commercial breeds that are characterized by rapid growth and efficient food conversion efficiency, nonetheless they are sensitive to high temperatures which makes them more susceptible to heat stress [3].Various methods have been developed to avoid the harmful 1259 (2023) 012063 IOP Publishing doi:10.1088/1755-1315/1259/1/012063 2 effects of heat stress on poultry, including the use of plant-based feed additives, minerals and vitamins [5,4].Selenium is one of the rare essential elements that are added to poultry feed, as it participates in many physiological functions in the bird's body, the most important of which is its effectiveness as an antioxidant, as it inhibits the production and excretion of cell-damaging free radicals.It is an essential component of the enzyme glutathione peroxidase found in body tissues that acts as an antioxidant enzyme that helps control levels of hydrogen peroxide and lipid peroxides that are produced during normal metabolic activity [6,7].The bioavailability of Se is related to its physical form [8]. Se exists in different forms, organic, inorganic and nano.These forms differ in efficiency, absorption mechanism, and level of metabolism, as studies have shown that organic-Se has a similar efficiency to nanoscale-Se compared to inorganic-Se [9].Nanoparticles are highly absorbable and can augment vaccines and dietary supplements due to their high surface -to-volume ratio and minimal energy loss.In addition, they can improve animal health and growth by delivering compounds directly to target organs or systems while avoiding the rapid degradation seen with some antibiotics, thereby increasing the health and growth of animals.Rahimi et al. [10] showed the effect of selenium supplementation on production traits of broiler chickens raised under heat stress, they mentioned higher body weight gain and feed conversion ratio after organic selenium supplementation.Also Safiullah et al. [11] pointed out that the supplementation of organic selenium in broiler chicken feed can improve productivity traits, immunity and antioxidant capacity under heat stress conditions.Although there are many studies and researches related to the supplementation of selenium in poultry diets, but at the same time it was found that there is a significant shortage and conflicting results of studies related to role of Se in reducing the effects of heat stress, Therefore, this study aimed to demonstrate the effect of adding three sources of Se, and compare between these sources , and to determine the best source of selenium in increasing the productive characteristics.

Experience Design Site
The experiment was carried out at the Al-Anwar company's field in the Al-Mouradia region/Babylon province and laboratories in Musel university Ethical approval No. um.VET.2021.5 for a period of 35 days, from July 10, 2022 to August 17, 2022, using 560 one-day-old chicks, randomly assigned into 7 transactions, with 4 replications for each transaction, where one replicate contained 20 chicks, and replicates distributed in 1 × 1.5 pens, a selenium source was added to the diet according to the following transactions: T1 no supplement, T2 supplemented at a concentration of 1 mg/kg feed organic-Se, T3 added concentration of 1.5 mg/kg feed organic-Se, T4 added concentration of 1 mg/kg feed inorganic-Se, T5 added concentration of 1 mg/kg inorganic-Se 1.5 mg/kg feed kg feed, nano-Se was added to T6 at a concentration of 1 mg/kg feed, and nano-Se was added to T7 at a concentration of 1.5 mg/kg feed.Chicks were fed starter diet (23.04% protein ratio and 3021.45kcal/kg energy feed) (from 1 day of age to the third week of life of the birds, after which it was replaced by a grower diet (20.06 protein ratio and 3194.92kcal/kg energy feed) until the end of the fifth week, with free access to food and water ad libitum.

Breeding Room Temperature
The temperature inside the hall was recorded daily at 600, 1200, 1800 and 2400 hours by 4 thermometers distributed inside the hall.

Materials Used in the Experiment
Organic-Se was obtained from the local market in Uruk in the form of gray powder weighing 25 kg and inorganic-Se was obtained from Al-Bashir's office in the form of sodium selenite weighing 100 g with a purity of 99,9% , in the form of white powder.The organic nano-Se material is from Nanosany Company of Iran, with a size of 30nm and a purity of 99%.The average live weight of the bird and the average weekly weight gain were calculated according to [13].

Feed Consumption and Feed Conversion Factor
The average weekly feed consumption for birds and the feed conversion factor were calculated according to [14].

Total Fatality Rate and the Ratio Total Vitality
The average total fatality rate and the ratio total vitality were calculated according to [14].

Average Live Body Weight (g/bird)
The analysis of findings in Table No. (1) shows the transactions T1, T4 were significantly (P≤0.01)superior to the rest of the transactions, and the table did not record significant differences between the transactions T2, T3, T5 , T6, T7.In the second week, the statistical analysis showed a significant (P≤0.01)superiority of transaction T4 over T1, T2, T3, T5, T6, and T3, T5 outperformed T2, T6, and no significant difference was observed between T3 and T5.The superiority of T4 continued in the third week, as it was significantly superior (P≤0.01) over the rest of the transactions, and T7 excelled at a significant level (P≤0.01(compared to transactions T1, T2, T3, T5, T6 and excelled T1,T3 on T2, T5, T6, and there were no differences between T1 and T3.In fourth week, the organic selenium transaction T2 was superior at a significant level (P≤0.05) over the rest of the transactions, followed by nano-selenium T6 at a level (P≤0.05)compared to the transactions T1, T3, T4, T5, T7.In the fifth week of the experiment's life, it witnessed the continued superiority of organic selenium T2 over the rest of the transactions, and superiority of T4 over the transactions T1, T3, T5, T6, T7,where the weights of birds for the transactions T1, T2, T3, T4, T5, T6, T7 (1905.75 2006.55 ,1956.75 ,1994.50,1916.00 ,1965.00 ,1942.00)respectively.
Table 1.The effect of add organic, inorganic and nano-selenium on the average live body weight (g/bird) for 1-5 weeks of age of the bird.2): shows in the first week a highly significant increase (p≤0.01) for the transaction T4 over the addition transactions, but it did not differ significantly with the transaction of the control, the T6 which outperformed the transactions T2, T3, T5, T7 and also had similar at the level of (p ≤0.01) transactions T3,T5,T7 in terms of weight gain for this week, but it outperformed T2, and the last mentioned transaction did not show any significant difference with transaction T5.As for the second week, it outperformed, at a highly significant level (p≤0.01)transactions T3, T4, T5, T7 on T2, T6, but it did not differ significantly with the transaction of control, also we note that T2 has been superior to T5 in weight gain for the same week.

Transactions
In the third week, T4 witnessed a highly increase (p≤0.01)compared to all studied transactions, the T5, which was similar to T3 in weekly weight gain, but it outperformed transactions T1, T2, T5, T6 and we note that T6 did not show Significant with T3, but it was superior at the level of (p≤0.01) over transaction T1, T2, T5 and it was noted that T5 gave the lowest rates of weight gain for this week.The statistical analysis table in the fourth week showed superiority at the level (p≤0.01) in favor of the T2 transaction birds compared to all the experimental transactions and T6 which outperformed T1, T3, T4, T5, T6 and T3, as it outperformed T1, T4, T5, T7 and also T4 was significantly superior at (p≤0.01) level over T1,T5,T7 and we note that T5 was similar to the control transaction in the significance of this characteristic and it gave the lowest measured rates of weekly weight gain.The high increase (p≤0.01)continued for T2 for the fifth week in weight gain and T4, which was superior to T1, T3, T5, T6, T7, while transactions T5 was superior to T1, T3, T6,T7 and did not differ significantly.T6 and T3 were overweight, but they were superior to transactions T7 and T1.As for the total rate of weight gain, it was found to be highly significant (p≤0.01) for T2 over all transactions of the experiment, and T4, which outperformed on T1, T3, T5, T6, T7, and then transaction T6, which outperformed T1, T3, T5.T7 The transactions T3, T5, T7 were superior to the control transaction in the total rate of weight gain, where the rate was respectively (1866.75, 1966.00, 1917.25, 1954.00, 1904.50, 1927.25, 1876.50).

Feed Consumption Rate (g/bird)
In Table No. ( 3): shows in the first week decrease at the level (P≤0.01) in the rate of feed consumption for all addition transactions compared to the control transaction, and theT2, T4 which outperformed T3, T5, T6, T7.As for the transaction T3, it was significantly similar with T7, but it outperformed T6 and T5 in the same capacity.
In the second week, a significant (P≤0.01)superiority was observed for the T4, T5 over the T2, T3, T6, T7 but it was similar to the control transaction in the rate of feed consumption, also, it was noted in the same week that the T2 was superior to the T7, T3, but it did not show any significant difference with the T6, while the T3 was superior to the T7 in the rate of feed consumption.A highly significant increase (P≤0.01) for the T7 obtained all the studied transactions in the rate of feed consumption, and the T2, T4, T5 which did not show any significant difference between them, but it outperformed the T1, T3, T6, and also decrease (P≤0.01) was observed for the T3, T6 compared to the control transaction, and T3 was recorded lowest measured rates of this feed consumption rate were observed in the third week of the experiment.
In the fourth week, there was increase significant (P≤0.01) in the rate of feed consumption for T2 and all transactions, and then T3, which outperformed transactions T7, T6, T5, T4, T1, and while T7, T6, T5, T4 decreased the rate of feed consumption compared to the control transaction, and the T4 and T5 were among the lowest transactions that gave their birds an average of feed consumption for this week.As for the total rate of feed consumption a significant superiority was observed at the level (P≤0.01) for the transactions T2, T5 over the T1, T3.T4, T6, T7 and T3, T4, T6, T7 recorded decrease significant (P≤0.01)compared to the control transaction, and then T7 recorded an superiority over T6, T4, T3, and T4 was similar in the significance of the total rate of feed consumption once with T3 and again with T6.Table 3.The effect of add different concentrations of Se to on the average total feed consumption (g / bird) for the 1-5 weeks of the bird's life.

Feed Conversion Factor (g-feed/g-weight gain)
In Table No. ( 4): shows in the first week of the experiment that there was improvement significant (P ≤ 0.01) in the food conversion coefficient for T5, T6 compared to T1, T2, T3, T4, T7 and then T3 which was similar in the food conversion coefficient with T7, which showed improvement significant over T1, T2, and T4 and the T4 has outperformed T1 and T2, which have recorded the lowest rates of improvement in the food conversion factor for this week.
In the second week, improvement significant (P ≤ 0.01) was observed for transaction T3, T7 compared to the rest of the transactions, and then T2 which had outperformed T1, T4, T5,T6 and T6 has been superior to the T1 , T4 , T5 as the transactions did not differ in the food conversion factor.In the third week, the statistical analysis table showed improvement significant (P≤ 0.01) in the food conversion coefficient in favor of transaction T3 over T1, T2, T4, T5, T7, but it was similar to transaction T6, while T4 outperformed.T2, T5, T7, but they did not show any significant difference with the control transaction in the food conversion coefficient, and the transactions T2,T5,T7 did not show any significant difference between them in the same capacity.The fourth week witnessed a highly improvement significant (P≤ 0.01) for T6.In the feed conversion coefficient, compared with all the transactions of the experiment after T2 which were similar to T4 on the one hand and outperformed T3, T5, T7, and T1 on the other hand, As for the transactions T3,T5,T7 they were similar in the significance of this characteristic but they were superior to the control transaction.
In fifth week, the data of the experiment recorded improvement significant (P≤ 0.01) for transaction T2, T4 over all transactions in the food conversion coefficient, than T3,T6, which did not show any significant difference between them, but they outperformed transactions T1, T5, T7.As for T5, it was superior to T1,T7 in the same capacity.In measuring the total rate of the food conversion coefficient, it was found that transaction T4,T6 were more "significant" improvements at a level (P≤ 0.01) than the rest of the transactions of the experiment, than T2,T3, which outperformed transactions T1, T5, T7.We also note that the T5 was similar to the T7, but they were superior to the control transaction, which in turn gave the lowest rates, as shown in

Fatality Rate and the Ratio Vitality
The analysis of findings in Table No. (5) shows the indicate a highly significant decrease (P≤0.01) in the percentage of total deaths for the addition transactions Compared with the control transaction T1, which recorded the highest percentage of death, amounting to 7.5%, and then gave the transactions T3 and T6 gave the lowest rates of death throughout the experiment period.Table 5.The effect of add different concentrations of Se on the total fatality rate and the ratio vitality percentage %.

Discussion
The results of the study showed that organic selenium was superior in terms of live body weight, the rate of weekly weight gain, the feed conversion factor, the ratio vitality %, and the reduction of fatality in birds for the two transactions T2,T3 compared with the control transaction.These results are consistent with the study by Sahin et al. [15] and the study of Rahimi et al. [10] who pointed out that selenium supplementation has an effect on production traits of broiler chickens raised under heat stress.They stated that higher body weight gain and dietary conversion was greater with organic selenium supplementation may be attributed to high intestinal absorption and bioactivity that differentiate organic forms of selenium from inorganic forms.This in turn improves broiler growth, survival and antioxidant enzyme activity [16,17,18].On the other hand, the current research results contradict the study by Khajali et al. [19] and Ghazi Harsini et al. [20] who showed that selenium supplementation in poultry diets did not affect production traits in broiler chickens raised under heat stress conditions.This may be due to their use of low concentrations of selenium supplementation compared to the environmental conditions of the field.The research results also showed the superiority of T7, T6 and nano-selenium transactions in terms of live weight, feed conversion rate, fatality rate, and the ratio vitality %.This result is consistent with Vish et al. [21] and Abdel-Moneim et al. [22] who reported that nanoselenium supplementation resulted in increased production traits in broiler chickens.The reason for this is that nanoselenium affects the growth of birds through the metabolism of thyroid hormones, which play an important role in growth, protein production and metabolism by increasing the active hormone Tryodothyronine (T3) and decreasing the hormone Tetraiodothyronine (T4), thereby improving feed conversion to promote growth and live weight gain [23,24].Jamima et al. [25] reported that adding 0.15 mg/kg of nanoselenium particles to the feed could improve the weight gain and live weight of broiler chickens.The reason for the improved performance of poultry treated with nano-selenium may be due to biological activity, which can effectively help maintain cell function against oxidative stress and lipid peroxidation, improve immunity and better growth of broiler chickens [27,26 ].These results are inconsistent with the study by Cai et al. [28] and Rao et al. [29] who reported that the use of nanoselenium did not significantly increase the body weight of broiler chickens.The findings also showed that organic selenium resulted in increased live weight and feed intake.These results are consistent with the studies of Sahin and Kucuk [30] and Sahin et al. [15] who indicated that the addition of inorganic selenium supplements to the diets of broilers and marmalades under heat stress resulted in increased live weight and increased feed intake.The reason may be that broiler chickens are susceptible to heat stress, which regulates the expression of many selenoproteins responsible for skeletal muscle development in response to heat stress damage.These selenoproteins include selenoprotein N (SEPN1), skeletal muscle is considered to be the most important eating part of broiler chickens, and its poor growth mainly affects the growth performance of poultry.Therefore, Se can maintain and enhance growth performance by mitigating the deleterious effects of heat stress on skeletal muscle development [31].Our results differ from the study by Zainali et al [32] pointed out that the use of inorganic selenium alone had no significant effect on increasing the feed intake rate of broiler chickens, which may be due to the insufficient selenium absorption and the short duration of the experiment.

Conclusions
The addition of selenium sources generally led to an improvement in most of the productive traits, and a concentration of 1 mg/kg of Se gave better results in terms of productive traits compared to a concentration of 1.5 mg/kg.

Table 2 .
The effect of add different concentrations of Se on the rate of weight gain (g / bird) for the 1-5 weeks of the bird's life.
** Different letters in a column indicate significant differences in levels (p ≤ 0.01).

Table 4 .
The effect of add different concentrations of Se on the feed conversion factor (g-feed / gweight gain) for 1-5 weeks of age of the bird.

Transactions Arithmetic mean ± standard error Total fatality rate % Ratio vitality %
Different letters within one column indicate a significant difference at the level (p ≤ 0.01).* The different letters within the same column indicate a significant difference at the level (p ≤ 0.05).