Figure 1 shows the effect of adding different levels of lemon grass leaves to the fodder or its extract to drinking water in the broiler index for broiler chickens for the five weeks, where the second, third, fourth and fifth treatments recorded the highest production index (431.59, 443.96, 456.85 and 457.77, respectively, with a significant difference (P≤0.05) from the first treatment (control) that recorded the lowest production index of (401.00).
Figure 1. effect of adding different levels of lemon leaves to fodder and its extract to drinking water in the production index of broiler
First treatment: control group free from any addition. The second treatment: a basic feed added to 10 g of lemon grass / kg feed, the third treatment: a basic feed added with 20 g of lemon grass / kg feed, the fourth treatment: adding 100 ml of the aqueous extract of the lemongrass / liter of drinking water, and the fifth treatment: adding 200 ml of the aqueous extract of the lemongrass liter of drinking water.
Table 6 shows the results of the statistical analysis of the effect of adding different levels of lemon grass to the diet or its extract to drinking water in the rate of water consumption for broiler for the 5-week trial weeks, in the absence of significant differences between all treatments in the first and second week of the experiment. As for the third week, we noticed that the third and fifth treatment birds recorded the highest rate of water consumption (1299.33 and 1332.67 ml / bird), respectively, and with a significant difference (P≤0.05) for the first, second and fourth transaction birds that recorded the lowest water consumption rate reached (1240.00, 1239.33 and 1249 .33 ml / bird), respectively. While in the fourth and fifth week, we noticed that there were no significant differences between all treatments of the experiment. As for the total water consumption rate, we noticed the registration of the fifth treatment with the highest total water consumption rate (6792.66 ml / bird) and a significant difference (P≤0.05) from the second treatment birds that were recorded consumption total water was 6508.66 ml / bird, which in turn did not differ significantly from the first, third and fourth treatment birds.
Table 6. Effect of adding different levels of lemon grass to fodder and its extract to drinking water on the rate of water consumption of broiler (mean ± standard error)
First treatment: control group free from any addition. The second treatment: a basic feed added to 10 g of lemon grass / kg feed, the third treatment: a basic feed added with 20 g of lemon grass / kg feed. The fourth treatment: adding 100 ml of the aqueous extract of the lemongrass / liter of drinking water, and the fifth treatment: adding 200 ml of the aqueous extract of the lemongrass liter of drinking water.
Discussion and conclusion
The use of medicinal plants and their extracts as food additives in poultry diets generally improves body weight and overweight . The significant increase in the rate of live body weight and the total weight increase in the treatments of the third, fourth and fifth lemon grass leaves compared with the first (control) treatment was due to the role of the active substances present in the lemon leaves, such as Flavonoids, Linalool and Phenoles as catalysts for the digestive system and improving digestion [9,10], as it increases the production of digestive enzymes such as the enzyme Chemotrypsin, Lipase, Amylase, and Trypsin in birds . The digestion process also improves and the birds benefit more from the food intake and this is reflected in the growth of birds and the final return is positive on the rate of weight gain and the final weight of the bird [12,13]. There is a positive correlation between the ratio of digestion, body weight, and the amount of feed intake  or the significant improvement in body weight and the overall weight increase of the treatments of lemon grass leaves (third, fourth and fifth) may contain Myrcener, which is considered as an opening of the appetite . It is also clear from the results of Table 5 on recording of the third and fourth treatments, the best cumulative food conversion factor is compared with the first treatment (control); this is due to the role of active substances and compounds in lemon grass in improving digestion and the absorption capacity of the digested food as well as increasing the process of food analysis by beneficial microorganisms the creation of microbial balance inside the intestine . The significant role of active substances in lemon grass lies in improving the physiological efficiency of the digestive system in utilizing feed material that leads to improved production performance and feed conversion ratio . This improvement in the characteristics of productive performance is all reflected positively on the values of the production guide, which is one of the important indicators in the evaluation of the productive performance of broilers, due to the high value in the transactions of lemon leaves as a result of the high rate of live body weight and the vital percentage. Also, the improvement of the food conversion factor in these transactions, as the scale of the productive guide, is directly proportional to the rate of live body weight and the vital ratio. As for the increase in the rate of water consumption, it is known that the bird’s water consumption is estimated to be twice as the amount of feed consumed  and this was in agreement with what Kellems and Church (2002) indicated, in which the bird consumes water about 1.6-2 times higher as much as feed consumed. Lemon leaves may have a role in improving the flavor and taste of feed or drinking water, so that the bird is palatable to it, and then increases the feed or water consumption of lemon grass compared with the first treatment (control).
We would like to thank The College of Agriculture, AL-Qasim Green University for giving us this opportunity to express our science.
We certify that all authors have seen and approved the final version of the manuscript being submitted. They warrant that the article is the authors' original work, hasn't received prior publication and isn't under consideration for publication elsewhere.
Nihad Abdul-Lateef Ali: https://orcid.org/0000-0002-2684-9243
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