The Effect of Substituting De-Hulled Sunflower Meal Instead of Soybean Meal with or Without Adding Xylanase Enzyme to the Ration on Productive Performance and Carcass Characteristics of Broiler Chicks

This study was conducted to investigate the effect of replacing de-hulled sunflower meal (Dh-SFM) with soybean meal (SBM) by (0, 33, 66 and 100)% as a protein source in diets with or without the addition of xylanase on productive performance and some Characteristics of broiler carcasses. Where he used (360) unsexed broiler chicks (Ross-308), distributed randomly in a two-factor experiment (4×2) into eight treatments, in each treatment three replications, with (15) chicks for each replicate, homogeneous in weights. and for a period lasted (42) days. The results showed that the replacement of de-hulled sunflower meal by (33%) did not significantly affect the live body weight, feed consumption, feed conversion factor and the percentage of dressing compared with the control treatment. While a significant deterioration (P≤0.05) was observed in all of these traits when the substitution level was increased to 66 and 100%. The results also showed that the partial substitution treatment (33% Dh-SFM with xylanase enzyme) did not differ significantly from the negative and positive control treatments in live body weight, weight gains, feed conversion factor, and the relative weight of the gizzard. While a significant decrease (P≤0.05) was observed for the partial and total substitution treatments (66 and 100% Dh-SFM with or without xylanase enzyme) in live body weight, feed consumption, feed conversion factor, and carcass characteristics, with an increase in relative weight compared with the control treatment.


Introduction
Soybean meal is one of the most important vegetable protein sources used in poultry feed due to its high protein content and most of the amino acids needed by poultry in balanced proportions, except for the methionine [1].All these reasons led to an increase in demand for it globally and, consequently, to a rise in its prices, which prompted many researchers to grow and develop local crops that could fill the shortage of food and fodder in order to reduce the costs projects of poultry.Dehulled Sunflower Meal is considered one of the most important sources of protein after soybean meal [2], and it is commonly used in many countries of the world in animal and poultry feeding due to the cheapness of its protein unit.The chemical composition of the sunflower meal, including its content of protein and amino acids, depends on several factors, including the strain or variety of the seeds, whether the seeds are hulled or not, the technique used to extract the oil, as well as the temperature to which it is subjected while being extracted [3,4], de-hulled sunflower meal contains a percentage of crude protein ranging between 36.6-48% and crude fibers ranging between 11.8-24%, and its metabolic energy content is 2800 kcal/kg [5].and the high percentage of fiber in the sunflower meal led to several studies with the aim of benefiting from this meal in poultry feed by reducing the percentage of these fibers through sifting or increasing the digestion of these fibers by adding enzymes that analyze non-starch polysaccharides [6].The counteracting or negative effect that complex sugars possess in this meal is their interference with other nutrients, which reduces their utilization, in addition to increasing the speed of passage of the food substance in the gastrointestinal tract.and thus reducing the period of which the food mass is exposed to the action of enzymes and digestive juices, and as a result Therefore, digestion and absorption rates decrease, thus reducing the amount of energy and protein available to birds [7][8][9].Domestic birds do not possess microorganisms that secrete digestive enzymes for non-starch polysaccharides, as is the case in ruminant animals, and here the importance of enzymatic additions to liberate nutrients and increase their [10,11].Accordingly, this study aimed at the possibility of partial and total replacement of de-hulled sunflower meal protein with soybean meal protein with the use of xylanase enzyme in the productive performance of broiler chickens.

Experiment Chicks
In this study, a total of (360) chicks of the unsexed Ross-308 broiler breed were used in this study, which were equipped from one of the approved private hatcheries Ethical standards were considered in all steps of performing procedures and animal handling and the study was approved by the Ethical Committee [Approval letter No. UoM.Dent/A.L.66/21].No. Um.VET.2021.5.The average weight of the chicks at hatching was (41.5) grams, which was adopted as the initial weight for the experimental treatments.They were distributed randomly in a factorial experiment with two factors (4×2) to (8) feeding treatments, in each treatment three replicates, and at the rate of 15 chicks for each replicate, homogeneous in their weights.and for a period that lasted (42) days.

Diets
De-Hulled sunflower meal (Dh-SFM) was used in this study as a partial and total substitute for soybean meal at levels (0, 33, 66 and 100)% in experimental diets with or without the addition of enzyme xylanase.The rearing period was divided into (42) day into two phases and formed two diets of different substitution levels for both periods (Table 1), The first is the starter ration for the period from one to 21 days, then it was replaced with a finished ration that was used to feed the broilers for the period from 22 to 42 days.The formation of experimental relationships was based on the recommendations of the American National Research Council [12].The process of replacing the dehulled sunflower meal with the soybean meal was carried out on the basis of nitrogen symmetry (isonitrogiouse) and the represented energy (iso-caloric), meaning that the replacement was calculated on the basis of protein / protein for both meal.The enzyme endo-1,4-β-Xylanase (3.2.1.8)was used, where the enzyme product was added to the diets at an amount of 150g/ton of feed, according to the manufacturer's instructions.Feed and water were freely available, Ad-libitum, throughout the period.

The Traits Studied
The growth and carcass characteristics of all treatments were studied, where the live body weight and the amount of feed consumed were measured weekly, and the weekly weight gains and feed conversion factor were calculated, was also calculated of the Production Index (PI) and the European Productive Efficiency Factor (EPEF), At the end of the experiment period, (6) birds were selected from each treatment and their weight was recorded to represent the live weight at marketing, then they were slaughtered and the weight of the hollow carcass was recorded and the dressing percentage, was calculated on this basis.After that, the carcass was cuts to the major and minor pieces, as reported by [13], and their percentage was calculated relative to the weight of the hollow carcass.The relative weight of the ingested internal organs (liver, heart and gizzard) and Abdominal Fat was measured, and their weights were attributed to the final live body weight.

Statistical Analysis
The statistical analysis of the experiment data was carried out using a complete random design (C.R.D) for a factorial experiment with two factors (2×4), and the significance of the differences was tested using Duncan's multinomial test [14] and at the level of probability (P≤ 0.05), and the statistical analysis was performed For data using the ready-made statistical analysis program [15]..54*-The amount of energy represented, the percentage, amino acids and mineral elements were calculated from the tables of chemical analysis [12] and according to the proportions of raw materials in the diets.

Growth Parameters
It is clear from the results of the statistical analysis (Table 2) that there are no significant differences between the control treatment (0% Dh-SFM) and the second treatment in which de-hulled sunflower meal was used by (33%) as a protein source replacing soybean meal in the final weight and total weight gains and overall relative growth rate.While a significant (p≤0.05) and linear decrease was observed in all of these traits, with an increase in the levels of substitution of de-hulled sunflower meal to 66 and 100% (the third and fourth treatments) compared with the control treatment.As for the effect of the interaction between the replacement of de-hulled sunflower meal instead of soybean meal and the addition of xylanase enzyme.It is noted from the results in Table (2) that there was a significant improvement (p≤0.05) in the final weight, the total weight gain and overall relative growth rate when adding the xylanase enzyme to all levels of replacement of de-hulled sunflower meal (33, 66 and 100%) compared to the corresponding empty level from add.When comparing the performance of birds for all substitution treatments, whether with or without xylanase enzyme added, with the negative and positive control treatments, we notice a significant decrease (P≤0.05) in the final weight, the total weight gain, and overall relative growth rate, for all cases of interference at the substitution levels by 66 and 100% compared with the negative and positive control treatments.The results of this 1259 (2023) 012074 IOP Publishing doi:10.1088/1755-1315/1259/1/0120744 study are consistent with [16,17] that the live weight and weight gain of broiler chickens were not affected by the presence or absence of fiber-degrading enzymes in diets containing 25% sunflower meal compared to the control treatment, while the use of The high ratios sunflower resulted in a significant decrease in the weights of the birds.While it differed with the results of [18] which indicated a significant improvement (P≤0.05) in live body weight when total and partial replacement of sunflower meal with soybean meal Without or with the addition of fiber-degrading enzymes (NSPase).The reason for the decrease in growth performance when replacing de-hulled sunflower Table 2. Effect of substituting de-hulled sunflower meal as a substitute for soybean meal without or with the enzyme xylanase on the growth performance of broiler chickens.Meal by 66 and 100% may be attributed to the increase in the level of non-starch polysaccharides (NSP) in these diets [19], as NSP works to cach nutrients inside the cell wall and make them unavailable for the action of digestive enzymes in addition to To reduce the transit time of the food mass (Digesta) inside the gastrointestinal tract [20,21] and thus increase the amount of undigested nutrients excreted outside the body, which reduces feeding efficiency.On the other hand, the reason for the improvement in growth performance when adding xylanase enzyme to the control treatment and substitution treatments may be due to the role of the enzyme in the degradation of non-starch polysaccharides (NSP), and the release of encapsulated nutrients, which improves their bioavailability, and also facilitates the decomposition of non-starch polysaccharides (NSP) leads to the entry of water and endogenous enzymes into cells and increases the efficiency of digestion and utilization of nutrients [22].

Feed Consumption, Feed Conversion Factor
Table (3) shows that the replacement of Dh-SFM sunflower meal by (33%) in the second treatment did not significantly affect the feed consumption and feed conversion factor compared with the control treatment, while the partial replacement resulted in (66%Dh-SFM) and the total (100%Dh -SFM) Significant decrease (p≤0.05) in feed consumption and feed conversion factor.As for the effect of the interaction between the replacement of De-hulled sunflower meal instead of soybean meal and the addition of xylanase enzyme, it is clear from the results there was a significant decrease (p≤0.05) in the average feed consumption and a significant deterioration in the feed conversion factor for the case of the overlap between the partial substitution level by (33 and 66% Dh-SFM) with the addition of xylanase enzyme compared with the corresponding level without xylanase enzyme.and When comparing all substitution treatments, whether without or enzyme-added, with the negative and positive control treatments, we notice a significant deterioration (p≤0.05) in all of these traits for all cases of interference at the level of partial substitution (66% Dh-SFM) and total (100% Dh-SFM) with or without xylanase enzyme compared with the negative and positive control treatments.The results of the study are consistent with the results of [23], which included that the amount of feed consumed and the feed conversion factor of broiler chickens were not affected by the addition of enzymes degradle of fiber (NSPase) to the partial replacement diet of sunflower meal by (25%), while it was observed that the level of substitution increased to 50 and 75%.Feed consumption was significantly reduced (p≤0.05)when compared with the control treatment.The reason for the decrease in the amount of feed consumed with the increase in the replacement of De-hulled sunflower meal instead of soybean meal by 66 and 100% may be due to the increase in the proportion of non-starchy polysaccharides, as mentioned [24] that the physical density of the feed changes depending on the level of fiber in the flower meal The sun, which leads to a reduction in feed consumption due to the large volume occupied by fiber in the digestive system, which can also interfere with the ability of these fibers to retain water, which reduces feed consumption.While the reason for the decrease in the amount of feed consumed when adding the xylanase enzyme can be attributed to the products of the enzyme and its effects on intestinal fermentation and then on the peptide hormone (YY), which works to slow the emptying rate of the stomach and reduces the rate of passage of food mass through the various parts of the digestive system Which leads to a decrease in feed consumption [25].

Productive Performance Measures
It is inferred from the results of the statistical analysis are no significant differences between all treatments in the Mortality under the influence of the factors under study (Table 3).and The results also indicate second treatment (33% Dh-SFM) did not differ from the control treatment (0% Dh-SFM). ) in the production index (PI) and the European productive efficiency factor (EPEF), while a significant (P ≤ 0.05) and linear decrease was observed in these measures with an increase in the levels of Dh-SFM substitution to 66 and 100% compared with the control treatment.As for the effect of the interaction between the replacement of peeled sunflower meal instead of soybean meal and the addition of xylanase enzyme.It is noted that was a significant improvement (P≤0.05) for the case of overlap between the levels of partial and total substitution of De-hulled sunflower meal at a ratio of (33, 66 100% Dh-SFM) with the addition of xylanase enzyme, compared with the corresponding level without the enzyme.and When comparing the values of PI and EPEF for all substitution treatments, whether without or with the enzyme added to it, with the negative and positive control treatments, we notice a significant decrease (P≤0.05) for all cases of interference at substitution levels of 66 and 100% of peeled sunflower meal compared with the two treatments Positive and negative control.The reason for the improvement in the production performance measures (PI and EPEF) for the partial replacement treatment (33% Dh-SFM) may be due to the occurrence of a state of nutritional balance as a result of mixing between peeled sunflower meal and soybean meal, which led to an increase in the digestion parameters and the availability of nutrients, which It was positively reflected on the weight gain and the food conversion factor of this treatment.

Dressing Percentage and Internal Viscera
The results in Table (4) show no significant differences between the control treatment and the second treatment (33% Dh-SFM) in the dressing percentage, while a significant decrease (P≤0.05) is noted in its percentage with an increase in the percentage of replacement in the 3th treatment (66% Dh-SFM) and 4th (100%Dh-SFM) compared with the control treatment.He results also indicate an increase in the relative weight of the gizzard and a decrease in the relative weight of Abdominal Fat, significantly (P≤0.05) in the partial and total replacement treatments (33, 66 and 100% Dh-SFM) compared with the control treatment.As for the effect of the interaction between the replacement of de-hulled sunflower meal instead of soybean meal and the addition of xylanase enzyme,The dressing percentage was not affected by the addition of xylanase enzyme, to the levels of substitution of de-hulled sunflower meal, compared to the corresponding levels without the enzyme.Except for the partial substitution treatment (33% Dh-SFM) containing xylanase enzyme, which was significantly superior Table 4. Effect of substituting de-hulled sunflower meal as a substitute for soybean meal without or with the enzyme xylanase in dressings percentage and internal viscera of broiler chickens.(p≤0.05)than its counterpart free of enzyme.while an increase in the relative weight of the gizzard and a decrease in the relative weight of Abdominal Fat were observed significantly (P ≤ 0.05) for all interference cases at substitution levels of (66% Dh-SFM) and (100% Dh-SFM) compared with the negative and positivecontrol treatments.These results agreed with [17,26,27] when they used sunflower meal with the addition of fiber-dissolving enzymes (NSPase) in broiler diets, as the relative IOP Publishing doi:10.1088/1755-1315/1259/1/0120748 weight of the heart did not differ between treatments, and their results differed.Which showed that there were no significant differences between the treatments in the relative weights of liver, gizzard and Abdominal Fat.Perhaps the reason for the significant decrease in the percentage of dressings with the increase in the percentage of substitution of sunflower meal to 66 and 100% is due to the decrease in the live body weight of these treatments, due to the existence of a direct relationship between the live body weight and the percentage of dressings.Birds with high weight have higher dressings, compared to birds with low weigh [13] .While the reason for the increase in the relative weight of gizzards in a linear manner (P≤0.05) with the increase in the levels of substitution of de-hulled sunflower meal in the diets may be attributed to the increase in the level of non-starch polysaccharides, as they accumulate in the gizzard and are preserved for a longer period than the rest of the other nutrients due to The need to grind it into fine particles before entering the small intestine [23].On the other hand, the reason for the significant improvement in the dressings, which was observed in the partial replacement treatment (33% Dh-SFM) and the positive control treatment, may be due to the addition of the xylanase enzyme to the ability of the enzyme to increase energy and protein utilization [28] , or it may be due to the improvement In the growth rate of birds added to their diets xylanase enzyme by increasing the rate of absorption of starch, fats and amino acids.

Carcass Cuts
The results of the statistical analysis (Table 5) showed that were no significant differences in the percentage of the major and minor carcass cuts under the influence of the factors under study, with the exception of the breast piece, as we note that the control treatment and the second treatment (33% Dh-SFM) did not differi between them in the percentage for the chest piece, while it decreased significantly (P≤0.05) and linearly with an increase in the replacement percentage to (66% Dh-SFM) and (100% Dh-SFM) compared with the control treatment.As for the case of overlap between substitution levels (33, 66 and 100% Dh-SFM) and the addition of xylanase enzyme did not produce a significant difference in the same characteristics compared to the same corresponding level free of the enzyme.When comparing all substitution treatments with the two control treatments, we notice a significant decrease (P≤0.05) in the percentage of the thorax segment at the level (66% Dh-SFM) free of enzyme and the level of total substitution (100% Dh-SFM) without and with enzyme added compared to With the negative and positive control coefficients.These results agreed with [23] that carcasses cuts were not affected due to the presence or absence of NSPase in diets containing sunflower meal by 25-75% compared to the control treatment.While it did not agree with the results of [27] , which indicated that there was a significant increase (p≤0.05) in carcass cuts as a result of the partial and total replacement of sunflower meal with soybean meal without or with the addition of fiber-degrading enzymes (NSPase).The reason for the significant decrease in the percentage of the breast piece in the partial and total replacement treatments (66 and 100% Dh-SFM) may be attributed to the decrease in the average total weight gain of the birds of these two treatments, which was reflected negatively on the weights of the major pieces of carcasses, where there is a direct relationship between the live body weight and the percentage The percentage of carcass cuts, which is represented by the dressing of the broiler carcass.When the live body weight increases, this will positively affect the dressing of the carcasses of these birds, and thus on the major and minor pieces of it [13].
Table 5.Effect of substituting de-hulled sunflower meal as a substitute for soybean meal without or with the enzyme xylanase in the major and minor cuts of the carcass of broiler chickens.

Conclusion
The possibility of substituting de-hulled sunflower meal protein by 33% instead of soybean meal protein without any negative effect on productive performance and carcass characteristics, while the rising levels of substituting led to a deterioration in productive performance.The addition of xylanase enzyme to diets containing de-hulled sunflower meal resulted in an improvement in the productive performance of birds.

Table 1 .
Dietary ingredients and chemical composition of starter and finisher diets experiment.

Table 3 .
Effect of substituting de-hulled sunflower meal as a substitute for soybean meal without or with the enzyme xylanase in feed consumption, feed conversion factor, and Productive Performance Measures of broiler chickens (means ± standard error).
Different letters in the column represent significant differences at the probability level (p ≤ 0.05).Dh-SFM is de-hulled sunflower meal; W.O is without; EPEF is European Production 20±0.53 14.67±1.3318.42±0.1511.05±0.347.85±0.45Differentletters in the column represent significant differences at the probability level (p ≤ 0.05).Dh-SFM is de-hulled sunflower meal; W.O is without.