The increasing population and food demand require more food production and sustainable plans to ensure food availability for the next generations. In the poultry industry, the probability of infectious diseases is high, resulting in a substantial economic loss and antibiotic resistance and other environmental hazards. Under the United Nations and Food and Agriculture Organization regulations involved in food security and the production of safe animal protein products, it has become necessary to develop natural additives to substitute antibiotic usage. The supplementation of phytogenic feed additives is proven safe and efficient to be widely applied in fish, birds, and livestock production for their productive efficiency if used in the optimal dose and reasonable duration (1, 2).

Macleaya cordata is a herbal plant that has abundant amounts of sanguinarine, which is commercially known as Sangrovit^® (3). The M. cordata plant contained in Sangrovit^® (as a feed additive used in animal nutrition) is reliable as per the list of the European Food Safety Authority (4). Furthermore, Sangrovit^® is not metabolized into potentially harmful metabolites and is excreted without being absorbed through the small intestine (3). Traditionally, M. cordata is used as a Chinese herbal with many biomedical properties (depurative, analgesic, carminative, antiedemic, and diuretic) (3, 5). It contains alkaloid substances (e.g., benzophenanthidrine), which are extracted from the rhizomes of the Sanguinaria canadensis plant (6). Incorporating M. cordata in birds' diet resulted in improving the feed efficiency resulting from enhanced intestinal health (7–12). M. cordata has antioxidant activity as well as enhanced immunity in livestock and birds (13).

Turkey meat is preferred by consumers as a source of protein and essential amino and fatty acids, minerals, and vitamins. Recently, expensive raw materials made it imperative to search for alternative feed ingredients and feed additives that will help to reduce the overall cost of the rations. As a result, the application of phytobiotics besides understanding their potential effect on performance and wellbeing is crucial to protect against antibiotic resistance. To the best of the author's knowledge, there are no previous trials that have investigated the effects of M. cordata dietary inclusion in turkey. Therefore, the present study aimed to evaluate the impact of M. cordata dietary supplementation on the growth measurements, hematological, and biochemical parameters, and the expression of growth-related genes in turkey.

The effects of the experimental diets on performance traits in turkeys throughout the experiment are presented in Table 3. The results of linear contrast showed that growth was unaffected by Sangrovit^® inclusion, however, it was marginally improved (p > 0.05) in SG50 over the whole experimental period compared with control, by 6.29, 6.6, 5.6, and 14.9% for FBW, ADG, FCR, and BPEF, respectively.

Contrast analyses of hematological and biochemical parameters are displayed in Tables 4, 5 during the experimental period at the age of 2^nd and 20^th weeks, respectively. No meaningful changes were recorded among the birds' groups that delivered M. cordata in terms of hematological and blood biochemical traits at the age of 2^nd week, except for white blood cell (WBC), SG50 recorded the highest value (p < 0.05) compared with other supplemented groups, and triglyceride, SG50 showed the least value (p < 0.05) compared with SG100. Similarly, at 20^th week among the birds' groups that delivered M. cordata, the changes recorded for mean cell volume (MCV) where SG50 was the highest value (p < 0.05) compared with SG25, WBC, SG50 recorded the highest value (p < 0.05) compared with control and other supplemented groups, GOT where SG100 showed the highest value (p < 0.05) compared with control, triglyceride where SG50 and SG100 recorded the least value (p < 0.05) compared with SG25, HDL where SG100 showed the highest value (p < 0.05) compared with SG25.

The results of growth gene expression are shown in Figures 1A–E. Figures 1A–C showed that the expressions of GHR, insulin-like growth factor 1 IGF-1, and COX-3 in the Sangrovit^® supplemented groups were increased (p < 0.001), compared with control one, and their values upregulated (p < 0.001) in SG50 followed by SG100 and SG25, respectively. Data in Figure 1D show the mRNA expression of adenine nucleotide translocase (ANT); the SG50 group had higher (p < 0.001) level than control and SG25 groups. Moreover, its value was similar to SG100 group. As shown in Figure 1E, the fold change of uncoupling protein 3 (UCP-3) in SG50 group was upregulated (p < 0.001), compared with other groups, while their values in SG25 and SG100 groups were similar.

Using antibiotics is virtually required for maintaining the performance and wellbeing of birds to resist the expected infectious diseases and stressors. However, the crucial need to reduce chemotherapies to keep food security guided the researchers' need to continue their efforts in finding more sustainable solutions for birds' production (24). M. cordata, with its abundant amounts of sanguinarine, is an effective growth promoter and anti-bacterial additive (5, 11, 12). Concurrently, this study assessed the potential effect of M. cordata on growth performance regarding some growth-related genes, hematological, and biochemical parameters of turkeys during hatching and grow-out stages. The results have clearly shown similar growth rate (p > 0.05) in turkeys delivered M. cordata during hatching and grow-out stages. These findings are similar to Kozlowski et al. (25) who stated that M. cordata supplementation 20 ppm in the diet had no significant effect on FI, BWG, or FCR. The recommended dietary level of Sangrovit^® for broilers and growing turkeys was previously reported at 20–50 ppm. As a result, Zdunczyk et al. (26) investigated the dietary inclusion of Sangrovit^® at 30 ppm, which did not support performance parameters and was ineffective in protein utilization. In addition, Juskiewicz et al. (27) found that the FCR in both the starter and grower period were unaffected by 15 ppm Sangrovit^® supplementation. Moreover, Sangrovit^® dietary supplementation at the level of 0.05 and 0.1% had no significant differences among treatments regarding FI, feed utilization rate, and small intestine morphology (28).

On the other hand, some studies approved the positive effect of M. cordata in improving the growth of chickens and livestock animals either at a level of 25–50 ppm (29) or 30 ppm (30). The enhanced feed efficiency and nutrients' digestibility are previously reported in various studies that correlated the improved feed utilization in birds treated with M. cordata at a level of 20 and 50 ppm (31). Variations between these studies may be attributed to the differences in the composition of the used diets, age, and sex of the birds, dose of M. cordata, plant extracts, and other bioactive constituents.

Evaluation of turkey's health status can be explained by testing the hematological and blood biochemical traits (32). It gives a precise diagnosis of the metabolic rates, levels of nutrients in the blood, hematic and anemic status, and immune and antioxidative responses. The present study results showed no meaningful changes (p > 0.05) among the birds' groups delivered M. cordata at the age of 2^nd week in terms of hematological and biochemical indices as urea and creatinine (33). The obtained results regarding hematological and biochemical indices at the age of 20^th week are in agreement with Gilani et al. (34) who examined the efficacy of organic acids and phytobiotics in poultry feed, observing significant increases in RBC and WBC counts, as well as an increase in PCV in broiler chickens. These results confirm that dietary M. cordata has no adverse effects on turkey's health status in hatching or grow-out stages. The outputs of the experiment are in accordance with previous studies (8, 35–37) that approved M. cordata in in pig and poultry feeding without impairing their health and immune status; consumption of M. cordata in the feed at up to 1,000 mg/kg had no adverse effect on blood plasma. In contrast, both (31, 38) approved the cholesterol lowering effect of M. cordata.

Interestingly, the results showed upregulated growth-related genes, such as GHR, IGF-1, ANT, COX-3, and UCP-3 were upregulated (p < 0.001) in M. cordata supplemented groups with the highest value for SG50 in birds treated with M. cordata. These genes were investigated as promising biomarkers for enhancing the growth performance of quail (39). Previous studies clarifying the impact of M. cordata on the expression of the growth-related genes were limited; however, the related anti-inflammatory gene (e.g., NF-kB) showed upregulated expression in birds delivered M. cordata (13). The upregulated NF-kB was probably linked with the growth-related genes (e.g., IGF-1) and regulated its expression as a health-involved gene (40). However, intensive research is needed to determine the possible influence of M. cordata in controlling growth related genes in turkey. Although not relevant to the present study; yet other phytogenic extracts have been confirmed to upregulate animals' growth-related genes (41). Under the current trial conditions, growth performance is not correlated with the turkey's upregulated expression of growth-related genes. This may be explained as the genotypic effect is expressed earlier than the phenotypic performance, which appears after transcription of DNA into RNA, which is measured in our study (gene expression), and then RNA is translated into proteins to exert its function on the phenotypic performance (42).

In conclusion, exogenous M. cordata dietary supplementation upregulated the expression of growth-related genes in turkey at a level of 50 ppm without adverse effects on their heath status regarding hematological and biochemical indices. Further research is needed to investigate the possible influence of M. cordata on gut health and in controlling growth-related genes in turkey in addition to its evaluation as an antibiotic alternative.

The data presented in this study are available on request from the corresponding author.

This investigation was approved by the Committee of Local Experimental Animal Care, Damanhour University, Egypt, Faculty of Veterinary Medicine (VMD: 15/2018).

EM and MA-D: conceptualization and supervision. EM, MA-L, and MA-D: data curation. GA and AE-k: funding acquisition. SI: investigation. EM, MA-D, MA-L, AS, AE-k, and BS: methodology. AS and BS: resources. GA, AS, SI, MA-L, and BS: software. EM, MA-D, SI, GA, AS, MD, AE-k, MA-L, and BS: writing—review and editing. All authors contributed to the article and approved the submitted version.

This research was supported by Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R30), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia. This research was supported by King Khalid University, Grant number (R.G.P.2/35/43), Abha, Saudi Arabia.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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