1. Introduction
The key factors influencing animal performance and productivity are the accessibility and effective utilization of feed resources. Ensuring a stable and reliable feed supply is crucial for managing, extending the use of, conserving and intensifying production to enhance productivity [
1]. However, it is important to recognize that the current availability of animal proteins is insufficient to meet the growing demands of the human population, especially considering the dwindling resources [
1,
2]. The global poultry industry has historically encountered challenges in sourcing feed ingredients due to competition with other animal sectors [
3,
4]. D’Souza et al. [
3] observed that the rising demand for poultry consumption has led to a substantial shortage of accessible feed grains for sustaining poultry meat production. However, as noted by Hinrichs and Steinfeld [
4], in the competition for limited feed resources, poultry enjoys a competitive advantage over other livestock due to its superior feed conversion efficiency.
For decades, antibiotics have been extensively utilized in animal production. While some are administered for therapeutic purposes to enhance animal health and well-being, the majority were used prophylactically and to enhance growth rate and feed conversion efficiency, known as antimicrobial growth performance promoters [
5,
6]. In light of the emergence of antibiotic-resistant microbes impacting both human and animal health, the developed countries decided to progressively phase out the marketing and use of antibiotics from poultry feed. In the poultry industry, antibiotics have been utilized to augment meat production by enhancing feed conversion, accelerating growth rates and preventing diseases [
7]. They can be administered at sub-therapeutic levels to achieve these goals and safeguard bird health by modifying the immune response of broiler chickens [
8]. This is primarily accomplished by controlling gastrointestinal infections and modifying the composition of the intestinal microbiota [
9,
10].
A multitude of agriculture-based by-products are generated during their processing, potentially leading to environmental pollution. These by-products garnered significant attention during the COVID-19 crisis owing to lockdowns, border closures and transportation limitations [
11]. Employing alternative feed sources and utilizing locally accessible feed components could offer a viable remedy. Date by-products, sourced from arid and desert regions, represent the most recognized among these by-products, occasionally finding application in livestock and poultry nutrition. The options for feedstuffs accessible for poultry nutrition are constrained, presenting a significant challenge to global poultry production. This challenge has been exacerbated by the inclination to utilize grains for biofuel production, leading to a subsequent surge in feedstuff prices [
12].
Dates hold a significant status as a primary crop in arid and semi-arid regions [
13]. The date palm’s fruit consists of a succulent pericarp and an inedible seed. Several by-products stem from dates, including intact culled dates, date pits (date stone, seeds or kernels), fruit date pulp and pressed cakes, are recycled. These resources are valuable to the date industry [
14]. Dates are characterized by low protein and fat content, but they are notably rich in sugars [
15]. They serve as an excellent energy source, providing approximately 1.31 MJ per 100 g [
11]. Additionally, dates offer essential minerals of health importance. A daily intake of 100 g can fulfill roughly 15% of the recommended mineral requirements [
11]. While dates contain about 8.0 g of dietary fiber per 100 g, the majority of this fiber is insoluble [
16]. In terms of vitamins, dates are abundant in vitamin C and various B-complex vitamins. Furthermore, they serve as a valuable source of antioxidants [
11]. This suggests that dates can be incorporated effectively as their anti-nutritional content is minimal, ensuring no disruption to the absorption of essential nutrients like minerals and proteins in the body. Approximately 20% of dates are not suitable for human consumption [
17]. In numerous regions across the globe, the availability of cost-effective feedstuffs for animal production is significantly constrained, often necessitating the importation of such feed materials. This predicament is further exacerbated by the adoption of various crops, like maize, for biofuel manufacturing, which consequently drives up the cost of energy sources in animal diets [
17]. Tabook et al. [
18] highlighted that incorporating date fiber into a broiler diet at a 5% level does not have an adverse impact on the performance of broiler chickens. Shaba et al. [
19] reported that date palm fruits contain minimal quantities of anti-nutritional components. Despite variations among varieties, all of them serve as exceptional sources of fiber and can potentially be utilized as valuable sources of functional foods [
20,
21,
22]. Date pits, also known as date seeds or date stones, constitute the largest by-product derived from date fruits. Consequently, a significant portion of research pertaining to broilers has been dedicated to exploring the incorporation of date stone meal (DSM) into their diets [
23,
24,
25,
26]. Due to its elevated fiber content, which poses limitations on its applicability in poultry diets, various methods of processing DSM have been employed to enhance both feed utilization efficiency and chicken performance. The addition of dates as a feed supplement has resulted in better economic output. For example, the highest net profit of 44.51 Rs. per bird was observed in broilers fed 4% date palm kernel [
27]. These cost-effective feed ingredients have emerged as viable alternatives in poultry nutrition, capable of lowering ration costs.
Due to its high fiber content, utilizing dried date seed meal (DSM) in poultry diets has been challenging. However, studies have explored processing methods to enhance feed efficiency and chicken performance. In this context, certain researchers have also employed multienzyme complexes, encompassing enzymes such as myloglucosidase, protease, hemicellulose, cellulase, glucanase and xylanase [
24,
28] to counteract the adverse repercussions of excessive cellulose presence. Al-Saffar et al. [
28] found that DSM could constitute up to 30% of diets when supplemented with multienzymes without compromising laying performance. Similarly, Hussein and Alhadrami [
24] observed that incorporating date stone at various percentages had no significant impact on broiler performance during the starter and finisher phases. These findings suggest potential avenues for improving the incorporation of dates in poultry nutrition.
Therefore, the aim of the present study was to utilize the while dried date meal not consumable for human consumption on the production performance, carcass characteristics, nutrient digestibility, fecal microbiota and economics in broilers.
4. Discussion
The crisis of poultry feed significantly impacted the demand and pricing of feed and feedstuffs, leading to a heightened interest in local feed sources and a reduction in imported feed sources. The date stands out for its rich content of carbohydrates, fat and crude protein when compared to corn and barley [
11]. Additionally, dates contain higher levels of calcium and phosphorus (0.76% and 0.52%, respectively) than barley and maize. The protein content of date seeds at 8.1% surpasses that of whole dates and closely approaches that of maize grains (8.6%) [
23]. This trial aims to consolidate findings from experiments on date fruit by-products, encompassing their chemical composition, nutritional value, impact on growth performance, carcass traits and economic aspects in broilers. Date waste’s chemical composition generally aligns with that of corn and barley, with the exception of higher crude fiber values compared to corn and barley [
20]. The amino acid content in date seeds is largely comparable to corn [
11]. Several studies have explored the incorporation of date wastes as a supplement in poultry diets [
12,
32,
33]. These economical feed additives are promising sources of potential alternatives in poultry nutrition, potentially leading to cost savings in feed formulations. However, it is important to note that the impact of these wasted feed additives on production performance has demonstrated variation across different studies.
From the results of the present study, it was clear the growth performance, carcass characteristics and nutrient digestibility were significant in birds fed DDM
9 ration. Significant fluctuations in the market price of maize were observed following its utilization for biofuel production. As a result, there has been a revived interest in harnessing agro-industrial by-products, such as abundant and reasonably priced date waste, to address the scarcity of grains encountered in animal nutrition [
17]. Recently, Attia et al. [
11] reviewed and concluded that the synthesis of outcomes from various studies suggests that by-products derived from date fruit, specifically date stone meal, can be integrated at levels of up to 10%. This incorporation can effectively substitute maize (10.5 vs. 7.7 CP; 9.43 vs. 3.8 EE; 28.9 vs. 2.3 CF) or barley (9.43 vs. 2.00 EE; 14.2 vs. 5.00 CF) grains to maintain production performance, thereby potentially reducing production costs [
20,
34]. Nevertheless, the utilization of DSM is commonly disregarded due to its elevated content of crude fiber (14.2%), which restricts its inclusion in the diets of poultry [
35]. The chemical composition of date waste typically resembles that of cereals, except for the values related to crude fiber [
11]. In studies involving broiler chickens, the inclusion of date waste in their diet up to 200 g/kg led to a decrease in feed intake and an improvement in feed efficiency at a 50 g/kg inclusion level. However, these parameters remained similar to the control group for other levels of date waste supplementation [
36]. In a separate study by Kamel [
23], diets containing varying proportions of whole Zahidi dates (5, 10, 30 and 47.7%) were fed to broiler chicks and found that 47.7% of whole dates as a complete replacement for corn resulted in a reduced feed conversion ratio (FCR) for the chicks. Most of the studies in the published literature have investigated the effect of DSM on broiler performance [
24,
28,
33]. However, few research articles are available on the effect of date flesh on the broilers’ performance and nutrient digestibility. In the present study, the weight gain was significantly higher in DDM
9 compared to the control group. It is evident that the weight gain seems to be developed during the finisher phase. The age of the bird typically influences the advantages of incorporating dates into their diets, with mature birds benefiting more from the dietary fiber compared to younger ones. Given the elevated fiber content present in date wastes, their inclusion in finisher diets should involve a higher percentage compared to starter diets [
11].
In the present study, the weight of the breast, leg and GIT was significantly higher in DDM
9 compared to the control. The weight of the breast and leg could be attributed to the higher body weight in the corresponding groups. Conflicting evidence is available on the use of dates and their by-products on the carcass quality of broilers. Kamel et al. [
23] conducted a study involving broiler chicks, where they provided diets containing various proportions of date pits (0%, 5%, 10% and 15%) or whole Zahidi dates (0%, 5%, 10%, 30% and 47.7%). The study revealed notable differences in carcass weight between the 5% group and the control group, while differences between the 5% group and the other groups were not statistically significant. The control group exhibited higher carcass weight percentages compared to the other groups, with the exception of the 10% group. Additionally, giblet weights did not show significant variations across all groups. It was documented that the inclusion of date waste in the diets of broiler chickens at levels ranging from 0 to 200 g/kg had no discernible impact on dressing percentage or the weight (%) of the liver and gizzard [
36]. However, it did bring about changes in various other carcass traits, including the weights of the pancreas, heart, intestine and spleen. Similarly, the addition of date waste up to 150 g/kg in the diet of broiler chickens failed to show any influence on dressing percentage. Nevertheless, there were variations in the weight (%) of the pancreas, heart and spleen across the different levels of inclusion [
33]. Absolutely, the emphasis on weight differences among various bird parts, particularly in relation to different levels of date waste supplementation, raises an important question about their potential implications on overall health, meat quality and other economically significant factors. Understanding these potential impacts can provide a more comprehensive evaluation of the effectiveness of date waste supplementation in poultry diets. This broader perspective would contribute to a more thorough assessment of its overall benefits and drawbacks in poultry production.
In the present study, the digestibility of DM, CP and EE were significantly higher in DDM
9 compared to the control. The improved growth performance could be linked with improved digestibility of nutrients. In comparison, the digestibility values of CP, CF and nitrogen-free extract (NFE) for date waste are typically lower than those observed for barley and corn. However, the digestibility of EE in date waste tends to outperform the corresponding coefficients for barley and corn, as noted by Attia et al. [
11]. It was conducted an assessment of the impact of date waste on broiler chickens’ diets, replacing wheat bran at levels from 0 to 200 g/kg [
36]. These levels were selected to match energy and protein concentrations. The results indicated that nutrient digestibility remained largely unaffected, except for a reduction in CP digestibility observed at the 200 g/kg inclusion level. Similarly, El-Deek et al. [
17] found that the inclusion of date waste in broiler chicken diets at various levels (ranging from 0 to 150 g/kg at six different levels) did not bring about any discernible impact on nutrient digestibility. Notably, the results highlight that optimal growth performance and nutrient digestibility were observed at the 9% inclusion level, which also led to lower production costs per bird. To delve deeper, it is crucial to contemplate the potential ramifications of these differing digestibility rates on bird health, overall growth trajectories and the economic aspects of production. This exploration could provide valuable insights into the holistic impact of integrating date waste into poultry diets, encompassing both performance and financial considerations.
In the present study, no significant change in mortality was observed between the control and supplementation of different levels of DDM in broilers. Kamel et al. [
23] observed no significant impact of DSM levels on broiler mortality percentage and concluded that there was no discernible connection between chick mortality and date pits in the diets of broilers. Similarly, Al-Homidan [
32] noted there was no notable effect on the broiler mortality rate, which remained at 2.2% throughout the entire experimental period of 0 to 7 weeks. This observation held true regardless of the inclusion of whole date waste meal (at levels of 0, 8, 16 and 24%) or DSM (at levels of 5, 10 and 15%) during the starter period, as well as during the finishing period with different inclusion rates. Additionally, substituting wheat bran with date waste at a level of up to 200 g/kg in the diet did not lead to any significant changes in chicken mortality [
33].
In this study, it was observed that the inclusion of 9% dried date meal (DDM) led to an increase in the microbial load of Lactobacillus and a decrease in the presence of E. coli. Maintaining a balanced microbial population in the intestinal tract is crucial for promoting growth and ensuring the overall health of the birds [
36]. Bacteria in the intestine play a vital role in metabolizing nutrients from the diets, producing essential substances like vitamins, lactic acid and short-chain fatty acids [
37]. It is worth noting that the composition of microbial populations in the gut can vary depending on the animal species, their age, the components of their diet and the environment of their gastrointestinal tract [
38]. Certain plant-based substitutes and additives can have probiotic and/or prebiotic effects on gut microflora through both direct and indirect mechanisms [
38]. In birds, the nutritional benefits derived from microflora are relatively less significant compared to other animal species, as most of this activity occurs in the hindgut [
36]. In a study by Alyileili et al. [
12], broilers that were fed diets containing 5% and 10% dried date pits (DDP) demonstrated a noteworthy reduction in the total bacterial count in their gut. Specifically, the 10% DDP diet proved to be the most effective when compared to other dietary treatments.
In our current study, it was observed that the inclusion of DDM9 and DDM12 led to significant increases in revenue, profit and cost–benefit ratio in broilers. Specifically, when broilers were fed with varying percentages of date palm kernel (0, 1, 2, 3 and 4%), the net profits per broiler were recorded as 27.01, 32.77, 36.78, 43.47 and 44.51 (in Rs.), respectively. The highest net profit was achieved by birds fed with 4.0% date palm kernel (44.51 per bird), closely followed by those fed with 3.0% date palm kernel (43.47 per bird) [
27]. Furthermore, in broilers, the feed cost was significantly lower in birds fed date waste compared to those on the basal diet [
39]. Additionally, Al-Homidan [
32] reported that incorporating date wastes at levels of 5, 10 and 15% in broiler diets resulted in a reduction in diet costs compared to the control group. This suggests that the inclusion of date waste materials in broiler diets can lead to cost-saving benefits.