Among the various agro-industrial by-products, distiller dried grains with solubles (DDGS) obtained from rice fermentation have become a promising option due to their accessibility, cost-effectiveness and nutrient richness. DDGS byproducts are obtained from the fermentation of cereal grains with enzymes and yeasts to produce ethanol (Shurson and Noll, 2005). Rice DDGS contains nutrients like proteins, fats, essential fatty acids, minerals, vitamins, xanthophylls, mannan polysaccharides and yeast biomass with b-glucan, nucleotides and microbiological phytase (Raun et al., 2017). The increasing demand for soybean meal has caused in a steep rise in its price (Dinani et al., 2019). This has led to an ongoing search for economical alternatives to replace soybean meal in order to enhance net returns. Hence, incorporating the rice DDGS into poultry diets could replace the traditional protein-rich feed components like soybean meal, thus reducing feed expenses in poultry production systems.
       
The formulation of feed or feedstuff can influence the relative yield and composition of the carcasses (Loar et al., 2010). Moreover, favorable growth performance was observed when low to moderate levels of DDGS were included in broiler diets (Elbaz, et al., 2022). Conversely, higher inclusion levels did not yield additional advantages and, in certain instances, adversely affected meat quality (Dang et al., 2021). A significant issue related to the incorporation of DDGS in broiler diets is its high amounts of polyunsaturated fatty acids (PUFAs), especially oleic acid (omega-9) and linoleic acid (omega-6), which may impact meat quality (Swiątkiewicz et al., 2021; Georganas et al., 2023). The amount of PUFAs present in DDGS is also depends upon the source grain (maize, wheat, or rice) and the quantity of soluble added during its production (Schingoethe et al., 2009). Palmitic acid, oleic acid and linoleic acid are the primary fatty acids found in DDGS, accounting for approximately 21.05%, 22.12% and 49.92% of the overall fatty acid composition, respectively (Abudabos et al., 2017). The high levels of linoleic acid in DDGS enhanced meat quality by increasing the ratio of polyunsaturated fatty acids (Min et al., 2015). Considering the above facts, the current study was conducted to evaluate the effects of incorporating rice distiller dried grains with solubles into the diets on carcass characteristics and yield, fatty acid profile and meat composition in broiler chickens.

The research work was carried out at the Experimental Poultry Shed of the Animal Nutrition Department, West Bengal University of Animal and Fishery Sciences, Kolkata, India during the year 2023. 400 unsexed day-old chicks were allocated to five different dietary treatments having 80 birds in each, each group with eight replicates having 10 birds in each. Rice DDGS was included in a corn-soy based diet at various levels (0, 2.5, 5, 7.5 and 10 kg/100 kg) as a partial substitute for soybean meal throughout all three phases (0-11, 12-22 and 23-42 days) (Table 1). The duration of the study was six weeks.


       
At the end of 42-day experiment, two birds were randomly chosen from each replicate for analysis of carcass parameters, breast meat composition and organoleptic and meat quality characteristics. The ratios of carcass, organs and all cut-up parts, including non-edible components, were expressed in relation to the live body weight. The sensory quality (organoleptic) evaluation of chicken breast meat samples utilized a 9-point Hedonic scale (Bratzler, 1971). The composition of the breast muscles was estimated by using standard procedures as per AOAC (2005). The pH values were recorded at 45 minutes and 24 hours post-slaughter by a digital pH meter (Trout et al., 1992). The water holding capacity (WHC) of the meat was calculated as:
 

 

 
Drip loss was assessed as:
 

 

 
The percentage of cooking loss was determined as:
 

   

 
The quantity of thiobarbituric acid reactive substances (TBARS) was evaluated using a modified technique (Strange et al., 1977).
       
Fatty acid profiles were examined in samples of broiler thigh muscle from each treatment group across 40 replicates (n = 40). The concentrations of fatty acids in breast meat were evaluated using a capillary gas chromatograph (GC) on an HP-88, 100 m x 0.25 mm x 0.20 ìm capillary column (Agilent Technologies Inc., Santa Clara, CA, USA), which was connected to a Varian 450 GC and fitted with a flame ionization detector (Varian B.V., The Netherlands), in accordance with the standard protocol established by Mandal et al., (2014). Helium gas was utilized as the carrier gas at a flow rate of 2 ml/min. The initial oven temperature of 120°C was sustained for 1 minute before being increased at a rate of 10°C/min to 175°C, which was maintained for 10 minutes and subsequently raised to 210°C at a rate of 5°C/min, holding for 5 minutes. Ultimately, the temperature was increased at 5°C/min to reach 230°C. The injector and detector temperatures were fixed at 260°C. The identification as well as quantification of each fatty acids were executed using the purified standard (Supelco 37 component FAME mix, trans-11-vaccenic methyl ester and octadecadienoic acid conjugated methyl ester; Sigma-Aldrich Chemical Pvt. Ltd., Kolkata, India) and the internal standard (tridecanoic acid; Sigma-Aldrich Chemical Pvt. Ltd., Kolkata, India).
 
Statistical analysis
 
As described by Snedecor and Cochran (1994), one way ANOVA was employed for evaluation of the effects of treatments. The data analysis was performed through ANOVA (SPSS 21.0, Chicago, IL, USA). Further, to determine the differences between mean values, Turkey’s test was applied to compare the treatment means with a significance level set at P<0.05. Linear as well as quadratic responses were also assessed via polygonal contrasts.

Carcass quality
 
With the exception of back yield, the dressing percentage and the yield of cut-up parts were not influenced (p≥0.05) by the treatments (Table 2). Shim et al., (2011) observed no significant differences in abdominal fat, breast meat yield or carcass quality in broilers fed diets containing up to 24% DDGS.


 
Organoleptic evaluation
 
Broiler meat is frequently assessed for its color, tenderness and sensory acceptability, as consumers tend to favor meat which is juicy, tender and not excessively pale (Schilling et al., 2003). No significant differences were observed (P>0.05) in the flavor, texture, appearance and general acceptability of meat from breast portion of broilers those were given various levels of rDDGS. This suggests that a diet containing rDDGS at 10% inclusion rate did not affect the organoleptic properties of broiler meat. The current findings are in accordance with Borah et al., (2020), who indicated that consumer acceptability was not influenced by 24% dietary levels of DDGS in broilers.
 
Meat composition
 
The chemical composition of breast muscle exhibited no variations (P>0.05) among the experimental groups (Table 2). This suggests that a diet containing rDDGS at 10% inclusion rate did not affect the nutritional quality of broiler meat. The contemporary results are in agreement with Schilling et al., (2010), who reported that the proximate composition of breast muscle (protein, fat, moisture) did not differ (p³0.05) at the inclusion levels of 0, 6, 12, 18 and 24 percent DDGS in a corn-soy based diet.
 
Fatty acid composition of meat
 
The fatty acid profile of the feed is the primary factor influencing the fatty acid profile in the resultant broiler breast and thigh meat (Cortinas et al., 2004). Six (out of 19) fatty acids identified in broiler breast muscle showed differences (P<0.05) in proportion among the DDGS treatments (Table 3). No significant differences (P>0.05) were observed in total saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA); however, in the case of PUFA, alpha-linolenic acid exhibited significant differences among the treatment groups. Eicosapentaenoic (C22:5) and docosahexaenoic acid (C22:6) displayed significant (P<0.05) differences among the experimental groups, with the highest concentrations found in T3 and T4 groups, respectively (Table 3). Additionally, docosadienoic acid (C22:2) was also significantly elevated (P<0.05) in the 7.5 and 10% DDGS dietary treatments.

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Meat pH, water holding capacity, cooking loss, drip loss and TBARS
 
The quality of broiler meat is based on pH levels and WHC (Schilling et al., 2003). No significant differences (P>0.05) were observed in water holding capacity, cooking loss, drip loss percentage and TBARS at various inclusion levels of rice DDGS (Table 4). This suggests that a diet containing rDDGS at 10% inclusion rate did not affect the overall meat quality of broiler meat. Incorporation of DDGS in the rations of birds did not affect water holding capacity, cooking loss with TBARS and drip loss as revealed by Moreno et al., (2023), Schilling et al., (2010) and Yang et al., (2019), respectively. 

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According to the results of the current study, it can be concluded that rice DDGS can be included into broiler diets at levels of up to 10% without adversely affecting carcass traits, meat composition, or sensory evaluation. Moreover, the levels of essential fatty acids in breast muscles were significantly increased (P<0.05) due to the addition of rDDGS.

The current research received support from the West Bengal University of Animal and Fishery Sciences located in Kolkata.
 
Disclaimers
 
The opinions and conclusions articulated in this article are exclusively those of the authors and do not necessarily reflect the perspectives of their associated institutions. The authors bear the responsibility for the precision and thoroughness of the information presented; however, they disclaim any liability for any direct or indirect damages arising from the utilization of this content.
 
Informed consent
 
The experiment was conducted with guidelines and authorization from the Institutional Ethical committee of the WBUAFS, Kolkata.

The authors affirm that there are no conflicts of interest associated with the publication of this article. Furthermore, no funding or sponsorship has impacted the study’s design, data collection, analysis, decision to publish, or the preparation of the manuscript.