Investigating the impacts of raisin-supplemented large animal feed on growth metrics, nutritional behavior, and offspring outcomes in female rats

1. Introduction

Standard laboratory feeds are meticulously formulated to meet the nutritional requirements of laboratory animals, ensuring optimal growth, reproduction, and overall health. These feeds are critical for maintaining experimental consistency, as they minimize variability arising from dietary deficiencies or excesses. The standardization of such feeds is essential in research settings, where precise control over external variables can significantly impact the validity of experimental outcomes. Laboratory feeds are developed through advanced technological processes to ensure precision and uniformity in nutritional content. Recent advancements in feed formulation and processing have introduced innovative approaches that enhance the quality and functionality of laboratory animal feeds. (Tepe and Altaş, 2024). highlighted how these technological processes not only improve feed stability and bioavailability but also support new feeding strategies tailored to specific research needs. However, challenges such as supply chain disruptions, high costs, and economic constraints underscore the necessity of identifying alternative feeding solutions that maintain nutritional adequacy and experimental reliability. One promising alternative is large animal feeds, which are typically designed for livestock but may have potential applications in laboratory settings when appropriately supplemented. These feeds are widely available, cost-effective, and can serve as a base for developing alternative diets for laboratory animals during emergencies or when standard feeds are inaccessible. Supplementation with nutrient-dense ingredients is critical to aligning large animal feeds with the specific requirements of laboratory animals. Among potential supplements, raisins stand out due to their unique nutrient profile. Raisins are rich in natural sugars, providing a quick source of energy, as well as essential vitamins, minerals, and antioxidants. These attributes make them a promising candidate for enhancing the nutritional value of alternative feeds. Moreover, raisins are widely available as an agro-industrial by-product, making them an economically and environmentally sustainable option. The health-promoting properties of raisins have been demonstrated in previous studies, such as Ali et al. (2019), who reported reno-protective effects against hypercholesterolemia-induced renal damage in albino rats. This underscores the potential of raisins as both a nutritional and therapeutic feed supplement. Maternal diet during gestation plays a pivotal role in shaping reproductive outcomes, offspring health, and long-term development. Carlin et al. (2019) demonstrated that maternal high-protein diets influence offspring body weight and insulin signaling pathways. Vanselow et al. (2016) highlighted the long-term epigenetic and metabolic consequences of maternal high-protein diets, while Hallam et al. (2013) found that dietary protein levels during pregnancy could predispose offspring to altered fat mass and metabolic profiles. Ajuogu et al. (2020) further emphasized that maternal protein intake significantly affects reproductive efficiency, while Jahan (2024) examined how gestational obesity and protein diets interact to affect offspring glucose metabolism and body composition. Xie et al. (2024) demonstrated that maternal vitamin D3 supplementation in an oxidized-oil diet could mitigate oxidative stress in the placenta and protect the fetus from developmental impairments. (Fassarella et al., 2024) added to this body of knowledge by showing that fish oil supplementation during pregnancy reduces liver endocannabinoid activity and lipogenic markers in offspring exposed to a maternal high-fat diet. Despite these advances, the role of alternative feeding approaches in laboratory settings remains underexplored. As highlighted by Tepe and Altaş (2024), the integration of new feeding strategies, including the use of alternative feeds and innovative supplementation, is essential for ensuring sustainability and flexibility in laboratory research. Large animal feeds, supplemented with nutritionally rich ingredients like raisins, may provide a viable solution. Strategic supplementation can help align these feeds with the specific nutritional needs of laboratory animals, ensuring that growth, feeding behavior, and reproductive outcomes are optimized.

The research aims to evaluate the effect of raisin-supplemented large animal feed on female mice, focusing on growth parameters, nutritional behavior, and offspring outcomes. By addressing the paucity of data in this area, the study seeks to provide the research community with practical insights into alternative feeding strategies. That is particularly critical in contexts where standard laboratory feeds are inaccessible or prohibitively expensive. Ultimately, this work contributes to the broader effort to enhance the resilience and sustainability of laboratory animal research.

A total of 30 female Wistar rats, each weighing between 125 and 130 g, were obtained from the Animal Care Center. The animals were housed individually in cages under controlled conditions, maintaining a temperature of 22–24°C, a 12-h light/dark cycle, and open access to food and water.

2. Materials and Methods

3. Results

3.7 Analysis of offspring number and gender distribution across dietary treatment groups

The Fig. 1 displays the number and gender distribution of offspring born in each dietary treatment group in the control group (C). A total of 65 births were recorded, consisting of 34 males (52%) and 31 females (48%). For Treatment 1 (T1), there were 68 total births, with 33 males (49%) and 35 females (51%). Treatment 2 (T2) recorded the lowest number of births, with a total of 50 offspring, including 24 males (48%) and 26 females (52%). The results show that the total number of births was highest in the T1 group, followed by the control group (C), and lowest in the T2 group. In terms of gender distribution, all groups exhibited a nearly balanced ratio of males to females, with slight variations: the control group had a slightly higher proportion of males, while T1 and T2 had a slightly higher proportion of females. Overall, the number of births and sex distribution were influenced by the dietary treatments, with T1 showing the highest reproductive output.

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Fig. 1.

Number and sex distribution of offspring across different dietary treatment groups.

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3.8 Comparison of newborn body weights across dietary treatment groups after birth

The Fig. 2 shows the average body weight of newborns in the control group (C), the average body weight of newborns was approximately 7 grams. For Treatment 1 (T1), the average weight was slightly lower but comparable to the control group. In Treatment 2 (T2), the average body weight was similar to or marginally higher than the other groups, suggesting no significant difference in newborn weights among the groups. Overall, the Fig. 2 indicates that the dietary treatments, including large animal feed with or without raisin supplementation, had no substantial impact on the body weight of newborns at birth compared to the standard diet provided to the control group. The suggests that all three diets supported similar fetal growth during the gestation period.

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Fig. 2.

Average body weight of newborns across dietary treatment groups after birth.

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3.9 Comparison of body length and width of newborns across dietary treatment groups

The Fig. 3 illustrates the average body measurements (length and width) of newborns the body length, all three groups show similar measurements, with the control group (C), Treatment 1 (T1), and Treatment 2 (T2) averaging approximately 65 mm. The results suggest that dietary treatments, including large animal feed with or without raisin supplementation, had no noticeable effect on the length of newborns. For body width, all groups also exhibit comparable measurements, with a slight variation around 15 mm. The control group (C) and Treatment 1 (T1) had nearly identical widths, while Treatment 2 (T2) was marginally higher but not significantly different. Overall, the Fig. 3 suggests that the dietary treatments did not significantly influence the body length or width of newborns, indicating that fetal development in terms of body size was consistent across all groups.

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Fig. 3.

Body length and width of newborns across dietary treatment groups.

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4. Discussion

The study by Tepe and Altaş (2024) explores the advancements in technological processes applied to laboratory animal feeds and discusses innovative feeding strategies that enhance both the quality and functionality of these diets. Their work provides a broader framework for contextualizing the results of our study, which focuses on alternative dietary strategies, including raisin supplementation, to evaluate their effects on reproductive and offspring outcomes in female Wistar rats. Tepe and Altaş (2024) emphasize the critical role of technological innovations in feed production, such as improving nutrient bioavailability, standardizing formulations, and incorporating functional ingredients to meet specific research objectives. In our study, the inclusion of raisins as a supplement to large animal feed (T2 group) represents a practical application of such feeding innovations. Raisins, as a cost-effective and nutrient-rich agro-industrial by-product, offer an example of how functional ingredients can be integrated into alternative feeds to maintain or enhance performance metrics, particularly under conditions of economic or resource constraints.

Tepe and Altaş (2024) also highlight the importance of tailoring feeding strategies to the needs of specific research goals. In this regard, our results align with their insights, as the diets tested in our study were designed to evaluate their impact on key outcomes such as maternal feed and water intake, reproductive performance, and offspring growth. The comparable performance of the T2 group to the control group (C) suggests that raisin supplementation in alternative feeds can be a viable strategy to meet nutritional requirements while ensuring consistency in research outcomes. Furthermore, Tepe and Altaş (2024) underscore the necessity of maintaining feed quality to ensure the validity of experimental results. This aligns with our results, where raisin supplementation supported stable offspring outcomes (body weight, length, and width) and maternal performance metrics, indicating that alternative feed formulations can maintain high experimental standards when designed thoughtfully. The potential for functional ingredients, such as raisins, to enhance the nutritional profile of large animal feed reflects the innovative feeding approaches discussed by Tepe and Altaş (2024).

The work of Tepe and Altaş (2024) provides a valuable context for understanding the broader significance of our study. By exploring new feeding approaches and the integration of functional ingredients into laboratory animal diets, their results reinforce the practical implications of using alternative feeding strategies, such as raisin supplementation, to address challenges posed by feed shortages or high costs. Together, these studies underscore the importance of innovation and adaptability in laboratory animal nutrition to ensure both scientific rigor and resource efficiency.

The study by Asad (2024) provides valuable insights into the physiological and histological effects of dietary interventions, particularly focusing on the role of raisin extract in mitigating adverse effects caused by diet changes in mice. The results from this study align with certain aspects of our research, particularly regarding the potential benefits of incorporating raisins into alternative diets. in our study, the addition of raisins to large animal feed (T2 group) did not significantly alter growth metrics, feed intake, water consumption, or reproductive outcomes compared to the control group fed standard laboratory diets. However, trends in the data, such as slightly lower feed and water intake during the lactation period in the T2 group, might suggest a metabolic adjustment or a nutrient efficiency facilitated by the raisin supplementation. These subtle effects could reflect the antioxidant and nutrient-rich properties of raisins, as highlighted in the work by Asad (2024), which emphasizes their protective and restorative effects on the hepatic system.

Results on the histological improvements in the hepatic system due to raisin extract supplementation resonate with the potential systemic benefits observed in our research. (Asad, 2024) While our study focused primarily on reproductive performance, offspring outcomes, and growth parameters, the consistent performance of the T2 group across various measures could indicate a broader physiological benefit of raisins, as suggested by their ability to support metabolic health in the hepatic system. This might explain why the offspring body weight, length, and width in the T2 group were comparable to the control group despite being fed an alternative diet. The connection between the study by Asad, (2024) and our results lies in the capacity of raisins to act as a nutritional supplement that mitigates potential deficits associated with alternative feed sources. (Asad, 2024) The emphasis on the antioxidant and restorative properties of raisins could provide a mechanistic explanation for why raisin supplementation supports consistent outcomes in growth and reproduction, even when the base diet deviates from a standard laboratory formulation. This further underscores the potential of raisins as a cost-effective supplement to improve the quality of alternative feeds during times of feed shortages or economic constraints, as highlighted in our study. In summary, Asad’s (2024) results reinforce the idea that raisins, through their nutrient composition and protective properties, can contribute to maintaining physiological stability and performance in animals subjected to dietary modifications. This complements our research by providing a deeper understanding of the potential mechanisms underlying the observed effects in the T2 group, particularly during critical phases such as lactation and offspring development.

The study by Bhouri et al (2025) explores the functional properties of raisins, particularly their antioxidant and antiglycation activities, highlighting their potential as a functional food ingredient. The work provides an essential foundation for understanding the broader implications of raisin supplementation in animal diets, as investigated in our research.

Our study demonstrated that adding raisins to large animal feed (T2 group) supported consistent reproductive and growth outcomes in female Wistar rats, comparable to those achieved with a standard laboratory diet. While no significant differences were observed in parameters such as feed and water intake or offspring measurements, the performance of the T2 group remained stable throughout the study. Bhouri et al (2025) findings suggest that the antioxidant activity of raisins could play a pivotal role in maintaining physiological balance, even under alternative feeding conditions. The antioxidant properties highlighted by Bhouri et al (2025). may explain the stable maternal body weights observed in the T2 group during critical periods, such as after birth and lactation, despite a deviation from the standard laboratory diet. That aligns with the study’s assertion that raisins can counter oxidative stress, which could otherwise negatively impact metabolic and reproductive processes. The antiglycation properties of raisins, as emphasized in Bhouri et al’s (2025) work, could also contribute to improved metabolic efficiency in animals fed alternative diets, potentially preventing the accumulation of harmful metabolic byproducts during high-demand periods such as pregnancy and lactation. Furthermore, Bhouri et al (2025). underscore the functional benefits of raisins in maintaining health and mitigating diet-induced stress. This provides a mechanistic explanation for the comparable growth parameters and offspring outcomes in the T2 group of our study. The observed consistency in offspring body weights, lengths, and widths suggests that raisins may enhance the nutritional profile of alternative feeds by delivering bioactive compounds that support both maternal and fetal development. The result by Bhouri et al (2025) also resonates with the broader implications of our research, particularly the potential of raisins to act as a cost-effective dietary supplement during feed shortages or economic constraints. Their antioxidant and antiglycation properties not only enhance the nutritional quality of alternative diets but also promote metabolic health, reducing the risk of adverse outcomes associated with non-standard feed formulations. In conclusion, Bhouri et al, (2025) work provides a critical context for interpreting the results of our study, offering insights into how the bioactive properties of raisins might contribute to the stability and efficiency of alternative diets. The antioxidant and antiglycation activities of raisins likely underpin the consistent outcomes observed in the T2 group, further supporting their role as a functional supplement in laboratory and agricultural animal feeding practices.

The study by Carlin et al, (2019) investigates the effects of a maternal high-protein diet during pregnancy on offspring outcomes, particularly focusing on body weight, insulin signaling, and macronutrient preferences in adulthood. The study provides a relevant framework for contextualizing the results of our research, which examined the impact of alternative diets, including raisin-supplemented feed, on reproductive performance, offspring growth, and developmental parameters in female Wistar rats. Carlin et al. demonstrated that dietary modifications during pregnancy could have long-term implications for offspring physiology, particularly body weight and insulin signaling pathways. In our study, although the dietary interventions (T1 and T2 groups) did not significantly alter offspring body weight, length, or width at birth compared to the control group (C), subtle trends in the T2 group (raisin-supplemented diet) suggest the potential for dietary components to influence metabolic outcomes. Raisins, as highlighted in related studies (Bhouri et al, 2025), possess antioxidant and bioactive properties that may help stabilize metabolic processes during gestation, which could explain the comparable offspring measurements across all dietary groups. The findings of Carlin et al. also underscore the importance of maternal diet in shaping early developmental outcomes, such as body weight and metabolic health. Similarly, in our study, the stability of offspring outcomes in the T2 group, despite deviations from standard laboratory feed, may reflect the nutrient-enhancing and potentially metabolic-regulating properties of raisins. While Carlin et al. focused on high-protein diets, the mechanisms they highlighted, such as the modulation of insulin signaling, may overlap with the bioactive effects of raisins in promoting metabolic efficiency, even under alternative feeding conditions.

The study by Vanselow et al (2016) highlights the long-term effects of maternal high-protein diets during pregnancy on offspring, specifically focusing on hepatic gene expression changes in adulthood. While our research differs in scope, examining the impact of alternative diets, including raisin supplementation, on reproductive performance and offspring growth parameters, it provides complementary insights into how maternal diet influences offspring physiology during critical developmental period. Vanselow et al (2016) demonstrated that maternal high-protein diets induced significant alterations in the expression of hepatic genes in adult offspring, suggesting epigenetic modifications during gestation. This result aligns with the broader understanding that maternal diet plays a pivotal role in shaping offspring development, not only at birth but also in their long-term metabolic trajectory. In our study, while we did not analyze epigenetic or hepatic gene expression changes, the consistent offspring outcomes in terms of body weight, length, and width across all groups, including those fed raisin-supplemented diets, highlight the potential of specific dietary components to support stable developmental conditions The hepatic gene changes observed by Vanselow et al (2016) suggest that the maternal diet has a significant impact on metabolic programming. Similarly, our results indicate that raisin supplementation (T2 group) might influence maternal metabolism during pregnancy and lactation, potentially affecting nutrient transfer to the offspring. Raisins are known for their antioxidant and nutrient-dense properties, as supported by Bhouri et al (2025), and could mitigate oxidative stress and stabilize metabolic processes during gestation. This Compatible with Vanselow et al (2016) results, suggesting that dietary interventions during pregnancy have profound systemic effects on offspring, even if not immediately observable at birth.

5. Conclusions

This study evaluated the effects of large animal feed and raisin-supplemented diets on growth, reproduction, and offspring outcomes in female Wistar rats. The results showed no significant differences between the alternative diets and the standard laboratory diet in terms of maternal weight, feed and water intake, or offspring body weight, length, and width. Fertility rates and the number of offspring were consistent across all groups, demonstrating the suitability of the alternative feeds. Raisin supplementation (T2) provided a nutritionally rich addition, supporting comparable outcomes to the standard diet, likely due to its antioxidant properties. These results suggest that raisin-supplemented large animal feed is a viable, cost-effective alternative during feed shortages or economic constraints, without compromising growth or reproductive outcomes. Further studies are recommended to explore long-term metabolic effects.