Effects of bean sprouts on productivity and egg quality in Ac laying hens at 25-35 weeks of age

Le Thu Thuy, Nguyen Thi Kim Dong¹ and Pham Tan Nha

Cantho University, Cantho City, Vietnam
ptnha@ctu.edu.vn
¹ Tay Do University, Cantho City, Vietnam

Abstract

This study aimed to determine the most appropriate level of bean sprout supplementation in the diet of laying hens to evaluate their performance and egg quality. The experiment was designed as a completely randomized design, including 250 hens aged 25–35 weeks, divided into five treatment groups with five replications per group (10 hens per replication). The treatments were as follows: Control (BD): Basal diet; C50: BD + 50 g of fresh bean sprouts/day; C100: BD + 100 g of fresh bean sprouts/day; C150: BD + 150 g of fresh bean sprouts/day; and C200: BD + 200 g of fresh bean sprouts/day. The results showed that the highest laying rate was observed in the C150 and C200 groups (43.9% and 43.1%; p<0.05), while the lowest feed conversion ratio (FCR) was found in the C150 and C200 groups (3.60 g feed/g egg and 3.61 g feed/g egg; p<0.05). Furthermore, some egg quality parameters were improved. Notably, the which C150 and C200 showed the highest egg weight (36.9 g/egg and 36.5 g/egg) and Haugh unit (83.5 and 83.7) compared to the other treatments (p<0.05). The C200 treatment had the highest yolk index (0.45), albumen index (0.11) and yolk color score (7.74) compared to the other treatments (p<0.05). In conclusion, supplementing fresh bean sprouts at levels of 150–200 g/10 hens/day improved egg productivity and reduced FCR. In addition, fresh bean sprouts also improved several egg quality indicators such as egg weight, yolk index, albumen index, Haugh unit and yolk color score.

Keywords: Ac chicken, egg quality, productivity, bean sprouts

Introduction

The Ac chicken (Gallus gallus domesticus Brisson) is one of the native chicken breeds that has long been raised in the Mekong Delta. According to (Le et al 2023), Ac chicken has a significantly higher carnosine content (798.3 mg/100 g breast meat) than white chicken (417.2 mg/100 g breast meat). Carnosine is a protein abundant in the meat and brain of vertebrates, playing an important role in physiological functions such as anti-aging, antioxidant activity, anti-fatigue and neurotransmission (Caruso et al 2019). It has been used in medical applications to treat diseases such as diabetes, Alzheimer’s disease, aging, cancer and other chronic conditions (Derave et al 2019).

Additionally, Ac chicken eggs are favored by consumers for their lack of fishy odor, rich and fragrant taste, high-protein whites, elevated yolk ratio and highly appealing dark color. Ac chickens reach sexual maturity early (Le et al 2023), at 119–123 days old. Their eggs weigh 31.3–36.2 g/egg and the laying rate is 52.3–58.1% at 23–37 weeks of age. Ac chickens are raised industrially for egg production in Tien Giang and Long An provinces on a large scale (Le et al 2023). Research in this field is limited; most studies focus on nutrition (Truong et al 2019) and gene polymorphism (Le et al 2023).

Bean sprouts may provide some benefits to laying hens, although there is limited specific research on their effects in poultry. Bean sprouts provide nutrients such as protein, vitamins, minerals and fiber, which can support the overall health of chickens, including egg production. However, it is important to note that bean sprouts should not be the main food for laying hens but should be fed as part of a varied and balanced diet to ensure adequate nutrient intake. Bean sprouts are rich in vitamins, especially vitamin E. Vitamin E has been shown to improve productivity, egg quality and hatchability in chickens. Many studies have shown that adding vitamin E to the diet or drinking water increases egg productivity in Isa Brown chickens (Nguyen and Pham, 2018). Therefore, the combination of vitamin E contained in bean sprouts added to chicken feed is expected to improve productivity, egg quality and hatchability rate in Ac chickens.

This study aimed to determine the most appropriate level of bean sprout supplementation in the diet of laying hens to evaluate their performance and egg quality.

Materials and methods

Experimental animal

The study was conducted from January to April 2025 at a farm in Binh Minh District, Vinh Long Province, Vietnam. Ac chickens used in the research were sourced from this farm and were vaccinated against hepatitis, cholera and H5N1. The experiment involved 250 Ac hens, aged 25 to 35 weeks.

Tools used in the study included an electronic scale for weighing chickens and feed, as well as a notebook and pen for data recording. Five hens were randomly placed in each cage (dimensions: 0.5 m length × 1.2 m width × 0.45 m height), with a stocking density of 0.12 m² per bird (area = 0.5 m × 1.2 m = 0.6 m²). The cage floor was lined with coconut fiber. Chickens had free access to water via automatic drinking nipples.

Experimental design

From weeks 25 to 35, the Ac chickens were housed in pens and fed a standard diet containing 17% crude protein and 2,860 kcal/kg of metabolizable energy (as detailed in Table 1). They had unrestricted access to both food and water throughout the study period.

Animal Husbandry Laboratory

Experimental design

The experiment was arranged in a completely randomized design with five treatments, each consisting of five replications. A total of 250 hens were numbered from 1 to 250. These numbers were written on individual slips of paper and randomly drawn to assign hens to treatment groups. There were 25 experimental units in total, with 10 hens per unit:

Control (C0): Basic diet (BD)

C50: BD + 50 g of fresh bean sprouts/day

C100: BD + 100 g of fresh bean sprouts/day

C150: BD + 150 g of fresh bean sprouts/day

C200: BD + 200 g of fresh bean sprouts/day

*Care: Hens were fed twice daily at 7:00 A.M. and 2:00 P.M., while water was provided ad libitum through automatic nipple drinkers. The lighting system provided 16 hours of light per day using LED bulbs with a rated power of 3 W/m². All treatments were managed and administered in accordance with the protocols established by Asia Nutrition Technologies Company Limited (Vietnam).

Throughout the experimental period, the number of eggs produced was recorded daily to calculate egg production as the laying rate, expressed as the percentage of eggs produced per hen. A list of reproductive and egg quality indicators was also documented, with data collection methods detailed in Table 3. Eggs were collected daily at 5:00 P.M., numbered and monitored to assess treatment yields. Additionally, egg weight and egg shape index were measured daily throughout the entire experiment.

Bean sprout making process

Step 1: Remove wormy or broken green beans and rinse them thoroughly. Soak the beans in cold water for 10–12 hours, changing the water a few times to help whiten the beans. After soaking, the beans will begin to crack and show signs of germination. Rinse them under running water to clean them.

Step 2: Place a layer of muslin cloth at the bottom of a basket. Spread the beans evenly on top and cover them with another layer of muslin cloth. Then, place a plate or cutting board on top of the basket to press the beans gently.

Step 3: Cover the entire basket with a black plastic bag or place it in a dark area. Twice a day—morning and evening—lift the plate and rinse the sprouting beans (while keeping the muslin cloth intact) under running water. Let them drain, then return them to the basket. After three days of incubation, the bean sprouts will be ready for harvest.

Measurements and data collection

Chemical analyses

The chemical composition of the feed samples was analyzed to determine the contents of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), crude fiber (CF) and ash, following the procedures established by AOAC (1990). Neutral detergent fiber (NDF) was measured using the method developed by Van Soest et al (1991) and metabolizable energy was calculated based on Janssen's (1989) formula.

Statistical analyses

Data analysis was performed using the General Linear Model (GLM) in Minitab version 18.1.0 (Minitab, 2018). Treatment differences were evaluated using the Tukey method within the same software.

Results

Figure 1. Effect of bean sprouts on Eggs number of Ac Chickens at 30-40 weeks old	Figure 2. Effect of bean sprouts on FCR of Ac Chickens at 30-40 weeks old

Table 4 shows that the reproductive performance indicators across treatments were statistically different (p<0.05). At the start of the experiment, there were no significant differences in initial body weight among the five treatment groups, indicating that the Ac hens used were comparable in condition.

Figure 1 shows that the total number of eggs was highest in the C200 group (431 eggs) and lowest in the C0 group (406 eggs; p<0.05). Similarly, the highest laying rate was observed in the C200 group (43.9%), while the lowest was in the C0 group (36.1%; p<0.05). In general, diets supplemented with fresh bean sprouts resulted in higher total egg production and laying rates than the control group. This improvement is likely due to the presence of vitamins and minerals in bean sprouts, which support digestive health and nutrient absorption—factors that positively affect reproductive performance. In particular, vitamin E present in bean sprouts is well known for its role in supporting reproductive functions in poultry.

Similarly, Jiang et al (2013) reported that supplementing 200 mg/kg of vitamin E increased the laying rate of Hyline Brown hens to 82.7%, compared to 80.7% in the control. Zhao et al (2021) found that a 100 mg/kg vitamin E supplementation increased laying rates to 89.0% compared to 83.5% in the control group. In the present study, the combined effect of B vitamins, vitamin C, vitamin E and minerals found in fresh bean sprouts yielded results consistent with those reported by Neupane et al (2019) and Zhao et al (2021). However, the laying rate of Ac hens in this study was lower than in some previous studies, such as 54.6% at 28–39 weeks (Nguyen et al 2022) and 52.3–58.1% at 23–37 weeks (Nguyen & Nguyen, 2022). These discrepancies may be attributed to differences in survey timing, management practices, or rearing conditions.

Feed intake was highest in the C200 group (51.5 g/hen) and lowest in the C100 group (49.7 g/hen). In general, feed consumption across diets supplemented with bean sprouts was similar to the control group. However, feed intake per 10 eggs tended to decrease with bean sprout supplementation—likely due to improved productivity. The lowest feed intake per 10 eggs was observed in the C100, C150 and C200 groups at 1,295 g, 1,300 g and 1,310 g, respectively, while the highest was recorded in the C0 group (1,400 g). This suggests that bean sprout supplementation improved feed efficiency, resulting in better nutrient and energy conversion into eggs. Notably, the C100, C150 and C200 treatments showed the most efficient feed conversion per 10 eggs, contributing to enhanced economic performance in egg production.

As illustrated in Figure 2, the regression analysis yielded an R² value of 0.98, indicating a strong fit with the experimental data. Additionally, the feed conversion ratio (FCR) was lowest in the C150 and C200 groups (3.60 and 3.61, respectively) and highest in the C0 group (4.05; p<0.05). Overall, FCR values were lower in treatments supplemented with bean sprouts compared to the control (p<0.05). This improvement in FCR may be attributed to enhanced digestion, better immunity and more efficient nutrient absorption promoted by the vitamins and minerals in bean sprouts. These findings highlight the C150 and C200 treatments as especially effective in improving feed efficiency and the economic viability of egg production. Similarly, Nguyen and Nguyen (2022) reported FCR values of 2.94 and 2.98 in Ac chickens fed diets supplemented with Moringa leaf powder and turmeric powder, respectively, at 23–29 weeks of age.

Effect of treatments on egg quality

Table 5 presentes the egg quality indicators in the treatments, which were all statistically significant (p<0.05). Egg weight was highest in the C100, C150 and C200 treatments (36.8 g/egg, 36.9 g/egg and 36.5 g/egg, respectively) and lowest in the C0 treatment (35.1 g/egg; p <0.05). In general, egg weight in the treatments using bean sprouts was higher than in the control treatment. This suggests that the product had the effect of increasing egg weight in Ac hens. The effect of vitamins and minerals, especially vitamin E, on egg weight has been published in previous studies around the world. In addition, the present study also showed that the Ac Chicken had lower egg weight than the native chickens in Southern Ethiopia (46.6 g/egg raised in the lowland; 48.6 g/egg in the midlands; and 45.4 g/egg in the highland) (Berhanu et al 2022). The differences in the results of the above studies may be due to differences in care and nutritional conditions.

Moreover, eggshell thickness was greatest in the C200 treatment (0.39 cm), followed by the C150 and C100 treatments (0.38 cm) and thinnest in the C0 treatment (0.36 cm). A study by Bodhi et al (2023) on ISA Brown laying hens showed that supplementing probiotics (L. acidophilus, Bifidobacteriumspp. and L. plantarum) in the diet at a dose of 5 ml probiotic/kg of feed resulted in an eggshell thickness (0.36 cm) equal to that of the control (0.36 cm). Good nutrient absorption from the feed facilitated eggshell formation, thereby increasing shell thickness. Improvements in eggshell quality were also observed when vitamin D3 was added to the diet of Brown chickens in a study by Hatairat et al (2015). Eggshell thickness (0.37 cm) was improved by supplementing 6,000 IU of vitamin D3 in a diet containing 3.5% calcium, compared to a control diet without vitamin D3 (0.34 cm). This finding suggested that dietary vitamin D3 supplementation may offset the adverse effects of low calcium levels (3.5% in feed) on eggshell quality. Increasing vitamin D3 levels may improve eggshell quality by increasing the active form of vitamin D3 (1,25(OH)₂) produced in the kidney. This active compound stimulates the synthesis of a calcium-binding protein required for calcium transport across the intestinal membrane and eggshell formation. The present study used a vitamin D3-supplemented formulation, which also resulted in an increase in eggshell thickness compared to the control.

Similarly, the HU tended to increase gradually across the supplemented treatments. The highest HU was observed in the C200 treatment (83.7) and the lowest in the C0 treatment (79.6). A study by Bodhi et al (2023) supplemented probiotics in the diets to improve the HU of ISA Brown eggs. The treatment involving a mixture of probiotics (L. acidophilus, Bifidobacterium spp. and L. plantarum with a density of 1.2×10⁹ CFU/mL) at a dose of 3 ml/kg of feed helped the eggs achieve an HU value of 106.8, much higher than that of the control (97.3). Neijat et al (2015) also observed an increase in yolk color score, HU, yolk index and albumen index in laying hens treated with a product containing Bacillus subtilis DSM29784. This probiotic enhanced the intestinal environment and improved the absorption of nutrients necessary for egg formation. Sjofjan et al (2021) suggested that a healthy intestinal environment promotes improvement in both internal and external egg quality by enhancing the absorption of minerals and nutrients.

Besides, the yolk color score was highest in the C200 treatment (7.74) and lowest in the C0 treatment (7.39). This result was similar to the findings of Bodhi et al (2023), where supplementing probiotics in the diets improved the yolk color score of ISA Brown eggs. Specifically, the probiotic-supplemented treatments had higher yolk color scores (6.75–8.82) than the control (6.70). Neijat et al (2015) observed an increase in yolk color score, HU, yolk index and albumen index in laying hens treated with a product containing Bacillus subtilis DSM29784. Sjofjan et al (2021) suggested that the intestinal environment promoted improvement in both internal and external egg quality by enhancing the absorption of minerals and nutrients necessary for egg production.

Conclusions

Supplementing fresh bean sprouts at levels of 150 to 200 g per 10 heads per day in the diet of Ac chickens increased egg productivity and reduced the feed conversion ratio (FCR).

Moreover, the inclusion of fresh bean sprouts enhanced several egg quality parameters, including egg weight, yolk index, albumen index, Haugh unit (HU) and yolk color index.

Conflicts of Interest

The authors have declared no conflict of interest.

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