Effects of yeast culture (Bioyeastar 4C) on laying performance and egg quality of laying hens in late laying period

Poultry Nutrition and Feed Innovation Team, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China

Abstract: This tudy was to evaluate the effects of saccharomyces cerevisiae culture on laying performance and egg quality of laying hens in the late laying period, to provide technical basis for the promotion and application of the product. A total of 384 52-week-old healthy Hyline brown laying hens were randomly divided into 4 groups with 8 replicates per group and 12 hens per replicate. The birds in control group were fed a basal diet, groups 1, 2 and 3 were fed the basal diet supplemented with 0.1%, 0.2% and 0.3% Bioyeastar 4C, respectively. The pre-test period was 1 week and the formal test period was 12 weeks. The results showed as follows: (1) Dietary yeast culture improved laying performance, egg shell and albumen quality of laying hens. Egg production performance and egg quality were the best in 0.10% supplemental group. According to production performance, eggshell quality and albumen quality indexes, the optimal supplemental level of yeast culture in laying hen diet was 0.11~0.19%. (2) Dietary yeast culture  increased the albumen height and yolk color of eggs stored at 25 ℃ for 14 days, and prolonged the storage period of eggs, which may be related to the improvement of protein composition and albumen quality.

Key words: Yeast culture; Egg production performance; Egg quality; Gut microbes; Short-chain fatty acid

1 Purpose

To evaluate the effect of saccharomyces cerevisiae culture on laying performance and egg quality of laying hens in the  laying later stage, to provide technical basis for product popularization and application.

2 Trial materials and methods

2.1 Time and place

The experiment was conducted in Zhuozhou Experimental Base of Feed Research Institute of Chinese Academy of Agricultural Sciences from April 27, 2023 to September 19, 2023.

2.2 Trial materials

The Saccharomyces cerevisiae culture (Bioyeastar 4C) was provided by Beijing Enhalor Biotechnology Co., LTD. Crude protein ≥20%, mannan ≥2%, ash ≤13%, water ≤1%.

2.3 Trial design

A total of 384 52-week-old healthy Hyline brown laying hens were randomly divided into 4 groups with 8 replicates per group, 12 hens per replicate and 1 cage position per 3 hens. The hens in control group were fed a basal diet, and the others in  groups 1, 2 and 3 were supplemented with 0.1%, 0.2% and 0.3% Bioyeastar, respectively. Pre-trial period was 1 week, and the formal trial period was 12 weeks. Composition and nutritional level of basic diet were shown in Table 1.

Table 1   Basic diet composition and nutritional level

(1) Nutritional values are calculated according to NRC Edition 31.

(2) Premix (per kg diet) : VA, 12,500 IU; VD₃, 4,125 IU; VE, 15 IU; VK, 2 mg; VB₁, 1 mg; VB₂, 8.5 mg; VB₆, 8 mg; VB₁₂, 5 mg; Calcium pantothenate, 50 mg; Niacin, 32.5 mg; Biotin, 2 mg; Folic acid, 5 mg; Choline, 500 mg; Mn, 65 mg; I, 1 mg; Fe, 60 mg; Cu, 8 mg; Zn, 66 mg; Na₂SO4, 4 grams.

2.4 Statistical analysis of data

One-way ANOVA program of SPSS 19.0 statistical software (SPSS Inc, Chicago IL) was used for variance analysis, Duncan's method was used for difference significance test, P < 0.05 was used as the difference significance criterion, and 0.05 ≤ P < 0.1 was used as the trend effect. The results are expressed as mean and standard error. Other data were analyzed by t-test method, and the results were expressed as average values and standard errors.

3 Results and analysis

3.1 Effects of yeast culture on laying performance of laying hens

It can be seen from Table 2 that dietary yeast culture (YC) had a linear trend of decreasing average daily feed intake of laying hens from 1 to 12 weeks (P = 0.07).

Table 2  Effects of dietary YC on production performance of laying hens (52-64 wk, n=8)

Note: AEW, Average egg weight. EP, Egg production. ADFI, Average daily feed intake. FCR, Feed conversion ratio.

P-value: A represents one-way ANOVA and Duncan’s multiple comparisons; L and Q represent linear and quadratic analysis using regression analysis, respectively.

3.2  Effects of yeast culture on egg quality

As shown in Table 3, With the increase of dietary yeast culture supplemental level, albumen height and Haugh unit showed a quadratical upward trend  (P < 0.05). Among them, compared with control group, the addition of 0.1% to 0.3% yeast culture significantly increased  albumen height and Haugh unit at week 9 (P < 0.05), and significantly increased Haugh unit at week 12 (P < 0.05). However, yeast culture had no significant effect on albumen ratio (P > 0.05).

With the increase of yeast culture supplemental level, eggshell thickness and eggshell strength showed a quadratical increase trend (P < 0.05). Compared with control group, adding 0.2% and 0.3% yeast culture significantly increased eggshell thickness at week 9 (P = 0.02). The addition of 0.1% and 0.2% yeast culture significantly increased eggshell thickness (P < 0.01) and eggshell strength (P = 0.01) at week 12. Yeast culture had no significant effect on eggshell ratio (P > 0.05). In addition, adding 0.30% yeast culture significantly increased egg shape index at the 9th week (P < 0.05).

Table 3  Effects of dietary YC on egg quality of laying hens (52-64 wk, n=8)

3.3 Effects of yeast culture on ultrastructure of eggshell

As shown in Table 4, compared with the control group, dietary 0.10% yeast culture significantly decreased eggshell mastoid density (P < 0.05), and had a tendency to increase the thickness and width of the mastoid (P = 0.08 and P = 0.06).

Table 4 Effects of dietary YC on the eggshell ultrastructure of laying hens (n=8)

Note: P-value: A represents one-way ANOVA and Duncan’s multiple comparisons; L and Q represent linear and quadratic analysis using regression analysis, respectively.

3.4 Effects of yeast culture on egg quality during storage

As can be seen from Table 5, with the increase of yeast culture supplemental level, yolk color score was linearly and  quadratically increased (P < 0.05). After 7 days of storage, the proportion of egg yolk among experimental treatment groups was quadratically increased twice (P < 0.05).

Compared with control group, the albumen height of eggs in the 0.20% yeast culture group stored at 25 ℃ for 14 days was significantly increased (P < 0.05, Table 6), and the yolk color of eggs in the 0.20% and 0.30% yeast culture groups stored at 25 ℃ for 14 days was significantly increased (P < 0.05). The Haugh unit of eggs stored at 25℃ for 14 days was increased (P = 0.08), and the pH value of albumen stored at 25℃ for 7 days was increased (P = 0.08).

Dietary yeast culture linearly decreased the eggshell proportion of eggs stored at 25 ℃ for 7 days (P > 0.05), and linearly increased the yolk color of eggs stored at 25 ℃ for 14 days (P < 0.05, Table 6). Dietary yeast culture quadratically increased the albumen height and yolk color of eggs stored at 25 ℃ for 14 days (P < 0.05), and quadratically decreased the pH value of  albumen of eggs stored at 25 ℃ for 7 days (P < 0.05).

Table 5 Effects of dietary YC on storage period egg quality of laying hens (n=8, 4 ℃)

Note: P-value: A represents one-way ANOVA and Duncan’s multiple comparisons; L and Q represent linear and quadratic analysis using regression analysis, respectively.

Table 6 Effects of dietary yeast culture on the protein content of albumen during storage (n=8, 25 ℃)

3.5  Effects of dietary YC on the protein content of albumen during storage

Compared with control group, 0.10% yeast culture group decreased (P < 0.05, Table 7) OVA content in albumen of fresh eggs (D0).

Figure 1 Effects of dietary YC on the protein content of albumen during storage (n=8)

3.6 Optimal dosage of yeast culture

Table 7 showed the quadratic equation fitted according to the daily feed intake, eggshell thickness, eggshell strength,  albumen height and Haugh unit in the whole period. The results showed that with performance, eggshell quality and albumen quality as the main evaluation indexes, the recommended supplemental level of yeast culture in basal diet is 0.11~0.19.

Table 7 Optimal dose of Yeast Culture

4 Conclusion

4.1 Dietary yeast culture (Bioyeastar 4C) can improve laying performance, eggshell and albumen quality of laying hens, which may be related to improving body immunity and regulating tubal protein secretion. According to the performance, eggshell quality and  albumen quality as the main evaluation indexes, the optimal supplemental level of yeast culture in the diet of laying hens is 0.11~0.19%.

4.2 Dietary addition of yeast culture (Bioyeastar 4C) can increase the albumen and yolk color of eggs stored at 25 ℃ for 14 days, and prolong the storage period of eggs, which may be related to improving the protein composition of albumen and improving   albumen quality.

Bioyeastar^® 4C (concentrated Saccharomyces cerevisiae and its metabolites), Bioyeastar® 4C is a new generation of yeast Postbiotics created by Enhalor Institute of Biotechnology on the basis of more than 10 years of focus on yeast research. It is an upgrade product of Bioyeastar® with more metabolites. The concentration is higher. These abundant nutritional active ingredients are high-quality nutrient substrates for intestinal probiotics, which can balance intestinal microecology, protect intestinal mucosal structure, regulate intestinal immune function, effectively protect animal health, and improve production performance. Bioyeastar® 4C is used less and more economically.