1. Experiment Background

Currently, in the egg-laying chicken breeding process, as the breed is improved and the laying cycle is extended (target at 100 weeks of age), the metabolic pressure of the egg-laying chickens reaches its limit. 25-hydroxyVitamin D3, as the active metabolite of vitamin D3, is becoming a key nutrient to solve the core pain points in egg-laying chicken breeding. 25-hydroxyVitamin D3 bypasses liver metabolism and is less affected by liver and intestinal damage, significantly enhancing calcium and phosphorus absorption, strengthening bone structure, preventing egg-laying fatigue syndrome in egg-laying chickens, reducing paralyzed chickens and death losses, improving eggshell quality, and reducing the proportion of cracked eggs, cracked eggs, and dark spot eggs.

D-NOVO® is a 25-hydroxyVitamin D3 product independently developed by Key Ingredients Biotechnology (Yichang) Co., Ltd. using biotechnological synthesis technology. It has the characteristics of high absorption efficiency (all active ingredients are fully water-soluble), good stability, good mixing uniformity, and is environmentally friendly and green.

2. Experiment Objective

To evaluate the effects of using D-NOVO (25-hydroxyVitamin D3) on the production performance and eggshell quality of laying hens in the later stage of egg production.

3. Materials and Methods

➢ Experimental site: A large-scale egg chicken farm in Xunwu County, Jiangxi Province (with 1 million chickens)

➢ Experimental period: 35 days, from October 21, 2024 to November 25, 2024

➢ Experimental animals: Two buildings of 460-day-old Hy-line Grey egg chickens, 52,500 chickens per building, totaling 105,000 chickens

➢ Experimental treatments:

a) The experimental group's basal diet was supplemented with D-NOVO at 0.05% (125g/ton),

b) The control group was fed the basal diet.

➢ Measurement indicators: After 15 days of feeding, the egg production rate and mortality rate were continuously collected for 20 days. The eggshell strength, eggshell thickness were measured, and the proportions of dark spot eggs and cracked eggs were statistically analyzed for comparison.

Test Results and Discussion

1. Egg production rate:

The egg production rate of the experimental group was generally stable. In contrast, the egg production rate of the control group fluctuated significantly. This indicates that the use of 0.05% D-NOVO can alleviate the decline in egg production rate during the later stage of laying, and compared with the control group, the average egg production rate increased by 0.68% (see Figure 1).

2. Mortality and abortion rate

As shown in Figure 2, the mortality and abortion rate of the experimental group decreased significantly after 4 weeks of using D-NOVO. The average mortality and abortion rate dropped from 4.38 to 3.28, indicating that D-NOVO can enhance the immunity of laying hens in the later stage and reduce the number of dead and aborted chicks.

Figure 1: Line graphs showing the egg-laying rates during the experimental period for the two groups

Figure 2. Line graph showing the number of deaths and culls in the two groups during the experimental period

3. Eggshell Quality:

When using D-NOVO during the later stage of laying by egg-laying hens, it can also improve the quality of eggshells. The thickness of the eggshells increases by 5.50%, cracked eggs decrease by 29.29%, and the score for dark spot eggs reduces by 30.52% (the scoring standard for dark spot eggs is provided later) 

International Eggshell Rating System

Score 5: Extremely transparent, numerous bright spots, and a large number of black spots

Score 4: Highly transparent, with fine and large bright spots, and many black spots.

Score 3: Moderate transparency, numerous fine bright spots, a small number of black spots

Score 2: Lightly translucent, with numerous fine highlights, no black spots

Score 1: Slightly transparent, with a few minor bright spots, no black spots.

Score 0: Opaque, with very few faint highlights, and no black spots.

Conclusion:

Supplementation of D-NOVO during the laying period of laying hens can not only increase eggshell thickness, reduce the occurrence of cracked eggs and dark spot eggs, but also increase the laying rate by 0.68%, reduce the mortality and culling rate of chickens, and the input-output ratio can reach 1:5.5, thereby improving the overall breeding efficiency of the farm.