Abstract: In order to study the efficacy of stress Ning in improving the meat quality of commercial broiler chickens. Select 200 healthy 1-day-old AA broiler chickens with similar body weight and randomly divide them into 2 treatments, with 5 replicates per treatment and 20 chickens per replicate (see Table 1). Treatment 1: Control group, broiler chickens were fed a regular diet (NRC recommended nutritional level) without adding any antibiotics to the diet; On the basis of the same diet as treatment 1, supplement stress Ning with 250 mg/kg for treatment 2. The experiment is divided into two stages (0-21d; 22-42d). Experimental chicken cage feeding, feeding pellet feed, with consistent dietary composition and nutritional levels between treatments. At 21 and 42 days, 10 chickens were randomly selected from each treatment (2 chickens/replicate) for slaughter experiments. One side of the chest and leg muscle samples were dissected to determine meat color and drip loss. The measurement results indicate that:

Chest and leg muscle color: Adding stress Ning significantly increased the leg muscle redness value (a value) and decreased the leg muscle yellowing value (b value) (P<0.05), with a trend of reducing the chest muscle redness value (a value) (P=0.056) and improving the leg muscle color score (P=0.075). From a numerical comparison analysis, taking the muscle color indicators of the control group as 100%, the brightness values (L value), a value, and b value of the chest and leg muscles after adding stress Ning were 97.2%, 72.51%, 84.49%, and 95.92%, 126.73%, and 88.78%, respectively. The color scores of the chest and leg muscles increased by 9.39% and 12.56%, respectively. It can be seen that adding stress Ning improved the muscle color of the chest and leg muscles.

Drip loss of chest and leg muscles: Adding stress Ning significantly reduced the drip loss of leg muscles (P<0.05) and showed a trend of decreasing the drip loss of chest muscles (P=0.08). From a numerical comparison analysis, with the control group's various indicators as 100%, the addition of stress Ning reduced the drip loss of chest and leg muscles by 8.62% and 51.21%, respectively.

Keywords: commodity broiler, stress Ning, meat color, drip loss

1. Materials and Methods

1.1 Test Materials

Stress Ning: A high-yield stress additive formula mainly composed of microecological active ingredients. Provided by SD BIOTECH GROUP.

1.2 Experimental animals and design

Select 200 healthy 1-day-old AA broiler chickens with similar body weight and randomly divide them into 2 treatments, with 5 replicates per treatment and 20 chickens per replicate (see Table 1). Treatment 1: Control group, broiler chickens were fed a regular diet (NRC recommended nutritional level) without adding any antibiotics to the diet; On the basis of the same diet as treatment 1, supplement stress Ning with 250 mg/kg for treatment 2. The experiment is divided into two stages (0-21d; 22-42d).

1.3 Experimental diet

Conventional diet for commercial broiler chickens in Shandong Province (see Table 2).

1.4 Test Method

Feeding experiment: The experiment is divided into two stages: broiler chickens (0-21d) and broiler chickens (22-42d). Experimental chicken cage feeding with powdered feed.

Slaughter experiment: 10 chickens were randomly selected for each treatment (2 chickens/replicate) at 21 and 42 days. Conduct slaughter experiments.

1.5 Measurement indicators

Meat quality: At the end of the experimental period (42 days), 10 chickens were selected for each treatment, and the right chest and leg muscles were dissected to measure the meat color value (L value, a value, b value), drip loss (%), etc.

1.6 Data statistics and analysis

The data was analyzed using SAS 9.2 software, and Duncan's multiple range test was used to compare the mean values, with a significance level of p<0.05.

2. Results and Analysis

2.1 Comparative analysis of muscle color

The effect of supplementing 250 mg/kg of stress Ning in the diet of commercial broiler chickens on the color of chest and leg muscles is shown in Table 3. The analysis of variance showed that the addition of stress Ning significantly increased the leg muscle redness value (a value), decreased the leg muscle yellowing value (b value) (P<0.05), and showed a trend of reducing the chest muscle redness value (a value) (P=0.056) and improving the leg muscle color score (P=0.075). From a numerical comparison analysis, taking the muscle color indicators of the control group as 100%, the brightness values (L value), a value, and b value of the chest and leg muscles after adding stress Ning were 95.98%, 85.38%, 91.74%, and 90.93%, 106.93%, and 90.30%, respectively. The color scores of the chest and leg muscles increased by 15.39% and 23.09%, respectively. It can be seen that adding stress Ning improved the muscle color of the chest and leg muscles.

2.2 Comparative analysis of muscle drip loss

The effect of supplementing 250 mg/kg of stress Ning in the diet of commercial broiler chickens on drip loss of chest and leg muscles is shown in Table 4. Analysis of variance showed that the addition of stress Ning significantly reduced the drip loss of leg muscles (P<0.05) and showed a trend of reducing drip loss of chest muscles (P=0.08). From a numerical comparison analysis, with the control group's various indicators as 100%, the addition of stress Ning reduced the drip loss of chest and leg muscles by 8.62% and 51.21%, respectively.

3. Conclusion

Compared to the control group:

Supplementing with stress Ning in the diet of commercial broiler chickens improved the color of chest and leg muscles, resulting in good meat color scores. The color scores of chest and leg muscles increased by 9.39% and 12.56%, respectively.

Supplementing with stress Ning in the diet of commercial broiler chickens reduced drip loss in chest and leg muscles and improved muscle water holding capacity.

Table 1 Experimental Design

Table 2 Experimental Diet Composition and Nutritional Level

Table 3 Effect of Stress Ning on the Color of Chest and Leg Muscles in Commercial Broiler Chickens at 42 Days

Table 4 Effect of Stress Ning on Drip Loss of Chest and Leg Muscles in Commercial Broiler Chickens at 42 Days