Abstract: In order to study the efficacy of stress Ning in improving the production performance and meat quality of 63 day commercial broiler chickens. 300 healthy 1-day-old AA broiler chickens with similar body weight were selected and randomly divided into 2 treatments, with 5 replicates per treatment and 30 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 500 mg/kg for treatment 2. Experimental chicken cage feeding, feeding pellet feed, with consistent dietary composition and nutritional levels between treatments. Experiment 63d, randomly select 10 animals from each treatment (2 animals/replicate) for slaughter experiments, take samples of chest muscle, leg muscle, and liver, and determine meat production performance and quality. The measurement results indicate that:

Production performance: Supplementing with stress Ning in the diet of commercial broiler chickens significantly increased their daily weight gain (P<0.05) and showed a trend of decreasing feed to weight ratio (P=0.050). From a numerical comparison analysis, with the control group's various indicators as 100%, supplementing with stress Ning increased the daily weight gain of broiler chickens by 2.19%, while the average daily feed intake, feed to weight ratio, and mortality rate decreased by 1.33%, 2.09%, and 31.3%, respectively.

Slaughter performance: Supplementing with stress Ning in the diet of commercial broiler chickens significantly increased leg muscle percentage at 63 days (P<0.05), but="" had="" no="" significant="" effect="" on="" other="" indicators="" p="">0.05). From a numerical comparison and analysis, with the control group's slaughter performance indicators set at 100%, supplementing with stress Ning resulted in an increase of 1.43%, 0.27%, 4.98%, and 17.23% in the full bore rate, half bore rate, chest muscle rate, and leg muscle rate, respectively, and a decrease of 36.46% in abdominal fat rate.

Meat color index: Supplementing with stress Ning in the diet of commercial broiler chickens significantly increased the redness value (a value) of chest muscles (P<0.05), and="" showed="" a="" trend="" of="" increasing="" the="" yellowing="" value="" b="" p="" meat="" color="" score="" there="" was="" no="" significant="" effect="" on="" brightness="" l="">0.05). Comparing and analyzing numerically, with the control group's various indicators at 100%, supplementing with stress Ning resulted in a 4.23% decrease in L value, and an increase of 28.21%, 32.32%, and 18.34% in a value, b value, and meat color score, respectively.

Antioxidant properties: Supplementing commercial broiler diets with stress Ning showed a trend of increasing chest muscle GSH activity (P=0.074) and decreasing leg muscle MDA content (P=0.086). There was no significant impact on other indicators (P>0.05). From a numerical comparison analysis, with the control group's various indicators as 100%, supplementing with stress Ning resulted in a decrease of 31.34% and 33.92% in MDA content, an increase of 26.86% and 7.34% in GSH activity, and an increase of 1.3% and 4.7% in SOD activity in chest and leg muscles, respectively.

Muscle Vitamin Reserve: Supplementing with Stress Ning in the diet of commercial broiler chickens significantly increased the vitamin E content in chest and leg muscles (P<0.05). there="" was="" no="" significant="" effect="" on="" the="" vitamin="" content="" in="" liver="" p="">0.05). Comparing and analyzing numerically, with the control group's various indicators at 100%, supplementing with stress Ning increased the vitamin E content in chest and leg muscles by 20.83% and 57.43%, respectively; The content of vitamin A in the liver decreased by 4.03%, while the content of vitamin E increased by 44.88%.

Keywords: Stress Ning, 63d commercial broiler, production performance, slaughter performance, meat color, antioxidant properties, vitamin reserves

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

300 healthy 1-day-old AA broiler chickens with similar body weight were selected and randomly divided into 2 treatments, with 5 replicates per treatment and 30 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 500 mg/kg for treatment 2.

1.3 Experimental diet

Temporary shortage (regular diet for commercial broiler chickens in Shandong Province)

1.4 Test Method

Feeding experiment: The experiment is divided into two stages: broiler chickens (0-21d), broiler chickens (22-42d), and broiler chickens (42-63d). Experimental chicken cage feeding with powdered feed.

Slaughter experiment: 63 days of experimental chickens, with 10 randomly selected from each treatment (2 chickens/replicate). Conduct slaughter experiments.

1.5 Measurement indicators

Production performance: Record feed intake daily and weigh on an empty stomach at 8:00 am for 63 days. Calculate the average daily feed intake, average daily weight gain, and feed to gain ratio. Record death

Meat production performance: At 63 days, 10 chickens were slaughtered for each treatment, and the meat production performance (net bore rate, semi net bore rate, leg muscle rate, chest muscle rate, etc.) was measured;

Meat color index: At 63 days, 10 chickens were slaughtered for each treatment, chest muscles were taken, and meat color indices (L, a, b) were measured;

Antioxidant performance: At 63 days, 10 chickens were slaughtered for each treatment, and chest and leg muscles were collected to measure antioxidant performance (SOD, GSH, MDA);

Vitamin reserve: At 63 days, 10 chickens were slaughtered for each treatment, and the chest muscle, leg muscle, and liver were collected to determine the vitamin content.

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 production performance

The effect of supplementing 500 mg/kg of stress Ning in the diet of commercial broiler chickens on 63 day production performance is shown in Table 2. The analysis of variance showed that supplementing with stress Ning in the diet of commercial broiler chickens significantly increased their daily weight gain (P<0.05), with a trend of decreasing feed to weight ratio (P=0.050). From a numerical comparison analysis, with the control group's various indicators as 100%, supplementing with stress Ning increased the daily weight gain of broiler chickens by 2.19%, while the average daily feed intake, feed to weight ratio, and mortality rate decreased by 1.33%, 2.09%, and 31.3%, respectively. It can be seen that adding stress Ning to the diet of 63d commercial broiler chickens can significantly reduce the feed to weight ratio, improve nutrient utilization efficiency, and improve the survival rate of broiler chickens.

2.2 Comparative analysis of slaughter performance

The effect of supplementing 500 mg/kg of stress Ning in the diet of commercial broiler chickens on slaughter performance at 63 days is shown in Table 3. Analysis of variance showed that supplementing with stress Ning in the diet of commercial broiler chickens significantly increased leg muscle percentage at 63 days (P<0.05), but="" had="" no="" significant="" effect="" on="" other="" indicators="" p="">0.05). From a numerical comparison and analysis, with the control group's slaughter performance indicators set at 100%, supplementing with stress Ning resulted in an increase of 1.43%, 0.27%, 4.98%, and 17.23% in the full bore rate, half bore rate, chest muscle rate, and leg muscle rate, respectively, and a decrease of 36.46% in abdominal fat rate.

2.3 Comparative analysis of muscle color

The effect of supplementing 500 mg/kg of stress Ning in the diet of commercial broiler chickens on breast muscle color at 63 days is shown in Table 4. Analysis of variance showed that supplementing with stress Ning in the diet of commercial broiler chickens significantly increased the chest muscle redness value (a value) (P<0.05), and="" showed="" a="" trend="" of="" increasing="" the="" yellowing="" value="" b="" p="" meat="" color="" score="" there="" was="" no="" significant="" effect="" on="" brightness="" l="">0.05). Comparing and analyzing numerically, with the control group's various indicators at 100%, supplementing with stress Ning resulted in a 4.23% decrease in L value, and an increase of 28.21%, 32.32%, and 18.34% in a value, b value, and meat color score, respectively.

2.4 Comparative analysis of muscle antioxidant performance

The effect of supplementing 500 mg/kg of stress Ning in the diet of commercial broiler chickens on muscle antioxidant activity at 63 days is shown in Table 5. Analysis of variance showed that supplementing with stress Ning in the diet of commercial broiler chickens showed a trend of increasing GSH activity in chest muscles (P=0.074) and decreasing MDA content in leg muscles (P=0.086). There was no significant impact on other indicators (P>0.05). From a numerical comparison analysis, with the control group's various indicators as 100%, supplementing with stress Ning resulted in a decrease of 31.34% and 33.92% in MDA content, an increase of 26.86% and 7.34% in GSH activity, and an increase of 1.3% and 4.7% in SOD activity in chest and leg muscles, respectively.

Comparative analysis of muscle and liver vitamin reserves

The effect of supplementing 500 mg/kg of stress Ning in the diet of commercial broiler chickens on antioxidant activity in muscle and liver at 63 days is shown in Table 6. Analysis of variance showed that supplementing with stress Ning in the diet of commercial broiler chickens significantly increased the vitamin E content in chest and leg muscles (P<0.05). there="" was="" no="" significant="" effect="" on="" the="" vitamin="" content="" in="" liver="" p="">0.05). Comparing and analyzing numerically, with the control group's various indicators at 100%, supplementing with stress Ning increased the vitamin E content in chest and leg muscles by 20.83% and 57.43%, respectively; The content of vitamin A in the liver decreased by 4.03%, while the content of vitamin E increased by 44.88%.

3. Conclusion

Compared with the control group,

Adding Yanning C1 to the diet of commercial broiler chickens can increase daily weight gain, reduce feed to weight ratio and mortality rate, improve production performance, and achieve good breeding profits; It can increase daily weight gain by 2.19%, and reduce average daily feed intake, feed to weight ratio, and mortality rate by 1.33%, 2.09%, and 31.3%, respectively.

Adding stress Ning to the diet of commercial broiler chickens can significantly increase the chest muscle percentage and leg muscle percentage at 63 days, by 4.98% and 17.23% respectively, and significantly reduce abdominal fat percentage by 36.46%;

Adding stress Ning to the diet of commercial broiler chickens can significantly improve breast muscle color, increasing the meat color score by 18.34%;

Adding stress Ning to the diet of commercial broiler chickens can improve the antioxidant performance of chest and leg muscles and prolong muscle shelf life by reducing MDA content and increasing SOD and GSH activity.

Adding stress Ning to the diet of 3.5 commercial broiler chickens improved vitamin E reserves in the chest, leg, and liver muscles, with vitamin E content in the chest, leg, and liver increasing by 20.83%, 57.43%, and 44.88%, respectively.

In summary, adding stress Ning to the diet of commercial broiler chickens improved the production and meat performance of 63 day old chickens. At the same time, by improving meat color, antioxidant properties, and vitamin reserves, high-quality (non resistant, nutritious, good meat color, long shelf life) muscle quality was obtained.

Table 1 Experimental Design

Table 2: The Effect of Stress Ning on the Production Performance of 63d Commercial Broiler Chickens

Table 3 Effect of Stress Ning on Slaughtering Performance of 63d Commercial Broiler Chickens

 Table 4 Effect of Stress Ning on Breast Muscle Color of 63d Commercial Broiler Chickens

Table 5: Effects of Stress Ning on Antioxidant Properties of 63d Commercial Broiler Muscle

Table 6 Effects of Stress Ning on Vitamin Reserves in Muscle and Liver of 63d Commercial Broiler Chickens