Effects of Sanguinol Supplementation in Low Protein Diets on Broiler Performance

Research Background

The main active components of Sanguinol, sanguinarine and chelerythrine, possess strong anti-inflammatory activity. They can reduce intestinal inflammation, minimize ineffective energy and nutrient losses, improve gut health, and enhance the digestibility and absorption of dietary nutrients, thereby improving nutrient utilization efficiency, animal health, and growth performance. To investigate the effects of dietary supplementation with Sanguinol in low-protein diets on growth performance, health status, mortality, European Production Index (EPI), and uniformity of broilers, the present study was designed.

Research Objective

To evaluate the effects of dietary supplementation with Sanguinol in low-protein diets on growth performance, health status, mortality, European Production Index (EPI), and uniformity of broilers.

Materials and Methods

3.1 Experimental Design
A total of 500 healthy, active, and uniform one-day-old AA broiler chicks were randomly assigned to five groups according to Table 1, with 10 replicates per group and 10 birds per replicate (the number of experimental animals may be adjusted according to practical conditions).

– Group 1 (CN): Fed a non-antibiotic basal diet (CP: starter 21.5%, grower 19.5%).
– Group 2 (LPB300): Fed a low-protein diet (CP: starter 20.5%, grower 18.5%) supplemented with Sanguinol at 300 g/mt (formulation ratio 100 g:0.375 g).
– Group 3 (LPB500): Fed a low-protein diet supplemented with Sanguinol at 500 g/mt (formulation ratio 100 g:0.375 g).
– Group 4 (LPAA): Fed a low-protein diet supplemented with synthetic amino acids (Lys, Met, Thr, Try).
– Group 5 (LPAAB300): Fed a low-protein diet supplemented with synthetic amino acids (Lys, Met, Thr, Try) plus Sanguinol at 300 g/mt (formulation ratio 100 g:0.375 g).

The formulations of the basal diet and low-protein diets are shown in Table 2.

Table 1 Experimental Groups and Dietary Treatments

Table 2 Basal Diet, Low-Protein Diet

¹ Premix provided vitamins and minerals.

² Nutrient levels are calculated values.

3.2 Feeding Management
Broilers were reared in a fully enclosed, three-tier caging system. The experimental period was divided into the starter phase (days 1–21) and grower phase (days 22–42). Birds had free access to feed and water under 24 h continuous lighting. Immunization and daily management were conducted according to standard commercial practices.
Feeding period: August 3, 2022 – September 13, 2022.

3.3 Measured Parameters and Methods
(1) Growth Performance
Body weight and residual feed were recorded on days 0, 21, and 42 by replicate, and mortality was documented daily. The following indicators were calculated for the starter (1–21 d), grower (22–42 d), and entire (1–42 d) periods: average body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR).
– Without mortality:
ADG = (Final BW – Initial BW) / (Number of birds × Days)
ADFI = Total feed intake / (Number of birds × Days)
FCR = Total feed intake / Total weight gain
– With mortality:
ADG = (Final BW – Initial BW) / (Number of birds × Days)
*Mortality-affected individuals were excluded from ADG calculation.*
ADFI = (Feed offered – Residual feed – Feed consumed by dead birds) / (Number of surviving birds × Days)
*Feed consumed by dead birds = (Feed offered up to the day of death – Residual feed on the day of death) ÷ (Dead birds + Surviving birds at that time).*

(2) Slaughter Performance and Meat Quality
Chickens were euthanized by jugular vein bleeding. Slaughter performance indices were determined according to the Chinese Agricultural Industry Standard NY/T 823—2004 Poultry Production Performance Terminology and Statistical Methods.
– Slaughter performance indices included carcass weight, eviscerated weight (half-clean and fully clean weight), abdominal fat weight, Pectoral muscle weight, and leg muscle weight.
– Meat quality indices included pH values, meat color (L*, a*, b*), pressing loss, and shear force.

pH values: Measured using a PH-STAR direct-reading pH meter at three points (anterior, middle, posterior) of the Pectoral muscle at 45 min postmortem (pH45min). Samples were then sealed in PE plastic bags and stored at 4 °C for 24 h, after which pH24h values were determined.

Meat color (L, a, b*):** Determined with a colorimeter at three points (anterior, middle, posterior) of the muscle.

Pressing loss: Within 30 min postmortem, approximately 1 g of muscle sample (1.0 cm thick) was weighed (w1), placed between 18 layers of medium-speed filter paper on each side, and subjected to 90 N pressure on a compression platform for 5 min. The sample was then removed and reweighed (w2).

Shear force: Within 30 min postmortem, 3–5 samples (~2 g each, ≥6 cm × 3 cm × 3 cm) were collected from each bird, with tendons and fat removed. Measurements were conducted using a tenderness meter according to the manufacturer’s instructions, and mean values were expressed in Newtons (N).

Definitions of weights:

Live weight: Body weight after 12 h fasting before slaughter.

Carcass weight: Weight after complete exsanguination and defeathering; water was completely drained after wet-plucking before weighing.

Half-clean weight: Carcass weight after removal of trachea, esophagus, crop, intestines, spleen, pancreas, gallbladder, and reproductive organs, while retaining the heart, liver, lungs, kidneys, proventriculus, gizzard (without cuticle and contents), and abdominal fat (including abdominal fat pad and fat surrounding the gizzard).

Fully clean weight: Half-clean weight after removal of the heart, liver, proventriculus, gizzard, abdominal fat, head, and feet.

Abdominal fat weight: Weight of fat dissected from the abdominal cavity and around the gizzard.

Pectoral muscle weight (left side): The left pectoral muscle (pectoralis major, pectoralis minor, and supracoracoideus) was separated from the sternum along the keel line and weighed.

Leg muscle weight (left side): The left thigh and drumstick muscles were dissected by cutting along the dorsal midline from the last thoracic vertebra to the tail, then separating skin along the abdominal and thigh regions, dislocating the hip joint, and removing the entire leg. Thigh and drumstick muscles were then stripped and weighed.

Slaughter ratios:

Slaughter rate (%) = (Carcass weight ÷ Live weight) × 100

Half-clean rate (%) = (Half-clean weight ÷ Live weight) × 100

Fully clean rate (%) = (Fully clean weight ÷ Live weight) × 100

Pectoral muscle yield (%) = (Pectoral muscle weight ÷ Fully clean weight) × 100

Leg muscle yield (%) = (Leg muscle weight ÷ Fully clean weight) × 100

Abdominal fat rate (%) = (Abdominal fat weight ÷ (Fully clean weight + Abdominal fat weight)) × 100

Pressing loss (%) = [(w1 – w2) ÷ w1] × 100%

(3) Morbidity
Morbidity (%) = (Number of diseased birds ÷ Total birds per group) × 100

(4) Mortality
Mortality (%) = (Number of dead birds ÷ Total birds per group) × 100

(5) Uniformity
Uniformity: = (Number of chickens within ±10% of the average weight) / Total number of weighed chickens × 100%

Note: For large groups, weight sampling is performed on 1% of the chickens, and for small groups, it is performed on 5%, but the sample size should not be fewer than 30-50 chickens.

(6) European Production Index (EPI)
EPI = (Survival rate % × Market BW, kg) ÷ (FCR × Rearing days)

3.4 Data Analysis
The experimental data were initially organized using Excel software, and one-way ANOVA was performed using SPSS 20.0 software to analyze the inter-group differences.

Data are expressed as mean ± standard deviation, with P < 0.05 considered statistically significant, and 0.05 < P < 0.1 considered a trend of difference.

Results and Analysis

4.1 Effects of Sanguinol in Low-Protein Diets on Growth Performance
As shown in Table 3, compared with the CN group, there were no significant differences (P > 0.05) in ADG, ADFI, and FCR among LPB300, LPB500, LPAA, and LPAAB300 groups. Final BW in all treatment groups was higher than CN, and FCR in the grower phase was lower than CN.

Table 3: Effects of Low-Protein Diet with Sanguinol on Broiler Chicken Growth Performance

4.2 Effects of Sanguinol in Low-Protein Diets on Slaughter Performance
As shown in Table 4, supplementation with Sanguinol in low-protein diets increased slaughter rate and half-dressed yield. Compared with CN, no significant differences (P > 0.05) were observed among LPB300, LPB500, LPAA, and LPAAB300 groups in slaughter rate, half-dressed rate, fully dressed rate, Pectoral muscle yield, leg muscle yield, or abdominal fat rate. However, all supplemented groups showed higher slaughter rates than CN.

Table 4: Effects of Low-Protein Diet with Sanguinol on Broiler Chicken Slaughter Performance

4.3 Effects of Sanguinol in Low-Protein Diets on Meat Quality
As shown in Table 5, supplementation with Sanguinol and amino acids improved meat quality. Compared with CN:
– Pectoral muscle yellowness (b*) was extremely significantly increased in LPB300, LPB500, and LPAAB300 (P < 0.01), and significantly increased in LPAA (P < 0.05).
– Pectoral muscle pH45min was significantly decreased in LPB300 (P < 0.05).
– Shear force was significantly reduced in LPB500, LPAA, and LPAAB300 (P < 0.05).
– Leg muscle lightness (L*) was significantly increased in LPAA and LPAAB300 (P < 0.05).

Table 5: Effects of Low-Protein Diet with Sanguinol on Broiler Chicken Meat Quality

L* (Leg muscle lightness) a* (Redness) b* (Pectoral muscle yellowness)

4.4 Effects of Sanguinol in Low-Protein Diets on Organ Indices
Compared with CN, no significant differences (P > 0.05) were observed among LP, LPB300, LPB500, LPAA, and LPAAB300 groups in heart, liver, spleen, lung, or kidney indices (Table 6).

Table 6: Effects of Low-Protein Diet with Sanguinol on Organ Index of Broiler Chicken

4.5 Effects of Sanguinol in Low-Protein Diets on Mortality
As shown in Table 7, supplementation with Sanguinol significantly reduced mortality. Mortality rates in LPB300, LPB500, LPAA, and LPAAB300 were all significantly lower than CN.

Table 7: Effects of Low-Protein Diet with Sanguinol on Broiler Chicken Mortality Rate

4.6 Effects of Sanguinol in Low-Protein Diets on Uniformity
As shown in Table 8, supplementation with Sanguinol improved flock uniformity. Compared with CN, all supplemented groups showed improved uniformity, with LPB500 achieving the highest uniformity.

Table 8: Effects of Low-Protein Diet with Sanguinol on Broiler Chicken Uniformity

4.7 Effects of Sanguinol in Low-Protein Diets on EPI
As shown in Table 9, supplementation with Sanguinol improved EPI. Compared with CN, all supplemented groups showed higher EPI, with LPAAB300 achieving the highest, followed by LPB500.

Table 9: Effects of Low-Protein Diet with Sanguinol on Broiler Chicken European Efficiency Index

Conclusion

Supplementation with Sanguinol in low-protein diets improved growth performance, slaughter performance, meat quality, mortality, uniformity, and EPI in AA broilers. Reducing dietary CP by 1% and supplementing with 300–500 g/mt Sanguinol (formulation ratio 100 g:0.375 g) had no negative impact on production performance, and improved meat quality, uniformity, and EPI while reducing mortality.

Table: Effects of Low-Protein Diet with Sanguinol on Feed Cost and Cost per Unit Weight Gain

This table presents the feed cost and cost per unit weight gain for broiler chickens on a low-protein diet supplemented with Sanguinol.

Economic analysis (soybean meal price: 5000 CNY/mt; corn price: 3000 CNY/mt):
1. Early Stage diet formulation: Supplementation with Sanguinol at 300 g/mt reduced feed cost by 52.75 CNY.
2. Late Stage diet formulation: Supplementation with Sanguinol at 300 g/mt reduced feed cost by 53.18 CNY.

Therefore, supplementation with Sanguinol in low-protein diets not only reduces feed cost but also improves broiler production performance.