Effect of Lysine Supplementation in Low-Protein Diets on Nutrients Digestion, Growth Performance, Serum Biomarkers, and Production Performance of Female Blue Foxes (Alopex lagopus) in Fur-Growing Phase
Simple Summary
Abstract
1. Introduction
2. Materials and Methods
2.1. Animals, Diets, and Management
2.2. Digestion Experiment
2.3. Blood Sampling and Measurement
2.4. Chemical Analysis
2.5. Growth Performance Evaluation
2.6. Pelt Quality
2.7. Statistical Analysis
3. Results
3.1. Nutrients Digestibility
3.2. Amino Acid Digestibility
3.3. Nitrogen Metabolism
3.4. Growth Performance
3.5. Serum Biomarkers
3.6. Pelt Quality
4. Discussion
4.1. Feed Intake and Nutrients Digestibility
4.2. Amino Acid Digestibility
4.3. N Retention
4.4. Growth Performance and Pelt Quality
4.5. Serum Parameters
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Items | Basal Diet (0.75% Lysine) | Control Diet |
---|---|---|
Ingredients | ||
Extruded corn | 47.90 | 45.00 |
Soybean meal | 15.70 | 15.00 |
Bone and meat meal | 18.00 | 18.00 |
Corn germ meal | 5.00 | 6.40 |
Fish meal | 5.00 | 7.00 |
Soybean oil | 7.00 | 7.00 |
Salt | 0.30 | 0.30 |
Premix (1) | 1.00 | 1.00 |
Lys | 0.00 | 0.20 |
Met | 0.10 | 0.10 |
Total | 100.00 | 100.00 |
Nutrient levels (2) | ||
CP (%) | 26.11 | 28.10 |
EE (%) | 10.39 | 10.59 |
Ash | 8.53 | 8.83 |
CC% | 52.31 | 52.01 |
Lys (%) | 0.75 | 0.99 |
Met (%) | 0.89 | 0.89 |
ME (MJ/kg) | 14.51 | 14.48 |
% of ME | ||
CP | 21.52 | 23.48 |
EE | 34.16 | 34.43 |
CC | 44.32 | 42.09 |
Items | Basal Diet (0.75% Lysine) | Control Diet |
---|---|---|
Aspartic acid | 1.25 | 1.33 |
Threonine | 0.62 | 0.66 |
Serine | 0.76 | 0.80 |
Glutamic acid | 2.44 | 2.54 |
Glycine | 0.81 | 0.86 |
Alanine | 1.08 | 1.12 |
Valine | 0.70 | 0.74 |
Methionine | 0.93 | 0.94 |
Isoleucine | 0.64 | 0.69 |
Leucine | 1.57 | 1.68 |
Tyrosine | 0.52 | 0.56 |
Phenylalanine | 0.80 | 0.85 |
Lysine | 0.75 | 0.99 |
Histidine | 0.39 | 0.41 |
Arginine | 1.03 | 1.07 |
Proline | 0.77 | 0.79 |
Items | Lysine | Control | p Value | |||||
---|---|---|---|---|---|---|---|---|
0.75% | 0.95% | 1.15% | 1.35% | 1.55% | 1.75% | |||
DM intake (g/d) | 387.42 ± 1.16 | 387.55 ± 1.52 | 385.71 ± 3.75 | 386.92 ± 0.67 | 387.24 ± 0.49 | 387.88 ± 0.55 | 385.03 ± 2.28 | 0.13 |
DM output (g/d) | 135.85 ± 13.58 | 134.10 ± 8.49 | 129.36 ± 8.35 | 134.48 ± 6.70 | 129.43 ± 11.86 | 126.67 ± 10.80 | 125.94 ± 7.79 | 0.37 |
DM (%) | 64.93 ± 3.55 | 65.40 ± 2.20 | 66.46 ± 2.18 | 65.24 ± 1.76 | 66.57 ± 3.07 | 67.34 ± 2.78 | 67.30 ± 1.86 | 0.41 |
CP (%) | 62.23 ± 4.82 | 63.10 ± 2.84 | 66.41 ± 5.02 | 66.41 ± 4.44 | 67.12 ± 4.79 | 65.15 ± 3.98 | 65.57 ± 4.25 | 0.22 |
EE (%) | 85.29 ± 3.01 a | 87.47 ± 2.66 ab | 86.37 ± 2.87 ab | 88.03 ± 0.81 b | 88.85 ± 1.49 b | 86.48 ± 2.45 ab | 88.97 ± 0.91 b | 0.03 |
Items | Lysine | Control | p Value | |||||
---|---|---|---|---|---|---|---|---|
0.75% | 0.95% | 1.15% | 1.35% | 1.55% | 1.75% | |||
Aspartic acid | 41.63 ± 5.61 a | 41.33 ± 2.74 a | 52.30 ± 5.62 b | 58.69 ± 7.75 b | 58.04 ± 7.60 b | 60.36 ± 3.67 b | 57.10 ± 8.56 b | <0.01 |
Threonine | 45.42 ± 7.47 a | 45.23 ± 6.11 a | 49.20 ± 7.40 ab | 57.96 ± 6.64 c | 58.16 ± 5.32 c | 57.75 ± 3.45 c | 54.51 ± 2.88 bc | <0.01 |
Serine | 49.75 ± 8.43 a | 51.67 ± 4.01 a | 55.27 ± 4.36 abc | 62.29 ± 4.49 c | 61.96 ± 5.33 c | 60.57 ± 2.64 bc | 53.65 ± 10.19 ab | <0.01 |
Glutamic acid | 53.19 ± 6.50 ab | 51.68 ± 3.43 a | 56.75 ± 7.38 abc | 68.89 ± 12.78 d | 63.64 ± 6.35 cd | 61.80 ± 2.59 cd | 58.70 ± 2.96 abc | <0.01 |
Glycine | 23.84 ± 7.77 a | 25.74 ± 6.59 a | 34.80 ± 10.07 b | 39.28 ± 8.22 bc | 39.50 ± 9.75 bc | 46.44 ± 1.40 c | 40.19 ± 6.44 bc | <0.01 |
Alanine | 51.09 ± 8.45 ab | 48.34 ± 10.21 a | 48.53 ± 9.74 a | 57.77 ± 7.13 ab | 60.10 ± 5.54 b | 56.25 ± 2.63 ab | 57.55 ± 3.70 ab | 0.03 |
Valine | 28.00 ± 6.53 a | 32.40 ± 1.97 ab | 49.74 ± 5.79 c | 50.58 ± 5.75 c | 52.04 ± 8.22 c | 51.87 ± 3.89 c | 43.83 ± 4.59 bc | <0.01 |
Methionine | 85.54 ± 1.49 a | 86.43 ± 2.22 ab | 92.51 ± 1.42 c | 91.47 ± 1.75 c | 90.96 ± 1.38 c | 91.22 ± 1.19 c | 87.63 ± 1.79 b | <0.01 |
Isoleucine | 55.96 ± 5.54 ab | 53.76 ± 4.55 a | 60.53 ± 5.39 bc | 67.35 ± 6.48 d | 67.26 ± 5.44 d | 66.97 ± 2.25 d | 64.90 ± 2.36 cd | <0.01 |
Leucine | 68.07 ± 4.53 ab | 65.11 ± 5.64 a | 67.16 ± 4.80 ab | 73.81 ± 5.15 bc | 73.64 ± 4.87 bc | 72.04 ± 2.45 abc | 76.03 ± 9.58 c | 0.02 |
Tyrosine | 65.05 ± 3.99 a | 61.92 ± 4.23 a | 73.80 ± 2.49 b | 78.53 ± 4.36 b | 75.16 ± 4.52 b | 78.39 ± 3.07 b | 65.72 ± 3.64 a | <0.01 |
Phenylalanine | 21.31 ± 6.35 a | 25.99 ± 7.15 a | 50.23 ± 5.57 c | 53.88 ± 6.19 c | 57.41 ± 6.11 c | 54.35 ± 6.69 c | 35.97 ± 5.44 b | <0.01 |
Lysine | 56.28 ± 4.76 a | 63.07 ± 1.93 b | 73.17 ± 2.92 d | 79.91 ± 2.79 e | 82.33 ± 3.02 e | 68.14 ± 3.82 c | 56.83 ± 4.18 a | <0.01 |
Histidine | 54.35 ± 7.08 a | 53.22 ± 3.17 a | 56.30 ± 5.32 ab | 61.93 ± 3.71 bc | 62.68 ± 7.48 bc | 64.05 ± 5.17 c | 64.72 ± 3.79 c | <0.01 |
Arginine | 74.78 ± 4.72 a | 73.48 ± 2.89 a | 75.54 ± 2.92 a | 78.89 ± 2.84 b | 77.87 ± 3.08 b | 77.83 ± 2.15 b | 78.49 ± 2.63 b | 0.03 |
Proline | 44.98 ± 8.25 ab | 41.76 ± 8.95 a | 50.94 ± 9.12 abc | 64.00 ± 7.51 c | 62.65 ± 7.89 bc | 59.70 ± 10.03 bc | 60.18 ± 9.27 bc | 0.04 |
Items | Lysine | Control | p Value | |||||
---|---|---|---|---|---|---|---|---|
0.75% | 0.95% | 1.15% | 1.35% | 1.55% | 1.75% | |||
N intake (g/d) | 16.90 ± 0.05 a | 16.35 ± 0.06 b | 16.32 ± 0.16 b | 16.57 ± 0.16 cd | 16.71 ± 0.02 d | 17.52 ± 0.03 e | 16.47 ± 0.15 bc | <0.01 |
Fecal nitrogen (g/d) | 5.82 ± 0.72 | 6.03 ± 0.45 | 6.16 ± 0.76 | 5.36 ± 0.65 | 5.49 ± 0.80 | 6.19 ± 0.60 | 5.68 ± 0.36 | 0.12 |
Urine nitrogen (g/d) | 7.10 ± 0.61 | 7.15 ± 0.45 | 6.96 ± 0.29 | 6.94 ± 0.31 | 6.90 ± 0.63 | 6.76 ± 0.57 | 6.72 ± 0.42 | 0.60 |
N retention (g/d) | 3.98 ± 1.13 ab | 3.17 ± 0.73 a | 3.20 ± 1.00 a | 4.26 ± 0.50 ab | 4.31 ± 1.26 ab | 4.57 ± 1.14 b | 4.08 ± 0.47 ab | 0.04 |
Items | Lysine | Control | p Value | |||||
---|---|---|---|---|---|---|---|---|
0.75% | 0.95% | 1.15% | 1.35% | 1.55% | 1.75% | |||
Body weight (kg) | ||||||||
Day 0 | 4.54 ± 0.32 | 4.69 ± 0.34 | 4.62 ± 0.32 | 4.67 ± 0.32 | 4.60 ± 0.45 | 4.62 ± 0.33 | 4.59 ± 0.29 | 0.10 |
Day 15 | 5.0 ± 0.38 | 5.22 ± 0.33 | 5.36 ± 0.38 | 5.34 ± 0.40 | 5.24 ± 0.51 | 5.29 ± 0.36 | 5.10 ± 0.43 | 0.72 |
Day 30 | 5.51 ± 0.39 | 5.84 ± 0.39 | 6.07 ± 0.46 | 6.09 ± 0.45 | 5.93 ± 0.45 | 6.00 ± 0.32 | 5.79 ± 0.52 | 0.22 |
Day 45 | 5.82 ± 0.48 | 6.23 ± 0.46 | 6.40 ± 0.52 | 6.46 ± 0.52 | 6.35 ± 0.46 | 6.39 ± 0.33 | 6.13 ± 0.47 | 0.26 |
Day 60 | 6.20 ± 0.58 | 6.73 ± 0.57 | 6.98 ± 0.64 | 6.98 ± 0.57 | 6.93 ± 0.45 | 6.96 ± 0.39 | 6.57 ± 0.43 | 0.08 |
Day 75 | 6.65 ± 0.61 | 7.14 ± 0.65 | 7.49 ± 0.71 | 7.45 ± 0.63 | 7.42 ± 0.60 | 7.50 ± 0.50 | 7.09 ± 0.29 | 0.07 |
Daily weight gain (g) | ||||||||
D0–D15 | 33.38 ± 20.50 a | 35.74 ± 12.60 ab | 49.12 ± 11.92 b | 43.83 ± 15.30 ab | 42.11 ± 8.55 ab | 44.72 ± 13.63 ab | 33.54 ± 11.96 a | 0.02 |
D16–D30 | 31.18 ± 17.86 a | 41.33 ± 12.04 ab | 47.19 ± 10.49 b | 48.71 ± 8.00 b | 46.28 ± 15.75 ab | 47.33 ± 11.96 b | 46.36 ± 19.61 ab | 0.03 |
D31–D45 | 21.13 ± 12.75 | 25.95 ± 7.38 | 22.00 ± 7.75 | 26.19 ± 12.35 | 28.22 ± 9.63 | 26.11 ± 9.30 | 22.56 ± 8.72 | 0.48 |
D46–D60 | 25.44 ± 11.82 | 32.92 ± 10.04 | 38.57 ± 11.85 | 34.86 ± 8.70 | 38.11 ± 9.42 | 37.56 ± 13.37 | 29.13 ± 14.62 | 0.03 |
D61–D75 | 29.64 ± 12.46 | 27.18 ± 16.46 | 34.00 ± 20.20 | 33.05 ± 15.66 | 33.22 ± 15.13 | 36.00 ± 15.84 | 35.08 ± 15.15 | 0.81 |
Items | Lysine | Control | p Value | |||||
---|---|---|---|---|---|---|---|---|
0.75% | 0.95% | 1.15% | 1.35% | 1.55% | 1.75% | |||
TP (g/L) | 42.64 ± 8.69 a | 44.1 ± 3.11 a | 63.95 ± 6.12 b | 65.62 ± 5.36 b | 61.41 ± 2.99 b | 67.43 ± 12.28 b | 67.85 ± 12.56 b | <0.01 |
ALB (g/L) | 35.56 ± 1.36 ac | 35.04 ± 1.72 c | 35.85 ± 1.21 ac | 36.50 ± 1.38 ac | 37.90 ± 1.19 a | 38.73 ± 1.84 b | 38.29 ± 1.39 bc | <0.01 |
ALP (U/L) | 104.40 ± 39.19 a | 103.90 ± 10.04 a | 77.18 ± 14.65 ab | 57.77 ± 17.86 b | 74.9 ± 4.86 ab | 73.29 ± 9.36 ab | 58.18 ± 7.23 b | <0.01 |
GOT (U/L) | 97.98 ± 13.41 a | 137.80 ± 20.02 a | 149.70 ± 44.61 a | 145.00 ± 25.98 a | 158.40 ± 60.51 a | 243.10 ± 41.15 b | 111.5 ± 25.31 a | <0.01 |
GPT (U/L) | 358.40 ± 110.30 | 375.6 ± 147.8 | 261.50 ± 115.60 | 300.00 ± 108.60 | 410.90 ± 84.05 | 306.40 ± 39.35 | 237.60 ± 45.55 | 0.56 |
Items | Lysine | Control | p Value | |||||
---|---|---|---|---|---|---|---|---|
0.75% | 0.95% | 1.15% | 1.35% | 1.55% | 1.75% | |||
Pelt length (cm) | 94.50 ± 3.26 | 96.75 ± 3.79 | 96.83 ± 3.30 | 99.88 ± 2.20 | 97.33 ± 2.94 | 96.58 ± 4.41 | 94.67 ± 2.81 | 0.13 |
Pelt weight (g) | 611.7 ± 30.44 | 635.0 ± 59.16 | 637.5 ± 37.65 | 660.8 ± 48.93 | 636.7 ± 55.11 | 651.7 ± 29.10 | 632.5 ± 32.98 | 0.60 |
Guard hair length (mm) | 6.74 ± 0.25 a | 6.48 ± 0.15 ab | 6.28 ± 0.15 bc | 6.23 ± 0.16 bc | 6.27 ± 0.16 bc | 6.22 ± 0.29 bc | 6.10 ± 0.11 c | <0.01 |
Underfur length (mm) | 5.08 ± 0.13 a | 5.10 ± 0.12 a | 5.27 ± 0.18 a | 5.38 ± 0.19 bc | 5.47 ± 0.16 b | 5.42 ± 0.20 b | 5.25 ± 0.14 a | <0.01 |
Guard hair/ underfur | 1.32 ± 0.03 a | 1.27 ± 0.02 b | 1.20 ± 0.02 c | 1.16 ± 0.02 cd | 1.15 ± 0.02 d | 1.15 ± 0.03 d | 1.16 ± 0.02 cd | <0.01 |
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Geng, Y.; Wu, X.; Gao, X.; Zhang, T.; Jiang, Q. Effect of Lysine Supplementation in Low-Protein Diets on Nutrients Digestion, Growth Performance, Serum Biomarkers, and Production Performance of Female Blue Foxes (Alopex lagopus) in Fur-Growing Phase. Animals 2025, 15, 1559. https://doi.org/10.3390/ani15111559
Geng Y, Wu X, Gao X, Zhang T, Jiang Q. Effect of Lysine Supplementation in Low-Protein Diets on Nutrients Digestion, Growth Performance, Serum Biomarkers, and Production Performance of Female Blue Foxes (Alopex lagopus) in Fur-Growing Phase. Animals. 2025; 15(11):1559. https://doi.org/10.3390/ani15111559
Chicago/Turabian StyleGeng, Yeye, Xuezhuang Wu, Xiuhua Gao, Tietao Zhang, and Qingkui Jiang. 2025. "Effect of Lysine Supplementation in Low-Protein Diets on Nutrients Digestion, Growth Performance, Serum Biomarkers, and Production Performance of Female Blue Foxes (Alopex lagopus) in Fur-Growing Phase" Animals 15, no. 11: 1559. https://doi.org/10.3390/ani15111559
APA StyleGeng, Y., Wu, X., Gao, X., Zhang, T., & Jiang, Q. (2025). Effect of Lysine Supplementation in Low-Protein Diets on Nutrients Digestion, Growth Performance, Serum Biomarkers, and Production Performance of Female Blue Foxes (Alopex lagopus) in Fur-Growing Phase. Animals, 15(11), 1559. https://doi.org/10.3390/ani15111559