| Literature DB >> 33195497 |
Shawky Mahmoud1, Michel Saad1, Ahmed M El-Shehawi2,3, Foad Farrag4, Mahmoud M Abo Ghanima5, Mahmoud A O Dawood6, Mustafa Shukry1.
Abstract
Delayed puberty and lower fertility are among the most challenging concerns in rabbit development during the summer season. This study was, therefore, aimed at enhancing male NZ rabbits' performance by using L-tyrosine. Thirty male, New Zealand rabbits, were employed for this purpose at the age of 60 days. Rabbits were divided accidentally into two groups: a control group and another treated with L-tyrosine (100 mg/kg body weight). After 4 weeks, three bucks of each group were assassinated. A comparable oral dose of L-tyrosine was administered to half of the treated group left untreated during the second half. Weekly blood samples were assembled from each group for testosterone, T3, and T4 hormone testing. The results showed that body weight and serum testosterone, T3, and T4 increased exponentially with increasing age in both groups. L-tyrosine contributed to another vital rise in dose-dependence than control, in bodyweight, GSI, and testosterone, T3, and T4. At the end of the third month, tests fell in the scrotum, compared to 2 weeks before in the L-tyrosine group. In the middle of the fourth month, the semen evaluations were first carried out for the L-tyrosine group and 1 month after for the control group. L-tyrosine has contributed to a substantial upsurge in semen quality and motility, and abnormalities have reduced dramatically (P < 0.01). The L-tyrosine-treated group showed significantly increased mRNA expression of steroidogenesis markers STAR, CYP11A1, and 3B-HSD. Besides, free sperm in the seminiferous tubular lumen was discovered at the end of the third month. Nevertheless, it achieves only in control of the spermatocyte stage. The research suggests that L-tyrosine supplements promote puberty and improve male New Zealand rabbit fertility during high-temperature periods in the year.Entities:
Keywords: L. tyrosine; New Zealand rabbits; fertility; steroidogenesis markers; summer; testosterone
Year: 2020 PMID: 33195497 PMCID: PMC7592602 DOI: 10.3389/fvets.2020.00605
Source DB: PubMed Journal: Front Vet Sci ISSN: 2297-1769
Primer sequences.
| STAR | F | ACCAAACTCACTTGGCTGCT | 270 bP | XM_017350352 |
| R | ACACTATTGTCCCACTGCCG | |||
| CYP11A1 | F | TACCATTTGGCTGAGGAGAAGG | 210 bP | S59219 |
| R | GTACTCGTGATAGGCGACCC | |||
| 3B-HSD | F | TGGGACACAGTTCCTGGTCT | 102 bP | XM_008248712 |
| R | GCCTCATATGGGGTGTCCTC | |||
| GAPDH | F | AGACACGATGGTGAAGGTCG | 164 bP | L23961 |
| R | TGCCGTGGGTGGAATCATAC |
STAR, steroidogenic acute regulatory protein; CYP11A1, cytochrome P450 cholesterol side-chain cleavage enzyme; 3B-HSD, hydroxy-delta-5-steroid dehydrogenase, 3 beta-and steroid delta-isomerase 7; GAPDH, glyceraldehyde-3-phosphate dehydrogenase.
Total body weight, testes weight, and GSI of New Zealand bucks treated with L. tyrosine.
| Initial weight | 1,256.7 ± 40.9f | – | – | |
| One month | Control | 1,756.7 ± 57.3e | 4.93 ± 0.27e | 0.280 ± 0.02c |
| One dose | 1,990.0 ± 44.8d | 6.14 ± 0.43d | 0.309 ± 0.03c | |
| Two doses | – | – | – | |
| Two months | Control | 2,256.7 ± 63.6c | 6.61 ± 0.22c | 0.293 ± 0.03c |
| One dose | 2,696.7 ± 87.4a | 9.90 ± 0.95b | 0.367 ± 0.03b | |
| Two doses | 2,960.0 ± 99.5b | 14.04 ± 1.31a | 0.474 ± 0.04a |
Values are mean ± S.E. Means with different letters in each column are significantly different (P < 0.05).
Serum testosterone level (ng/ml) in control and L. tyrosine-treated New Zealand bucks.
| Control | 0.250 ± 0.05F | 0.470 ± 0.17bE | 0.663 ± 0.09bD | 0.817 ± 0.09cC | 1.143 ± 0.11cB | 2.120 ± 0.12cA |
| One dose | 0.266 ± 0.06F | 0.833 ± 0.09aE | 1.117 ± 0.11aD | 1.550 ± 0.17bC | 2.190 ± 0.21bB | 3.177 ± 0.23bA |
| Two doses | 0.267 ± 0.05F | 0.813 ± 0.09aE | 1.163 ± 0.11aD | 1.970 ± 0.18aC | 2.580 ± 0.24aB | 3.900 ± 0.36aA |
Values are mean ± S.E. W, weeks after treatment. Means with different small letters in the same column are significantly different (P < 0.05). Letters with different capital letters in the same row are significantly different (P < 0.05).
Serum T3 level (ng/dl) in control and L. tyrosine-treated New Zealand bucks.
| Control | 107.3 l ± 10.8E | 146.3 ± 13.5bD | 183.3 ± 17.3bC | 215.3 ± 13.5bB | 240.3 ± 12.8cA | 241.0 ± 22.6cA |
| One dose | 111.0 l ± 9.8D | 190.0 ± 13.8aC | 289.7 ± 20.6aB | 343.0 ± 27.1abA | 353.3 ± 20.3bA | 303.3 ± 19.5bAB |
| Two doses | 108.7 l ± 11.0D | 183.3 ± 15.2aC | 285.0 ± 17.5aB | 369.7 ± 16.4baA | 390.7 ± 27.1aA | 354.0 ± 22.3aAB |
Values are mean ± S.E. W, weeks after treatment. Means with different small letters in the same column are significantly different (P < 0.05). Letters with different capital letters in the same row are significantly different (P < 0.05).
Serum T4 level (μg/dl) in control and L. tyrosine-treated New Zealand bucks.
| Control | 1.22 ± 0.07D | 1.52 ± 0.09bC | 1.76 ± 0.12cB | 2.01 ± 0.16cA | 1.98 ± 0.14cA | 1.73 ± 0.15cB |
| One dose | 1.22 ± 0.12E | 2.46 ± 0.16aC | 2.94 ± 0.23bA | 2.71 ± 0.15bB | 2.52 ± 0.22bC | 2.21 ± 0.21bD |
| Two doses | 1.21 ± 0.09E | 2.51 ± 0.11aD | 3.47 ± 0.19aC | 4.27 ± 0.31aA | 3.97 ± 0.18aB | 3.48 ± 0.24aC |
Values are mean ± S.E. W, weeks after treatment. Means with different small letters in the same column are significantly different (P < 0.05). Letters with different capital letters in the same row are significantly different (P < 0.05).
Seminogram and reaction time in control and L. tyrosine-treated New Zealand bucks.
| Volume (ml) | No semen | 0.9 ± 0.034d | 1.1 ± 0.077c | 0.7 ± 0.044e | 1.2 ± 0.071c | 1.6 ± 0.093a | 0.7 ± 0.06e | 1.1 ± 0.034c | 1.4 ± 0.110b |
| Sperm count(million/ml) | No semen | 569.7 ± 11.17c | 680.0 ± 23.4a | 380.0 ± 19.8e | 490.0 ± 24.5d | 620.0 ± 24.7b | 310.0 ± 11.4f | 470.0 ± 17.9d | 590.0 ± 20.3bc |
| Mass motility (0-5) | No semen | 3.80 ± 0.07c | 4.20 ± 0.09ab | 3.20 ± 0.09d | 3.80 ± 0.11e | 4.33 ± 0.08a | 3.40 ± 0.10d | 4.00 ± 0.19bc | 4.03 ± 0.15bc |
| Individual motility (%) | No semen | 82.0 ± 3.6a | 92.7 ± 6.6a | 72.0 ± 2.9bc | 85.7 ± 5.1a | 89.0 ± 4.3a | 70.0 ± 3.6c | 82.3 ± 5.6ab | 88.0 ± 7.2a |
| Alive sperm (%) | No semen | 87.0 ± 3.3ab | 90.7 ± 4.3a | 80.7 ± 2.8bc | 90.0 ± 5.1a | 92.7 ± 3.8a | 77.0 ± 2.9c | 88.0 ± 4.1a | 92.0 ± 5.0a |
| Total abnormality | No semen | 5.3 ± 0.27bc | 4.7 ± 0.22cd | 9.1 ± 0.34a | 5.1 ± 0.21c | 4.3 ± 0.19b | 9.7 ± 0.62a | 5.9 ± 0.31b | 4.80 ± 0.16cd |
| Reaction time (sec.) | No semen | 55.0 ± 2.2bc | 42.0 ± 3.7cd | 99.0 ± 4.2a | 50.3 ± 1.9cd | 40.0 ± 2.1d | 95.0 ± 7.2a | 65.0 ± 5.8b | 49.7 ± 3.2cd |
Values are mean ± S.E. Means with different letters in each raw are significantly different (P < 0.05).
Figure 1Expression of fold changes of rabbit testicular tissue STAR, CYP11A1, and 3B-HSD mRNA levels after 1 (A) and 2 (B) months. Data were analyzed with ANOVA followed by Tukey's multiple comparison test. P < 0.05, Error bars represent mean ± SD.
Figure 2Histopathology of rabbit testicular tissues after 1 month from the beginning of the experiment in control, (A) and L-tyrosine treated New Zealand rabbit groups (B) and after 2 months from the beginning of the experiment in control, (C) and one-dose L-tyrosine (D) and two-dose of L-tyrosine treated New Zealand rabbits (E) (H & E × 400).