Impact of propyl thiouracil on testes functions and semen characteristics of New Zealand white rabbits

الملخص EN

This study was carried out at Intensive Rabbit Production Unit, belonging to Agriculture Studies and Consultation Center, Faculty of Agriculture, Ain Shams University.

The study was designed to investigate the effect of 6-n-propyl-2-thiouracil (PTU) injection on testicular development and semen characteristics of male rabbits under intensive production.

Sixty three New Zealand White (NZW) male rabbits were used.

Three male rabbits (zero time) were slaughtered, the rest was divided randomly into two groups, the first group (PTU) 30 animals were subcutaneously injected daily with PTU 20 μg/g live body weight from the 1st day until the weaning (28 day of age) and the second group (C) of 30 animals served as control and injected daily with the.

The study showed that the treatment with PTU reduced (P≥ 0.001) live body weight during pre and post weaning periods.

Testis measurements increased (P≥ 0.0001) in PTU treated group compared with control group at 30, 60, 90, 120 and 150 days of age.

Seminiferous tubules and Leydig cells indices increased (P ≥ 0.001) in PTU treated group (71.42 % and 18.97 %) compared with control group, respectively.

The ejaculate volume of PTU treated rabbits was larger (P≥ 0.001) compared with control rabbits.

The average sperm concentration /ml and advanced motility were 485.57 X 106 vs.

312.07 X 106 and 87.21 % vs.

78.23 % for PTU and control groups, respectively.

The percentages of abnormal and dead spermatozoa were 16.07 % vs.

20.95 % and 5.03 % vs.

12.33 % for treated and control groups, respectively.

In conclusion, the 6-n-propyl-2-thiouracil can be used to increase testis size, ejaculate volume and sperm concentration.

Despite these promising results, the use of PTU to produce male rabbits with larger testes and a better quality of semen needs further investigations in order to reduce the number of males breeding for artificial insemination purposes.