Frozen semen collecting form Bulls that have superior genetic quality. The Bull gets professional treatment form the expert, such as:

1. High-quality feed provision
2. Exercise
3. Weighing periodically
4. Hoof trimming
5. Good Sanitation
6. Health monitoring

Frozen semen production consists of:

1. Semen Collection

Semen was collected twice a week. All bulls were sexually stimulated using bull teaser and allowed to false mount three until five times until the bulls reach optimum libido. Semen were collected from all bulls using artificial vagina with the temperature around 40 – 43 o C.

2. Frozen Semen Production

Semen that had been collected was given tris egg yolk based extender. Dilution is divided into three stage the first step was by adding diluent A1, the second step was by adding diluent A2, and the third step was by adding B. Diluents A1 and A2 had the same composition consisting of 1.6% tris aminomethane, 0.9% citric acid, 1.4% lactose, 2.5% raffinose, 80% aquades, and 20% egg yolk. The composition of diluent B was the same as those of diluent A but was added by 13% glycerol. Equilibration was performed for 3 until 4

hours. Liquid semen (extended semen) is packaged in 0.25 ml straw, cooled quickly to reach -140 O C using IMVTechnology®digitcool, and frozen in liquid nitrogen until -196 O C.

3. Fresh, Liquid, and Frozen Semen Quality Measurement

Fresh semen collected from each ejaculation were assessed for their volume, individual motility, mass motility, concentration, and pH immediately. Volume was measured with a collector tube inside an artificial vagina. Individual motility and mass motility were assessed by dripping 0.1 µl fresh semen, which had been mixed with 0.1 µl tris egg yolk based extender on the glass object above the Minitube® Slide Warmer. Individual motility was observed with a microscope at 200x magnification and mass motility observed at 10x magnification. Concentration was evaluated by mixing 35 µl fresh semen with 3.5 mL 0.9% NaCl, then it was placed in a cuvette tube and homogenized using a stirrer. Concentration was measured using Minitube® Photometer SDM6 spectrophotometer. pH was measured directly after collecting semen using a pH meter. Pre freeze motility (liquid semen) and post-thaw motility (frozen semen) evaluation use the same method as the evaluation of individual motility on fresh semen. Pre freeze was evaluated directly after equilibration. Post-thaw motility was evaluated after frozen semen had been thawed at 37 o C for 15 seconds.

Straw Colour

• Every Straw contains 25 million Spermatozoa (Bull) and 50 spermatozoa (Buck), with minimal motility of 40% and mass motility of 2.
• Produced following international standard.
• Frozen semen storage in liquid nitrogen (-196^o C)

Before distributed, frozen semen stored in sperm bank. While in sperm bank, frozen semen should be cared for and maintained in order to keep it in good condition 

1. Frozen Semen Maintanance

            Frozen semen stored  in container contain liquid nitrogen. Liquid nitrogen should be added to container periodically.

2. Container identification

The purpose of container identification is to make it easier to find frozen semen in containers before distribution.

3. Monitoring frozen semen quality

Frozen semen stored in the sperm bank is monitored for a certain period by conducting periodic sampling