The quality of porcine semen deteriorates very rapidly during the semen preservation process. The aim of this study is to find alternative diluents for Duroc semen preservation by changing different semen diluents. Two Duroc pigs, ± 3 years old, were trained twice weekly for semen collection. Immediately after collection, sperm were examined macroscopically and microscopically. Semen with sperm motility ≥ 70%, sperm concentration ≥200 x 106 cells/ml, and abnormality ≤20%) was diluted with six diluents, namely: Beltsville Thawing Solution® (BTS), Durasperm, Citrate Egg Yolk (CEY), Tris Egg Yolk (TEY), CEY + Olive Oil (CEYO) and TEY + Olive Oil (TEYO) in the ratio of one part semen and four parts diluent. The liquid sperm was stored at 18-20 oC and examined every eight hours for 80 hours. The result shows that sperm motility, viability and plasma membrane integrity of Duroc semen with CEYO and TEYO are comparable to BTS. No significant difference was found in sperm abnormalities. The results suggest that citrate egg yolk and Tris egg yolk in combination with olive oil are suitable as alternative diluents for the preservation of porcine sperm. Further studies are needed to determine the most suitable olive oil concentration for the preservation of porcine sperm of different breeds.

This study aimed to examine the quality of frozen sperm of duroc boar in modified Tris diluent with different equilibration time. Semen was collected from two duroc males and evaluated macroscopically and microscopically. Semen with motility 75%, concentration 200x106 cell/mL and abnormality <20% was diluted in Tris modified diluent, then held for two hours at room temperature (27-28ºC). The semen that has been in the holding time is then centrifuged at 2000 rpm for 15 minutes. The pellet from centrifuge were diluted again with modified Tris diluent + 3% glycerol. The diluted semen was packed in 0,50 mL mini straws and equilibrated according to the treatment equilibration time, namely P1: 1 hour equilibration time, P2: 2 hour equilibration time, P3: 3 hour equilibration time. After equilibration , it was frozen over liquid nitrogen vapor (-110ºC) at a distance of  5 cm for 10 minutes, then stored in liquid nitrogen (-196ºC) and left for 24 hours. Then thawing with warm water at 37ºC for 30 seconds in a water bath. The result showed that motility, viability, abnormality, intact plasma membrane and recovery rate were significantly  higher (P<0,05) at two hour equilibration , namely 23.12%, 45.44%, 4.65%, 50,15%, 33.03% respectively compared  to one and two hour equilibration time, namely 20%, 42.17%, 8.19%, 42.67%, 28.57% and 16,87%, 36.39%, 7.64%, 37.73%, 24.99% respectively. This study conclude that the equilibration time of two hours resulted in higher quality of frozen sperm of duroc boar than one and three hours.

The purpose of this study was to determine the effect of adding onion extract (OE) to Tris-egg yolk (T-EY) diluent on the quality of bali bulls spermatozoa. The semen of three bali bulls aged 3-4 years were collected twice a week using the artificial vaginal method. Semen with good quality, motility 79%, viability 84.63%, abnormality 2.93% diluted with T-EY diluent with the addition of OE: T0: 0%; T1 1%; T2: 2%; T3: 3%; T4: 4%; and T5: 5%. The diluted semen was preserved in a refrigerator at 3-5 °C and evaluated for the quality of the spermatozoa every 24 hours. The results showed that the addition of OE in T-EY diluent had a positive effect on the quality of bali bulls spermatozoa. The addition 3% of OE (T3) in T-EY diluent resulted in higher spermatozoa quality (P <0.05) than the other treatments, namely motility 42.01%, viability 48.74%, and abnormalities 4.13% on the sixth day of preservation. It was concluded that the addition of onion extract in Tris - egg yolk diluents could improve the quality of bali bulls spermatozoa,  with the best level of onion extract being 3%.

The purpose of this study was to test the influence of the equilibration time on the frozen semen quality of duroc pig in modified tris-egg yolk with the addition of extracellular cryoprotectants. Semen is collected twice per week using massage methods from two duroc males aged ±2.5 years which in good health and have been trained in semen colection. The design used is a completely randomized design with 4 tests and 3 treatments T1: equilibration time of 1 hour, T2: equilibration time of 2 hours, T3: equilibration time of 3 hours at a temperature of 50C. Observed parameters were motility, viability, abnormality, MPU, and recovery rate (RR). The results showed that motility, viability, abnormalities, MPU, and RR were higher (P<0.05) at 2 hours of equilibration (25.63±3.15%, 55.86±5.41%, 4.92±0.53%, 56.69±5.64%, 36.61±4.49%) compared to 1 and 3 hours (20.00±3.54%, 39.28±9.89%, 7.93±0.76%, 40.21±9.39%, 28.57±5.05%) and (15.00±4.08%, 32.19±7.0%, 8.41±0.70%, 32.71±7.07%, 21.43±5.83%). It was concluded the motility of duroc pig spermatozoa in the tris-modified diluents after 2 hours of equilibration reached 64.375% and 25.63% post thawing, but did not reach the requirement of 40% spermatozoa motility for artificial insemination. It was concluded that the sperm motility of Duroc pig in tris-modified diluent after 2 hours of equilibration reached 64.375% and 25.63% post thawing, but did not reach the standard of 40% spermatozoa motility for artificial insemination.

An experiment was carried out to recognize the effect of long equilibration time on the quality of spermatozoa and to obtain optimal equilibration time in the process cryopreservation of landrace pig semen. Semen was obtained from a landrace boar aged 2-3 years using glove hand method. The semen was than evaluated macroscopically and microscopically, good quality semen was diluted in a basic diluent, than kept for two hours at a temperature of 27-28oC. The semen were then centrifuged at 2000 rpm for 15 minutes, the supernatant was discarced and the pellets was re-diluted into basic diluent with a ratio of 1:1. Then, semen was diluted in treatment diluent with modified durasperm + 6% lactose + 4% glycerol with a concentration of 500 x 106/0.5 mL. Furthermore, the semen was packaged in 0.5 ml straws, then equilibrated at a temperature of 3-5oC appropriate to treatment, with 1 hour equilibration (T1), 2 hours equilibration (T2) and 3 hours equilibration (T3). After equilibration, the straws was frozen horizontally 5 cm above the liquid N2 vapor for 10 minutes at a temperature of ± -110oC and then stored in a liquid N2 container  (-196oC). To test frozen semen, it was done by stored frozen semen at 37oC for 30 seconds. The results showed that the highest quality of spermatozoa (P <0.05) was found in T2 and T3 when compared to T1 (P> 0.05), with the motility value was T2: 28.13 ± 2.39%; T3: 25.00 ± 4.08%; and T1 18,15±3,23%. It can be concluded that 2 hours and 3 hours equilibration time was able to maintain the quality of frozen semen landrace boars and the statistically was not significant.