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Research article - Peer-reviewed, 2009

Effects of straw volume and Equex-STM® on boar sperm quality after cryopreservation

Buranaamnuay, K.; Tummaruk, P.; Singlor, J.; Rodriguez-Martinez, H.; Techakumphu, M.


The present experiments were designed to study the effect of adding the detergent Equex-STM (R) to freezing extender, and of straw volume (0.25 ml vs 0.5 ml), on boar sperm quality after cryopreservation. Three ejaculates from each of four purebred boars (three Landrace and one Yorkshire) were collected and frozen with a lactose-egg yolk extender containing glycerol with or without 1.5% Equex-STM (R). The extended semen was loaded into either 0.25- or 0.5-ml straws. The straws were placed in liquid nitrogen (LN2) vapour approximately 3 cm above the level of LN2 for 20 min and then were plunged into LN2. Thawing was achieved in warm water at 50 degrees C for 12 s and then was incubated in a 38 degrees C water-bath for 30 min before evaluating sperm quality. Results showed that the individual motility, viability and acrosomal normal apical ridge (NAR) were improved (p < 0.001) when Equex-STM (R) was added to the freezing extender. There was no difference (p = 0.48) in sperm motility between 0.25- and 0.5-ml straws when Equex-STM (R) was added. The percentages of viable and of NAR sperm in 0.5-ml straws were higher than those in 0.25-ml straws (p = 0.02, p = 0.0003 respectively). The percentages of membrane intact sperm evaluated using the short hypo-osmotic swelling test were not affected by straw volume or the adding of Equex-STM (R) (p > 0.05). The results of these investigations suggested that Equex-STM (R) exerts a beneficial effect on the quality of cryopreserved boar semen and this cryopreservation protocol was favourable for a 0.5-ml straw.

Published in

Reproduction in Domestic Animals
2009, volume: 44, number: 1, pages: 69-73
Publisher: Wiley-Blackwell

Authors' information

Buranaamnuay, K
Chulalongkorn University
Tummaruk, P
Chulalongkorn University
Singlor, J
Chulalongkorn University
Rodriguez, Heriberto
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Techakumphu, Mongkol
Chulalongkorn University

UKÄ Subject classification

Animal and Dairy Science
Veterinary Science

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