Comparison of Different Extenders on the Preservability of Rabbit Semen Stored at 5°C for 72 Hours

Abstract

This study was designed to compare Cortalap ® extender with tris-citric acid-glucose (TCG), Lepus ® and Merk III ® , to assess the in vitro preservability of rabbit spermatozoa stored for 72 h at 5°C. The best extender identified in vitro was then compared with fresh semen to determine fertility and prolificacy rates in vivo. Eight semen pools were split into four subsamples and each of them was diluted to a ratio of 1:10 (volume:volume) with four different extenders (Lepus ® , Cortalap ® , TCG and Merk III ® ) and stored at 5°C for 72 h. Sperm motility, viability, sperm membrane and acrosome integrity were evaluated in both fresh and chilled semen at 4, 24, 48 and 72 h of storage. The results showed that Cortalap ® was the best extender to preserve the quality of rabbit semen in vitro over 72 h in comparison with the other extenders (P<0.05). Then, Cortalap ® was used for an artificial insemination (AI) trial to be compared with fresh semen. Two groups of does (n=30 each) were inseminated with fresh and chilled semen. The fertility and prolificacy rates for the does inseminated with chilled semen were significantly lower compared with those inseminated with fresh semen (P<0.05). In conclusion, although Cortalap ® proved to be the best extender to preserve semen quality in vitro after 72 h at 5°C, the in vivo results showed that its use is not recommended in AI programmes.

Evaluation of effectiveness of an innovative semen extender (Formula®) comparing with a traditional extender (Lepus®) for artificial insemination in rabbits does

“…While Di Iorio et al (2014) Lavara et al (2005) in a study on a total of 2765 AI in rabbit a significant correlation exists between kindiling rate and the percentage of total motile cells in the semen doses. In our study, we evaluated the use of an innovative source of energy (sucrose) associated to hydrolytic enzyme for the rabbit spermatozoa metabolic needs during liquid storage at 15-17 C (Bettini et al International Publication Number WO 2015/ 193265 A1).…”

“…Currently, rabbit insemination is mostly performed with fresh diluted semen collected and conditioned on site or with cooled semen provided by a semen production farm, generally stored for no longer than 18 h (Morrell 1995;Roca et al 2000;Brun et al 2002;Nagy et al 2002;Daniel & Renard 2010). The availability of semen that can be stored for longer periods would allow an extension of the interval between semen collection and insemination of the females (Di Iorio et al 2014). Thus, enhancing AI performance in case of farms without male located far away from semen collection centres (Gogol, 2013).…”

Initial cooling time before freezing affects post‐thaw quality and reproductive performance of rabbit semen

“…The mounted slides were then observed on a warm plate at ×400 magnification using a phase‐contrast microscope (Leica Aristoplan; Leitz Wetzlar, Heidelberg, Germany). Percentage of TM (spermatozoa showing any type of sperm head movement) and FPM (spermatozoa showing linear movement) were measured in five microscopy fields (Di Iorio, Manchisi, Rocco, Chrenek, & Iaffaldano, ; Iaffaldano et al., ).…”

Artificial insemination in rabbits: factors that interfere in assessing its results

“…However, the demand for stored semen to be used in AI programs of livestock animals (Zhao et al 2009) and rabbit (Di Iorio et al 2014) is increasing. Storage of rabbit semen for longer than 24 to 48 h causes damage of semen quality with a decrease in fertility (Rosato and Iaffaldano 2011;Di Iorio et al 2014). Rabbit spermatozoa are more sensible to hypertonic solutions, causing a reduction in storage ability and consequently a decrease in kindling rates (Seleem and Rowida 2005).…”