Custom Cryomax™ LE CF2 Freezing extender
Custom E-Z Freezin® Cryomax™ LE CF2 Equine Semen Freezing Extender is designed for stallions that are "poor freezers" in other commercial freezing extenders. Cryomax™ LE CF2 uses a completely different small molecule cryoprotectant than is found in the standard Cryomax™ LE and it is also glycerol free.
Recent research has shown that most stallions semen freezes best in extenders that combine both large and small molecule cryoprotectants. In rare occasions, some poor freezing stallions achieve better results in extenders that contain only small molecule cryoprotectants. E-Z Freezin® Cryomax™ LE CF1 and Cryomax™ LE CF2 Equine Semen Freezing Extenders were developed as a collaboration between Colorado State University and Animal Reproduction Systems, Inc. These two new custom extender formulas include different small molecule cryoprotectants that typically help stallions that are considered "Poor Freezers".
These two custom formulas can be tried as a last resort on high value stallions that do not freeze in normal commercial freezing extenders.
E-Z Freezin® CryoMax™ LE CF2 freezing extenders are packaged in 15 ml hermetically sealed packets and sold in 5-packs containing a total volume of 75 ml. All ARS extenders are evaluated by the Colorado State University Animal Reproduction and Biotechnology Laboratory to ensure a superior quality product.
|ARS Part Number ||EZF-CMF1-LE/5|
|Volume per packet||15 ml|
|Packets per container||5|
|Total extender volume ||75 ml|
All shipments of E-Z Freezin® CryoMax Extenders include certification of production using eggs that are produced by a flock that is certified Specific Pathogen Free. The flock is certified free of the following pathogens: Avian Adenovirus Group I, Avian Adenovirus Group II (HEV), Avian Adenovirus Group III (EDS), Avian Encephalomyelitis, Avian Influenza (Type A), Avian Reovirus, Fowl Pox, Infectious Bronchitis-Ark., Infectious Bronchitis-Conn., Infectious Bronchitis-JMK, Infectious Bronchitis-Mass., Infectious Bursal Disease, Infectious Laryngotracheitis, Lymphoid Leukosis (A, B), Lymphoid Leukosis Viruses, Marek's Disease (Serotypes 1,2,3), Mycoplasma gallisepticum, Mycoplasma synoviae, Newcastle Disease, Reticuloendotheliosis Virus, Salmonella enterica seruvari, Pullorum and Gallinarum, and Salmonella.
Research at the Colorado State University Equine Reproduction Laboratory has determined that thawing during shipment and subsequent refreezing does not adversely affect this product and have decided to have their E-Z Freezin® Cryomax? Extenders shipped using more economical services during the cooler months of the year.
E-Z Freezin® Stallion Semen Freezing Extenders are sold by Animal Reproduction Systems under exclusive license with the Colorado State University Foundation. The formulas for these Extenders were developed in coordination with the Colorado State University, Animal Reproduction and Biotechnology Laboratory. Each E-Z Freezin® lot is evaluated by the CSU to ensure a superior product.
A series of studies were performed at the Equine Reproduction Laboratory, Colorado State University to compare commercial extenders for cryopreservation of stallion semen. Three freezing extenders contained a combination of glycerol and an amide as cryoprotectants (BotuCrio®, CryoMax™ LE and CryoMax™ MFR5), while two freezing extenders utilized glycerol as the only cryoprotectant (LE, MFR5).
Study 1. Semen was collected from a total of 12 different stallions. Aliquots of each ejaculate were diluted in one of five different extenders, loaded into 0.5 ml straws, cooled to 5 to 8° C over a 30 to 60 minute period and subsequently cryopreserved. One representative straw from each extender for every stallion was thawed in a 37° C water bath for 30 seconds. The thawed sperm was allowed to warm for 10 minutes and then evaluated for total and progressive motility using a computer assisted semen analysis (CASA) system. The highest average post-thaw motility was noted for the CryoMax™ LE extender (Table 1).
Table 1. Post-thaw motility for spermatozoa from 12 stallions cryopreserved in each of 5 commercial freezing extenders. Data are presented as the mean ? SEM.
|Extender||Total Motility (%) ||Progressive Motility (%)|
|CryoMax™ LE||57.4 ± 4.4a,y||43.5 ± 4.6a|
|CryoMax™ MFR5 ||51.7 ± 4.2a||38.7 ± 4.4ab|
|BotuCrio®||50.4 ± 4.6a,x||39.8 ± 4.3a|
|LE||38.3 ± 4.1b||27.5 ± 3.8b|
|MFR5||36.4 ± 4.4b||25.7 ± 4.0b|
ab Values within a column with different superscripts are significantly different (p<0.05) [ANOVA] xy Values are statistically different (p=0.032) [paired T-test]
Study 2. Semen was collected from 30 different stallions. Aliquots of each ejaculate were diluted in one of four commercial extenders, loaded into 0.5 ml straws, cooled to 5 to 8° C and cryopreserved. One straw from each extender for every stallion was thawed in a 37° C water bath for 30 seconds. The thawed sperm was allowed to warm for 10 minutes and then evaluated for total and progressive motility using a CASA system. Again, the highest average post-thaw motility was noted for the CryoMax™ LE and CryoMax™ MFR5 extenders (Table 2).
Table 2. Post-thaw motility for spermatozoa from 30 stallions cryopreserved in each of 4 commercial freezing extenders (mean ? SEM).
|Extender||Total Motility (%) ||Progressive Motility (%)|
|CryoMax™ LE||60.2 ± 2.7a||47.5 ± 2.9a|
|CryoMax™ MFR5 ||55.0 ± 2.3a||43.4 ± 2.4a|
|LE||42.5 ± 4.0b||31.5 ± 3.7b|
|MFR5||39.0 ± 3.5b||29.1 ± 3.2b|
Summary. Freezing extenders containing a combination of glycerol and amide cryoprotectants yielded better post-thaw sperm motility than extenders containing glycerol alone. CryoMax™ LE extender yielded a higher post-thaw total motility when directly compared to BotuCrio® extender.
Studies from 2015 Breeding Season
CryoMax™ LE and CryoMax™ MFR5 are new Equine Freezing Extenders that were developed by Animal Reproduction Systems in conjunction with Colorado State University. Initial testing for these extenders were performed at the Colorado State University Equine Reproduction Laboratory. During the 2015 breeding season, the majority of their client stallion semen was cryopreserved using one of the new CryoMax™ freezing extenders.
Preliminary data showed that overall, the new CryoMax™ Equine Semen Freezing Extenders improved post-thaw total and progressive motility by an average of 10 % over other commercially available extenders. In addition, the new CryoMax™ extenders yielded a markedly higher post-thaw motility in five stallions with low post-thaw progressive motility (< 35 %) when frozen in their original extenders. Post-thaw progressive motility in the poor-freezer stallions improved from 30 % to 58 %, for an average improvement of 28 %.
- Stallion 1. Post-thaw motility in original extender was 22 %; post-thaw motility in new CryoMax™? LE was 53 % (31 % improvement).
- Stallion 2. Post-thaw motility in original extender was 31 %; post-thaw motility in new CryoMax™ LE was 73 % (42 % improvement).
- Stallion 3. Post-thaw motility in original extender was 34 %; post-thaw motility in new CryoMax™ MFR5 was 56 % (22 % improvement).
- Stallion 4. Post-thaw motility in original extender was 31 %; post-thaw motility in new CryoMax™ LE was 52 % (21 % improvement).
- Stallion 5. Post-thaw motility in original extender was 32 %; post-thaw motility in new CryoMax™ MFR5 was 57 % (25 % improvement).
It should be noted that post-thaw motility and potential for fertility with frozen thawed semen are not necessarily synonymous. Most of the semen frozen with the new CryoMax™ extenders is destined to be used in future breedings. So far this past season, four mares were bred using semen frozen in CryoMax™ extenders and three became pregnant on their first cycle.
Overall, the new CryoMax™ series of equine semen freezing extenders demonstrated superior post-thaw sperm motility in 73 % of stallions (8 out of 11) as compared to other commercially available extenders.