Brito Leonardo F C, Linardi Renata L, Rosales Leslie A S, Balamurugan Nithiya Sri, Hernández-Avilés Camilo, Ramírez-Agámez Luisa
Department of Clinical Studies - New Bolton Center, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA.
Equine Fertility Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA.
Reprod Domest Anim. 2025 Sep;60(9):e70126. doi: 10.1111/rda.70126.
Efficient use of stallion semen in liquid state is limited by its relatively short shelf-life. A chemically defined extender (Beyond) is now available for long-term liquid semen preservation. The objectives of the present study were to compare Beyond with milk extenders for the preservation of semen at two temperatures, and to evaluate fertility of semen cooled for 4-8 days before artificial insemination. Semen was processed using different extenders: milk, cholesterol (BotuSemen Special); milk-based (INRA 96); and Beyond. Sperm motility, membrane and acrosome integrity, and chromatin structure were evaluated in semen stored at 17°C for 7 days or at 5°C for 14 days. Sperm motility decreased in the first few days of storage regardless of extender or storage temperature. Sperm motility continued to decline at relatively constant rates in semen extended in milk extenders, but the rate of decline was substantially reduced with Beyond. Sperm motility in semen extended with Beyond was greater than in semen extended with milk extenders after 4 days of storage at 17°C, or after 7 days of storage at 5°C. Extender did not affect sperm DNA damage during storage, but sperm with intact membrane and intact acrosome were lower with Beyond. Inseminations with semen stored with Beyond at 5°C for an average of 5.5 days resulted in embryos in 61% of cycles (11/18). In conclusion, Beyond extender resulted in greater sperm motility longevity when compared to milk extenders, especially when semen was stored at 5°C. Satisfactory fertility was obtained with semen cooled for 4-8 days before artificial insemination.
液态种马精液的有效利用受到其相对较短保质期的限制。现在有一种化学成分明确的稀释剂（Beyond）可用于精液的长期液态保存。本研究的目的是在两个温度下比较Beyond与牛奶稀释剂对精液的保存效果，并评估在人工授精前冷却4 - 8天的精液的受精能力。精液使用不同的稀释剂进行处理：牛奶、胆固醇（BotuSemen Special）、基于牛奶的（INRA 96）和Beyond。对在17°C保存7天或在5°C保存14天的精液进行精子活力、膜和顶体完整性以及染色质结构评估。无论稀释剂或储存温度如何，精子活力在储存的最初几天都会下降。在牛奶稀释剂中稀释的精液中，精子活力以相对恒定的速率持续下降，但使用Beyond时下降速率大幅降低。在17°C储存4天后或在5°C储存7天后，用Beyond稀释的精液中的精子活力高于用牛奶稀释剂稀释的精液。在储存期间，稀释剂不影响精子DNA损伤，但使用Beyond时，具有完整膜和完整顶体的精子比例较低。用在5°C下用Beyond储存平均5.5天的精液进行人工授精，61%（11/18）的周期产生了胚胎。总之，与牛奶稀释剂相比，Beyond稀释剂能使精子活力保持更长时间，尤其是在精液于5°C储存时。在人工授精前将精液冷却4 - 8天可获得令人满意的受精率。
