Department of Medicine, Surgery and Veterinary Anatomy, University of Leon, Leon, Spain.
Anim Reprod Sci. 2010 May;119(1-2):160-5. doi: 10.1016/j.anireprosci.2009.11.001. Epub 2009 Nov 5.
Causes of poor fertility after insemination of frozen-thawed (FT) sperm include reduced sperm viability at thawing and a shorter longevity of surviving sperm in the female genital tract due to sub-lethal damage. The present studies examined the effect of incubating thawed boar sperm in seminal plasma (SP) on sperm membrane integrity (viability), and motility in vitro (experiment 1), and fertility in vivo (experiment 2). For experiment 1, FT sperm from five individual boars and a sperm pool from these boars were thawed and incubated for 4 h in media containing 0%, 10%, or 50% autologous seminal plasma (individual boars) or pooled seminal plasma (sperm pool). At approximately 10 min (0 h) and again at 1 h, 2 h, 3 h, and 4 h, sperm populations were examined for percentage sperm viability and percent sperm motility. Each variable progressively decreased during the incubation period. Incubation in 50% SP increased percentages of live sperm (P < 0.0001) and percent sperm motility (P < 0.01) at all time points compared to incubation in either 0% or 10% SP. For experiment 2, multiparous Large white x Landrace sows (n = 82) each received 900 IU eCG at weaning and 750 IU hCG 80 h later to control time of ovulation. Sows were assigned on the basis of parity to be inseminated with pooled semen with or without SP from the boars used in experiment 1. Sows received 3 x 10(9) live fresh-extended sperm (n = 30) or FT sperm thawed in 80 mL BTS extender (n = 26) or 3 x 10(9) live FT sperm thawed in 80 mL BTS containing 50% SP (FT-SP; n = 26). Sows were inseminated at 36 h, and 42 h after hCG injection. Compared to sows receiving fresh semen, the pregnancy rate of FT inseminated sows tended (P = 0.06) to be lower with the FT-SP group being intermediate. Farrowing rates were not different (83.3%, 69.2%, and 65.4% for fresh, FT, and FT-SP, respectively). Inseminations with FT sperm were associated with a reduction in litter size (P < 0.05), which was not evident in the FT-SP group. Taken together, these data confirm an adverse effect of inseminating FT sperm on sperm quality and sow fertility but suggest that thawing FT sperm in 50% SP may partially alleviate these adverse effects.
冷冻-解冻（FT）精子授精后生育力差的原因包括解冻时精子活力降低，以及由于亚致死性损伤，存活的精子在雌性生殖道内的寿命缩短。本研究检测了在精液中孵育解冻公猪精子对精子膜完整性（活力）和体外运动性的影响（实验 1），以及体内生育力（实验 2）。在实验 1 中，将来自 5 头个体公猪和这些公猪的精子库的 FT 精子解冻，并在含有 0%、10%或 50%自体精液（个体公猪）或混合精液（精子库）的培养基中孵育 4 小时。在大约 10 分钟（0 小时）和 1 小时、2 小时、3 小时和 4 小时时，检查精子群体的精子存活率和精子运动率百分比。在孵育期间，每个变量都逐渐下降。与在 0%或 10% SP 中孵育相比，在 50% SP 中孵育可增加活精子的百分比（P < 0.0001）和精子运动率的百分比（P < 0.01）。在实验 2 中，多产大白 x 长白母猪（n = 82）断奶时接受 900 IU eCG，80 小时后接受 750 IU hCG，以控制排卵时间。母猪根据胎次分配，与实验 1 中使用的公猪的精液混合或不混合精液进行授精。母猪接受 3 x 10(9)个活的新鲜延长精子（n = 30）或在 80 mL BTS 稀释液中解冻的 FT 精子（n = 26）或在含有 50% SP 的 80 mL BTS 中解冻的 3 x 10(9)个活的 FT 精子（FT-SP；n = 26）。母猪在 hCG 注射后 36 小时和 42 小时进行授精。与接受新鲜精液的母猪相比，FT 授精母猪的妊娠率有降低的趋势（P = 0.06），FT-SP 组处于中间水平。分娩率无差异（新鲜、FT 和 FT-SP 分别为 83.3%、69.2%和 65.4%）。FT 精子的授精与胎仔数减少有关（P < 0.05），但在 FT-SP 组中并不明显。总之，这些数据证实了 FT 精子授精对精子质量和母猪生育力的不良影响，但表明在 50% SP 中解冻 FT 精子可能部分缓解这些不良影响。
