Khalifa T A A, El-Saidy B E
Department of Theriogenology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
Anim Reprod Sci. 2006 Jul;93(3-4):303-15. doi: 10.1016/j.anireprosci.2005.08.008. Epub 2005 Sep 19.
During the breeding season of goats (12 bucks and 64 does) in Egypt, five experiments were conducted using a chemically defined cryoextender (CDE) to investigate: (1) the influence of rates of semen dilution (1:2, 1:4 and 1:19) and methods of thawing of frozen semen pellets (dry thawing versus wet thawing) on sperm progressive motility (SPM), sperm acrosome abnormalities (SAA) and rate of lipid peroxidation in semen as measured by malonaldehyde (MAL) production, and (2) the effect of insemination of does in natural (n = 38) and cloprostenol-synchronized (n = 26) estrus with frozen semen on their kidding rates and prolificacy. Semen (two successive ejaculates/buck) was collected twice a week via an AV and only ejaculates of >2500 x 10(6) sperm/ml and 70% SPM were diluted in one step at 30 degrees C with the CDE, cooled to 5 degrees C over a 4h-period, frozen in the form of 0.30 ml pellets and stored in liquid nitrogen for 72 h. The results revealed that post-thaw SPM of semen diluted at a rate of 1:4 was significantly (P < 0.01) higher than that of semen diluted at the other rates. Dilution of semen at a rate of 1:19 (< or =151 x 10(6) sperm/ml) not only minimized (P < 0.01) pre-freeze and post-thaw SPM, but also augmented (P < 0.01) pre-freeze and post-thaw rates of lipid peroxidation as evidenced by the high level of MAL production and the ability of antioxidants (1mg/ml EDTA, 200 U/ml bovine liver catalase, 0.61 mg/ml reduced glutathione and 0.11 mg/ml sodium pyruvate) to restore (P < 0.01) pre-freeze and post-thaw SPM. Frozen semen pellets exposed to dry thawing had a greater percentage of SPM (P < 0.01) as well as lower values of SAA and MAL (P < 0.01) than those exposed to wet thawing. Although the kidding rates did not vary significantly among does in natural (55.26%) and synchronized (53.85%) estrus, a higher (P < 0.05) prolificacy was obtained after their insemination in natural (1.81+/-0.16) rather than in synchronized (1.22+/-0.11) estrus.
在埃及山羊的繁殖季节（12只公羊和64只母羊），进行了五项实验，使用化学成分明确的冷冻稀释液（CDE）来研究：（1）精液稀释比例（1:2、1:4和1:19）和冷冻精液颗粒解冻方法（干解冻与湿解冻）对精子前向运动率（SPM）、精子顶体异常（SAA）以及精液中通过丙二醛（MAL）生成测定的脂质过氧化率的影响，以及（2）用冷冻精液对处于自然发情期（n = 38）和氯前列醇同步发情期（n = 26）的母羊进行授精对其产羔率和繁殖力的影响。精液（每只公羊连续采集两次射精）每周采集两次，通过假阴道采集，仅将精子浓度>2500×10⁶/ml且SPM为70%的射精在30℃下用CDE一步稀释，在4小时内冷却至5℃，制成0.30 ml颗粒冷冻，并在液氮中储存72小时。结果显示，以1:4比例稀释的精液解冻后的SPM显著（P < 0.01）高于以其他比例稀释的精液。以1:19的比例（≤151×10⁶精子/ml）稀释精液不仅使冷冻前和解冻后的SPM最小化（P < 0.01），还增加了冷冻前和解冻后的脂质过氧化率（P < 0.01），这由高水平的MAL生成以及抗氧化剂（1mg/ml乙二胺四乙酸、200 U/ml牛肝过氧化氢酶、0.61 mg/ml还原型谷胱甘肽和0.11 mg/ml丙酮酸钠）恢复冷冻前和解冻后SPM的能力所证明。与湿解冻的冷冻精液颗粒相比，干解冻的冷冻精液颗粒具有更高百分比的SPM（P < 0.01）以及更低的SAA和MAL值（P < 0.01）。尽管处于自然发情期（55.26%）和同步发情期（53.85%）的母羊产羔率没有显著差异，但在自然发情期（1.81±0.16）而不是同步发情期（1.22±0.11）进行授精后，获得了更高的（P < 0.05）繁殖力。
