稀释液渗透压对绵羊精液冷冻效果的影响

本试验对绵羊冻精采用两次稀释时,从调整Ⅱ液中葡萄糖含量和降低甘油浓度两方面,改变稀释液的渗透压,测定冻精效果。先增减糖的比例,配制9-2(对照), 84-1和84-2等试验组,其稀释Ⅱ液渗透压1191,1026、1499mmol/kg,获冻精情期产羔母羊率61.69, 63.31, 54.55(P<0.05)。随后, 以84-1为对照,降低甘油浓度,设3个试验组,即87-2,88-1和88-1a,渗透压相应为747,456,463mmol/kg,冻精情期受胎率1987年84-1,87-2为65.37,67.37;1988年87-2,88-1,88-1a为63.16,62.50,46.55(P<0.05)。试验说明,绵羊冻精采取2次稀释法,第Ⅱ液以4％甘油,渗透压为747mmol/kg时,冻精效果最佳。     

维生素E对绵羊鲜精及冻精精液品质的影响

日粮中添加维生素E可以提高绵羊鲜精的活率 ,对照组和试验组的活率分别为 0 72± 0 0 7和 0 78± 0 0 6(P <0 0 5 ) ,显著改善鲜精精液品质。采用两步稀释法在绵羊冷冻精液稀释液中添加维生素E ,可以极显著降低冷冻对精子顶体的冷刺激损害程度 ,试验组的活率 ( 0 43 5± 0 0 2 0 )极显著高于对照组 ( 0 3 65± 0 0 2 6) (P <0 0 1) ,精子顶体的总异常率试验组 ( 3 3 72 % )极显著低于对照组 ( 4 4 3 5 % ) (P <0 0 1) ,其中试验组顶体膨胀率和脱落率与对照组分别为 1 2 8%±0 5 8%、2 3 0 8%± 1 45 %与 2 68%± 0 5 9%、2 8 96%± 3 14 %。冷冻精液品质显著改善。     

保持公羊精液卫生无菌的措施

公羊包皮、四肢被毛、母台羊、采精及精液处理环境条件、饲养条件、人员操作、精液稀释液等十大因素可能是造成精液污染的主要因素。因此,必须从上述各方面采取技术措施保持精液卫生无菌。     

冷冻前后牛羊精子表面三种凝集素受体的定量研究

 用自己设计的酶标凝集素法测定了乳用牛、乳肉兼用牛、中国美利奴羊、澳洲美利奴羊新鲜和冷冻精子表面的麦芽凝集素（WGA）受体、大豆凝集素（SBA）受体及伴刀豆球蛋白A（Con A）受体的相对数量。在乳用牛精子，冷冻后WGA受体数量显著下降（P< 0.01），穿透实验表明WGA受体数量与精子的穿透率呈高度正相关（r=0.86），另两种受体的数量在冷冻后无显著变化，与精子的穿透率也无相关关系。在乳肉兼用牛精子，冷冻后数量显著下降的是SBA受体（P< 0.01）在中国美利奴羊精子是WGA受体（P< 0.05）和Con A受体（P< 0.05），而在澳州美利奴羊精子三种受体的数量均无显著变化。     

种公羊锌摄入量与精液品质的关系研究

以成年小尾寒羊种公羊为对象,采用随机区组试验设计,将10只种公羊随机分成5组,分别饲喂锌含量不同的日粮,研究日粮锌水平及补饲时间与种公羊精液品质的关系。A组:对照组,饲喂锌含量39.69 mg/kg的基础日粮;B组:基础日粮+Zn 40 mg/(d.头)(锌含量48.12 mg/kg);C组:基础日粮+Zn 60 mg/(d.头)(锌含量53.83 mg/kg);D组:基础日粮+Zn 80 mg/(d.头)(锌含量59.55 mg/kg);E组:基础日粮+Zn 100 mg/(d.头)(锌含量65.26 mg/kg)。结果表明:①各试验组间射精量差异不显著(P>0.05)。②鲜精活率,A组与其余各组之间均差异极显著(P<0.01);B组与C、D组差异极显著(P<0.01),与E组差异不显著(P>0.05);其余各组均差异不显著(P>0.05)。③精子密度,A组与其余各组之间均差异极显著(P<0.01);B组与D组差异显著(P<0.05),与C、E组差异不显著(P>0.05);C、D两组间差异不显著(P>0.05);D、E两组间差异显著(P<0.05)。④不同锌水平各组间精子畸形率均差异极显著(P<0.01)。⑤精液pH值,A组与其余各组之间均差异极显著(P<0.01);B组与C组差异不显著(P>0.05),与D、E组差异显著(P<0.05);C、D、E 3组间差异不显著(P>0.05)。⑥缺锌公羊补锌2个月后精液品质能够达到较好水平。     

当年公羔与羯羔产肉性能对比试验

用细杂一代当年公羔和羯羔进行试验,结果表明,在生长发育、屠宰指标等方面,二者无显著差异。农户喜养羯羊,主要是因为容易管理和减少乱交乱配。山西省山区养羊主要靠自然草坡放牧,当年出栏羊最好在１２ 月份屠宰,可减少投资,提高效益。     

稀释液中添加维生素E对绵羊冷冻精液品质的影响

采用两步稀释法 ,在绵羊冷冻精液中添加维生素E ,精液稀释平衡后精子活率 ,试验组 (0 .6 35 )高于对照组(0 .5 75 ) ,但无显著性差异 (P >0 .0 5 ) ;而解冻后 ,试验组活率 (0 .4 35 )极显著高于对照组 (0 .36 5 ) (P <0 .0 1) ;精子顶体总异常率 ,试验组 (33.72 % )极显著低于对照组 (4 4 .35 % ) (P <0 .0 1) ,其中试验组顶体膨胀率和脱落率与对照组分别为 1.2 8% ,2 3.0 8%与 2 .6 8% ,2 8.96 %。添加维生素E可以降低冷冻对精子顶体的损害程度 ,提高精液品质。试验也证明在解冻后保存 1h内 ,精子活率呈现缓慢下降的趋势 ,但 1h后活率急剧下降 ,因而 ,绵羊冻精颗粒解冻后应在 1h内输精完毕     

Analyses of parental and seasonal influences on the synchrony of dexamethasone-induced lambing and lamb characteristics

Synchronization of parturition in a commercial flock of sheep has many advantages including the maintenance of the efficiency of the operation as well as optimization of care for periparturient animals. In a research setting, using an ovine model for experiments involving the induction of parturition yields the results that can be applied to other mammalian species. In sheep, as well as in a variety of other farmed species, dexamethasone is the drug used to induce synchronized parturition at the end of gestation. However, considerable variations have been noticed in the time between induction and the onset of lambing. This study set out to determine the role that the breed of dam and sire, the age and reproductive history of ewes, the month of induction and the litter/lamb characteristics played in determining the time between dexamethasone treatment and parturition. The lambing was induced in 146 ewes (4 purebred Dorset, 19 purebred Rideau Arcott and 123 Rideau Arcott × Dorset ewes) using a single i.m. dose of 20 mg dexamethasone (Unidex^®, Univet Pharmaceuticals, Milton, ON, Canada) on day 140 of gestation. The ewe breed was weakly correlated (r = − 0.19, P < 0.05) whereas the sire breed was moderately correlated (r = − 0.37, P < 0.001) to the time between dexamethasone treatment and the onset of parturition (the breed in this study was defined as the % of the Rideau Arcott genotype). The time between induction and the onset of labour averaged 57.3 ± 5.3 h and 64.3 ± 8.2 h in February and April, respectively, and it was significantly longer (P < 0.05) compared with the times recorded in July, September and November (42.0 ± 2.0 h, 38.7 ± 2.8 h and 36.1 ± 5.0 h, respectively). There was a negative correlation (r = − 0.41, P < 0.001) between the proportion of ram lambs and the mean birth weight of ewe lambs. These results can be interpreted to suggest that the breed and time of the year may both affect the synchrony of dexamethasone-induced lambing. The reasons for the associations found between the month of induction and the time elapsed to the onset of parturition as well as between the proportion of ram lambs and birth weights of ewe lambs are not fully understood and warrant further studies.     

中草药添加剂对种公羊精液品质和耐冻性的影响

为探索中草药添加剂对种公羊精液品质的影响,用当归(Radix angelicae sinensis)、党参(Radix codonop sis)、黄芪(Radix astrag ali)、淫羊藿(Herba epimedii)、菟丝子(Semen cuscutae)等19味中草药复方配伍作饲料添加剂,按每头种公羊饲料量1%的比例饲喂3周,对种公羊的性反应和精液品质进行分析研究。结果表明:饲喂中草药添加剂后公羊性反应时间显著缩短;射精量、精子密度较对照显著和极显著提高;每次射精有效精子数达到61.64×109,比对照组增加2.36倍,差异极显著(P<0.01);精子头部畸形率较对照组降低8%(P<0.05);饲喂1周对精液质量有明显改善,饲喂3周至停药1周后可延缓精子质量下降的速度;且饲喂后种公羊的冻后精子活率和精子复苏率较对照和饲喂前显著提高(P<0.05),分别增加38.7%和28.9%。该复方中草药添加剂适用于高频度采精种公羊,可改善公羊的精液品质,提高人工授精过程中精液保存质量,有利于进一步发挥优良公羊的种用价值。