不同季节繁殖母牛发情及受胎率的比较

通过对云南省碧城镇6个中小规模养牛场2011-2012年发情授配母牛数的逐月统计分析,揭示母牛发情和配种受胎率随季节变化的规律。结果发现,1年中,发情母牛冬季所占的比例最小,只16.9%;夏季最高,达41.5%。春、秋季,春、冬季,秋、冬季间差异不显著(P0.05);春、夏季间差异显著(P0.05);夏、秋季,夏、冬季间差异极显著(P0.01)。情期受胎率以冬季最高,为60.00%,夏季的情期受胎率最低(36.73%),秋季居中为(52.38%),春季(50.00%),配种后返情时间主要集中在配种后10~24 d,此区间返情率占全年配种母牛的26.63%。     

不同繁殖季节规模化胚胎移植受体羊同期发情处理研究

为了研究繁殖与非繁殖季节大规模羊胚胎移植最优同期发情处理方法,依据繁殖季节与非繁殖季节每个处理成本及结果对现有主要绵羊同期发情方法进行了对比。结果表明:在繁殖季节,海绵栓+PMSG250U+PG组获得同期发情率最高93.33%,与海绵栓组差异显著(P0.05),移植受胎率各组间差异不显著(P0.05),但成本较高。2次PG处理组鲜胚移植受胎率最高68.68%,与海绵栓+PG组、海绵栓+PMSG250U+PG组差异不显著(P0.05)。在非繁殖季节,海绵栓+PMSG500U+PG处理方法获得同期发情率最高91.36%,与海绵栓+PMSG250U+PG、海绵栓+PMSG500U组差异极显著(P0.01),鲜胚移植受胎率差异不显著(P0.05)。结果提示:在繁殖季节2次PG注射法效果较优,非繁殖季节海绵栓+PMSG500U+PG法结果较好。     

CUE-MATE诱导新疆褐牛同期发情试验

[目的]为了探索新疆褐牛同期发情处理的有效时间段和最佳处理方法.[方法]采用CUE-MATE孕酮栓+PGF2α法进行新疆褐牛同期发情试验,[结果]表明:同期发情主要集中在取栓后的2 d,平均发情率为72.5%,情期受胎率为66.7%;3月的同期发情率显著高于5月和7月(P＜0.05),达到90.8%,但情期受胎率低于5月和7月,为61.0%,差异不显著(P＞0.05);母牛卵巢上以有黄体的同期发情率最高,达到95.3%,其次是有卵泡的,无黄体、卵泡的最低,三者差异显著(P＜0.05);有卵泡的情期受胎率略高于有黄体的,差异不显著(P＞0.05),无黄体、卵泡的同期发情率和受胎率都最低,差异显著(P＜0.05);育成牛的同期发情率略高于经产牛,为92%,差异不显著(P＞0.05);育成牛的情期受胎率显著高于经产牛(P＜0.05),为73.9%.[结论]环境温度、营养水平及母牛卵巢上有无黄体、卵泡影响发情率的高低,CUE-MATE孕酮栓+PGF2α法可用于诱导新疆褐牛的同期发情.     

适龄母牛“短期优饲”与诱导发情处理试验研究

本试验旨在通过对适龄母牛"短期优饲"技术应用,缩短母牛产间距,提高肉牛养殖经济效益。在哈密市伊州区天山乡吐克塔尔养殖专业合作社以圈舍养殖"集中短期优饲"(试验组1)与伊吾县前山乡以"草原放牧+补饲"(试验组2),采用不同的处理方法对适龄母牛进行人工授精改良。结果显示:试验组1筛选60头母牛,发情授精49头,发情率81.6%;试验组2筛选母牛446头,发情受配246头,发情率55.2%,两组相比较差异极其显著(P0.01)。通过B超妊娠检查,试验组1受配牛48头,妊娠42头,试验组2受配母牛抽检209头,妊娠183头;两者受胎率均为87.5%,两组间差异不显著(P0.05)。结论:舍饲"短期优饲"组,母牛发情集中,发情率高,且便于观察和适时授精。     

影响西门塔尔母牛情期受胎率因素的分析

为探讨影响新疆地区西门塔尔母牛情期受胎率的因素,本试验采用SAS 8.1对影响情期受胎率的配种季节、与配公牛和母牛年龄3个因素进行最小二乘方差分析,各水平间进行Duncan多重比较并分析不同水平对情期受胎率的影响。结果表明,不同配种季节对西门塔尔母牛情期受胎率影响极显著(P<0.01),春季西门塔尔母牛情期受胎率极显著低于夏季、秋季、冬季(P<0.01),冬季情期受胎率最高(64.7%),而春季情期受胎率最低(40.0%);与配公牛对西门塔尔母牛情期受胎率无显著影响(P>0.05);母牛年龄对西门塔尔母牛情期受胎率的影响极显著(P<0.01),随着母牛年龄的逐渐增加情期受胎率有降低的趋势。依据本研究结果,可针对各影响因素合理有效的调控,从而提高母牛的情期受胎率,最终提高牛场经济效益。     

超排后不同发情时间对荷斯坦青年母牛回收卵数和有效胚胎率的影响

共分析比较了916头14～15月龄的荷斯坦青年母牛不同发情时间对超排效果和有效胚胎的影响.结果表明,上午发情的供体母牛,超排效果和有效胚胎明显高于下午发情的供体母牛（P＜0.01）.在供体超排后,以撤栓后大约24 h表现发情为多(81.11％),而下午发情的供体仅占18.89％.下午发情的多数供体是在撤栓34 h以后,...     

断奶母猪不同月份和季节再发情规律调查

调查湛江某猪场所有母猪不同月份和季节的断奶至发情间隔以及正常发情(7天以内)和不正常发情(7天以上)母猪所占的比例。结果表明,(1)断奶母猪不正常发情比例为4.1%～37.8%,其中8月份最高,1～3月份低于4～12月份;(2)断奶至发情间隔平均为4.57～6.53天,8月份最长,3月份最短,不同月份和季节之间差异较大;(3)断奶至发情间隔与气温呈极显著正相关(P<0.01)。     

母牛自然发情与同期发情受胎率的对比分析

通过试验观察受体母牛在自然发情和同期发情后的发情表现，直肠检查卵巢上黄体的生长发育情况，判断最佳移植黄体级别与时间。本试验采取3种方法：I、自然发情法，II、PGF2α单次注射法，III、PGF2α两次注射法，对受体牛做冷冻胚胎移植时发情率和受胎率的对比试验。结果显示，方法II和方法Ⅲ同期发情率明显高于自然发情母牛，差异显著（P＜0.05）；方法II和方法Ⅲ两组之间的移植受胎率差异不显著（P＞0.05）；方法Ⅲ的同期发情率高达82.76%，高于方法II 12.39%；方法Ⅲ黄体A级率70.10%，显著高于方法I和方法II（P＜0.05），方法I、方法II分别为51.60%和57.40%。在小规模散养条件下使用方法I比较经济方便，规模化饲养条件下使用方法Ⅲ，节省人力物力，比较实用。     

甘加型藏羊发情周期阴道细胞变化规律

采用阴道涂片法,观察了8只甘加型藏羊连续2个发情周期阴道细胞涂片,统计分析了发情周期不同时期阴道细胞种类、形态变化特点及其所占比例。结果显示:甘加型藏羊发情周期阴道涂片中主要有副基底层上皮细胞、中间层上皮细胞、表层上皮细胞、不完全角化上皮细胞、完全角化上皮细胞、白细胞和细胞碎片。发情期角化细胞所占比例最高,显著高于发情前期、发情后期和间情期(P0.05);发情前期表层上皮细胞所占比例显著高于其他三个时期(P0.05);间情期和发情后期白细胞所占比例显著高于发情前期和发情期;中间层上皮细胞在各时期所占比例差异不显著(P0.05)。结果表明:根据涂片中阴道细胞种类和各类细胞所占比例的变化特点可以简便、快速准确地鉴定和区分甘加母羊发情周期的不同阶段,阴道凃片是高效、准确的发情鉴定方法。     

奶牛初乳对细毛羊非繁殖季节发情的影响

利用奶牛初乳对340只中国美利奴军垦细毛羊在非繁殖季节进行诱导发情处理,结果表明,发情率为85%（289/340）,受精率85.12%（246/289）;对照组发情率35%（21/60）,差异极显著（P＜0.01）。     

奶牛冷冻胚胎移植受胎率影响因素的探讨

为了提高奶牛冷冻胚胎移植受胎率,笔者对移植季节、加入胚胎细胞团、胚胎发育阶段、移植技术水平等因素进行了试验研究,研究结果表明：7、9、12月移植,受胎率分别为50．9％、38．4％、57．9％,7、12月差异不显著（P〉0．05）,但与9月份差异极显著（P〈0．01）;移植时加入胚胎细胞团与对照组的受胎率分别为52％、69．23％,差异极显著（P〈0．01）;胚胎发育阶段不同,受胎率不同,桑葚胚、早期囊胚、囊胚、扩张囊胚的受胎率分别是56．25％、58．82％、0、0,桑葚胚和囊胚之间差异不显著（P〉0．05）,桑葚胚、囊胚与早期囊胚、扩张囊胚差异极显著（P〈0．01）;技术水平对受胎率的影响,高水平和一般水平的移植受胎率分别是52．86％、17．86％,差异极显著（P〈0．01）。     

影响北京地区荷斯坦牛牛奶尿素氮的环境及生理因素分析

为探究北京地区荷斯坦牛牛奶尿素氮(MUN)的影响因素及夏季热应激相关指标对MUN的影响,实测北京地区7个牛场2016年7、8月的荷斯坦牛直肠温度和体况评分(BCS),收集北京地区68个牛场生产性能测定数据,利用固定模型分析环境和生理因素,以及4%乳脂校正乳(FCM)、乳蛋白量和体细胞分(SCS)对MUN全年测定值的影响,并重点分析夏季MUN随BCS和直肠温度的变化趋势。结果表明:数据测定月份和产犊季节对MUN影响极显著(P0.01),冬季MUN水平偏低,夏季普遍较高,春季产犊的牛MUN高于其他产犊季节;泌乳121~180 d MUN水平最高;MUN随胎次的增加显著降低(P0.05);SCS、FCM和乳蛋白率分别与MUN夏季测定值呈极显著的回归关系(P0.01);BCS对夏季MUN影响显著(P0.05),但直肠温度对MUN无显著影响(P0.05)。综上,利用产犊季节和测定月份可以预估群体MUN的水平,夏季则可通过奶牛体况变化及泌乳性能预测个体MUN,及时调整饲养管理,管控夏季奶牛健康和牛奶品质。     

Effect of seasonal conditions on oestrus occurrence and postpartum period in Anatolian water buffaloes

Oestrus and calving records of Anatolian buffaloes were analyzed to investigate influence of climatic conditions on oestrus occurrence and postpartum period. Oestrus records showed a seasonal pattern concentrated between July and September which is the warmest period of the year. Likewise, more than half (52.7%) of the total calvings occurred between May and August. Month of calving significantly influenced the length of calving to first oestrus interval and open period (P < 0.01). The average length of open period was significantly shorter in autumn and summer calvers compared to those calved in spring and winter (P < 0.05) during long days. The humidity rate was negatively correlated with both calving to first oestrus interval and open period (P < 0.05). In conclusion, exposure to high environmental temperatures around 20 degrees C exerted no suppressive influence on ovarian activity in Anatolian buffaloes. Although humidity rate (P < 0.05) and ambient temperature (P < 0.01) was found to be correlated with the duration of postpartum period, day length might be the main factor regulating reproductive biorhythm and postpartum events in Anatolian buffalo cows.     

Effects of seasons on some semen parameters and bacterial contamination of Awassi ram semen

The objectives of the present study were to determine the effects of season on some semen parameters and bacterial contamination of Awassi ram semen. Semen samples from six mature Awassi rams were used in this study. Semen collection was performed with artificial vagina every week, from September 2009 to October 2010. Volume, sperm concentration, mass motility, individual motility, percentage live sperm and sperm abnormalities were evaluated. Moreover, determination of viable bacterial count of the rams was also recorded weekly. Higher (p < 0.05) semen volume in the hot summer and spring months was observed of August (1.55 ± 0.08 ml) and March (1.27 ± 0.15 ml). Sperm concentration was highest (p < 0.05) in the breeding season (late summer to early autumn) of September (4.21 ± 0.86 × 10(9) sperm/ml). Sperm individual motility and percent of live sperm observed in August (summer) and May (end of spring) when the environmental temperature started to increase were recorded highest values and differed significantly (p < 0.05) from December and January (winter). The highest value of the mean sperm acrosomal defects (13.33 ± 0.63%) was recorded in December. The highest value of the mean viable bacterial count (138.3 ± 21.6) was recorded in July (summer). A significant decrease (p < 0.01) in the mean viable bacterial count was observed from the middle of winter towards the end of spring. The lowest bacterial count was noted in January (60.5 ± 2.98). It could be concluded from the results of the present study that there is an effect of season on ram semen quality, and summer high temperature in northern Iraq has no effect on Awassi ram semen. There is a significant effect of season on bacterial count on Awassi ram semen.     

围产前期饲喂DCAD对奶牛营养代谢疾病的影响

试验通过在奶牛围产前期日粮中以?瘙
厫560 g/kg的标准添加阴离子盐,以观察DCAD的饲喂效果.结果表明:在奶牛围产前期饲喂阴离子盐有利于牛体健康,能显著降低产后瘫痪及乳房炎的发病率(P＜0.05),极显著降低胎衣不下和子宫内膜炎的发病率(P＜0.01),同时有利于奶牛产后体况的恢复,缩短奶牛产后第一次发情时间26.5天(P＜0.05),显著提高奶牛产奶量,产后30天奶牛日产奶量可提高11.7%(P＜0.05).     

合肥市某奶牛场隐性乳房炎发生规律的研究

2002年1月至2002年12月,对合肥市某奶牛场泌乳母牛进行隐性乳房炎的SMT逐月检测。结果表明:阳性牛的分布无明显季节性,但存在牛群差异性,而新感染阳性率与季节有明显关系(P<0.01),以三、四季度为高;二、三胎牛阳性率极显著高于其他胎次(P<0.01);第五、第六个泌乳月和第九个泌乳月以上牛新感染阳性率极显著高于其它牛(P<0.01);右侧乳区阳性率极显著高于左侧乳区(P<0.01)。     

Seasonality of oestrus,ovulation and ovulation rate of Sicilo‐Sarde sheep

This study aimed to investigate monthly changes in oestrus and ovulatory activity of Sicilo‐Sarde sheep. Experimental animals comprised 25 adult and 10 maiden ewes at the start of the experiment. For 12 consecutive months (September–August), the females were exposed to natural photoperiod and permanently kept in presence of seven aproned rams. Oestrus was checked daily and ovarian activity was monitored by monthly endoscopies during the last week of each month. Ovulation rate for a particular month was assessed as the sum of corpora lutea or corpora albicans present on both ovaries at the time of endoscopy. Proportions of ewes observed in oestrus at least once a month were lowest in March (24.3%) and highest in June and October (100%). They tended (p < 0.06) to be different according to age, dropping during summer from a common value of 100% in June to 85.7% and 90% in July and then to 57.1% and 70% in August for, respectively, the Adults and Maiden females. Overall, the experimental period, 92.5% and 83.8% of Adult and Maiden ewes ovulated at least once per month (p < 0.01) respectively. Least proportions ovulating, attained 60% and 30% in April for, respectively, Adult and Maiden ewes before peaking up at 100% again in May (p < 0.05). Mean (±SD) ovulation rate of Sicilo‐Sarde sheep is 1.40 ± 0.503. Adult females had a higher (p < 0.001) ovulation rate than Maiden sheep with respective average values of 1.51 ± 0.516 and 1.16 ± 0.373. It varied little between months and decreased in Adults from a maximum value of 1.95 in October to a minimum value of 1.16 in April. It is concluded that benchmarking seasonal variations of reproductive activity in Sicilo‐Sarde breed would be valuable in designing improved management calendars for this breed.     

气温对种猪繁殖性能的影响

为研究气温对种猪繁殖性能的影响，对杭州市种猪试验场2004、2005两年3866胎长白和大白母猪的分娩记录、断奶后发情配种记录及75头长白公猪精液检测记录进行分析。结果表明：两品种母猪产仔数随状气温上升而下降。长白猪2～6月份总产仔数及活仔数均高于年均值（9．62、9．02头），7月份产活仔数开始下降，8月份死仔数达1．08头，比年均值高1倍，8月份至翌年1月份产仔数都在年均值以下。大白猪表现同样规律，8月份死仔数为0．85头，也是年均值的2倍，7～11月份产仔数在年均值（10．37、9．96头）以下。两个品种的返情率都随气温上升而升高，8月份达到高峰，长白猪前后持续3个月，大白猪仅1个月。长白公猪的精液品质亦随气温上升而下降，精子活力与气温的相关系数为-0．77（P〈0．05）。长白母猪受热应激的影响比大白母猪要严重，在热应激下产生的负面影响母猪大于公猪。     

祁连山南麓高寒灌丛GPP变化特征及对生长季积温的响应

全球气候变化背景下气温逐渐升高,将会对陆地生态系统碳循环产生重要影响。研究利用2003?2016年的涡度相关系统观测资料,研究了祁连山南麓高寒灌丛生长季(5月?9月)总初级生产力(gross primary productivity,GPP)在不同时间尺度上对生长季有效积温(growing season degree days,GDD)的响应,对于研究气候变暖对高寒生态系统碳循环的影响有重要意义。结果表明:高寒灌丛生态系统在生长季的月GPP、GDD都表现为先增大后减小的单峰变化趋势,都在7月或8月达到峰值,在5月达到最小值。在整个生长季尺度上,GPP与GDD具有较高变异性,但整体上表现为逐渐增加的趋势(P<0.05)。2003?2016年整个生长季GPP与GDD的均值分别为507.11 g·m^?2和975.93℃。在月尺度和生长季尺度上,GPP与GDD都呈显著正相关关系(P<0.05)。但是,通过比较生长季每个月GPP与GDD的关系发现,5、9月的GPP与GDD没有显著相关性(P>0.05),而在7月相关性最为显著(P<0.01)。整体上看,高寒灌丛生态系统植被的总初级生产力与热量条件表现为正相关关系,由此说明在全球气候变暖的背景下,青藏高原高寒灌丛生态系统植被的光合生产能力将会提高。