供体年龄对德国肉用美利奴羊超数排卵及胚胎移植效果的影响

提高绵羊体内胚胎生产的效率对促进优良品种扩繁及良种推广具有重要意义。为充分利用不同年龄段良种德国肉用美利奴羊,试验选用青年(18月龄,配种未受胎)、老龄(60~72月龄,经产)以及幼龄母羊(7月龄,性成熟前)做供体,用改进的程序进行超数排卵,研究供体年龄与超数排卵和胚胎移植效果的关系。结果表明:①青年、老龄组母羊超排后只均可用胚数分别为10.9枚、10.3枚,显著高于幼龄母羊的6.0枚。青年、老龄组母羊的胚胎经移植后受胎率分别为71.6%、58.3%,显著高于幼龄组的41.7%。②幼龄、青年组回收的胚胎中囊胚所占比例显著高于老龄组,说明幼龄、青年组供体的胚胎发育速度显著快于老龄供体。③青年、老龄组母羊超排前预注小剂量FSH,卵巢黄体数目明显增多,说明能提高超排效果。本试验优化了德国美利奴羊的超排程序,证明年龄显著影响德国美利奴羊的超排效果及胚胎质量,为进一步提高绵羊胚胎移植效率提供了参考依据。     

不同工艺制备的水产开口饵料溶失规律试验研究

为了比较不同工艺制备的水产开口饵料中不同成分的溶失规律,试验对挤出滚圆法、挤出滚圆-流化床包衣法及膨化破碎法制备的饵料进行了质量损失率、粗蛋白溶失率、游离氨基酸(FAA)溶失率的比较研究,结果表明:膨化破碎工艺制备的开口饵料质量损失率、粗蛋白的溶失率和游离氨基酸的溶失率均高于挤出滚圆工艺;包衣没有明显改善饵料的溶失情况;游离氨基酸的溶失速度非常快,入水初期几乎全部溶失(5 min内溶失率就达到53.54%～91.71%)。     

Pregnancy Rate in Zebu Cows with Two Different Postpartum Intervals Exposed to a Two-Bull Rotational System

In order to evaluate the reproductive effect of a rotational breeding system, the pregnancy rate of 69 Zebu cows was assessed, 32 late postpartum (211±93 days postpartum, LP) and 37 early postpartum (averaging 63±8 days after calving, EP). In the LP group, 60% (19/32) were cycling before exposure to the bulls but only 38% (14/37) in the EP group. The two groups were dissimilar from the start (p<0.05). The cows were exposed in a rotational breeding system, with six Brahman bulls with previous sexual experience paired off in three groups (A–B, C–D and E–F). The cows were exposed to each pair of bulls for a period of 3 weeks, with one week in between each period, when the females were without the presence of a male. In the LP group, the pair of bulls A–B obtained a pregnancy rate of 72% (23/32), whereas for bulls C–D the pregnancy rate was 33% (3/9) and for bulls E–F the pregnancy rate was 67% (4/6). In contrast, for the EP cows, bulls A–B obtained a pregnancy rate of 32% (12/37), bulls C–D a pregnancy rate of 67% (12/18) and for bulls E–F a pregnancy rate of 55% (6/11). The percentage pregnancy obtained using the pair of bulls A–B differed (p<0.05) between LP and EP, whereas for bulls C–D and E–F it was similar. The pregnancy rate was different (p<0.05) in the first 3 weeks of mating for the LP group, the highest number of cows becoming pregnant during the first 3 weeks of the study. In contrast, the highest number of pregnancies in EP occurred evenly during the last 6 weeks. This study suggests that the reproductive performance of pairs of bulls in a 9-week rotational programme with the overall pregnancy rate is similar (94% in the LP and 81% in the EP). However, the time taken for the females to become pregnant, and hence the performance of the bulls, is related to the average number of days postpartum for the cows.     

獒本杂交犬繁育性能研究

通过对獒本杂交犬与当地土种犬发情时间、配种时间、产活仔数、幼犬初生重等的对比研究,发现獒本杂交犬发情时间集中在9~11月份,发情受胎率与母犬年龄及养殖条件有关,常规养殖下3~4岁獒本杂交母犬发情率为100%,2~4岁獒本杂交母犬受胎率达到100%。獒本杂交犬产仔力和哺乳性能等繁育性能指标明显高于本地土种犬,1~5岁龄杂交母犬的平均活产仔数显著高于当地土种犬(P(0.05);仔犬平均初生重显著高于当地土种犬(P(0.05);仔犬断奶平均个体体重显著高于当地土种犬(P(0.01);仔犬断奶平均窝重显著高于当地土种犬(P(0.05);幼犬断奶成活数比土种犬高14.3%。     

提高烤烟C4F收购等级合格率的途径

烤烟C4F是中部烟叶相对其他等级价廉物美的一个等级,其配伍性强,工业企业需求量大。近年来,由于烟叶收购站点的收购人员、预检人员和烟农对C4F的标准把握不准确,造成C4F及其相邻等级收购等级合格率偏低。因此,通过研究提高C4F等级合格率的途径,对提高烟草等级的合格率具有重要的意义。     

断奶日龄对仔猪Et玫瑰花环形成率和T淋巴细胞转化率的影响

选取15窝杜洛克×长白×约克夏三元杂交初生仔猪 ,按14、21、28、35日龄断奶和不断奶随机分为5组(14E、21E、28E、35E、C) ,每组3窝 ,研究断奶及不同断奶日龄对仔猪外周血Et玫瑰花环形成率和T淋巴细胞转化率的影响。结果表明 :哺乳仔猪外周血Et玫瑰花环形成率、淋巴细胞转化率LTT(PHA、LPS刺激原)随日龄增长呈线性加大的趋势(P<0.05) ;断奶应激均使Et、LTT(PHA)、LTT(LPS)降低(P<0.05)。断奶越早 ,断奶后血液LTT(PHA/LPS)下降的幅度越大 ,恢复与哺乳猪相同水平的时间越长 ,其中14日龄断奶后1～3周 ,21、28日龄断奶后1周LTT(PHA)显著低于对照组(P<0.05) ;14日龄断奶后1～4周 ,21日龄断奶后1～3周 ,28日龄断奶后1～2周 ,35日龄断奶后1周LTT(LPS)显著低于对照组(P<0.05)。     

Heart Rate Variability in Horses Engaged in Equine-Assisted Activities

Although there has been a recent surge in using horses to treat mental and emotional human health issues, the consequences of horse-assisted interventions on the stress response of horses have not been well documented. Assessment of the autonomic nervous system and its regulation of cardiovascular function has been used as an indicator of acute and chronic stress in human beings and horses. Heart rate variability (HRV) is a noninvasive measurement that has been used to assess autonomic nervous system regulation of cardiovascular function. There is evidence to suggest that several factors including the genotype, behavior, environment, temperament, and nutritional status of the horse play a key role in the large inter-individual variations in basal HRV. The present study determined whether 24-hour HRV recordings in horses currently working in equine-assisted therapy (EAT) differ from those previously shown in Thoroughbred horses. Findings from the present study found that in contrast to previous studies in Thoroughbred horses, diurnal and nocturnal low frequency and high frequency powers were not significantly different in horses that are currently engaged in EAT. Future studies are needed to determine the short- and long-term consequences of horses participating in EAT programs. Findings from this study will provide the basis for the development of a physiological/behavioral assessment criteria to determine the consequences of EAT on the well-being of horses as well as to help EAT Centers to improve the beneficial effects of EAT in human beings.     

五种牧草及三种草坪草种子寄藏真菌检测初探

采用PDA平皿法和滤纸法检测了市售5个牧草品种和3个草坪草品种种子样品寄藏真菌的情况,并就分离获得的真菌对种子出苗及幼苗生长的影响进行了初步研究.结果表明,供试种子样品带菌率为0～70.5%,分离获得的35个真菌分离物大多属于镰刀菌(Fusarium spp.)、链格孢菌(Alternaria spp.)、蠕孢菌(Helminthosporium spp.)、小核菌(Sclerotium sp.)、匍柄霉菌(Stemphylium spp.)和曲霉菌(Aspergillus spp.).供试样品中假俭草和波多马各(鸭茅)种子带菌率较高,在PDA平皿检测中其未经表面消毒处理的种子带菌率分别为48.4%和70.5%,表面消毒处理种子带菌率分别为40.8%和28.8%,分离获得的种子寄藏真菌对假俭草和波多马各种子出苗及幼苗生长的影响较小.圣地亚哥(南苜蓿)和菊苣种子带菌率较低,但分离获得的真菌对其种子出苗和幼苗生长的影响较大.以镰刀菌与匍柄霉菌接种过的南苜蓿种子出苗率分别比未经表面消毒且未接种真菌的对照低44.0%和21.7%,出苗后的病苗率分别为22.7%和29.7%;以链格孢菌与曲霉菌接种过的菊苣种子的出苗率分别比未经表面消毒且未接种真菌的对照低22.0%和27.5%,出苗后的病苗率分别为2.3%和29.3%.     

含氟废水深度处理的研究

以火力发电厂的废树脂为载体 ,制备了负载锆水合氧化物的氟离子吸附树脂 ,并探讨了该负载树脂对氟离子的吸附和脱附性能 .结果表明 :制备该负载树脂的适宜锆浓度为 0 5mol L ,负载树脂吸附和脱附的适宜pH值分别为4 0和 12 0 .该负载树脂的吸附符合Langmuir型吸附等温线 ,通过这种等温线可以得出 ,CF- =1mg L时负载树脂的平衡吸附量qe 为 5 0 0 0mg L .利用该负载树脂对模拟火电厂的含氟废水进行处理 ,取得了较好的效果 .