林麝电刺激采精及精液品质分析

采用电刺激采精法对 8头林麝采精 2 6次 ,并对所采得的精液进行了品质分析。结果表明 ,林麝每次射精量平均体积 0 3 5 6ml± 0 0 62ml,pH值 7 3 1± 0 2 74,精子平均密度为 ( 4 0 3 8± 0 62 4)× 10 8/ml ,精子平均活率为 78 75 %± 4 43 2 % ,畸形精子率为 14 5 7%± 2 0 3 1%。电刺激法采得林麝精液品质稳定 ,采精过程中用 846合剂麻醉保定 ,证明是一种适合林麝的人工采精方法     

山羊电刺激采精技术的研究

使用电刺激采精仪对4只1～2岁的烟台本地山羊进行了精液采集。将4只公山羊的其中2只在采精前用鹿眠宁（盐酸赛拉嗪注射液）进行保定麻醉,其余2只没有保定麻醉。并用大小不同的电压对公山羊进行了直肠电刺激。最后,对麻醉与非麻醉两种不同状态下采精时的射精电压、射精时间、精液量、生殖器勃起状态及精子活力进行了分析。本试验结果表明,电刺激采精法对公山羊的精子活力影响不大,但其采精量偏少。总体来说,此采精法对公山羊是一种适宜的方法。     

天山马鹿电刺激采精技术的研究

选用20头6～9岁的成年天山马鹿公鹿进行电刺激采精.采精前对公鹿采用鹿眠宝(2 mg/kg)、静松灵(3～5 mg/kg)、静松灵(2 mg/kg)+鹿眠宝(1 mg/kg)3种方法麻醉.结果表明:采用静松灵+鹿眠宝麻醉保定后,6头公鹿均可以正常采精,采出的精液品质可以用于人工授精.采用单独的静松灵麻醉保定后,6头公鹿电刺激采精除1头公鹿未能采下精液外,其它公鹿均能正常采精,其精液品质也可正常用于人工授精;单独采用鹿眠宝麻醉保定,7头公鹿电刺激仅3头能正常采精.     

塔里木马鹿公鹿半麻站立式采精技术

为了筛选一种安全有效的、适合塔里木马鹿的电刺激采精保定方法,试验对10头塔里木马鹿种公鹿分别采用全麻侧卧式和半麻站立式电刺激方法进行采精.结果表明:半麻站立式采精方法取得的精液品质较好,各项指标较理想.全麻侧卧式保定方法的采精量平均1.71 mL,鲜精活力平均为0.72,电刺激采精时间为6min,精液稠密;半麻站立式保定方法采精量平均为3.45 mL,鲜精活力平均在0.85,电刺激采精时间为15 min,精液密度中等.     

貉按摩法采精技术的研究

试验成功地进行了貉按摩法采精与精液评定,并初步建立了貉按摩法采精技术。采精成功率为27．9％,每次平均射精量为（0．29±0．18）mL,pH值为6．64±0．19,密度为（0．99±0．83）×10^8个／mL,活力为0．81±0．71,畸形率为16．41％±2．20％,活精子率为85．11％±8．30％。     

家养海狸鼠人工采精技术初探

本试验在人工保定的情况下，对家养的性成熟海狸鼠，１９９３．６—１９９３．７月间环境温度１０—２０℃条件下，通过按摩和电刺激相结合进行采精获得成功。射精电压为３伏或６伏，精液量１毫升，精子活率０．５１，密度６亿／毫升，ＰＨ６．４。     

昆明犬的精液品质分析

以昆明犬核心种群公犬为研究对象，采用手握按摩采精法采集精液，并进行精液品质分析。结果表明：昆明犬公犬平均每次采精量（5．51±2．24）mL，平均精子密度为（3．71±2．82）×10^8／mL，平均精子活力为（83．784-13．29）％，平均精子活率为（91．57±8．02）％。a级精子、b级精子、c级精子和d级精子含量分别为（42．38±5．65）％、（42．38±6．50）％、（9．61-4-2．04）％和（5．64±1．05）％。昆明犬品系间，采精量狼青品系为（6．28±3．53）mL和草黄品系为（5．81±2．24）mL显著高于黑背品系的（3．48±2．71）mL；a＋b级精子含量狼青品系为（92．26±6．01）％显著高于草黄品系（85．77±5．56）％和黑背品系的（80．19±8．64）％；而精子密度、精子活力和精子活率在3个品系间差异均不显著。     

甘肃高寒牧区藏羊电刺激采精实验

为研究电刺激采精技术能否在甘肃高寒牧区藏系羊繁殖中推广应用,该技术是否对公羊精液品质和采精量有影响,项目课题组在甘肃省天祝县旦马乡进行了牧区藏羊种公羊电刺激采精实验。选择本土选育的欧拉型藏羊种公羊,配种期每日每只采精2次,即：首日（标注为d1）早上采用传统的假阴道采精法采精,下午采用电刺激法采精,次日（标注为d2）早上采用电刺激法采精,下午采用传统的假阴道采精法采精,依次不同采精方法交叉采精,减少误差,连续采精6d,及时检查采精量及精液密度、精子活力等品质。实验结果表明,甘肃天祝牧区藏羊种公羊电刺激采精所得精液量均在0.80 mL～0.96 mL之间,符合藏系羊正常精液量,平均精子活力均在0.80以上,平均精液密度均“中”以上,精液品质符合人工授精精液品质要求,可应用于藏羊繁殖生产实践。     

鹅的人工授精技术

一、鹅的采精方法 1.电刺激采精法 此法可不需事先对公鹅进行调教训练。在进行公鹅电刺激采精时,电刺激采精仪的输出电压应为20伏,电流为40～50毫安。公鹅保定后,采精仪的正电极刺入肠骨部下皮层,负电极插入直肠4厘米,以5秒钟的时间间隔重复刺激3～5次,即可引起公鹅射精。     

狸獭人工授精的试验研究

对１１只狸獭（Ｍｙｏｃａｓｔｏｒｃｏｙｐｕｓ）用按摩和电刺激相结合的方法人工采精３２只次，成功２７次，成功率８４．４％；射精量为（０．９７±０．１６）ｍＬ，精子密度（７．３４±１．４９）亿／ｍＬ，精子活力０．６５±０．１２，精子畸形率（８．８１±２．５１）％，精液ｐＨ值６．４４±０．１６。对诱排公狸施行输精管结扎术，先后给５只母狸人工输精，每只输精２～３次，在输精后４０～６０ｄ检查，４只受孕，其中有３只顺利产仔，产仔数分别为７只、７只、４只     

乌苏里貉电刺激采精技术

1996～ 2 0 0 3年在乌苏里貉配种期对 33只雄貉用地西泮和盐酸氯胺酮复合麻醉后 ,进行了 70次电刺激采精试验 ,结果成功 6 8次 ,成功率 97.1% ,采精量平均为 (1.5 5± 1.35 )mL ,精液品质优良。采精后 ,没有发现雄貉有不良反应。     

海福特牛精液品质及保存稀释液配方研究

对饲养在三峡库区重庆境内的4头海福特牛的精液品质及标温（37℃）和低温（0～5℃）条件下精液保存稀释液配方进行了研究。结果表明:海福特公牛精液品质符合种用公牛繁殖要求,精液呈乳白色或稍带黄色,云雾状明显,采精量为（8.28±1.13）mL,pH值为7.03±0.09,精子密度为（10.67±1.67）亿/mL,活力为0.88±0.05,精子畸形率（％）为9.52±2.46。对4头公牛精液品质进行了排序,提出了常温和低温条件下适宜的精液保存稀释液配方。     

Sulfated cholecystokinin‐8 increases ghrelin secretion but does not affect oxyntomodulin in Holstein steers

The effect of appetite regulatory hormone cholecystokinin (CCK) on the secretions of oxyntomodulin (OXM) and ghrelin, and the effect of ghrelin on the secretions of CCK and OXM were studied in ruminants. Eight Holstein steers, 7 months old, 243 ± 7 kg body weight (BW), were arranged in an incomplete Latin square design (8 animals × 4 treatments × 4 days of sampling). Steers were intravenously injected with 10 µg of sulfated CCK‐8/kg BW, 20 µg of acyl ghrelin/kg BW, 100 µg of des‐acyl ghrelin/kg BW or vehicle. Blood samples were collected from ?60 min to 120 min relative to time of injection. Plasma concentrations of ghrelin, sulfated CCK and OXM were measured by double‐antibody radioimmunoassay. Plasma acyl ghrelin was increased to peak level (428.3 ± 6 pg/mL) at 60 min after injection of CCK compared with pre‐injected levels (203.3 ± 1 pg/mL). These results showed for the first time, that intravenous bolus injection of CCK increased ghrelin secretion in ruminants. In contrast, injection of ghrelin did not change CCK secretion. Administration of ghrelin or CCK has no effect on plasma OXM concentrations. In conclusion, our results show that administration of CCK increased ghrelin secretion but did not affect OXM release in ruminants. Ghrelin did not affect the secretions of CCK and OXM.     

梅花鹿电刺激采精技术研究

为提高鹿产品质量,发展优良鹿群数量,扩大优良基因在时间和地域上的利用率,2004年11月份在梅花鹿配种期对5头雄性梅花鹿进行了5次电刺激采精试验,成功5次,成功率100%,采得的精液品质优良,采精量为0.4~2.0 mL,平均采精量为1.28 mL,精子密度为5~10亿个/mL,活力为0.4~0.6,采精后雄鹿食欲、精神正常。     

红腹锦鸡精液冷冻稀释液配方的筛选

为加强濒危珍稀动物种质资源的保护,开展了濒危珍稀禽类—红腹锦鸡的人工授精研究。2005年5月26日~6月8日,对8只红腹锦鸡用手按摩其背、尾部采精12次。初测其精液品质,结果表明,采精量平均(0.114±0.016)mL(0.01~0.2 mL),每毫升精液中精子平均3.2亿个(3.0~3.3亿),活力9级以上,pH值6.5,偏酸性,淡乳白色(半透明似冲熟的藕粉),微腥。鲜精分别加11%蔗糖—卵黄稀释液(3号液);11%蔗糖—0.1%柠檬酸三钠—卵黄稀释液(5号液);5%葡萄糖—卵黄稀释液(8号液)。精子活力达8~9级。用3%柠檬酸三钠—卵黄稀释液(2号液)稀释,精子活力2级。冷冻时,用11%蔗糖溶液100 mL中加16 mL鲜卵黄,加5 mL甘油,配制的3号冷冻稀释液稀释,解冻后,精子活力达4级。优于试验中选拟的其它配方(加入5 mL甘油的5号冷冻液,解冻后精子活力为3级;加入5 mL甘油的8号冷冻液,解冻后未见活的精子)。如果冷冻稀释液中甘油改为6 mL,则解冻后精子全部死亡。     

Depletion of florfenicol in lactating dairy cows after intramammary and subcutaneous administration

Eighteen Holstein dairy cows ranging in body weight from 500–700 kg and with an average milk yield of 37 ± 6 kg/day were used to investigate the depletion of florfenicol (FFL) in milk and plasma of dairy cows. Three groups of six were administered FFL: Group A, intramammary (IMM) infusion of ~2.5 mg FFL/kg BW at three consecutive milking intervals (total amount of ~7.5 mg/kg BW); Group B, one IMM infusion (20 mg/kg BW) into one quarter and Group C, one subcutaneous (SC) treatment (40 mg/kg BW). IMM infusions were into the right front quarter. Cows were milked daily at 06:00 and 18:00 h. The highest concentrations (C_max) and time to C_max (T_max) were: 1.6 ± 2.2 μg·FFL/mL milk at 22 h (Group A), 5.5 ± 3.6 μg·FFL/mL milk at 12 h (Group B), and 1.7 ± 0.4 μg·FFL/mL milk at 12 h (Group C). The half‐lives (t_1/2) were ~19, 5.5, and 60 h, for Groups A, B, and C, respectively. FFL was below the limit of detection (LOD) by 60 h in three Group B cows, but above the LOD at 72, 84, and 120 h in three cows. FFL was above the LOD in milk from Group C's cows for 432–588 h. Plasma values followed the same trends as milk. The results demonstrate that IMM‐infused FFL is bioavailable and below the LOD within 72–120 h. The concentration of FFL was detectable in both plasma and milk over the course of 2–3 weeks after SC administration. The absence of residue depletion data presents problems in determining safe levels of FFL residues in milk and edible tissues. The data presented here must not be construed as approval for extra‐label use in food animals.     

Performance,endocrine, metabolic,and reproductive responses of Nellore heifers submitted to different supplementation levels pre- and post-weaning

The present study was conducted to evaluate the effects of high and low supplementation levels pre- and post-weaning on performance, endocrine, metabolic, and reproductive responses of Nellore heifers. Fifty Nellore heifers with 132?±?9.9 kg average body weight (BW) and 138?±?19 days of age were supplemented from 4 to 14 months. The heifers were distributed into five supplementation plans: HH—6 g/kg of BW of supplement pre- and post-weaning, HL—6 g/kg of BW of supplement pre-weaning and 3 g/kg post-weaning, LH—3 g/kg of BW pre-weaning and 6 g/kg of BW post-weaning, LL—3 g/kg of BW pre- and post-weaning, and CC—control, no supplementation. Interactions were not significant (P?>?0.10). The level of supplement fed pre-weaning did not affect any of the performance variables evaluated at the end of the experiment (P?>?0.10). There was a significant effect of supplementation and level of supplementation fed post-weaning on average daily gain (ADG) and final BW (P?<?0.05). Overall ADG was also affected only by supplementation and level of supplement fed post-weaning (P?<?0.05) with animals receiving 6 g/kg of BW post-weaning gaining more weight. Follicular diameter was greater in animals that received 6 g/kg of BW post-weaning (P?<?0.05). In summary, performance, endocrine, metabolic, and reproductive variables evaluated in the current study were improved by the level of supplement fed post-weaning. Heifers receiving supplementation of 6 g/kg of BW post-weaning had greater responses, independent of the level received during the pre-weaning phase.     

13种激素对暖季天然草场放牧羔羊生长发育调控的研究

试验选取4月龄、平均体重为(24.71±2.07)kg的哈萨克土种公羔羊20只,于2008年5月15日-9月23日进行自然放牧羔羊各月龄体重、采食量和激素含量变化测定。试验结果表明,4～8月龄羔羊月平均日增重依次为175 g±34 g、92g±36 g、158 g±46 g和81 g±36 g,羔羊增重在4～5和6～7月龄出现2个高峰期,平均日增重高于5～6和7～8月龄。放牧羔羊干物质采食量逐月增高,4～8月龄依次为0.65 kg±0.21 kg、1.45 kg±0.32 kg、1.74 kg±0.48 kg、1.95 kg±0.50 kg和2.30 kg±0.45 kg,且各月龄间差异极显著(P0.01)。全期血清激素NPY含量5月龄最高(39.10 pg/mL±2.60pg/mL),7月龄最低(36.87 pg/mL±1.10 pg/mL);血清CCK、PP、SS、CORT含量,各月龄间差异不显著(P0.05),最高值分别为4月龄(45.19 pg/mL±9.70 pg/mL)、8月龄(108.53 pg/mL±19 pg/mL)、6月龄(160.34 pg/mL±10 pg/mL)、4月龄(22.1 ng/mL±4 ng/mL);GAS、T3、T4含量,4～8月龄逐渐升高;全期血清T4含量5月龄最高(78.30 ng/mL±12.7 ng/mL)、7月龄最低(65.83 ng/mL±13 ng/mL);MTL、SEC、GH、INS、T3变化规律相同,4～5和6～7月龄升高、5～6和7～8月龄降低。     

Intramuscular Fat Deposition in Steers Is Accelerated at a Set Body Weight

Seventy-two Angus crossbred steers (average initial BW, 351 ± 5.5 kg) were used to ascertain the breakpoint in BW above which intramuscular fat deposition was accelerated. Steers were randomly assigned to one of three treatments in an unbalanced study; treatment groups represented a BW at which steers would enter the feedlot (363, 408, or 454 kg). Until entering the feedlot, steers were grazed on pasture and supplemented to achieve 0.8 kg gain/d. Intramuscular fat deposition, measured ultrasonically, and live BW were acquired on d 0 and at 28-d intervals thereafter on each animal until harvest. In the feedlot, steers were fed a 13.4% CP concentrate diet until they reached a final BW of approximately 567 kg. After slaughter, carcass data were collected. No differences (P < 0.05) in ADG on pasture (0.85 ± 0.14 kg) or in the feedlot (1.70 ± 0.07 kg) occurred among treatments. There was good agreement between predicted and measured carcass quality grade (QG) (5.5 and 5.2, respectively). Based on broken-line analysis, deposition of intramuscular fat began to increase at approximately 378 kg regardless of BW at entry into the feedlot. The breakpoint BW for increased intramuscular fat accretion rate was calculated as 64% of mature BW of these steers.     

Oxytetracycline Pharmacokinetics in Rainbow Trout during and after an Orally Administered Medicated Feed Regimen

Abstract

The pharmacokinetic–pharmacodynamic predictor of antimicrobial activity for tetracyclines is reported to be the area under the concentration–time curve at steady state (AUC_ss) divided by the minimal inhibitory concentration of the targeted pathogen. Here, we estimate AUC_ss values for oxytetracycline (OTC) in serum of rainbow trout Oncorhynchus mykiss by using a destructive sampling study design. Seventy-two rainbow trout were fed OTC-medicated feed at 74.7 ± 1.5 mg/kg (mean ± SD) body weight (BW) by oral gavage for 10 consecutive days. Serum was collected from nine fish at 1, 3, 6, 8, 10, 12, 15, and 22 d after dosing began. Serum OTC concentrations were measured by high-performance liquid chromatography with a 0.01-μg/mL limit of detection. The average OTC AUC_ss was 29.2 μg × h/mL and was estimated using nonlinear mixed-effects modeling and bootstrap resampling techniques. The elimination half-life was estimated as 85.0 h, and the fraction of steady state achieved was estimated as 0.85. The calculated AUC_ss (24.8 μg × h/mL) following 10 d of oral dosing with 75 mg OTC/kg BW was less than the estimated AUC_ss. Results suggest that the pharmacokinetics of OTC exposure, including the AUC_ss, is better evaluated by using multiday dosimetry than by using a standard single-dose protocol.

Received September 29, 2011; accepted January 30, 2012