胆酸负荷对妊娠后期绵羊母体和胎儿血浆IGF—2及其代谢物水平的影响

以绵羊及其胎儿为试验对象，研究了胆酸负荷对妊娠后期母体和胎儿血浆胰岛素样生长因子－2(in-sulin-like growth factor-2,IGF-2）及其代谢物水平的影响。将7只确知妊娠时间的绵羊分为试验组5只和对照组2只，试验前装置颈静脉瘘，在妊娠90h和104d2闪给试验组静脉灌注胆酸盐1．1mg/kg，给对照组静脉灌注等量生理盐水，妊娠120d时手术安装胎儿后肢胫前动脉血管瘘。每天采胎儿和母体的血样，分离血浆，测定血浆IGF－2和主要代谢物水平。同时测定胎儿出生时生长发育指标。结果表明：（1）试验组母羊IGF－2水平低于对照组，相反其胎儿IGF－2水平却高于对照组（P＜0．05）；（2）试验组母羊的总蛋白和乳酸水平分别比对照组35．64％；（3）试验组胎儿出生重比对照组小29．00％，胎龄短7．50d。因此认为，胆酸重复灌注可引起妊娠绵羊早产和胎儿出生重降低，而这可能与IGF－2和主要代谢物水平变化有关。     

精氨酸对妊娠后期鄂尔多斯细毛羊胎儿生长发育的影响研究

旨在通过对鄂尔多斯细毛羊母羊颈静脉灌注L-精氨酸,研究其对鄂尔多斯细毛羊母羊妊娠后期（90-140d）胎儿生长与发育的影响。试验选择22只母羊,在90 d开始灌注115μmol L-Arg-HCl/kg体重（Arg1组）、155μmol L-Arg-HCl/kg体重（Arg2组）和生理盐水（对照组）,3次/d。妊娠第115天和第140天,进行实验母羊孕体检查,并记录胎儿体重、器官重量和体尺长度,收集母体及胎儿血浆测定血浆氨基酸浓度。结果表明,母羊妊娠第140天,Arg2组较Arg1组和对照组显著增加了胎儿心脏和肝脏重量（P〈0.05）。母羊妊娠第115天和第140天,灌注L-精氨酸显著增加母体血浆精氨酸和鸟氨酸浓度（P≤0.01）,增加胎儿血浆生糖氨基酸（苏氨酸、甲硫氨酸、苯丙氨酸和赖氨酸）浓度（P≤0.05）。     

胆酸负荷对妊娠大鼠母体及其胎儿IGF-2和营养代谢物水平的影响

30只成年妊娠SD大鼠随机分为A，B，C3组，在妊娠13－20d给A组和B组大鼠每天分别腹腔注射2.9mg/kg和5.5mg/kg胆酸，C组同步注射等量生理盐水。妊娠21d时宰杀母鼠，剖腹取胎，测定胎儿体重，胚胎成活率。并采集母体和胎儿血样，测定IGF－2、胰岛素和代谢物水平。结果表明，低剂量胆酸注射导致胎儿成活率降低7．02％，胎儿血浆IGF－2升高及乳酸和总蛋白水平降低，母体血浆IGF－2和胰岛素水平降低。较大剂量胆酸注射使胎儿成活率和体重分别下降38．27％和7．33％，血浆IGF－2、胰岛素和总蛋白水平下降。结果提示长期胆酸负荷对胎儿生长发育产生严重影响，胎儿死亡率增加及生长迟缓与IGF－2、胰岛素水平降低有关。     

绵羊大肠阻塞病理模型血浆及组织中内皮素-1含量的变化

选择绵羊建立反刍动物大肠阻塞病理模型 ,对手术前、后静脉血浆及死亡后心脏、肝脏、脾脏、肺脏、肾脏、胰脏和肠组织中内皮素 - 1( Endothelin- 1,ET- 1)含量进行测定 ,探讨了该模型血浆及组织中 ET- 1含量的变化和临床意义。结果表明 :模型组和对照组手术前血浆 ET- 1含量分别为 ( 5 7.81± 2 .95 ) ng/L 和 ( 6 2 .72± 3.17) ng/L,手术后含量分别为 ( 4 1.87± 8.0 6 ) ng/L 和 ( 6 0 .74± 4 .6 8) ng/L,模型组术后 ET- 1含量明显下降 ( P<0 .0 5 ) ;每 30 min间隔采血 ,模型组术前、术后第 2天和第 4天 ET- 1含量依次降低 ,差异极显著 ( P<0 .0 1) ;模型组心、肺、肾组织中的 ET- 1含量分别为 ( 2 73.2 8± 5 3.7)、( 2 70 .6 5± 98.6 )、( 2 4 9.32± 2 0 .8) ng/L,分别比对照组心脏 ( 10 5 .73± 32 .2 ) ng/L、肺脏 ( 34.34± 6 .73) ng/L、肾脏 ( 5 0 .4 3± 12 .89) ng/L明显升高 ( P<0 .0 1)。这些变化可能与肠阻塞的发生、发展有密切关系。     

5-羟色胺前体物对围产期母羊泌乳性能及血浆生化指标的影响

本试验旨在研究5-羟色胺(5-HT)前体物对围产期母羊泌乳性能及血浆生化指标的影响。选择体况良好、体重(64.52±4.11) kg、处于同一围产期的30只巴美肉羊母羊,按体重随机分为3组,即对照组(灌注生理盐水)、5-羟基色胺酸(5-HTP)组(灌注5-HTP)和色氨酸(Trp)组(灌注Trp),每组10只。在母羊围产期产前第7天至产后当天(第0天),进行颈静脉灌注,5-HTP和Trp的灌注剂量均为0.178 mg/kg BW,浓度为0.1 mg/mL;对照组灌注同等剂量的生理盐水。试验期为产前第7天至产后第30天。结果表明:1) 5-HTP和Trp对母羊泌乳量及乳蛋白含量无显著影响(P 0. 05),但使母羊产后第3天乳脂和乳中非脂固体含量显著降低(P 0.05)。2) 5-HTP和Trp可以显著提高母羊产前第0天及产后第3、6、9天的血浆5-HT浓度(P0.05)。3) 5-HTP和Trp可以显著提高母羊产前第0天及产后第3、6、9天的血浆葡萄糖浓度(P0.05),显著降低母羊羊产前第0天及产后第3、9天的血浆非酯化脂肪酸(NEFA)浓度(P0.05),显著降低母羊羊产前第0天及产后第3、6天的血浆胰岛素(INS)浓度(P0.05)。由此可见,灌注5-HT前体物可以影响围产期母羊乳脂和乳中非脂固体含量,提高血浆葡萄糖浓度,降低血浆NEFA和INS浓度     

利血平和氟哌啶醇对奶山羊血浆促乳素水平的影响

本试验将20只体况相近、未孕、不泌乳的奶山羊,随机分为利血平1组(R_1)、利血平2组(R_2)、氟哌啶醇组(H组)和对照组,每组各5只羊。R_1组和R_2组分别按每kg体重肌注利血平0.02和0.04mg,H组按每kg体重肌注氟哌啶醇0.1mg,对照组肌注生理盐水。各组于注射前的5分钟和注射后的30分钟、1、2、4、6、8和12小时采血,分离血浆,应用RIA测定血浆促乳素(PRL)水平的变化。结果对照组血浆促乳素水平波动在22.8±5.9～79.831.6ng/ml之间。R_1组和R_2组在注射后的30分钟,血浆促乳素从注射前的20.5±5.6和26.3±8.3ng/ml,分别上升到39.5±11.8和74.9±30.1ng/ml,4小时达到峰值,分别为554.4±149.2和641.6±193.8ng/ml,以后缓慢降低,于注射后的12小时降至对照组水平。H组在注射后的30分钟,血浆促乳素水平从注射前的49.0±17.2ng/ml上升到435.0±71.2ng/ml,1小时达峰值606.2±129.7ng/ml,4小时降到147.9±49.8ng/ml,于注射后12小时降到对照组水平。     

怀孕后期绵羊胎儿生长发育、生理特点及其与母羊营养状态的关系

选用10只怀单羔的威尔士山地种绵羊,在怀孕111～117天期间装置胎儿生长发育瘘管、后肢动脉和静脉瘘管以及母羊股动脉瘘管,通过测定胎儿曲线冠臀长度(CRL)增长率、胎儿及母体血液葡萄糖、乳酸和α-氨基氮含量以及计算母羊每天的饲料消耗,研究了怀孕后期绵羊胎儿的生长发育形式、某些血液生理生化特点及其与母体营养状态的关系。 结果表明:绵羊胎儿在年龄约125天前生长较快,以后生长率稍缓慢而较平稳,直至分娩或分娩前几天,胎儿年龄与CRL间呈显著的相关性;胎儿血浆葡萄糖含量为12.36±2.22mg/100ml,乳酸含量为15.47±5.82mg/100ml,α-氨基氮含量为4.75±0.67mM/l;母羊血浆葡萄糖含量为66.20±7.87mg/100ml,是胎儿的5.36倍,乳酸和α-氨基氮含量是4.71±1.55mg/100ml和3.20±0.43mM/l,分别为胎儿含量的29.92％和67.37％,母体血浆α-氨基氮含量与胎儿CRL呈正相关;实验期间母羊在精料定量200g/天的情况下,青干草的自由采食量为654.96±184.18g/天,与胎儿CRL亦呈正相关。 文章还对实验方法、胎儿代谢特点及胎儿与母体间某些营养物质的交换等问题进行了讨论。     

雌酮主动免疫对美利奴母羊发情产羔和生殖内分泌的影响

20头母羊在配种季节开始前6周和3周,用雌酮免疫原免疫2次(E组),13头不作处理为对照(C组)。免疫不影响母羊正常发情,可使母羊产羔率由115.38％提高到156.25％,发情当天的LH水平显著提高(3.06±0.61对1.93±0.88miu/ml);发情周期黄体期的孕酮水平亦增加,周期12天时差异显著(9.31±3.53对3.71±0.92ng/ml);整个发情周期内E组的睾酮水平显著高于C组,而17β-雌二醇水平两组间无差异。     

静脉灌注VFA盐对水牛采食量及血浆某些代谢物和激素水平影响的研究

3头健康雄性去势水牛 ,在正常饲养 (NF)和禁食 2 4h后 (FA) 2种状态下 ,经颈静脉分别灌注 50 0mL的 2mol/L丙酸钠、 1mol/L乙酸钠和 2mol/L乙酸钠。3头正常饲养牛灌注等量生理盐水作为对照。分时段经颈静脉血管瘘管采集血样 ,测定血浆葡萄糖、胰岛素和IGF Ⅰ及各时段采食量。NF动物灌注丙酸钠后 6h内的采食量显著低于对照组 (P <0 0 5) ;灌注乙酸钠 ,低浓度在 3h和 2 4h有显著影响 (P <0 0 1 ) ,高浓度对全天的采食量均有显著影响(P <0 0 1 ,P <0 0 0 1 )。灌注后 ,胰岛素水平均显著地高于对照组。灌注丙酸钠后 ,血液葡萄糖水平低于灌注前和同期对照组的水平 ,乙酸钠对血糖无影响。灌注丙酸钠或乙酸钠后 ,血浆IGF Ⅰ水平下降 ,但差异不显著。FA动物灌注丙酸钠 ,采食量均显著低于对照组。乙酸钠对采食没有显著影响。血浆胰岛素水平在灌注后均显著升高。灌注丙酸钠后 ,血糖水平在 6h内显著高于其他组。乙酸钠无明显影响。丙酸钠灌注后血浆IGF Ⅰ水平比灌注前上升差异显著 ,乙酸钠灌注组显著下降 (P <0 0 5)。     

5-羟色胺对围产期母羊生产性能及血浆和乳中钙转运相关生化指标的影响

本试验旨在研究5-羟色胺(5-HT)对围产期母羊生产性能及血浆和乳中钙转运相关生化指标的影响。试验选用30只巴美肉羊母羊,按体重随机分为3组,分别为对照组、5-羟基色胺酸(5-HTP)组(灌注5-HTP)和色氨酸(Trp)组(灌注Trp),每组10只。在母羊围产期产前第7天至产后第0天,进行颈静脉灌注,5-HTP和Trp的灌注剂量均为0.178 mg/kg BW,浓度为0.1 mg/mL;对照组灌注同等剂量的生理盐水。试验期为产前第7天至产后第30天。结果表明:1)各组间母羊体重无显著差异(P>0.05)。产后第5、9和15天,Trp组母羊泌乳量均低于对照组(P>0.05);产后第9和15天,5-HTP组母羊泌乳量均高于对照组(P>0.05)。产后第16~30天,5-HTP组羔羊平均日增重显著高于对照组(P<0.05)。2)产后第15天,Trp组血浆和乳中钙浓度显著高于对照组(P<0.05);产后第3、6和15天,5-HTP组血浆和乳中钙浓度显著高于对照组(P<0.05)。产后第6天,Trp组血浆5-HT浓度显著高于对照组(P<0.05);产后第30天,Trp组乳中5-HT浓度显著高于对照组(P<0.05);产后第6、9和30天,5-HTP组血浆和乳中5-HT浓度显著高于对照组(P<0.05)。产后第3、6和15天,Trp组和5-HTP组血浆甲状旁腺素相关蛋白(PTHrP)浓度均显著高于对照组(P<0.05)。由此可见,灌注5-HTP可以促进母羊泌乳,提高羊羔平均日增重;灌注5-HTP和Trp可以增加血浆和乳中钙、5-HT浓度及血浆PTHrP浓度。     

十二指肠灌注不同水平大豆小肽对奶山羊小肠小肽吸收的影响

本试验旨在研究十二指肠灌注大豆小肽对奶山羊小肠小肽和游离氨基酸吸收的影响。选择7只体况良好、体质量相近的奶山羊((37.88±3.03)kg),安装永久性十二指肠近端瘘管和门静脉、肠系膜静脉近端和远端以及颈动脉慢性血插管进行4×4拉丁方试验,分别从十二指肠灌注生理盐水、60、120、180g.d-1大豆小肽。结果表明,随着十二指肠大豆小肽灌注水平的提高,奶山羊肠系膜排流组织(MDV)总肽结合氨基酸净流量显著增加(P0.05或P0.01);60、120、180g.d-1组门静脉排流组织(PDV)总肽结合氨基酸净流量均显著高于对照组(P0.05),但3个大豆小肽灌注组间无显著性差异(P0.05)。奶山羊小肠对小肽的吸收率随小肠中肽量的增加而下降。随着大豆小肽灌注水平的增加,奶山羊MDV和PDV组织游离氨基酸净流量显著增加(P0.05)。随十二指肠大豆小肽灌注水平的提高,试验羊颈静脉血浆尿素氮浓度显著增加(P0.05),对血浆葡萄糖、胰岛素、生长激素、胰高血糖素和IGF-1浓度没有显著影响(P0.05)。研究结果表明,大豆小肽灌注增加奶山羊小肠中肽结合氨基酸的流量,提高了MDV肽结合氨基酸的净流量,但因肽结合氨基酸吸收率降低或/和肽结合氨基酸吸收细胞降解率提高,降低了进入肠系膜静脉的肽结合氨基酸的比率。     

Growth hormone-releasing hormone and somatostatin concentrations in the hypophysial portal blood of conscious sheep during the infusion of growth hormone-releasing peptide-6

The effects of growth hormone-releasing peptide-6 (GHRP-6) on peripheral plasma concentrations of growth hormone (GH) and hypophysial portal plasma concentrations of growth hormone-releasing hormone (GHRH) and somatostatin (SRIF) were investigated in conscious ewes. Paired blood samples were collected from the hypophysial portal vessels and from the jugular vein of nine ewes for at least 2 hr. The sheep were then given a bolus injection of 10 μg of GHRP-6 per kg followed by a 2-hr infusion of GHRP-6 (0.1 μ/kg · hr). Blood sampling continued throughout the infusion and for 2 hr afterwards. An increase in plasma GH concentration was observed in the jugular samples of six of the nine ewes (1.4 ± 0.3 vs 7.4 ± 2.0 ng/ml, P < 0.05) 5–10 min after the GHRP-6 bolus injection, but in no case did we observe a significant coincident release of GHRH. During the infusion period, mean plasma GHRH levels were not significantly increased but there was a 50% increase (P < 0.05) in GHRH pulse frequency; GHRH pulse amplitude was not changed. Mean SRIF concentration, pulse frequency, and pulse amplitude were unchanged by GHRP-6 treatment. These data indicate that GHRP-6 causes a small, but significant effect on the pulsatile secretion of GHRH, indicating action at the hypothalamus or higher centers of the brain. The large initial GH secretory response to GHRP-6 injection does not appear to be the result of GHRP-6 action on GHRH or SRIF secretion.     

围产期小尾寒羊血清T-SOD活性和MDA含量变化的研究

[目的]研究围产期小尾寒羊血清T-SOD活性和MDA含量的变化。[方法]选择20只年龄在2~5岁之间的小尾寒羊,其中10只为待产母羊,10只为空怀母羊,分别于产前20d、产前10d、产前1d、产后1d、产后10d、产后20d颈静脉采血,测定血清T-SOD活性和MDA含量。[结果]围产期小尾寒羊在整个围产期内血清中T-SOD活性呈先下降后逐渐升高的动态变化,其中,在产前1d出现最低值且围产期小尾寒羊T-SOD活性均低于空怀小尾寒羊;围产期小尾寒羊在整个围产期内血清中MDA含量呈先上升后逐渐下降的动态变化,其中,在产后1d出现最低值且围产期小尾寒羊MDA含量均高于空怀小尾寒羊。[结论]怀孕和分娩对小尾寒羊T-SOD活性和MDA含量有一定的影响。     

Effect of intracerebroventricular injection of IGF-I on circulating growth hormone concentrations in the sheep

The effect of intracerebroventricular administration of IGF-1 on circulating growth hormone (GH) concentrations has been studied in sheep. Twenty sheep were fitted with jugular vein catheters and with indwelling cerebroventricular cannulae. IGF-I was injected into a lateral cerebral ventricle and changes in the circulating concentrations of GH were measured in jugular vein blood samples. Administration of saline had no effect on circulating GH concentrations over a 3-hr period, and administration of IGF-I (at 1, 3 and 10 micrograms/sheep) also had no significant effect on circulating GH concentrations. From these data we surmise that centrally administered IGF-I does not influence GH secretion and it seems probable that cerebrospinal fluid concentrations of IGF-I do not have a role in regulating GH release in sheep.     

Catheterization of the caudal vena cava via the lateral saphenous vein in the ewe, cow, and gilt: an alternative to utero-ovarian and medial coccygeal vein catheters

Current methods for obtaining venous blood from the reproductive organs of livestock often have a low rate of success or involve intensive surgical procedures that may impair ovarian function. Therefore, the caudal vena cava was catheterized via the lateral saphenous vein to determine the feasibility of using this method for chronic sampling of blood draining from the reproductive organs of ewes (n = 6), cows (n = 6), and gilts (n = 7). Blood samples were collected at 2-cm (ewes and gilts) or 5-cm (cows) intervals during insertion of catheters. Correct placement, defined as the position at which plasma concentrations of progesterone or estrogen were at least threefold greater than in jugular venous plasma, varied among species and among animals within species. It seemed, however, that a majority of catheters would be placed correctly if secured at 48 to 52 cm in ewes, 52 cm in gilts, and 90 to 100 cm in cows. Saphenous vein catheters were secured for sequential sampling of vena caval blood during the follicular phase of ewes (n = 25), cows (n = 4), and gilts (n = 5). Catheters remained patent for the duration of sampling in all individuals. Concentrations of estrogen in jugular and vena caval plasma were correlated (ewe P less than .0003; cow P less than .0001; gilt P less than .0001). Profiles of progesterone and estrogen revealed an episodic pattern of secretion in vena caval but not jugular plasma. Catheterization of the vena cava via the saphenous vein is a relatively simple and noninvasive method for obtaining blood containing uterine and ovarian hormones before their metabolism.     

The effects of exogenous growth hormone on follicular steroid secretion and ovulation rate in sheep.

Growth hormone (GH) has diverse actions in many tissues, including the follicle. This paper summarizes three experiments that examined the effects of GH and insulin-like growth factor (IGF)-I on the ovary. Ewes given oGH and pregnant mane serum gonadotrophin were compared with control and pregnant mane serum gonadotrophin-treated ewes. Ewes, with synchronized cycles, were given varying doses of pregnant mane serum gonadotrophin and/or oGH to determine if oGH is able to augment ovulation rate (Experiment 1). Experiments 2 and 3 used the ovarian autotransplant model. Ewes were infused via the ovarian artery with oGH (Experiment 2) or insulin-like growth factor I (IGF-I) (Experiment 3). Both were administered for 12 hr on Day 10. In Experiment 2, ewes were given intravenous gonadotropin releasing hormone (150 ng i.v.) at -2.5 and 10.5 hr relative to infusion. Ovarian and jugular venous blood was collected every 15 min from -30 to 150 min relative to gonadotropin releasing hormone. In Experiment 3, luteolysis was induced at the end of infusion. Ovarian and jugular venous blood was collected every 3 hr from before and until 84 hr after the infusion. Estradiol and androstenedione were assayed in ovarian venous plasma and GH in jugular venous plasma. In Experiment 1, treatment with oGH increased the jugular venous concentration of GH. However, in Experiment 2 treatment with oGH via the ovarian artery did not increase jugular venous GH but did increase ovarian venous GH. Treatment with oGH had no effect on ovulation rate (Experiment 1) or the secretion of androstenedione and estradiol (Experiment 2). Infusion of IGF-I (Experiment 3) increased the secretion of estradiol during the follicular phase. These data show that short-term treatment of sheep with GH had no in vivo effects on the follicle and that IGF-I was a potent stimulator of follicular steroidogenesis in vivo.     

联合应用阿苯达唑和伊维菌素在线虫感染鄂尔多斯细毛羊体内的药动学研究

为阐明联合应用阿苯达唑(ABZ)和伊维菌素(IVM)在胃肠道线虫感染鄂尔多斯细毛羊体内的药动学互作关系,以感染胃肠道线虫的鄂尔多斯细毛羊为研究对象,比较研究了单独或联合应用阿苯达唑和伊维菌素后的药物动力学特征。通过粪便虫卵检查法,选取感染胃肠道线虫的鄂尔多斯细毛羊15只,随机分成3组,每组5只。第1组口服给予阿苯达唑(15mg/kg),第2组皮下注射伊维菌素(0.2mg/kg),第3组皮下注射伊维菌素(0.2mg/kg)的同时口服阿苯达唑(15mg/kg)。于给药后不同时间,由颈静脉采集血样,分离血浆,并用高效液相色谱法测定各时间点血浆阿苯达唑、阿苯达唑亚砜、阿苯达唑砜和伊维菌素浓度,并用PK Solution 2.0药物动力学软件计算出各药动学参数。结果表明,联合用药组绵羊血浆伊维菌素峰浓度(Cmax)、药时曲线下面积(AUC)和平均滞留时间(MRT)分别为44.80ng/mL±6.12ng/mL、5 007.46ng.h/mL±1 301.42ng.h/mL和85.47h±5.03h,均显著(P<0.05)小于单独用药组的对应参数值67.62ng/mL±9.06ng/mL、7 125.08ng.h/mL±908.52ng.h/mL和113.39h±9.00h。口服阿苯达唑组绵羊血浆中仅检测到了阿苯达唑砜和阿苯达唑亚砜,而未检测到阿苯达唑母药。联合用药后,除阿苯达唑砜的达峰时间(T max)显著推迟外,阿苯达唑砜和阿苯达唑亚砜的其他各参数之间均无显著性差异。因此,联合应用IVM和ABZ可影响它们在胃肠道线虫感染鄂尔多斯细毛羊体内的药动学特征,且对伊维菌素药动学特征的影响尤为明显,在临床联合用药过程中应予以重视。     

Changes in the level of endogenous leptin, FSH, 17beta-oestradiol and metabolites during lupin-induced increase in ovulation rate in ewes

The aim of the study was to determine the changes in the plasma concentration of leptin during lupin feeding-induced increase in the ovulation rate (OR) in ewes. Additionally, alterations in the plasma level of glycogenic amino acids and glucose (as the factors influencing leptin secretion) and the levels of follicle-stimulating hormone (FSH) and 17beta-oestradiol (E-2) (as the hormones regulated by leptin and engaged in recruitment, selection and development of ovulatory follicles) were analysed. Ninety-six female Polish Lowland Sheep were used. All ewes were cyclic and synchronized with PGF2alpha. The ewes were divided into two groups: control (n = 48), fed only with hay, and experimental (n = 48), received additionally lupin (Lupinus angustifolius) grain as a high-protein and a high-energy supplement. They were given lupin from the second to 13th day of the oestrous cycle at increasing doses (150-750 g/day per ewe). On the 11th day of cycle blood samples for analysis of hormones, amino acids and total glucose concentration, were collected from the jugular vein. OR was determined by laparoscopy of ovaries on the sixth day of the following oestrous cycle. Mean OR of ewes supplemented with lupin grain (1.687 +/- 0.463) was 30.67% higher than that of control (1.291 +/- 0.454). In spite of the unchanged body mass, a significant increase (P < or = 0.05) in mean concentration of plasma leptin in the experimental ewes [2.17 +/- 0.15 ng/ml human equivalent (HE)] was found in comparison with control (1.42 +/- 0.12 ng/ml HE). A significantly (P < or = 0.05) higher plasma FSH level in the ewes fed lupin (105.21 +/- 5.87 ng/ml) compared with those fed hay (67.88 +/- 6.03 ng/ml) was also found. However, plasma level of E-2 decreased after lupin feeding. Moreover, in the ewes fed lupin the plasma concentrations of glucose and nine glycogenic amino acids (Gly, Ala, Val, Met, Leu, Ile, Tyr, Phe and Arg) were increased. It can be concluded that lupin feeding exerts the stimulatory effect on the OR in Polish Lowland Sheep. The increase in OR is connected with significantly higher plasma leptin level and coincident with rise in FSH, glycogenic amino acids and glucose concentration. In contrast, the level of plasma E-2 was significantly decreased in lupin-fed ewes.     

Effects of glucose and amino acids on ghrelin secretion in sheep

Two experiments were conducted to elucidate the effects of post‐ruminal administration of starch and casein (Exp. 1), plasma amino acids concentrations (Exp. 2), and plasma glucose and insulin concentrations (Exp. 2) on plasma ghrelin concentrations in sheep. In Exp. 1, plasma ghrelin concentrations were determined by four infusion treatments (water, cornstarch, casein and cornstarch plus casein) in four wethers. Abomasal infusion of casein increased plasma α‐amino N (AAN) concentrations. Infusion of starch or casein alone did not affect plasma ghrelin concentrations, but starch plus casein infusion increased plasma levels of ghrelin, glucose and AAN. In Exp 2, we investigated the effects of saline or amino acids on ghrelin secretion in four wethers. Two hours after the initiation of saline or amino acid infusion into the jugular vein, glucose was also continuously infused to investigate the effects of blood glucose and insulin by hyper‐glycemic clump on plasma ghrelin concentrations. Infusion of amino acids alone raised plasma levels of ghrelin, but the higher plasma glucose and insulin concentrations had no effect on plasma ghrelin concentrations. These results suggest that high plasma levels of amino acids can stimulate ghrelin secretion, but glucose and insulin do not affect ghrelin secretion in sheep.