Participation of Opioid Peptides in Sucking‐induced Oxytocin and Prolactin Secretions in Lactating Goats

The role of opioid peptides in the secretion of oxytocin (OT) and prolactin (PRL) induced by sucking was studied in goats. Seven goats were isolated with their kids (four singletons and three twins) in individual corrals 3–4 weeks after parturition. On day 1 of the experiment, the kids were separated from the does for 7 h and were weighed before and 15 min after being reunited with their mothers to assess the amount of milk obtained by sucking. The does were blood‐sampled 10 min before and at the end of the sucking period. On day 2, a similar protocol was followed, but naloxone was given immediately after the first blood sample. On day 3, the protocol was repeated but saline vehicle was injected instead of naloxone. On day 5, the naloxone experiment was repeated as on day 2. Milk ejection was evaluated as the difference in the weight of the kids before and after sucking for 15 min, and the maternal serum levels of OT and PRL were measured by radioimmunoassay. A significant decrease in the weight gain of the kids was obtained when the mothers were treated with naloxone on day 2. Consistently, serum levels of OT and PRL induced by sucking were significantly reduced; indicating that sucking‐induced OT secretion for milk ejection in lactating goats is facilitated by opioid peptides. In a second experiment performed in the same animals 10 days later, the administration of OT, immediately after naloxone administration, prevented the decrease in the weight gain induced by naloxone, suggesting that the effect of the opioid antagonist on milk ejection in goats is a result of a reduced OT secretion. The results of this study confirm the importance of sucking‐induced OT secretion for milk ejection in lactating goats, and indicate that OT and PRL secretion are regulated by opioid peptides in this species.     

Boar Contact does not Induce Oxytocin Release During the Period of Embryo Migration in Sows

Nine multiparous cyclic sows with permanent jugular catheters were introduced to a boar at day 10 (n = 9) or 11 (n = 5) after ovulation to study the effect on oxytocin (OT) release. If it occurs, the release of OT might play a role in embryo migration which occurs around this time, by stimulating uterine contractions. Blood samples were taken before introduction of the boar and at 2-min intervals up to 10 min after boar introduction. On average, OT levels after boar introduction were not higher than before. In only three out of the 14 occasions of boar introduction, a rise in OT level was observed that was higher than two times the standard deviation above base level. However, even on these occasions OT levels were far below the range normally observed during other events where exogenous stimuli cause OT release, such as boar introduction during estrus and suckling during lactation. We conclude that boar contact around day 10 of the estrous cycle does not induce a biologically significant OT release in sows.     

影响母猪头胎产仔数的初配因素分析

提高母猪头胎产仔数,已成为饲养场和农村广大养殖户增加母猪单产效益,降低饲养成本的关键。笔者就影响母猪头胎产仔数的原因做了逐一分析,以期为提高母猪头胎产仔数,增加经济效益提供一定的参考。     

Uterine Motility in Sows During Spontaneous Parturition and Induced Parturitions with the PGF Analog Alfbprostol and Oxytocin

Contents: Uterine activity, i.e. myometrial contractions, were recorded in 11 sows prior to and during parturition by using strain gauges placed onto uterine horns about 15 to 20 cm cranial of the bifurcation. Tocographic patterns observed prior to and during spontaneous and alfaprostol induced parturitions were normal. Administration of 20, 10 or 5 I.U. oxytocin 22 hours after alfaprostol quickly initiated abnormal periparturient contraction patterns with 20 and 10 I.U. oxytocin and in one of two animals receiving 5 I. U. These were characterized initially by prolonged tetanic contractions resulting in delayed deliveries, and later by the premature occurrence of patterns seen normally only during the phase of placental expulsions, although not all piglets had been delivered. The importance to use myornetrial activity profiles to evaluate parturition induction methods was stressed .     

催产素、孕酮和促排卵素3号对长大母猪繁殖性能的影响

为了研究催产素、孕酮和促排卵素3号对母猪繁殖性能的影响,将180头长大母猪随机分成4组:对照组46头;试验Ⅰ组56头,配种前肌注催产素;试验Ⅱ组38头,配种后4~30 d口服孕酮;试验Ⅲ组40头,配种前肌注催产素、促排卵素3号,配种后口服孕酮。本交配种。结果表明:①各组的受胎率和分娩率差异不显著(P>0.05);②试验Ⅰ组与对照组、试验Ⅱ组比较,产仔数、产活仔数差异显著(P<0.05),其他组间差异不显著(P>0.05);③试验Ⅰ组与对照组、试验Ⅱ组或试验Ⅲ组与对照组比较,窝重差异显著(P<0.05);其他组间差异不显著(P>0.05)。各组的初生重差异不显著(P>0.05)。总之,单独使用催产素是最方便、经济而有效的。     

Effects of Feeding Level During Lactation on FSH and LH Secretion Patterns, and Follicular Development in Primiparous Sows

In the primiparous lactating sow undernutrition affects LH, but the effect on FSH is less clear. This study was conducted to investigate the effect of ad libitum (AL; n = 5) and restricted (RE; 70% of the AL feed; n = 5) feeding on the secretion patterns of FSH and LH, and on follicular development in primiparous lactating sows. Body side fat thickness (BSFT) was measured prior to farrowing and at weaning on day 21 postpartum (pp). Sows had an intravenous catheter fitted on day 6 or 7 pp. Blood samples were taken on days 12, 15 and 18 pp, every 15 min starting at 0700 h for 11 h, and plasma analysed for FSH and LH by radioimmunoassay (RIA). Daily transcutaneous ultrasonography of the ovaries was performed between days 10 and 20 pp to monitor follicular growth. Reduction in BSFT was higher in RE than in AL sows (p < 0.05). Mean and basal LH were significantly higher in AL than in RE sows on days 12 and 15 pp. (p < 0.05), and LH pulse frequency tended to be higher (p < 0.1). Mean FSH was higher in AL than in RE sows on days 15 and 18 (p < 0.05), and had a tendency to be higher on day 12 (p = 0.1). Follicle size increased in AL sows between days 10 and 20 of lactation (p < 0.05; r = 0.71), but remained unaffected in RE sows. In conclusion, the study demonstrates that feed restriction of primiparous sows during lactation affects not only LH, but also FSH, as well as lactational follicular growth. An association between those events is suggested.     

饲喂频率对妊娠母猪背膘厚和繁殖性能的影响

[目的] 研究饲喂频率对妊娠母猪背膘厚和繁殖性能的影响。[方法] 挑选加系杜洛克经产母猪480头,配种时按照胎次（2~7胎）、背膘厚（11~22 mm）相近的原则随机将母猪分为T1组（每天饲喂1次）和T2组（每天饲喂2次）,两组每天等量饲喂。T1组母猪220头,饲喂时间为8：00;T2组母猪260头,饲喂时间为8：00和15：00,每次饲喂量为总量的一半,定位栏饲养。[结果] ①饲喂频率不影响妊娠56 d、开配-妊娠56 d的背膘厚（妊娠56 d背膘厚-开配背膘厚）（P>0.05）;T2组妊娠110 d（P=0.06）、妊娠56-110 d（P=0.09）背膘厚（妊娠110 d背膘厚-妊娠56 d背膘厚）有高于T1组的趋势。②饲喂频率对窝产总仔数、活仔数、死胎数、木乃伊胎数、初生窝重以及初生个体重均无显著（P>0.05）影响。③在三胎母猪中,T2组妊娠110 d（P=0.01）、妊娠56-110 d（P=0.04）背膘厚均显著高于T1组;五胎及以上母猪,T2组妊娠56-110 d（P=0.08）背膘厚有高于T1组的趋势。④饲喂频率不影响二胎母猪窝产总仔数、死胎数、木乃伊胎数、初生窝重以及初生个体重（P>0.05）,但二胎母猪中T2组活仔数有高于T1组的趋势（P=0.07）。[结论] 饲喂频率由每天两餐减少到每天一餐不会对母猪的繁殖性能产生不利影响。     

母猪妊娠期营养水平对后代仔猪肌肉生长和发育的影响

本试验旨在研究母猪妊娠期营养水平对后代仔猪肌肉生长和发育的影响。选取体重和日龄相近的长大(LY)杂交后备母猪33头,按体重[(150±9)kg]和日龄[(255±10)日龄]随机分到3个组:低营养水平组(LN组)、适宜营养水平组(AN组)和高营养水平组(HN组)。每组11个重复,每个重复1头母猪。妊娠前期(1~30 d)各组营养摄入量分别是0.75、1.00和1.50倍维持需要,妊娠中期(31~90 d)在前期基础上提高20%,妊娠后期(91~112 d)在中期基础上提高25%。结果表明:1)与LN组相比,AN和HN组仔猪出生体重和断奶体重及初生仔猪肌肉重(除比目鱼肌)显著或极显著提高(P0.05或P0.01);AN组仔猪半腱肌和背最长肌相对重极显著高于LN组(P0.01),AN组新生仔猪肌肉蛋白质浓度显著或极显著高于LN和HN组(P0.05或P0.01)。2)AN组新生仔猪背最长肌肌球蛋白重链Ⅱx的mRNA表达量极显著低于LN组(P0.01)。3)AN组新生仔猪背最长肌生肌调节因子4的mRNA表达量显著高于LN和HN组(P0.05)。由此可见,母猪妊娠期营养水平能显著影响仔猪出生和断奶体重及肌肉重,但是过高或者过低的营养水平都会降低后代肌肉重和肌肉蛋白质的浓度,这可能与生肌调节因子4基因差异表达有关。     

不正确使用缩宫素造成母猪子宫破裂死亡

在农村,母猪分娩难产时有,但分娩造成子宫破裂极为少见,现将此病例报告下。1病例本县蓼皋镇文山村二组龙某饲养苏白母猪1头,年龄3·5岁,体重150 kg,中上等膘情,已产仔5窝,前4窝共产仔48头,平均每窝12头。本胎与配公猪为大约克种,于2006年8月11日12时30分分娩,产出大约克与苏白杂交一代仔猪1头,相隔17小时后,未见第2头仔猪产出。次日7时30分,畜主给母猪注射缩宫素100 IU,一直到8月13日6时仍未见产出第2头仔猪,畜主于7时30分来我站求诊。检查:母猪体温42℃,脉搏103次/分,呼吸55次/分,精神严重沉郁,努责停止。笔者手臂和患畜会阴部消毒后,用右…     

The Influence of Opioid Peptides on Steroidogenesis in Porcine Granulosa Cells

The present studies were undertaken to examine the influence of mu (beta-endorphin, DAMGO, FK 33-824), delta (met-enkephalin, leu-enkephalin, DPLPE) and kappa opioid receptor agonists (dynorphin A, dynorphin B, U 50488) used at different doses (1-1000 nM) alone and in combination with LH (100 ng/ml) on steroidogenesis in porcine granulosa cells derived from large follicles. The effects of mu, delta and kappa receptor agonists on both basal and LH-induced progesterone (P4) secretion were negligible. Agonists of mu opioid receptors reduced basal androstenedione (A4), testosterone (T) and oestradiol (E2) release. Co-treatment with LH entirely abolished the inhibitory effect of these agonists on A4 and E2 secretion and resulted in an increase in T release. The addition of delta receptor agonists was followed by a decrease in basal A4, T and E2 secretion. The cells incubated in the presence of LH increased the androgen production and abrogated the inhibitory effect of delta agonists on E2 output. Basal A4, T and E2 release was also suppressed by kappa receptor agonists. The presence of LH in culture media extended the inhibitory effect of these opioids on E2 output and caused either abolition of the inhibitory influence of kappa agonists or even augmentation of both androgen release in response to the opioids. In conclusion, these data support the involvement of three major types of opioid receptors in the regulation of porcine granulosa cell steroidogenesis.     

配种次数、配种方式与母猪产仔情况的关系分析

对某大型集约化养猪场2005年7月至2005年10月配种的长大(或大长)二元杂母猪分娩数据资料进行了整理和统计分析.结果表明,配种次数为3次的母猪其窝产活仔数多、窝重大、生产力综合指标较高;另一方面,混合配种方式母猪的情期受胎率、配种分娩率及产仔情况效果最好.     

配种次数、配种方式与母猪产仔情况的关系分析

对某大型集约化养猪场2005年7月至2005年10月配种的长大(或大长)二元杂母猪分娩数据资料进行了整理和统计分析。结果表明,配种次数为3次的母猪其窝产活仔数多、窝重大、生产力综合指标较高;另一方面,混合配种方式母猪的情期受胎率、配种分娩率及产仔情况效果最好。     

妊娠后期营养水平对初产母猪繁殖性能及血液生化指标的影响

为研究妊娠后期营养水平对初产母猪体况、繁殖性能及血液生化指标的影响,本试验选用背膘厚及体重相近的初产杂交母猪36头,按体况和配种时间随机分为3组（Ⅰ、Ⅱ、Ⅲ组）,每组6个重复,每个重复2头母猪,饲喂营养水平依次为维持需要的1.5、2.0和2.5倍的日粮,母猪妊娠81 d时开始试验至母猪分娩结束,试验期33 d。结果显示,分娩时Ⅰ组母猪背膘厚显著低于Ⅲ组（P<0.05）,断奶时各组背膘厚度差异不显著（P>0.05）;Ⅰ组母猪泌乳期背膘损失显著低于Ⅲ组（P<0.05）;Ⅲ组母猪分娩后体重、分娩前体重均显著高于Ⅰ组（P<0.05）,各组母猪妊娠81 d体重及泌乳期失重等差异均不显著（P>0.05）。试验组间窝产仔数、窝产活仔数、断奶个体重及母猪断奶-发情间隔均无显著差异（P>0.05）;Ⅲ组仔猪初生均重、断奶窝重、泌乳期窝增重均显著高于Ⅰ组（P<0.05）。随营养水平升高,Ⅱ、Ⅲ组雌激素水平显著高于Ⅰ组（P<0.05）;各组催乳素和孕酮水平差异不显著（P>0.05）;Ⅰ组甘油三酯水平显著低于Ⅱ、Ⅲ组（P<0.05）;各组尿素氮和葡萄糖含量随营养水平的升高逐渐增大,且差异显著（P<0.05）;Ⅲ组胰岛素含量显著高于I组（P<0.05）;各组总蛋白含量无显著差异（P>0.05）。结果提示,母猪妊娠后期饲喂营养水平为2.0倍维持需要的日粮时可使后备母猪分娩时体况达到标准水平,而饲喂营养水平为2.5倍维持需要的日粮可使母猪产仔性能得到提高。     

Dopaminergic and Opioidergic Regulation of Gonadotropin and Prolactin Release in Stallions

In the non‐breeding season, LH release is reduced via dopaminergic systems in the ram. On the other hand, our previous studies demonstrated an opioidergic inhibition of LH release in stallions outside the breeding season. Thus, in the present study we investigated the dopaminergic regulation of LH and prolactin secretion in stallions, considering interactions between dopamine and opioids. To achieve this, stallions (n=8) were treated with the dopamine antagonist sulpiride (0.6 mg/kg), the opioid antagonist naloxone (0.5 mg/kg), sulpiride plus naloxone or saline in December, March and June. Two hours after the respective treatments, they received a GnRH agonist. Sulpiride induced a significant prolactin release which was most pronounced in December, indicating seasonal variations in the inhibition of prolactin secretion by dopaminergic systems. Prolactin concentrations were not changed by naloxone. Neither during nor outside the breeding season, a dopaminergic regulation of LH release could be demonstrated. In contrast, naloxone caused a significant (p < 0.05) LH release, confirming an opioidergic inhibition of LH release. In conclusion, opioidergic regulation of LH and dopaminergic inhibition of prolactin secretion undergo seasonal changes. Neither during nor outside the breeding season, dopaminergic effects on LH release exist in the stallion.     

Genistein Alters the Release of Oxytocin,Prostaglandins, Cortisol and LH during Insemination in Gilts

Soya products containing phytooestrogens are widely used as feed for pigs. However, limited data are available on the effects of phytooestrogen on the endocrine status of pigs. The aim of this work was to study the impact of the phytooestrogen genistein added to a soya‐free diet on the hormonal pattern in gilts during oestrus and artificial insemination (AI). Ten gilts were fed a soya‐free diet and fitted with jugular vein catheter through vena auricularis. The gilts were randomly divided into two groups (G‐ and C‐group) where the G‐group was given pure genistein, 1 mg/kg body weight (BW) twice daily, per os. Blood samples were collected before, during and after AI. Oxytocin, prostaglandin E_2, prostaglandin F_2α, 13,14‐dihydro‐15‐keto‐prostaglandin F_2α (PGFM), cortisol and LH concentrations in blood plasma were analysed. Oxytocin concentrations were almost twice as high in the G‐group as in C‐group after the AI. Prostaglandin E₂ concentrations were higher in G‐group than in C‐group during the entire sampling period. After AI, the concentrations of prostaglandin E₂ increased in G‐group but not in C‐group. Prostaglandin F_2α concentration had a pulsatile pattern, with increasing pulses after AI in G‐group. Plasma PGFM concentrations increased after AI with a small variation between the groups. Plasma cortisol concentration increased after AI in C‐group. LH decreased after AI in G‐group. Genistein stimulated elevations of plasma oxytocin and prostaglandin E₂ concentrations and a pulsative pattern in prostaglandin F_2α concentration. The possible involvement of genistein in plasma cortisol and basal LH concentrations in gilts given genistein may also be suggested.     

吲哚美辛缓释片工艺制备与体外释放研究

目的 :制备吲哚美辛缓释片,确定最佳处方工艺,考察其体外释放度。方法 :采用正交设计,确定吲哚美辛缓释片最佳处方工艺,测定体外释放度。结果:吲哚美辛缓释片处方:吲哚美辛:尤特其L 100-55(1:1),羟丙甲纤维素(高粘度:低粘度=2:1),乳糖60mg,5%PVP K30醇溶液,硬脂酸镁1%。吲哚美辛缓释片体外释放度符合Higuchi方程(r=0.9858)。结论:吲哚美辛缓释片具有良好的缓释效果。     

母猪饲粮中添加过氧化氢酶对母猪及仔猪生长性能和抗氧化能力的影响

本试验旨在研究母猪妊娠后期和哺乳期饲粮中添加过氧化氢酶(CAT)对母猪繁殖性能、抗氧化能力、饲粮养分消化率以及仔猪生长性能和抗氧化能力的影响。试验选取二元杂交(长白×大白)经产母猪160头,按母猪预产期、胎次体重、体况相近均衡分布的原则随机分为4组(对照组和试验A、B、C组),饲粮中CAT添加量分别为0、50、100、150U/kg,每组40头,每头母猪为1个重复,试验周期从妊娠第90天开始至仔猪断奶。结果表明:与对照组相比,饲粮中添加CAT对总产仔头数、活仔数、健仔数、初生窝重有提高但未达到显著水平(P>0.05);在母猪饲粮中添加CAT对降低哺乳仔猪腹泻率效果显著(P<0.05);在母猪妊娠第104天,与对照组相比,试验B和C组中血清总抗氧化能力(T AOC)分别提高60.03%和53.70%(P<0.05);试验B组中血清CAT活性较对照组、试验A和C组都有显著提高(P<0.05)。在母猪哺乳第14天,与对照组相比,试验B组中血清CAT活性显著提高(P<0.05);与对照组相比,试验B组初乳中T AOC提高119.10%(P<0.05);试验B和C组的初乳CAT活性较对照组分别提高86.24%和76.95%(P<0.05);各试验组在粗蛋白质消化率上与对照组相比差异均为显著(P<0.05);各试验组在粗脂肪消化率上与对照组相比差异均为显著(P<0.05)。综上,在母猪饲粮中添加CAT可以一定程度上提高母猪总产仔数、母猪妊娠第104天及哺乳第14天血清中T AOC、CAT活性、初乳中T AOC、CAT活性,母猪抗氧化能力在饲粮中添加100U/kgCAT时提升最明显;在母猪饲粮中添加CAT可以显著提高粗脂肪和粗蛋白质消化率。     

妊娠后期日粮中添加苜蓿草粉对母猪繁殖性能及血清生化、抗氧化和免疫指标的影响

[目的] 探讨妊娠后期日粮中添加不同比例苜蓿草粉对母猪繁殖性能及血清生化、抗氧化和免疫指标的影响。[方法] 采用单因子完全随机试验设计,将胎次、体况、预产期相近的40头妊娠后期大长母猪随机分为4组,每组10头。试验母猪日粮中分别添加0（对照组）、5%（5%苜蓿草粉组）,10%（10%苜蓿草粉组）和15%（15%苜蓿草粉组）的苜蓿草粉。母猪确定妊娠85 d进入试验期,分娩后试验结束。妊娠第111天时,采集母猪血样,测定血清生化、抗氧化和免疫指标;母猪分娩12 h内,记录产仔数、产活仔数,测定仔猪初生窝重、初生个体重。[结果] 10%苜蓿草粉组的仔猪初生窝重显著（P<0.05）高于其他处理组。10%苜蓿草粉组的血清白蛋白含量和白/球比显著（P<0.05）低于对照组;5%和10%苜蓿草粉组的血清葡萄糖含量显著（P<0.05）高于对照组。5%和10%苜蓿草粉组的血清总抗氧化能力显著（P<0.05）高于对照组;10%苜蓿草粉组的血清丙二醛含量显著（P<0.05）低于其他处理组;10%苜蓿草粉组的血清谷胱甘肽过氧化物酶活力显著（P<0.05）高于对照组;10%苜蓿草粉组的血清超氧化物歧化酶活力显著高于（P<0.05）其他处理组,5%和15%苜蓿草粉组的血清超氧化物歧化酶活力显著高于（P<0.05）对照组。10%苜蓿草粉组的血清IgM含量显著（P<0.05）高于5%苜蓿草粉组。[结论] 妊娠后期日粮中添加苜蓿草粉对母猪的繁殖性能及血清生化、抗氧化和免疫指标有一定的改善作用,添加量以10%为宜。     

饲粮中添加发酵苜蓿对母猪繁殖性能和母猪、仔猪抗氧化能力的影响

本试验旨在研究饲粮中添加发酵苜蓿对母猪繁殖性能和母猪、仔猪抗氧化能力的影响。选用80头体况和预产期接近的“长×大”妊娠初产母猪,随机分为4组(对照组、试验Ⅰ组、试验Ⅱ组和试验Ⅲ组),分别饲喂添加0、5%、10%和15%发酵苜蓿的饲粮,每组5个重复,每个重复4头。试验从母猪妊娠开始到哺乳期结束。结果表明：1)与对照组相比,试验Ⅱ组的成活率、健仔数和健仔率显著升高(P<0.05),死胎数、弱仔数和产程显著降低(P<0.05);各试验组的宫内发育迟缓(IUGR)发生率显著降低(P<0.05)。2)与对照组相比,试验Ⅰ组母猪哺乳期平均日采食量显著升高(P<0.05),试验Ⅱ组有升高趋势(P=0.064);试验Ⅱ组、试验Ⅲ组妊娠30 d、妊娠60 d和产前背膘厚显著降低(P<0.05)。3)与对照组相比,试验Ⅱ组、试验Ⅲ组的初生窝重、第7天窝重及个体重、第14天窝重及个体重和断奶个体重显著升高(P<0.05);试验Ⅱ组的断奶窝重、窝平均日增重和初生个体重显著升高(P<0.05)。4)与对照组相比,试验Ⅱ组的初生窝重均匀度显著提高(P<0.05);试...