猪场批次化生产模式和激素的选择

批次化生产是猪场高效管理的繁殖技术手段。文章主要综述了目前猪场常用的6种批次化生产模式以及批次化生产中不同激素制剂的使用效果,介绍了以上批次化生产模式的适用情况,比较了6种批次化生产模式各自的优点和缺点,以期为猪场选择批次化生产提供参考。     

Effect of active immunization against GnRH on androstenone concentration, growth performance and carcass quality in intact male pigs

The objective of this study was to investigate the efficacy of active immunization against gonadotropin releasing hormone (GnRH) in male pigs and to compare it with surgical castration. Piglets were randomly assigned to two groups, one of 263 animals for surgical castration (SC) and one of 270 animals for immunocastration (IC). Surgery was done at 14 days of age and vaccination (Improvac®, CSL, Australia) performed twice at an interval of 4-5 weeks with the second injection given 4-7 weeks before slaughter. At slaughter, testes were weighed and fat samples collected for androstenone analysis. Androstenone was tested olfactorially by heating salivary glands in a microwave oven. Daily growth rate and meat quality were assessed in all animals. Regarding mean androstenone concentrations in backfat, no significant difference was found between SC and IC (0.042 (0.041; 0.044) μg/g vs. 0.058 (0.044; 0.071) μg/g; mean (95% confidence interval)). Testes weight was significantly (P<0.001) smaller in immunized (230.8 g (218.23; 243.52)) as compared to normal boars (761.8 g (722.77; 801.01)) of the same age, as a reference. In this study, androstenone production was suppressed in all vaccinated animals and the carcasses given free for consumption. Mean daily growth gain was not significantly different between SC (0.817 kg (0.804; 0.830)) and IC (0.827 kg (0.814; 0.840)), although there was a trend for better performance in the latter group. The yield of lean meat was significantly (P<0.001) improved in IC (54.50% (54.26; 54.73)) when compared to SC (53.76% (53.53; 54.00)). From our results, we conclude that vaccination against GnRH is a practical and effective method to suppress androstenone synthesis. Pain and stress associated with surgical castration can thus be avoided.     

新建与复养规模化猪场中生物安全工艺设计与改造

生物安全是猪场生产管理的关键,也是猪场搞好生产的基本保障。猪场生物安全贯穿于生产管理的各个环节,包括人员、物资、猪只、饲料、粪污等流转运输等。近两年的非洲猪瘟疫情使得很多生物安全设施和管理不健全的养殖场遭受灭顶之灾。为协助众多在疫情中遭受打击的规模养殖企业恢复生产,文章从更严格的生物安全角度出发,在传统猪场工艺设计的基础上,对猪场功能区设置、人员物料流线规划、进出场洗消设施配置等提出了一套较为完整的工艺技术方案,供养猪从业者在新建和改造猪场复养过程中参考。     

猪GnRH受体基因多态性分析及相关基因组织表达谱的构建

促性腺激素释放激素(GnRH)受体基因与猪的繁殖性状密切相关,本试验对不同猪种的GnRH受体基因的编码区进行了SSCP分析,未发现多态性。在GnRH受体基因5′侧翼序列上设计引物扩增了该基因大约2000 bp的侧翼序列,通过比对设计引物,对其中的一段含有GAGABox的插入突变序列和一段由于点突变而形成转录调控蛋白结合序列IRF-1的区域运用SSCP的方法进行了多态性分析。结果表明在插入突变处,基因频率在不同的猪种间存在着很大的差异性,其中民猪与其他猪种的差异性最大。IRF突变只存在于民猪中,并且只存在AA型和AB型。构建了3头大白猪母猪GnRH基因、GnRH受体基因、卵泡抑素(FST)基因、促卵泡素(FSH)基因、FSH受体基因、促黄体素(LH)基因、抑制素(inhibin)β(a)基因、inhibinβ(b)基因的组织表达谱,根据表达谱可以推测在下丘脑-脑垂体-性腺轴外不存在这些基因表达产物的相互作用系统。     

Orexin and orexin receptor like peptides in the gastroenteric tract of Gallus domesticus: An immunohistochemical survey on presence and distribution

This study reports the immunohistochemical localization and distribution of orexin A and B-like and their receptors-like peptides in the gastroenteric tract of chicken. The immunoreactivity is distributed in endocrine cells, nerve fibers and neurons, both in the stomach and intestine, and shows a discrete conformity with the data till now reported for Mammals. Our study suggests a possible participation of orexin-like peptides in the modulation of chicken gastroenteric activities and the preservation of their main distribution compared to Mammals. Western blot analysis has confirmed the presence of prepro-orexin and both receptors in the examined tissues.     

西农莎能奶山羊和布尔山羊GnRH基因多态性与产羔数的相关分析

根据牛GnRH基N序列设计4对引物,采用PCR—SSCP技术检测GnRH基因的多态性,同时用最小二乘法研究了其多态性与产羔数和生长体质量的关系。所研究的西农莎能奶山羊和布尔山羊群体在P4扩增片段存在多态性,分别定义为CC、CT和TT3种基因型;P1、P2和P3扩增片段均不存在多态性,只表现一种带型。通过测序发现CC型与GG型相比扩增片段的第185、336bp处同时有C—T的单碱基突变。在西农莎能奶山羊和布尔山羊群体中,CC和CT基因型产羔数最小二乘均值均极显著或显著高于TT基因型（P〈0．05）。研究结果表明,GnRH基因对西农莎能奶山羊和布尔山羊的产羔数均有显著影响,因此认为GnRH基因P4扩增位点的突变可作为西农莎能奶山羊和布尔山羊多胎性状的有效分子标记。     

促性腺激素释放激素受体及其基因表达调控

促性腺激素释放激素（ＧｎＲＨ）在体内的重要功能是由促性腺激素释放激素受体（ＧｎＲＨ－Ｒ）介导的,ＧｎＲＨ及其受体相互作用的调控在繁殖性能调控中是一个关键性位点。本文从ＧｎＲＨ－Ｒ结构与功能,ＧｎＲＨ－Ｒ基因表达调控、ＧｎＲＨ－Ｒ介导的细胞信号转导机制等三个方面对ＧｎＲＨ－Ｒ近年来的研究进展进行了综述了,并展望了ＧｎＲＨ－Ｒ研究的发展趋势和前景。     

促性腺激素释放激素及其类似物在动物繁殖上的应用

本文就GnRH的化学特性、生理功能、作用特点、作用机理、国内外应用GnRH及其类似物提高动物繁殖率的情况及应用时需注意的事项等进行综述。     

单色光对肉鸡脑内促性腺激素释放激素分布和表达的影响

24只刚出壳的雄性AA肉鸡分别在白(400～760 nm)、红(660 nm)、绿(560 nm)和蓝色(480 nm) LED灯下饲养7周,光照强度15 lx,光照制度23h∶1 h(L:D).49日龄时取脑,利用免疫组化的方法显示GnRH神经元和神经纤维的分布及比较各光色下GnRH神经元的表达强度.结果显示,GnRH神经元和神经纤维在下丘脑、丘脑和中脑均有分布,且蓝光组下丘脑的视前室周核、视前内侧核、室周核、室旁大细胞核以及丘脑的圆核和卵圆核GnRH神经元表达强度显著高于红、绿光组.结果表明,光色可影响家禽下丘脑和丘脑GnRH的表达与分泌.     

Immunohistochemical identification and localization of orexin A and orexin type 2 receptor in the horse gastrointestinal tract

The aim of the present study was to investigate the presence and the distribution of cells containing orexin A and orexin type 2 receptor in the horse stomach and gut, by means of immunohistochemical techniques.Orexin A was identified in the stomach fundic and pyloric regions and in the duodenum. In the same stomach regions, a large subset of orexin A-positive cells also showed orexin type 2 receptor-like immunoreactivity. Moreover, in the duodenum, many of them, seemed to store serotonin.Characteristically, enteric neurons or ganglia also displayed orexin A and, sometimes, orexin type 2 receptor immunoreaction.Orexin A and orexin type 2 receptor immunoreactivity was also found in the nerve fibers in the enteric submucosal layer.Our results, together with data present in the literature, could contribute to the understanding of complex mechanisms regulating the horse gut functionality that are depending very likely on the consequence of the co-operation of both a central and a peripheral control.     

发酵饲料概述及其在养猪生产中的应用

发酵饲料具有绿色、安全、高效等特点,能提升饲料品质、提高饲料利用效率,改善动物亚健康状态,是一种优质的饲料伴侣,长期使用发酵饲料对抗生素减量使用、食品安全、环境污染等养殖行业面临的共性问题,提供了有效的解决方案,文章就发酵饲料的定义、分类及其在养猪生产中的应用等方面进行论述。     

济宁青山羊生后发育阶段GnRH与GnRHR阳性细胞在下丘脑分布规律的研究

为研究济宁青山羊生后发育阶段GnRH及GnRHR在下丘脑内的形态学分布和变化规律,采用链霉亲和素-生物素-过氧化物酶复合物(Strept Avidin Biotin-Peroxidase Complex,SABC)免疫组织化学方法,对0、2、4和6月龄雌性济宁青山羊下丘脑中GnRH及GnRHR的分布进行了同步研究。结果显示,GnRH和GnRHR免疫阳性细胞在下丘脑内广泛存在,主要分布于视前内侧区、乳头体、视上核和视交叉上核。随月龄增长,GnRH和GnRHR阳性细胞不断增大,数量不断增多,其中0～2月龄是最快的时期。结果提示,下丘脑分泌的GnRH及GnRHR对生后发育阶段青山羊性成熟的启动及维持有重要作用。     

Local administration of Neurokinin B in the arcuate nucleus accelerates the neural activity of the GnRH pulse generator in goats

Kisspeptin neurons in the arcuate nucleus (ARC), which co-express neurokinin B (NKB) and dynorphin A, are termed KNDy neurons. These neurons are candidates for the intrinsic gonadotropin-releasing hormone (GnRH) pulse generator. The central and peripheral administration of NKB or its receptor (NK3R) agonist evokes GnRH pulse generator activity and the subsequent pulsatile GnRH/luteinizing hormone (LH) secretion. However, the mechanism responsible for neural activation of the GnRH pulse generator in goats is unclear. We conducted electrophysiological and histochemical experiments to test the hypothesis that KNDy neurons receive NKB and that the signal is transmitted bilaterally to a population of KNDy neurons. Bilateral electrodes aimed at a cluster of KNDy neurons were inserted into the ovariectomized goat ARC. We observed the GnRH pulse generator activity, represented by characteristic increases in multiple-unit activity (MUA volleys). The unilateral administration of NKB or vehicle in the close vicinity of KNDy neurons under simultaneous MUA recording from both sides revealed that only NKB evoked MUA volley(s) immediately after administration. The timing of the MUA volley(s) evoked on the ipsilateral side was synchronized to that on the contralateral side. The double-labeled ISH for KISS1 and TACR3, which encode kisspeptin and NK3R, respectively, revealed that most KNDy neurons co-expressed TACR3. Therefore, NKB could directly stimulate KNDy neurons, following which the stimulatory signal is immediately transmitted to the entire population of KNDy neurons via connection with their fibers. This mechanism helps synchronize burst activity among KNDy neurons, thereby generating neural signals that govern pulsatile GnRH secretion.     

山羊GnRH和促性腺激素的释放特点

通过外科手术分别连续收集活体山羊中黄体期及早卵泡期的垂体门脉血样和外周血样，经放射免疫测定，山羊中黄体期和早卵泡期的促性腺激素释放激素（ＧｎＲＨ）、促黄体生成素（ＬＨ）和促卵泡素（ＦＳＨ）均呈波动式释放。在早卵泡期，ＦＳＨ单位时间内波动次数和血浆平均水平显著高于中黄体期；ＧｎＲＨ与ＬＨ的波动型基本一致，ＦＳＨ的变化不太规则。表明山羊垂体促性腺激素的释放受丘脑下部ＧｎＲＨ的调节，但ＦＳＨ似乎还存在其他调节机理。     

GnRH免疫及其在畜牧业上的应用

激素免疫技术是近年兴起的一项新技术。本文较全面的综述了GnRH免疫的作用机理及其对动物生殖系统的影响，以及GnRH免疫在畜牧生产中的应用，为进一步研究GnRH免疫提供一定的参考价值。     

2020年世界生猪产业发展情况及2021年趋势

2020年世界猪肉总产量有较大幅度下降,为9788万吨,比2019年下降了4.02％,世界猪肉产量下降的主要原因是中国的生猪产能下滑.中国是世界上最大的猪肉生产国与进口国,2020年中国猪肉进口量为480万吨,比2019年上升了95.84％;占全球进口总量的46.31％,比2019年占比上升近17.30个百分点.预计2...     

Development, validation, and utilization of a novel antibody specific to the type III chicken gonadotropin-releasing hormone receptor

Two gonadotropin-releasing hormone receptors (GnRH-Rs) have been characterized in chickens to date: cGnRH-R-I and cGnRH-R-III, with cGnRH-R-III being the predominant pituitary form. The purpose of the present study was to first validate a novel antibody for the specific detection of cGnRH-R-III and second, using this antibody, detect changes in cGnRH-R-III protein levels in the pituitary gland of male and female chickens during a reproductive cycle. The localization of cGnRH-R-III within the anterior pituitary gland was also determined. Western blotting of pituitary extracts and transiently transfected COS-7 cell lysates revealed that our antibody is highly specific to cGnRH-R-III protein. Similarly, when used in immunocytochemistry, this antibody specifically detects cells expressing cGnRH-R-III and not cGnRH-R-I. Western blot analyses of chicken pituitary gland homogenates show that cGnRH-R-III protein levels are significantly greater in sexually mature birds than in immature birds or birds at the end of a reproductive cycle (P < 0.0001). A similar pattern was observed for both males and females. Additionally, the antibody was able to detect cGnRH-R-III in cells along the periphery of the cephalic and caudal lobes of the anterior pituitary where the cells containing the gonadotropins are located. In summary, we successfully validated a novel antibody to cGnRH-R-III and showed levels of cGnRH-R-III protein in the pituitary fluctuate with respect to the reproductive status in both male and female chickens.     

Association of SNPs in GnRH gene with sperm quality traits of Chinese water buffalo

Hypothalamic gonadotropin-releasing hormone (GnRH) controls the activity of hypothalamic–pituitary–gonadal axis and plays a key role in the reproductive performance of animals. In this study, five single nucleotide polymorphisms (SNPs), namely g.991T > C, g.1041T > C g.3424T > C, g.3462C > A and g.3463Inde A, were detected in the GnRH gene of 162 water buffaloes by Sanger sequencing. Each SNP was associated with more than two sperm quality traits of ejaculate volume, sperm concentration, post-thaw sperm motility and sperm abnormality. g.3424T > C and g.3462C > A were related to these four traits and had a remarkable effect on ejaculate volume. The three other SNPs were related to sperm concentration, post-thaw sperm motility and sperm abnormality. Moreover, six haplotypes (H1: TCCAI, H2: CTTC-, H3: TCCCI, H4: CTTA-, H5: CCTA- and H6: CTCC-) composed of five SNPs comprising seven different combined genotypes were generated by linkage disequilibrium analysis. Statistics followed by one-way ANOVA indicated that water buffaloes with the haplotype combination H1H1 had the highest genotypic frequency, and those with the H4H4 haplotype combination had the highest ejaculate volume. The sperm concentration of those with haplotype combination H1H5 was higher than that of the other genotypes. In summary, our study showed a remarkable association between the SNPs of GnRH and sperm quality traits of Chinese water buffalo.     

Comparative Efficacy of Histrelin Acetate and hCG for Inducing Ovulation in Brazilian Northeastern Jennies (Equus africanus asinus)

The goal of this study was to compare the efficiency of histrelin acetate (GnRH analog) and human chorionic gonadotropin (hCG) to hasten ovulation in Brazilian Northeastern jennies (Equus africanus asinus). Thirty cycles of ten jennies were randomly assigned in one of the three groups: G0 (control group), saline; G1, 250 μg of histrelin acetate; G2, 2500 IU of hCG. Jennies were evaluated by transrectal palpation and ultrasonography, and had the administration of an ovulation-inducing agent when a follicle measuring between 29 and 32 mm of diameter was diagnosed. Jennies were monitored every 6 hours by transrectal ultrasonography until ovulation. The interval between prostaglandin administration and ovulation was lower (P < .05) in jennies from the G1 (145.2 ± 34.6 hours) and G2 (147.4 ± 27.3 hours) groups compared with the control cycle (220.0 ± 41.8 hours). Both treatments (G1, 41.15 ± 3.5 hours; G2, 37.8 ± 2.5 hours) also reduced (P < .05) the interval that jennies took to ovulate after the administration of the ovulation-inducing agent compared with the control (81.8 ± 28.8 hours). All jennies from G1 and G2 ovulated up to 48 hours after ovulation induction, whereas 100% of jennies in the control cycle ovulated later (>48 hours from the administration of saline). In conclusion, both histrelin acetate and hCG at the used dose are efficient ovulation-inducing agents in jennies promoting ovulation up to 48 hours after administration.     

用GnRH类似物提高大通奶牛情期受胎率试验

对16头发情奶牛分两组注射GnRH类似物,第一组注射促排卵素3号200μg,第二组注射促排卵素2号100μg后进行配种。结果表明:第一组奶牛受胎率87.5%,第二组奶牛受胎率为75.0%,比对照组分别提高了43.1%和30.6%,但组间没有显著性差异(P>0.05)。