,中国农业大学动物科学技术学院/动物营养学国家重点实验室,北京 100193Research Progresses on Sensitive Index System of Heat Stress in Sows
YUAN XiongKun, JIANG LiLi, TAO ShiYu, ZANG JianJun, WANG JunJun,State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193通讯作者:
责任编辑: 林鉴非
收稿日期:2019-10-21接受日期:2020-08-31网络出版日期:2020-11-16
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Received:2019-10-21Accepted:2020-08-31Online:2020-11-16
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袁雄坤,Tel：17812080828;E-mail：
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袁雄坤, 姜丽丽, 陶诗煜, 臧建军, 王军军. 母猪热应激敏感指标体系的研究进展[J]. 中国农业科学, 2020, 53(22): 4691-4699 doi:10.3864/j.issn.0578-1752.2020.22.015
YUAN XiongKun, JIANG LiLi, TAO ShiYu, ZANG JianJun, WANG JunJun.
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热应激是指动物机体对高温环境所产生的非特异性生理反应的总和。母猪由于体重大、脂肪厚、汗腺不发达等生理特点,当温度高于其上限临界值时,容易遭受热应激[1]。母猪是猪场的核心群体,其生产性能将决定养猪业的经济效益。热应激会造成母猪内分泌紊乱,卵巢机能受到抑制,影响发情活动[2]、使其免疫力降低[3]、行为异常[4]、哺乳期产奶量降低[5],从而影响母猪的生产力、健康和福利。热应激状态下母猪容易发生流产或者产出死胎弱子且产仔数量减少,后代仔猪生长发育不良、成活率下降,且母猪死淘率升高等,严重损害养猪生产的经济效益[4]。St-Pierre等[6]研究表明,热应激导致美国生猪养殖每年损失达2.99亿美元;而对于世界上养猪业规模最大的中国,热应激造成的损失更大[7]。研究确定针对母猪不同生理阶段的适宜温度参数,是提高母猪繁殖力的重要依据。然而,母猪热应激受多种因素的影响,判定母猪的热应激状态比较困难。目前母猪热应激的敏感指标总体比较粗略,评价体系不够综合、全面。本综述结合已有的研究进展,从生产性能、繁殖性能、母猪行为、生理、血生化、免疫以及热休克蛋白表达等方面变化对热应激指标体系进行全面的综述,以期为母猪热应激诊断和环境参数限值研究提供技术与理论基础。
1 热应激对母猪生产性能和繁殖性能的影响
母猪是恒温动物,存在舒适温度。高航等[7]研究表明在热中性区,母猪可以仅依靠物理性调节即可使体温维持在正常温度范围内;但当环境温度超过上限临界值时,容易引起热应激。母猪的耐热性及热应激存在生理阶段特异性：后备母猪：金升龙[8]研究表明：后备母猪的适宜环境温度为18—21℃;当温度超过28℃时,母猪性成熟延迟;持续高温条件下,母猪性成熟会推迟22 d。由于性腺激素如雌激素分泌受抑制,后备母猪会出现发情明显减弱,短发情或乏情、甚至不发情。此外,热应激对后备母猪的不利影响会持续到妊娠期、哺乳期和断奶发情阶段,从而降低种猪的使用年限,最终影响猪场的生产效益。
妊娠母猪：妊娠阶段是胚胎附植、胎儿发育阶段,对高温更加敏感。母猪遭受热应激的负面影响与妊娠阶段有关[9]。妊娠前期是胚胎附植和存活的关键时期,对热应激最为敏感。EDWARDS等[10]研究表明：配种后1—30 d的母猪生活在温度为38.9℃的环境,使其遭受热应激,发现母猪受胎率和胚胎存活率降低,有少数流产甚至死亡;OMTVEDT等[11]研究发现妊娠中期（53—61 d）初产母猪在37.8℃环境条件下的受胎率、窝产总仔数及存活率等指标与常温环境差异不显著,说明妊娠中期受热应激影响较小;然而,妊娠后期热应激状态下的母猪（102—110 d）,窝产活仔数减少,仔猪初生重和21 d断奶重有下降的趋势,说明妊娠后期是胚胎生长发育最快速的时期,热应激会通过影响子宫内环境和抑制母猪的采食量,从而间接地影响胎儿的存活和生长,这个时期母猪对热应激较为敏感。目前的研究认为：妊娠母猪适宜环境温度为12—20℃[12,13],有研究进一步表明：妊娠前期适宜温度为13—19℃,妊娠后期适宜温度为16—20℃,高温临界值为27℃[12]或32℃[14]。
哺乳母猪：哺乳母猪采食量大、代谢强度高,对高温也较敏感。姜丽丽等[15]认为：高温环境主要影响哺乳母猪的代谢和内分泌功能,特别是甲状腺激素、皮质醇、促黄体素和促乳素的分泌,影响母猪繁殖性能和生产性能。热应激会导致母猪产后乳房炎-子宫内膜炎-泌乳障碍综合征等疾病的发病率增加,乳汁质量差,仔猪腹泻增加,死亡率增加[16]。高温或者热应激条件下母猪为减少产热,会主动减少采食,导致母猪产乳量下降、降低仔猪断奶重[17];同时也会增加母猪哺乳期体重和背膘损失,增加母猪断奶发情间隔,延长母猪的繁殖周期,减少年产窝数。有****研究表明：哺乳母猪适宜温度为15—20℃[14]或16—18℃[18],当分娩舍温度由18℃上升至29℃时哺乳母猪的采食量由5.67 kg·d-1下降到3.08 kg·d-1 [19],温度在21—27℃范围内时温度每增加1℃,哺乳母猪采食量降低0.1 kg·d-1 [20]。
空怀母猪：断奶发情间隔是母猪断奶至发情的时间间隔,是衡量母猪繁殖力重要指标,其长短不但影响母猪的年产窝数,而且可能制约下一窝的窝产仔数,最终关系到猪场的生产水平和经济效益[15]。断奶至发情的时间间隔一般为7 d,有试验表明：热应激会抑制卵母细胞的发育,减少成熟卵母细胞的数量[14,19],从而增加母猪的断奶发情间隔。高温季节空怀母猪发情延迟、发情率降低,出现隐性发情甚至不发情的现象,有研究报道,35℃时母猪断奶发情间隔期平均为9 d,显著长于30℃时的6 d[17];且与经产母猪相比,高温环境对初产母猪断奶后再发情的时间影响更大[15,16]。我国2008年版《规模猪场环境参数及环境管理》推荐空怀母猪适宜温度为15—20℃[12]。
综上,环境温度是表征母猪是否遭受热应激的重要指标,具有特异性。当超过适宜环境温度,母猪会逐渐出现不适应的症状直至达到上限值时就会发生热应激。热应激时母猪会通过减少采食量、增加呼吸率和皮肤血流量等途径来减少代谢产热、增加散热,同时母猪血液中促肾上腺皮质激素和皮质醇增加、甲状腺素降低、胰岛素敏感性增加,这些生理指标的变化会破坏母猪机体内分泌和能量平衡,进而导致胚胎早期死亡。有研究发现,母猪在配种11—12 d后处于温度为32—39℃环境中24 h,胚胎存活率降低40 %左右,热应激也会对母猪发情间隔、产仔数和泌乳量等生产性能造成不利影响,妊娠前期热应激主要影响返情率和产仔数,妊娠后期主要影响产活仔数和死胎数,分娩后则主要影响仔猪存活率,高温抑制泌乳母猪彩食,进而影响母猪泌乳量和仔猪生长性能及增加泌乳期母猪体重损失和体内生殖激素分泌紊乱,导致母猪断奶后发情延迟[21]。
2 行为变化
行为是动物健康与否的直观表现,是健康检查的重要指标。妊娠期和哺乳期母猪对热应激最为敏感,目前母猪热应激相关的研究主要集中在这两个阶段。母猪热应激时,在早期表现为行为比较暴躁、咬尾、呼吸加快;随着热应激时间的持续,母猪会出现精神萎靡、站立不稳、俯卧时间增加、严重时甚至死亡的现象。热应激时,母猪为减少产热和增加散热,其采食量下降、乳腺血流量减少、四肢伸展、饮水和排尿增加[5,19]。哺乳母猪在热应激情况下产乳量不足,仔猪未成功吸吮次数增加,导致仔猪更为频繁地吮吸母猪奶头,而妊娠母猪会出现分娩持续时间延长、分娩率下降、死胎率增加等现象[22]。母猪的上述行为变化都是为应对热应激而进行的自我保护,出现上述行为时,需要考虑母猪是否遭受热应激。尽管目前尚未有研究明确地表明母猪的哪些行为变化可作为判断热应激的指标,但是观察行为学是一个比较省时省力、应激较小的方法。此外,母猪在热应激环境中行为异常现象持续存在,其对于评价和鉴定热应激仍具有一定的参考价值,特别是物联网及智能化养殖技术的发展,需要结合生理生化等其它指标,对母猪热应激开展系统研究。
3 生理指标
大量研究表明：皮肤温度、呼吸频率以及直肠温度是热应激中常见且直观的生理评价指标,而且测量简单方便,目前国内外主要将这3个指标作为判断母猪热应激的生理指标。3.1 皮肤温度
母猪通过皮肤排汗散热,导致皮肤温度升高。QUINIOU等[19]报道：当环境温度从18℃上升到29℃时,哺乳母猪的体温从34.6℃增加到37.4℃,表明随着环境温度的升高,母猪皮肤温度也会随之升高,MUNS等[23]、MALMKVIST等[24]和WILLIAMS等[25]也得出类似结论。蒲红州等[26]研究发现用加权体表温度（Tsk）来表示皮肤温度更加合理,其计算公式为：Tsk = 0.1T耳 + 0.4T肩 + 0.4T臀 + 0.1T尾,T耳、T肩、T臀和T尾分别代表猪的耳、肩、臀、尾根4个部位体温,系数是根据各个部位在体表所占面积确定的,当生长猪处于高温环境（30℃）时,体表温度显著增加,由31.92℃升高至35.52℃。3.2 呼吸频率
母猪正常呼吸频率在13—20次/min,热应激条件下,母猪呼吸变浅、频率加快,呼吸频率随着温度升高而显著增加,每分钟最高达70次[26],变化非常显著。高温环境中母猪呼吸频率加快以增加热量散失、减轻体内热量过多带来的影响。因此,呼吸频率是一个敏感的生理指标,也是一个比较可靠的判断指标,陶源栋等[27]基于Kinect检测方法可以估算出梅山母猪侧卧的呼吸频率,正确率可达85.3 %,可以实现远程监测母猪的呼吸状况。3.3 直肠温度
猪的核心体温（core body temperature,CBT）是身体深处的温度,是主要的生命特征之一,最为常见和可行的是测定直肠温度[12]。猪是恒温动物,正常直肠温度为38—39.5℃,体温变化不大。WILLIAMS等[25]研究表明：热应激状态下,哺乳母猪直肠温度显著升高,从39.2℃升高至40℃,可以很好的表征母猪热应激状态。但是,热应激状态下直肠温度的变化慢于皮肤温度和呼吸频率,是热负荷的延迟指标[28];此外,测定母猪直肠温度时会造成一定的应激,可能会影响测定的结果。总之,皮肤温度、呼吸频率和直肠温度等生理指标在母猪热应激时显著升高,是评判母猪热应激比较可靠的指标,具有很强的表征特点。生理指标在生产中评定母猪热应激时具有重要价值。建议在评定母猪热应激的生理指标优先选择皮肤温度和呼吸频率,其次选择直肠温度。
4 生化指标
4.1 血液激素
热应激会干扰动物的内分泌系统,引起内分泌激素的分泌异常。因此,母猪体内激素的变化情况可作为评定热应激严重程度的指标。4.1.1 皮质醇（cortisol, COR） COR是由肾上腺皮质分泌的糖皮质激素,对糖类具有极强的代谢作用。相关研究表明：热应激条件下该激素有显著变化,是比较理想的指标。张敏红等[28]研究表明：急性热应激时猪血液中的COR水平会从8.4 ng·mL-1增加至25.1 ng·mL-1,当应激源消失后,血液中COR逐渐降低直至正常水平;丁升艳[29]试验研究进一步明确：在持续温热环境中,生长猪血清中COR浓度升高,并随着热应激时间的延长而大量增加;而RENAUDEAU等[22]试验指出：由于高温环境母猪采食量下降以及下丘脑-垂体-肾上腺轴（hypothalamic- pituitary-adrenal axis,HPA）受到持续热环境（30℃）的作用,母猪体内的COR浓度降低。该现象可以解释为：猪为适应热环境HPA轴被激活,导致体内肾上腺皮质激素分泌迅速增加;但随着热应激持续刺激HPA轴受到抑制、母猪采食量下降导致能量供给不足、引起皮质醇分泌不足,从而出现了低于初期正常水平的现象。
4.1.2 三碘甲腺原氨酸（triiodothyronine, T3）和四碘甲腺原氨酸（tetraiodothyronine, T4） 甲状腺激素是产热激素,有T3和T4两种形式,其中T4是T3的前体激素,T3是在组织中发挥生理作用的主要激素,可以提高器官组织代谢、使器官组织耗氧量和产热量增加。刘凤华等[30]研究发现鸡在热应激第一阶段时,机体为了抵抗高温的作用,为散热而增加产热,呼吸加快,外周血液加速,让体内的热量尽量散出去;随着热应激的持续,动物机体适应后,T3和T4的分泌逐渐降低至正常水平,因此,当动物体内T3先升高后降低时,很有可能是出于热应激状态。仲庆振等[31]研究表明籽鹅高温环境中8 h后血清T3和T4会分别从2.73、16.24 ng·mL-1下降至0.98和12.04 ng·mL-1。国外研究者也得到了一致结论,RENAUDEAU等[22,29]研究指出：母猪遭受热应激时通过抑制体内甲状腺素分泌活动、引起甲状腺激素水平明显降低,从而适应高温环境。由此可见,母猪机体内T3和T4在热应激时会先升高,随着时间的推移适应后,T3和T4恢复正常水平,也可作为是母猪热应激的评价指标。
4.1.3 性腺激素 BARB等[32]指出哺乳母猪热应激时,黄体生成素脉冲频率降低,表明母猪黄体生成素分泌在下降。有研究进一步发现：动物为对抗热应激会激活HPA轴,促使促肾上腺素分泌增加,使性腺激素促卵泡素（FSH）、促黄体素（LH）、雌激素分泌被抑制,雌激素分泌不足进而抑制孕酮的分泌[21]。性激素分泌被抑制必然会影响动物的发情、配种和分娩,从而制约母猪的繁殖力。然而,单一激素指标的变化还不足以表明母猪遭受热应激,其他应激也可能导致母猪内分泌变化。因此,判定母猪热应激时,还需要结合其他因素（如：环境温度和湿度等）,以确保诊断正确。
4.2 血液酶活性
正常情况下,动物血液中酶的种类和水平都比较稳定。但当处于高温热应激环境时,动物机体组织器官细胞膜通透性增加,细胞液中的酶流入血液,使血液中酶的水平上升。4.2.1 天门冬氨酸转移酶（aspartate transferase,AST）和丙氨酸转移酶(alanine transferase,ALT) AST和ALT是衡量肝脏功能的重要指标,而肝脏功能可表征动物是否遭受应激[33]。刘凤华等[30]研究发现：蛋鸡血清中ALT和AST水平随着温度升高而升高,热应激状态下AST和ALT分别从130、51.4 U·L-1增加到148、134.6 U·L-1,差异极显著。张小东[34]也得出类似结论,猪血液中热应激开始时ALT、AST变化不显著,但是高温持续10 d时,血中AST和ALT水平会从26.80、40.65 IU·L-1升高到44.45、66.85 IU·L-1,差异显著,说明不同动物对于高温环境的敏感程度有差异,ALT和AST可作为母猪持续热应激的检测指标。
4.2.2 肌酸激酶（creatine kinase,CK）和乳酸脱氢酶（lactate dehydrogenase,LDH） CK主要存在于心肌细胞,LDH主要位于骨骼肌细胞。有研究表明：CK和LDH属于胞内酶,由于细胞屏障作用,正常情况下不容易进入血液,只有少量CK和LDH随着组织器官新陈代谢而释放到血液中[35]。张小东[34]研究发现：在热应激情况下,猪血清CK水平会从369.45 IU·L-1增加到2 125.45 IU·L-1,可作为动物热应激状态下的敏感指标[36,37,38]。当母猪受到热应激刺激时,内脏器官血流量减少引起供氧量变少,使得心脏和骨骼肌细胞新陈代谢变慢,细胞通透性增加。张根军[39]研究发现应激过程中猪血浆中的LDH水平会显著升高,从367.70 IU·L-1增加至825.50 IU·L-1。由此可知,猪在热应激刺激下,皮肤血流量增加、肝脏供血量不足,导致新陈代谢变慢、细胞通透性增加,使胞内酶CK和LDH溢出进入血液,从而引起血液中这两种酶水平升高,CK和LDH是母猪可靠的热应激指标。
4.3 血液无机离子
Na+和K+是维持体液渗透压、酸碱平衡的重要电解质。张莉等[40]研究表明：血液中K+和Na+的含量在热应激的刺激下显著下降。可能原因是：热应激情况下动物呼吸加快,排出CO2过多、血液pH升高;为维持血液酸碱平衡,血液中Na+、K+通过肾脏排出体外以降低血液pH,从而引起血液中Na+、K+浓度显著下降[21]。张小东[34]研究表明生长猪血液无机离子中K+对短期急性热应激比较敏感,可作为猪短期急性热应激的检测指标,这与PATIENCE等[41]报道较为一致：模拟日变高温（20—38℃）的情况下,并不会显著改变猪血液中无机离子的浓度。试验结果的差异可能是由于后者的试验猪遭受的不是持续高温而是日变高温,试验适应期为10 d,猪在这10 d内可能已经逐渐适应了日变高温。总体而言,母猪血液中的离子特别是K+和Na+等离子浓度的变化较大,对于判定母猪热应激具有一定的参考意义。4.4 血糖
血液葡萄糖为动物机体代谢中的重要物质,热应激可通过胰高血糖素和儿茶酚胺而促进糖原降解,导致血糖增加。热应激状态下,巴马香猪血糖浓度明显增加,但随着时间推移会逐渐减低[40]。上述变化可以解释为：动物为应对热应激,体内肾上腺素水平会升高,致使肝糖原分解。因此,应激早期血糖水平升高;而随着应激时间延长,血液中皮质醇浓度增高引起蛋白质分解代谢加快、血糖利用加快,从而使血糖水平降低直至稳定[42]。4.5 血清蛋白
动物机体血清蛋白含量是衡量其蛋白质营养的重要特征。血清总蛋白的绝大部分由肝脏分泌,而肝脏的功能可以反映动物应激的严重程度[33]。动物在高温环境或者热应激状态下,会激活HPA轴、导致皮质醇分泌增多,而皮质醇可加快母猪血液中蛋白质的利用。刘圈炜等[43]试验发现：热应激情况下,生长猪在23℃环境中血清总蛋白和球蛋白含量显著增加。可见,血清蛋白也可作为母猪热应激的判断指标,但血清蛋白对热应激不具有特异性,其它应激也可能导致皮质醇的升高而使血清蛋白分解。因此,应结合其它环境因素和母猪的血液生化指标进行综合判定。5 免疫细胞变化
巨向红等[3]和刘胜军等[44]研究表明：热应激后,猪红细胞先升高后降低,中性粒细胞、单核细胞、嗜酸性粒细胞、嗜碱性粒细胞逐渐增加。红细胞具有免疫和参与机体免疫调节的功能,其含有许多与免疫有关的物质,在热应激初期增加以参与动物免疫;而随着动物对热应激的适应,红细胞数目逐渐恢复正常。白细胞是主要的免疫细胞,包括粒细胞、单核细胞和淋巴细胞,其中粒细胞又可根据胞质中颗粒的染色性质不同,分为中性粒细胞、嗜酸性粒细胞和嗜碱性粒细胞3种,当动物在热应激状态下发生炎症时,白细胞分泌增加以应对炎症。此外,动物在高温刺激下会导致中性粒细胞数目升高[3],可能的原因是高温导致动物皮质醇增多,从而导致中性粒细胞的运输方式改变,使中性粒细胞从骨髓储备中释放出来。T细胞是机体免疫应答的核心细胞。有研究表明：猪在慢性热应激情况下,脾脏中成熟T淋巴细胞表面标志物（CD3+）和辅助T淋巴细胞（CD4+）数目均显著增加,同时,CD4+/CD3+比值增高[44]。CD4+主要功能是增强吞噬细胞介导的抗感染作用和增强B细胞介导的体液免疫应答,CD3+和CD4+数目增加,是动物为抵御热应激而进行的自我保护。母猪在热应激刺激下为保护自身,体内免疫细胞的数目会增加,且增加程度与母猪热应激严重程度和持续时间有关。当母猪适应高温环境后,免疫细胞的数目会逐渐恢复至正常水平。但各种免疫细胞的变化并不完全同步,某些免疫细胞具有延迟性和时效性。
6 热休克蛋白
热休克蛋白（heat shock protein,HSP）HSP是在从细菌到哺乳动物中广泛存在一类热应激蛋白质,当动物暴露于高温的时候,就会由热激发合成此种蛋白,来保护动物机体自身。按相对分子质量及同源程度可分为HSP110、HSP90、HSP60、HSP40和小分子HSP家族。HSP家族中,HSP70受热应激的影响最大,其增强热耐受性的机制主要包括分子伴侣、抗氧化和协同免疫等作用[45]。HSP72和HSP73是HSP70的两种型态,动物热应激时HSP73增加非常少,几乎无变化,而HSP72在热应激状态下大量产生。有研究表明高温环境下猪小肠上皮细胞HSP70 mRNA和蛋白表达显著升高[45],猪血浆中HSP70蛋白水平在热应激时从300 μg·L-1迅速上升到600 μg·L-1左右,具有很强的特异性,高温过后仍能保持较高值,可准确地反应猪的热应激严重程度[33]。梁学武等[46]和张凡健等[47]研究表明HSP70是奶牛受热应激损伤严重程的综合评价指标。此外,熊一力等[48]和MALOYAN等[49]研究也表明：高温环境可以导致鼠肝脏中HSP70转录物及蛋白合成明显上升。与血液其它生化指标的变化比较,血浆HSP70在热应激时的变化具有持续时间长、反应敏感的特点,且HSP70的变化更能准确地反映应激的程度,表明血液HSP70含量可作为诊断热应激反应的首选指标[34]。7 小结
我国生猪生产占全球的一半,正处于数量型增长向绿色高质量发展的新阶段,特别是2018年8月发现首例非洲猪瘟以来,生猪生产生物、环境设施和工艺的改进迫在眉睫。准确的环境工艺参数的设定是高效生产和成本控制的重要前提,系统研究不同生理阶段母猪热应激的表现、危害及其防控措施,特别是研究提出生产中简便、快捷的热应激指标和评价方法尤显重要。在热应激相关评价指标中,环境温度是最为直接的体现,母猪适宜的环境温度为12—21℃,热应激温度阈值为27℃时,当超过阈值时很容易引起母猪行为异常、内分泌紊乱,进而影响生产性能。肝脏和血浆中HSP70,对热应激反应敏感, 当遭遇热应激时可从300 μg·L-1迅速上升到600 μg·L-1左右, 持续时间长,是生化指标中目前最为准确的。生理指标如：皮肤温度、呼吸频率和直肠温度等准确性也很高,而且测定简单易行。母猪表皮温度受环境影响较大,随着环境温度升高,可从34.6℃增加到37.4℃,耳皮处无背毛影响,与其他皮肤温度相比,测定温度更为可靠;母猪正常呼吸频率在13—20次/min,热应激状态下呼吸频率可达70次/min;直肠温度正常范围为38—39.5℃,热应激状态下直肠温度可达40℃。综合以上指标：HSP70、呼吸频率、直肠温度、皮肤温度等可作为母猪长期热应激的评价指标,具有很强的表征特点。此外,生化指标如：血液COR、AST、ALT、CK和LDH等准确性稍差,但在相关指标中,准确性依旧相对较高,例如热应激状态下母猪血中AST和ALT水平会从26.80、40.65 IU·L-1显著升高到44.45、66.85 IU·L-1。雌激素、血糖、血清Na+、K+等其他指标准确性不太高,但可作为辅助指标。生产性能和行为变化在实际生产过程中有一定滞后性,但具有操作简单、对动物无应激等特点,在生产中具有一定意义。总之,除环境温度外,对母猪热应激敏感指标评价体系建议为：首选环境温度、HSP70、表皮温度、呼吸频率、直肠温度;其次为COR、T3、AST、ALT、CK和LDH;血清蛋白、血糖、血液免疫细胞、K+、Na+等指标可作为辅助指标。参考文献 原文顺序
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被引期刊影响因子
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DOI:10.1016/0739-7240(91)90046-mURLPMID:1901537 [本文引用: 1]
Seven sows were placed into one of two environmental chambers at 22 C, 5 d prior to farrowing. On day 9 of lactation, one chamber was changed to 30 C (n = 4) and the other remained at 22 C (n = 3). On days 24 and 25, blood samples were collected every 15 min for 9 hr and 7 hr, respectively. On day 24, thyrotropin releasing hormone (TRH) and gonadotropin releasing hormone (GnRH) were injected iv at hour 8. On day 25 naloxone (NAL) was administered iv at hour 4 followed 2 hr later by iv injection of TRH and GnRH. Milk yield and litter weights were similar but backfat thickness (BF) was greater in 22 C sows (P less than .05) compared to 30 C sows. Luteinizing hormone (LH) pulse frequency was greater (P less than .003) and LH pulse amplitude was less (P less than .03) in 22 C sows. LH concentrations after GnRH were similar on day 24 but on day 25, LH concentrations after GnRH were greater (P less than .05) for 30 C sows. Prolactin (PRL) concentrations were similar on days 24 and 25 for both groups. However, PRL response to TRH was greater (P less than .05) on both days 24 and 25 in 30 C sows. Growth hormone (GH) concentrations, and the GH response to TRH, were greater (P less than .0001) in 30 C sows. Cortisol concentrations, and the response to NAL, were less (P less than .03) in 30 C sows. NAL failed to alter LH secretion but decreased (P less than .05) PRL secretion in both groups of sows. However, GH response to NAL was greater (P less than .05) in 30 C sows. Therefore, sows exposed to elevated ambient temperature during lactation exhibited altered endocrine function.
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DOI:10.3168/jds.S0022-0302(03)74040-5URL [本文引用: 1]
DOI:10.3864/j.issn.0578-1752.2018.16.018URL [本文引用: 2]
适宜的畜舍环境是保障畜禽健康养殖的重要条件。据国家统计局数据表明：在2017年我国猪肉产量5 340万t,增长0.8%,生猪存栏量68 861万头,增长0.5%,我国是传统的猪生产和猪肉消费大国,随着我国养猪业规模化、福利化的发展,在当前已经拥有了高产品种猪和优质全价的配合饲料之后,猪舍内小气候环境对猪群健康的影响引起越来越多的关注和重视。早在20世纪40年代,欧美等西方发达国家****就开始建立家畜人工气候室,通过在畜舍中模拟自然环境的气候变化,研究在不同气候条件下家畜的生理变化规律,制定猪适宜环境参数并应用于生产管理,以较好的环境换取更高的生产效益。近年来,欧美国家更加关注饲养环境对畜禽精准饲养和动物福利与健康的影响。美国NRC（2012）提出了以环境温度和饲养密度为变量的代谢能摄入量动态模型,实现营养供给的动态预测。我国生态气候复杂,生产要素的集成缺乏统一的环境基础,当猪舍环境较差时,会严重影响猪群的健康并制约猪生长性能的发挥。文章以我国现有的猪舍内环境参数标准为基础,结合国内外现有的相关环境参数标准与试验研究,比较并分析了国内外猪舍内环境温度、湿度、有害气体浓度和饲养密度等适宜参数的异同；畜舍中温度主要影响猪的采食量进而对其生长性能产生影响,在高温环境中生长猪采食量降低从而导致生产性能下降,低温环境条件下生长猪增加的采食量,更多的用于维持体温的恒定,能量利用率因而较低；畜舍中的湿度往往是伴随着舍内温度产生的协同效应；猪舍中的有害气体主要包括氨气、硫化氢、二氧化碳、甲烷和氧化氮,有害气体不仅影响人类身体健康,同时也会严重影响猪的健康生长,诱发疾病以及降低饲料转化效率。猪是社会性很强的动物,在规模化猪场发展的前提下,群居会给猪带来一定的好处,但因饲养密度增加导致的应激,会破坏猪的生理机能、行为习惯和环境之间的动态平衡,从而严重影响猪的健康,制约猪生长性能的发挥。
DOI:10.3864/j.issn.0578-1752.2018.16.018URL [本文引用: 2]
适宜的畜舍环境是保障畜禽健康养殖的重要条件。据国家统计局数据表明：在2017年我国猪肉产量5 340万t,增长0.8%,生猪存栏量68 861万头,增长0.5%,我国是传统的猪生产和猪肉消费大国,随着我国养猪业规模化、福利化的发展,在当前已经拥有了高产品种猪和优质全价的配合饲料之后,猪舍内小气候环境对猪群健康的影响引起越来越多的关注和重视。早在20世纪40年代,欧美等西方发达国家****就开始建立家畜人工气候室,通过在畜舍中模拟自然环境的气候变化,研究在不同气候条件下家畜的生理变化规律,制定猪适宜环境参数并应用于生产管理,以较好的环境换取更高的生产效益。近年来,欧美国家更加关注饲养环境对畜禽精准饲养和动物福利与健康的影响。美国NRC（2012）提出了以环境温度和饲养密度为变量的代谢能摄入量动态模型,实现营养供给的动态预测。我国生态气候复杂,生产要素的集成缺乏统一的环境基础,当猪舍环境较差时,会严重影响猪群的健康并制约猪生长性能的发挥。文章以我国现有的猪舍内环境参数标准为基础,结合国内外现有的相关环境参数标准与试验研究,比较并分析了国内外猪舍内环境温度、湿度、有害气体浓度和饲养密度等适宜参数的异同；畜舍中温度主要影响猪的采食量进而对其生长性能产生影响,在高温环境中生长猪采食量降低从而导致生产性能下降,低温环境条件下生长猪增加的采食量,更多的用于维持体温的恒定,能量利用率因而较低；畜舍中的湿度往往是伴随着舍内温度产生的协同效应；猪舍中的有害气体主要包括氨气、硫化氢、二氧化碳、甲烷和氧化氮,有害气体不仅影响人类身体健康,同时也会严重影响猪的健康生长,诱发疾病以及降低饲料转化效率。猪是社会性很强的动物,在规模化猪场发展的前提下,群居会给猪带来一定的好处,但因饲养密度增加导致的应激,会破坏猪的生理机能、行为习惯和环境之间的动态平衡,从而严重影响猪的健康,制约猪生长性能的发挥。
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DOI:10.2527/jas1968.2761634xURL [本文引用: 1]
DOI:10.2527/jas1971.322312xURLPMID:5543028 [本文引用: 1]
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DOI:10.1016/0301-6226(93)90188-NURL [本文引用: 1]
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DOI:10.2527/2005.8361385xURLPMID:15890816 [本文引用: 1]
The effects of relative humidity (RH) and high ambient temperature (T) on physiological responses and animal performance were studied using 12 groups (10 gilts per group) in pens inside respiration chambers. The microclimate in the chamber was programmed so that T remained constant within a day. Each day, the T was increased by 2 degrees C from low (16 degrees C) to high (32 degrees C). Relative humidity was kept constant at 50, 65, or 80%. The pigs' average initial BW was 61.7 kg (58.0 to 65.5 kg), and their average ending BW was 70.2 kg (65.9 to 74.7 kg). Respiration rate (RR), evaporative water (EW), rectal temperature (RT), skin temperature (ST), voluntary feed intake (VFI), water-to-feed ratio (rW:F), heat production (HP), and ADG were analyzed. The animals had free access to feed and water. We determined the T above which certain animal variables started to change: the so-called inflection point temperature (IPt) or
DOI:10.2527/1999.7782124xURLPMID:10461991 [本文引用: 4]
Multiparous Large White sows (n = 63) were used to investigate the effects of five ambient temperatures (18, 22, 25, 27, and 29 degrees C) and two dietary protein contents on their lactation performance. At each temperature treatment, ambient temperature was maintained constant over the 21-d lactation period. Dietary protein content was either 14 or 17% with essential amino acids levels calculated not to be limiting. The animals had ad libitum access to feed between the seventh and the 19th day of lactation. Diet composition did not influence lactation performance. Over the 21-d lactation, feed intake decreased from 5.67 to 3.08 kg/d between 18 and 29 degrees C. Between d 7 and 19, the corresponding values were 7.16 and 3.48 kg/d, respectively. This decrease was curvilinear; an equation to predict voluntary feed intake (VFI) from temperature (T, degrees C) and body weight (BW, kg) is proposed: VFI = -49,052 + 1,213 T - 31.5 T2 + 330 BW - .61 BW2 (residual standard deviation: 1,018). Skin temperature increased regularly with increased ambient temperature (34.6 to 37.4 degrees C between 18 and 29 degrees C), whereas udder temperature reached a plateau at 25 degrees C (38.3 degrees C). The gradient of temperature between skin and rectum was minimal (2 degrees C ) at 27 degrees C and remained constant at 29 degrees C. This constancy coincides with the marked reduction of feed intake. The respiratory rate increased from 26 to 124 breaths/min between 18 and 29 degrees C, and this indicates that the evaporative critical temperature was below 22 degrees C. The BW loss increased from 23 to 35 kg between 18 and 29 degrees C, but its estimated chemical composition remained constant. Pig growth rate was almost constant between 18 and 25 degrees C (241 g/d) and was reduced above 25 degrees C (212 and 189 g/d at 27 and 29 degrees C, respectively). In conclusion, temperatures above 25 degrees C seem to be critical for lactating sows in order to maintain their performance.
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DOI:10.2527/2003.811217xURLPMID:12597393 [本文引用: 3]
Two groups of three multiparous Large White x Landrace sows were used to investigate the direct effect of ambient temperature on mammary gland metabolism. Sows from the first group were exposed to temperatures of 28 degrees C between d 8 and 14 of lactation, and 20 degrees C between d 15 and 21; treatments were reversed in the second group. Four to six d after farrowing, an ultrasonic blood flow probe was implanted around the right external pudic artery and catheters were fitted in the right anterior mammary vein and in the carotid artery. After surgery all sows were fed 3.8 kg/d of a lactation diet. The arteriovenous (AV, mg/L) plasma samples were obtained every 30 min between 0915 and 1545 on d 5 of exposure to ambient temperature; the same day, milk samples were collected at 1630. Additional arterial samples were obtained between 1000 and 1100 on d 1, 4, and 6 of exposure. Milk yield was estimated from the body weight gain of the litter. Elevated temperature tended to reduce BW loss (2.44 vs 1.82 kg/d, P < 0.10), but did not affect milk yield (11.0 kg/d). Glucagon and leptin arterial concentrations increased (12 and 8%, respectively; P < 0.10), but thyroxin and triiodothyronine concentrations decreased (26 and 16%, respectively; P < 0.01) between 20 and 28 degrees C. Expressed as a percentage of total nutrients, AV difference, glucose, amino acids, triglycerides (TG), free fatty acids, and lactate A-V differences represented 60, 20, 11, 8, and 1%, respectively. Exposure to 28 degrees C increased the extraction rate of glucose, TG, and a-amino acid N (13, 8, and 2.5%, respectively; P < 0.10). The extraction rates of essential and nonessential amino acids were not affected by temperature. The right pudic artery mammary blood flow increased (872 vs 945 mL/min, P < 0.05) between 20 and 28 degrees C, whereas milk yield was unaffected by temperature. It is suggested that this apparent inefficiency of the sow mammary gland in hot conditions could be related to an increase of proportion of blood flow irrigating skin capillaries in order to dissipate body heat.
DOI:10.2527/jas.2015-9623URLPMID:26812342 [本文引用: 1]
The aim of the experiment was to study the impact of high ambient temperature (25 degrees C) around farrowing on crated sows unable to perform thermoregulatory behavior. Twenty sows were housed in 2 farrowing rooms in conventional farrowing crates. In 1 room (CONTROL) temperature was kept at 20 degrees C. In the other room (HEAT) temperature was initially kept at 20 degrees C and gradually raised until it reached 25 degrees C from d 112 to 115 of gestation. Then the temperature was gradually lowered to 20 degrees C. Sows were continuously video recorded for behavior recording. Sows' respiration rates were recorded from d 3 before farrowing to d 5 after farrowing. Sows' rectal temperatures were recorded from d 1 before farrowing to d 8 after farrowing, and sows' udder surface temperatures were recorded from the day of farrowing to d 3 after farrowing. All measures were recorded daily. Sows' BW were recorded at d 108 of gestation and at weaning. Sows' back fat was recorded on farrowing day, when room temperature was set again at 20 degrees C, and at weaning. Piglets were weighed at d 1, 14, and 21. The HEAT sows spent a higher proportion of time lying in the lateral position than CONTROL sows, both during the 16 h before farrowing and the 24 h after the start of farrowing ( < 0.05), but with no difference in the amount of time spent lying down between groups ( > 0.10). The HEAT sows had higher rectal temperature on d 1 after farrowing ( < 0.05) and had udder surface temperature 0.9 degrees C higher than that of CONTROL sows during the recording period ( < 0.05). The HEAT sows also tended to have longer farrowing duration ( < 0.10). Respiration rate was higher in HEAT sows on d 1 before farrowing and on the day of farrowing. On d 7, 8, and 9, CONTROL sows had higher feed intake ( < 0.05), and piglets from CONTROL sows were heavier at d 21 after farrowing ( < 0.05). High ambient temperature around farrowing altered sows' postural behavior. Sows reacted to the thermal challenge with higher respiration rate around farrowing, but both their rectal and udder temperatures were elevated, indicating that they were not able to compensate for the higher ambient temperature. High ambient temperature negatively influenced sows' feed intake, with negative impact on piglets' weaning weight. High temperatures around farrowing (25 degrees C) compromise crated sows' welfare, with a potential negative impact on offspring performance.
DOI:10.2527/jas.2008-1592URLPMID:19502502 [本文引用: 1]
Provision of additional floor heating (33 to 34 degrees C) at birth and during the early postnatal hours is favorable for newborn piglets of domestic sows (Sus scrofa). We investigated whether this relatively high temperature influenced sow behavior and physiology around farrowing. One-half of 28 second-parity pregnant sows were randomly chosen to be exposed to floor heating 12 h after onset of nest building and until 48 h after birth of the first piglet (heat treatment), whereas the rest of the sows entered the control group (control treatment) with no floor heating. Hourly blood sampling from 8 h before and until 24 h after the birth of the first piglet was used for investigation of temporal changes in plasma concentrations of oxytocin, cortisol, and ACTH. In addition, occurrence and duration of sow postures were recorded -8 to +48 h relative to the birth of the first piglet. There was a clear temporal development in sow behavior and hormone concentrations (ACTH, cortisol, and oxytocin) across parturition (P < 0.001), independent of treatment. In general, hormone concentrations increased from the start to the end of farrowing. The observed oxytocin increase and peak late in farrowing coincided with the passive phase where sows lie laterally with an overall reduced activity. Floor heating increased the mean concentration of cortisol (P = 0.02; estimated as 29% greater than in controls) and tended to increase the mean concentration of ACTH (P = 0.08; estimated as 17% greater than in controls), but we did not find any treatment effect on mean oxytocin concentrations, the course of parturition, or the behavior of sows. Behavioral thermoregulation may, however, have lost some function for the sows because the floor was fully heated in our study. In addition, exposure to heat decreased the between-sow variation of plasma oxytocin (approximately 31% less relative to control) and ACTH (approximately 46% less relative to control). Whether this decreased variation may be indicative of acute stress or linked to other biological events is unclear. In conclusion, inescapable floor heating (around 33.5 degrees C) may be considered a stressor for sows around farrowing, giving rise to elevated plasma concentrations of cortisol, but without concurrent changes in oxytocin or behavioral activity.
DOI:10.2527/jas.2012-6055URL [本文引用: 2]
Heat stress (HS) causes seasonal infertility in sows and decreases reproductive efficiency. The objective was to examine thermoregulation, metabolic responses, and reproduction in sows exposed to HS or thermoneutral (TN) conditions during different phases of a production cycle (gestation, lactation, and breeding). Fifty-eight first-parity Landrace (n = 26) or Landrace x Large White F1 (n = 32) sows were rotated through environmental chambers for 57 d beginning in late gestation. The ambient temperature sequences included either TN (18 degrees C to 20 degrees C) or HS (24 degrees C to 30 degrees C) for each production phase with the following treatment groups: TN-TN-TN (n = 15), TN-HS-TN (n = 14), HS-TN-HS (n = 14), and HS-HS-HS (n = 15) for gestation-farrowing-breeding (20, 24, and 13 d, respectively). Regardless of the temperature treatment, rectal temperatures were greater (P < 0.001) during lactation (39.36 degrees C +/- 0.01 degrees C) than during the gestation (38.27 degrees C +/- 0.01 degrees C) or the breeding period (38.77 degrees C +/- 0.01 degrees C). The increase in rectal temperature (P < 0.001) and respiration rate (P < 0.001) in response to the HS was greatest during lactation. There was an effect of day (P < 0.001) on serum IGF-1 and insulin concentrations because both insulin and IGF-1 increased after farrowing. Compared with HS sows, the TN sows had greater feed intake (P < 0.001) and greater serum concentrations of insulin (early lactation; P < 0.05) and IGF-1 (late lactation; P < 0.05) when they were lactating. The effects of HS on sow BW, back fat, and loin eye area were generally not significant. Average BW of individual piglets at weaning was approximately 0.5 kg lighter for the sows in the HS farrowing room (P < 0.05). Weaning-to-estrus interval, percentage sows inseminated after weaning, subsequent farrowing rate, and subsequent total born were not affected by treatment. In summary, regardless of ambient temperature, sows undergo pronounced and sustained changes in rectal temperature when they transition through gestation, lactation, weaning, and rebreeding. The effects of HS on rectal temperature, respiration rate, feed intake, and metabolic hormones were greatest during lactation. The controlled HS that we imposed affected piglet weaning weight, but rebreeding and subsequent farrowing performance were not affected.
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选用8头安置有颈静脉血导管的阉公猪研究急性短期高温应激（33℃，50%RH，3h）对喂食状态下猪的铬代谢、血液中激素含量的影响，得出以下结果：1.急性热暴露使猪的血浆铬含量急剧上升,热暴露30min时平均升高181%(P<0.05),60min时的血浆铬是热暴露前的4.7倍,此后逐渐下降,至热暴露结束2h后下降到热暴露前水平。说明急性热暴露使机体迅速动员铬代谢库中的铬参与代谢反应。2.急性热暴露显著增加尿铬的排出量(P<0.001),约为适温时的2倍,表明急性短期高温增加铬的丢失,因此高温时机体对铬的需要量增加。3.猪在急性热暴露期间血浆皮质醇浓度逐渐上升,自热暴露前的11.9ng/ml,经120min升至25.1ng/ml,180min时仍维持在24.7ng/ml,显著高于热暴露前(P<0.05),热暴露结束后逐渐下降。表明，急性热暴露促进猪机体释放皮质醇。4.热暴露日猪的日平均胰岛素含量显著低于热暴露前1d的(P<0.05)。
URL [本文引用: 2]
选用8头安置有颈静脉血导管的阉公猪研究急性短期高温应激（33℃，50%RH，3h）对喂食状态下猪的铬代谢、血液中激素含量的影响，得出以下结果：1.急性热暴露使猪的血浆铬含量急剧上升,热暴露30min时平均升高181%(P<0.05),60min时的血浆铬是热暴露前的4.7倍,此后逐渐下降,至热暴露结束2h后下降到热暴露前水平。说明急性热暴露使机体迅速动员铬代谢库中的铬参与代谢反应。2.急性热暴露显著增加尿铬的排出量(P<0.001),约为适温时的2倍,表明急性短期高温增加铬的丢失,因此高温时机体对铬的需要量增加。3.猪在急性热暴露期间血浆皮质醇浓度逐渐上升,自热暴露前的11.9ng/ml,经120min升至25.1ng/ml,180min时仍维持在24.7ng/ml,显著高于热暴露前(P<0.05),热暴露结束后逐渐下降。表明，急性热暴露促进猪机体释放皮质醇。4.热暴露日猪的日平均胰岛素含量显著低于热暴露前1d的(P<0.05)。
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DOI:10.1016/0739-7240(91)90046-mURLPMID:1901537 [本文引用: 1]
Seven sows were placed into one of two environmental chambers at 22 C, 5 d prior to farrowing. On day 9 of lactation, one chamber was changed to 30 C (n = 4) and the other remained at 22 C (n = 3). On days 24 and 25, blood samples were collected every 15 min for 9 hr and 7 hr, respectively. On day 24, thyrotropin releasing hormone (TRH) and gonadotropin releasing hormone (GnRH) were injected iv at hour 8. On day 25 naloxone (NAL) was administered iv at hour 4 followed 2 hr later by iv injection of TRH and GnRH. Milk yield and litter weights were similar but backfat thickness (BF) was greater in 22 C sows (P less than .05) compared to 30 C sows. Luteinizing hormone (LH) pulse frequency was greater (P less than .003) and LH pulse amplitude was less (P less than .03) in 22 C sows. LH concentrations after GnRH were similar on day 24 but on day 25, LH concentrations after GnRH were greater (P less than .05) for 30 C sows. Prolactin (PRL) concentrations were similar on days 24 and 25 for both groups. However, PRL response to TRH was greater (P less than .05) on both days 24 and 25 in 30 C sows. Growth hormone (GH) concentrations, and the GH response to TRH, were greater (P less than .0001) in 30 C sows. Cortisol concentrations, and the response to NAL, were less (P less than .03) in 30 C sows. NAL failed to alter LH secretion but decreased (P less than .05) PRL secretion in both groups of sows. However, GH response to NAL was greater (P less than .05) in 30 C sows. Therefore, sows exposed to elevated ambient temperature during lactation exhibited altered endocrine function.
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[D].
DOI:10.3897/phytokeys.152.50611URLPMID:32733137 [本文引用: 1]
Several genera of Nyctaginaceae, currently merged under Pisonia, have been described for the Indo-Pacific region. Results from a recent molecular phylogenetic study of tribe Pisonieae showed that Pisonia is non-monophyletic and comprises three well-supported lineages: one including typical Pisonia and allies (Pisonia s.str.), a clade of species which corresponds to the original description of Ceodes and a third lineage whose single representative was formerly treated under the monotypic genus Rockia. Thus, as part of an effort to achieve a natural classification for tribe Pisonieae, this work proposes to re-establish Ceodes and Rockia to accommodate taxa with inconspicuous glands on anthocarps, recognising 21 species (20 for the former and one for the latter), of which 16 are new combinations: Ceodes amplifolia comb. nov., Ceodes artensis comb. nov., Ceodes austro-orientalis comb. nov., Ceodes brownii comb. nov., Ceodes cauliflora comb. nov., Ceodes coronata comb. nov., Ceodes diandra comb. nov., Ceodes gigantocarpa comb. nov., Ceodes gracilescens comb. nov., Ceodes lanceolata comb. nov., Ceodes merytifolia comb. nov., Ceodes muelleriana comb. nov., Ceodes rapaensis comb. nov., Ceodes sechellarum comb. nov., Ceodes taitensis comb. nov. and Ceodes wagneriana comb. nov. A general distribution of each species recognised in this work is also included, along with line drawings and colour pictures of representative species of Ceodes, Pisonia and Rockia and an updated dichotomous key based on reproductive characters for the nine genera (Ceodes, Cephalotomandra, Grajalesia, Guapira, Neea, Neeopsis, Pisonia, Pisoniella and Rockia) comprising the tribe Pisonieae. Resume Plusieurs genres de Nyctaginaceae actuellement fusionnes sous Pisonia ont ete decrits pour la region Indo-Pacifique. Les resultats d'une recente etude phylogenetique moleculaire de la tribu Pisonieae ont montre que Pisonia est non monophyletique et comprend trois lignees bien supportees: une comprenant Pisonia typique et ses allies (Pisonia s.str.), un clade d'especes qui correspond a la description originale de Ceodes et une troisieme lignee dont l'unique representant etait auparavant traite sous le genre monotypique Rockia. Ainsi, dans le cadre d'un effort pour parvenir a une classification naturelle de la tribu Pisonieae, ce travail proposons de retablir les Ceodes et Rockia pour accueillir des taxons avec des glandes discretes sur les anthocarpes, reconnaissant 21 especes (20 pour les premieres et une pour les dernieres), dont 16 sont de nouvelles combinaisons: Ceodes amplifolia comb. nov., Ceodes artensis comb. nov., Ceodes austro-orientalis comb. nov., Ceodes brownii comb. nov., Ceodes cauliflora comb. nov., Ceodes coronata comb. nov., Ceodes diandra comb. nov., Ceodes gigantocarpa comb. nov., Ceodes gracilescens comb. nov., Ceodes lanceolata comb. nov., Ceodes merytifolia comb. nov., Ceodes muelleriana comb. nov., Ceodes rapaensis comb. nov., Ceodes sechellarum comb. nov., Ceodes taitensis comb. nov. et Ceodes wagneriana comb. nov. Une distribution generale de chaque espece reconnue dans ce travail est egalement incluse, ainsi que des dessins au trait et des images en couleur des especes representatives de Ceodes, Pisonia et Rockia, et prepare une cle dichotomique mise a jour basee sur les caracteres reproductifs des neuf genres (Ceodes, Cephalotomandra, Grajalesia, Guapira, Neea, Neeopsis, Pisonia, Pisoniella et Rockia) comprenant la tribu Pisonieae.
DOI:10.3897/phytokeys.152.50611URLPMID:32733137 [本文引用: 1]
Several genera of Nyctaginaceae, currently merged under Pisonia, have been described for the Indo-Pacific region. Results from a recent molecular phylogenetic study of tribe Pisonieae showed that Pisonia is non-monophyletic and comprises three well-supported lineages: one including typical Pisonia and allies (Pisonia s.str.), a clade of species which corresponds to the original description of Ceodes and a third lineage whose single representative was formerly treated under the monotypic genus Rockia. Thus, as part of an effort to achieve a natural classification for tribe Pisonieae, this work proposes to re-establish Ceodes and Rockia to accommodate taxa with inconspicuous glands on anthocarps, recognising 21 species (20 for the former and one for the latter), of which 16 are new combinations: Ceodes amplifolia comb. nov., Ceodes artensis comb. nov., Ceodes austro-orientalis comb. nov., Ceodes brownii comb. nov., Ceodes cauliflora comb. nov., Ceodes coronata comb. nov., Ceodes diandra comb. nov., Ceodes gigantocarpa comb. nov., Ceodes gracilescens comb. nov., Ceodes lanceolata comb. nov., Ceodes merytifolia comb. nov., Ceodes muelleriana comb. nov., Ceodes rapaensis comb. nov., Ceodes sechellarum comb. nov., Ceodes taitensis comb. nov. and Ceodes wagneriana comb. nov. A general distribution of each species recognised in this work is also included, along with line drawings and colour pictures of representative species of Ceodes, Pisonia and Rockia and an updated dichotomous key based on reproductive characters for the nine genera (Ceodes, Cephalotomandra, Grajalesia, Guapira, Neea, Neeopsis, Pisonia, Pisoniella and Rockia) comprising the tribe Pisonieae. Resume Plusieurs genres de Nyctaginaceae actuellement fusionnes sous Pisonia ont ete decrits pour la region Indo-Pacifique. Les resultats d'une recente etude phylogenetique moleculaire de la tribu Pisonieae ont montre que Pisonia est non monophyletique et comprend trois lignees bien supportees: une comprenant Pisonia typique et ses allies (Pisonia s.str.), un clade d'especes qui correspond a la description originale de Ceodes et une troisieme lignee dont l'unique representant etait auparavant traite sous le genre monotypique Rockia. Ainsi, dans le cadre d'un effort pour parvenir a une classification naturelle de la tribu Pisonieae, ce travail proposons de retablir les Ceodes et Rockia pour accueillir des taxons avec des glandes discretes sur les anthocarpes, reconnaissant 21 especes (20 pour les premieres et une pour les dernieres), dont 16 sont de nouvelles combinaisons: Ceodes amplifolia comb. nov., Ceodes artensis comb. nov., Ceodes austro-orientalis comb. nov., Ceodes brownii comb. nov., Ceodes cauliflora comb. nov., Ceodes coronata comb. nov., Ceodes diandra comb. nov., Ceodes gigantocarpa comb. nov., Ceodes gracilescens comb. nov., Ceodes lanceolata comb. nov., Ceodes merytifolia comb. nov., Ceodes muelleriana comb. nov., Ceodes rapaensis comb. nov., Ceodes sechellarum comb. nov., Ceodes taitensis comb. nov. et Ceodes wagneriana comb. nov. Une distribution generale de chaque espece reconnue dans ce travail est egalement incluse, ainsi que des dessins au trait et des images en couleur des especes representatives de Ceodes, Pisonia et Rockia, et prepare une cle dichotomique mise a jour basee sur les caracteres reproductifs des neuf genres (Ceodes, Cephalotomandra, Grajalesia, Guapira, Neea, Neeopsis, Pisonia, Pisoniella et Rockia) comprenant la tribu Pisonieae.
[本文引用: 2]
[本文引用: 2]
DOI:10.1016/j.livprodsci.2005.01.012URL [本文引用: 1]
DOI:10.1016/j.meatsci.2010.07.021URL [本文引用: 1]
Abstract
The effects of two transportation periods on physio- metabolic hemodynamic changes and gaseous exchange in commercial swine during transportation to the slaughterhouse was studied in 684 pigs, 357 barrows and 327 gilts, transported in 2 groups for 8 and 16 h. Transportation caused an increase of oxygen consumption and body temperature, a decrease in pH, lactic acid accumulation. Both transportation periods caused higher than normal plasma glucose levels, lactic acidosis and evidence of dehydration. The linear regression analysis for pigs transported for 8 h indicates that the PO2, lactate and Ca++ variables correlated negatively with the PCO2. Whilst the animals that were transported for 16 h had negative correlations between glucose, and calcium, hematocrit, lactate and potassium levels. It was concluded that regardless of transport time acidosis, hypocapnia, hypoxaemia, hypernatraemia, hypercalcaemia, hyperglycemia, lactacidemia and increased hematocrit levels occurred.DOI:10.3969/j.issn.1006-267x.2010.05.013URL [本文引用: 1]
本文旨在研究持续高温对生长猪血清生化指标及肌肉营养物质含量的影响。选取遗传背景（长×大）相近、初始体重（30.00±1.16） kg杂交公猪9头，随机置于3个处理：高温试验组，33 ℃持续高温，自由采食；适温自由采食组，23 ℃适温，自由采食；适温限制饲喂组，23 ℃适温，限制采食量与高温试验组相同。试验持续21 d。结果表明，1)高温试验组生长猪血清总蛋白含量在试验第21天极显著低于适温自由采食组（P<0.01）；高温试验组生长猪血清总蛋白（第2天）、球蛋白（第21天）、葡萄糖（第2天）、总胆固醇（第1、2、4天）及甘油三酯（第1天）含量均显著低于适温自由采食组（P<0.05）。2)与适温自由采食组相比，高温试验组生长猪背最长肌干物质、肌内脂肪含量较低，而粗蛋白质含量略高，但差异不显著（P>0.05）。结果提示，持续高温可使生长猪血清总蛋白、球蛋白及总胆固醇含量明显下降；持续高温能使生长猪背最长肌干物质和肌内脂肪含量有下降趋势，而粗蛋白质含量有升高趋势。
DOI:10.3969/j.issn.1006-267x.2010.05.013URL [本文引用: 1]
本文旨在研究持续高温对生长猪血清生化指标及肌肉营养物质含量的影响。选取遗传背景（长×大）相近、初始体重（30.00±1.16） kg杂交公猪9头，随机置于3个处理：高温试验组，33 ℃持续高温，自由采食；适温自由采食组，23 ℃适温，自由采食；适温限制饲喂组，23 ℃适温，限制采食量与高温试验组相同。试验持续21 d。结果表明，1)高温试验组生长猪血清总蛋白含量在试验第21天极显著低于适温自由采食组（P<0.01）；高温试验组生长猪血清总蛋白（第2天）、球蛋白（第21天）、葡萄糖（第2天）、总胆固醇（第1、2、4天）及甘油三酯（第1天）含量均显著低于适温自由采食组（P<0.05）。2)与适温自由采食组相比，高温试验组生长猪背最长肌干物质、肌内脂肪含量较低，而粗蛋白质含量略高，但差异不显著（P>0.05）。结果提示，持续高温可使生长猪血清总蛋白、球蛋白及总胆固醇含量明显下降；持续高温能使生长猪背最长肌干物质和肌内脂肪含量有下降趋势，而粗蛋白质含量有升高趋势。
[本文引用: 2]
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URL [本文引用: 1]
利用免疫学和分子生物学手段研究荷斯坦牛和娟-荷F1牛，在环境温湿指数(THI)影响下，血液淋巴细胞热应激蛋白70(HSP 70)的表达情况，旨在探索HSP 70表达量与THI相关性以及不同品种差异性。结果表明：(1)荷斯坦成乳牛在热应激和非热应激条件下均可表达HSP 70，严重热应激期(THI 93.5±2.1)HSP 70表达量分别是中度热应激期(THI 76.7±2.6)1.9倍(P<0.01)和非热应激期(THI 56.5±1.7)6.9倍(P<0.01)，中度热应激期HSP 70表达量是非热应激期3.6倍(P<0.05)，HSP 70表达量与THI呈强度正相关(R=0.91)(P<0.01)，THI每上升1个单位，HSP 70表达量增加2172 OD/mm2；(2)在严重热应(THI 95.3)条件下，娟-荷F1成乳牛HSP 70表达量极显著高于荷斯坦牛(P<0.01)。关键词：奶牛；热应激蛋白；温湿指数；相关性
URL [本文引用: 1]
利用免疫学和分子生物学手段研究荷斯坦牛和娟-荷F1牛，在环境温湿指数(THI)影响下，血液淋巴细胞热应激蛋白70(HSP 70)的表达情况，旨在探索HSP 70表达量与THI相关性以及不同品种差异性。结果表明：(1)荷斯坦成乳牛在热应激和非热应激条件下均可表达HSP 70，严重热应激期(THI 93.5±2.1)HSP 70表达量分别是中度热应激期(THI 76.7±2.6)1.9倍(P<0.01)和非热应激期(THI 56.5±1.7)6.9倍(P<0.01)，中度热应激期HSP 70表达量是非热应激期3.6倍(P<0.05)，HSP 70表达量与THI呈强度正相关(R=0.91)(P<0.01)，THI每上升1个单位，HSP 70表达量增加2172 OD/mm2；(2)在严重热应(THI 95.3)条件下，娟-荷F1成乳牛HSP 70表达量极显著高于荷斯坦牛(P<0.01)。关键词：奶牛；热应激蛋白；温湿指数；相关性
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URL [本文引用: 1]
URL [本文引用: 1]
DOI:10.1152/japplphysiol.01122.2001URLPMID:12070193 [本文引用: 1]
Heat acclimation upregulates 72-kDa heat shock protein (HSP72) and predisposes to faster activation of the heat shock response (HSR). This study investigates the role played by beta-adrenergic signaling and/or plasma thyroxine level in eliciting these features by using rats undergoing 1) heat acclimation (AC; 34 degrees C, 2 and 30 days); 2) AC with beta-adrenergic blockade; 3) AC-maintained euthyroid; 4) hypothyroid; 5) hyperthyroid; and 6) controls. The hsp72 mRNA (RT-PCR) and HSP72 levels (Western blot) were measured before and after heat stress (2 h, 41 degrees C, rectal temperature monitored). beta-Adrenergic blockade during AC abolished HSP72 accumulation, without disrupting HSR. Low thyroxine blunted the HSR at posttranscriptional level, whereas thyroxine administration in hyperthyroid and AC-maintained euthyroid rats arrested heat stress-evoked hsp72 transcription. We conclude that beta-adrenergic signaling contributes to the high HSP72 level characterizing the AC state. Thyroxine has two opposing effects: 1) direct repressive on rapid hsp72 transcription after heat stress; and 2) indirect stimulatory via beta-adrenergic signaling. Low thyroxine could account for diminished HSP72 synthesis via lower heat production and thermoregulatory set point.
