产蛋期母鸡血液激素的昼夜变化

用放射免疫方法检测了10只200日龄产蛋期母鸡血液激素的昼夜变化。结果:血浆雌二醇含量在11时出现一次峰值,孕酮在8时和17时出现两次峰值,黄体生成素在17时出现一次峰值,其他时间这几种激素的含量均波动不大;甲状腺素含量在一昼夜内一直较稳定,无明显波动。此外,对上述血液激素与排卵的关系作了讨论。     

初胎牛围产期某些代谢激素的分泌特点

12头初胎荷斯坦牛,经颈静脉采取预产期前10天、3天和产后3天、10天、17天血样,测定血浆中TSH、T_3、T_4和胰岛素的含量。结果表明:从预产期前10天开始到产后第17天,①T_3的水平呈平稳稍升高的趋势;②T_4的水平以预产期前10天的为最高,随后均显著下降(P<0.01);③TSH在产后的第3天和17天均显著高于预产期前10天的水平(P<0.05);④预产期前10天胰岛素含量显著高于其它时间的水平(P<0.01)。以上结果提示:初胎荷斯坦牛围产期TSH、T_3、T_4和胰岛素的含量均发生改变,以促进营养物质的转化和加强蛋白质的合成,适应机体泌乳的生理变化。     

水牛发情期唾液生殖激素和结晶与卵泡发育的关系

本研究旨在探明水牛唾液生殖激素、唾液结晶和卵泡发育变化的规律。应用ELISA试剂盒测定水牛唾液和血清中的生殖激素,制作唾液结晶,并分析生殖激素和唾液结晶与卵泡变化的关系。运用唾液结晶法、直肠检查法、唾液结晶+B超法、直肠检查+B超法4种方法在生产中进行验证。结果表明,水牛发情当天唾液雌激素（E₂）的水平为233.51 pg/mL,达到一个峰值,随后开始缓慢降低。水牛唾液中孕激素（P₄）水平在发情前2 d达到16.17 ng/mL,发情当天降到8.91 ng/mL。促卵泡素（FSH）在水牛发情前2 d逐渐下降,从37.91 ng/mL降到34.64 ng/mL,但在发情2 d后逐渐升高,达到61.20 ng/mL。促黄体素（LH）在发情前1 d逐渐下降,从5.15 ng/mL降至发情当天4.12 ng/mL,但在发情1 d后升至5.77 ng/mL。B超监测卵巢卵泡从发情前2 d迅速生长,到发情当天达到20 mm大小,直到破裂排卵卵泡的大小变化不显著。排卵后形成黄体,黄体期一直维持到下次发情前4 d左右,期间在发情后14~17 d的黄体最大,与水牛唾液中LH分泌峰一致。唾液结晶+B超鉴定方法判定的发情率最高（86.67%）,与其他几种方法比较差异显著（P<0.05）;妊娠诊断结果也表明,唾液结晶+B超鉴定方法判定的妊娠率（61.53%）显著高于直肠检查法、唾液结晶法和直肠检查+B超法3种方法鉴定的结果（P<0.05）。综上所述,卵巢上卵泡的发育与唾液中生殖激素的浓度显著相关,发情当天唾液结晶呈现典型的树枝状,唾液结晶+B超法的发情鉴定准确率最高。     

大豆黄酮对荷斯坦牛围产期某些代谢激素的影响

12头的初胎荷斯坦乳牛,分为对照期(添喂前)和试验期(添喂后)。于预产期前10d一次添喂大豆黄酮(80mg/d·头),在添喂前、添喂后的7d、产后3d、10d和17d采取血样,用放射免疫法测定血浆中TSH、T3、T4和胰岛素的含量。①添喂大豆黄酮后,T3的水平在第7d、产后3d和产后10d显著低于对照期(P<0.05/P<0.01),而产后17dT3含量则高于对照期21.60%(P<0.05);②试验期中T4的水平除分娩后第10d外,均显著低于对照期(P<0.05/P<0.01);③TSH水平仅在添喂大豆黄酮后的第7d显著低于对照期,而分娩后与对照期差异不显著(P>0.05);④胰岛素在大豆黄酮处理后的第7d和分娩后的第17d显著低于对照期,其余与对照无显著差异(P>0.05)。以上结果提示:大豆黄酮能影响分娩后初胎奶牛的代谢激素水平,促进营养物质的转化,加强机体蛋白质的合成,以适应机体泌乳的生理变化。     

环境温度和维生素A对育成期笼养公鸭睾丸发育及相关激素的影响

本试验旨在研究环境温度和维生素A(VA)对育成期(12～17周龄)笼养公鸭睾丸发育及相关激素的影响.选取12周龄金定公鸭144只,采用2×3两因素交互试验设计,随机分配到适宜舍温[(18±1)℃]和较低舍温[(2±1)℃]下的3个VA水平组(4 000、10 000和15 000 IU/kg)中,每组6个重复,每个重复4只试鸭.结果表明:(1)环境温度对三碘甲腺原氨酸(T3)和甲状腺素(T4)影响极显著(P<0.01),对胰岛素影响不显著(P>0.05);VA水平对T3影响不显著(P>0.05),对T4影响极显著(P<0.01),对胰岛素影响不显著(P>0.05);环境温度和VA水平对胰岛素有交互作用(P<0.05);(2)环境温度对血清促卵泡生成激素(FSH)影响显著(P<0.05),对血清促黄体生成激素(LH)和血清睾酮(T)影响极显著(P<0.01),VA水平对FSH和T影响不显著(P>0.05),对LH影响显著(P<0.05);(3)环境温度对睾丸相对重量和睾丸相对长度影响显著(P<0.05);VA水平对睾丸相对重量和相对长度影响均不显著(P>0.05).本试验条件下,15 000 IU/kg的VA能有效地调节较低舍温对激素水平产生的影响,使其与正常生理水平相接近,10 000 IU/kg的VA能降低较低舍温对睾丸发育造成的不利影响.     

Rat Articular Cartilages Change Their Tissue and Protein Compositions During Perinatal Period

Articular cartilage (AC) covers the surface of bones in joints and functions as a cushion against mechanical loading. The tissue contains abundant extracellular matrix (ECM), which mainly consists of proteoglycans (PG) and collagen (COL) fibres. The property of AC is gradually changing by ageing with gravity loading. To know the property change of AC by initial gravity loading during short period after birth, we performed histological assays and proteomics assay on the AC of the femoral condyle in knee joints of perinatal rats. The water content (%) was significantly decreased in neonate AC compared with fetal AC. During the perinatal stages (E19 and P0), the localizations of glycosaminoglycan (GAG) and type I and II COLs were homogeneous. The density of chondrocytes was significantly decreased in the deeper layers comparing with the surface layer in neonate AC. In addition, we found a drastic change in the protein expression pattern on proteomic analysis. The expressions of ECM components were relatively increased in neonate AC compared with fetal AC.     

Acyl Ghrelin and Metabolic Hormones in Pregnant and Lactating Sows

Ghrelin, the endogenous ligand of the growth hormone (GH) secretagogue receptor, is considered a pleiotropic regulator involved in a large array of functions, including control of energy balance, regulation of food intake and, more recently, modulation of the reproductive axis. The present study was aimed at determining the changes in plasma concentrations of acyl-ghrelin in pregnant and lactating sows, with special emphasis on the relationship with the levels of GH, leptin, non-esterified fatty acids (NEFA) and insulin-like growth factor (IGF-1). Blood samples were collected via jugular venipuncture from 22 multiparous sow 30, 60 and 90 days after artificial insemination, 7 and 21 days after farrowing and at first oestrus post-weaning. Plasma concentrations of acyl-ghrelin, leptin, GH and IGF-1 were quantified by validated radioimmunoassay; NEFA were determined using a colorimetric procedure. Plasma acyl ghrelin levels were highest at 30 days of pregnancy and decreased thereafter and during lactation. At the beginning of lactation, GH, IGF-1 and NEFA concentrations significantly increased, while a significant reduction occurred in leptin. In conclusion, ghrelin concentrations in sow maternal circulation does not seem to play an important role in maintaining circulating GH levels during lactation; moreover, ghrelin is not associated with leptin, NEFA and IGF-1 levels.     

麻雀的消化道在繁殖期间的形态变化及适应意义

麻雀的消化道在繁殖期总重量、鲜重及干重均高于繁殖前期，分别增加了６１．２１％、３９．４２％和３２．１２％。其中小肠的长度、重量、鲜重及干重也明显增加了４．９２％、１３２．９５％、１７３．７４％和１２８．３３％，而胃内含物重量的增加更为显著。表明了鸟类在繁殖期间通过改变消化道的形态以增加对能量的需求，是鸟类保证繁殖成功的生存对策之一．     

Changes in Testicular Steroidogenic Acute Regulatory (STAR) Protein,Steroidogenic Enzymes and Testicular Morphology Associated with Increased Testosterone Secretion in Bulls Receiving The Luteinizing Hormone Releasing Hormone Agonist Deslorelin

Testosterone secretion and the expression and relative contents of steroidogenic acute regulatory (StAR) protein and steroidogenic enzymes cholesterol side-chain cleavage cytochrome P450 (P450_scc), 3β-hydroxysteroid dehydrogenase /Δ⁵ → Δ⁴ − isomerase (3β-HSD), and 17α-hydroxylase cytochrome P450/C_17–20 lyase (P450_17α) were determined in testicular tissues of bulls treated with a LHRH agonist. Testis morphology and spermatogenesis were also examined. In Experiment 1, bulls (30-mo-old) received no treatment (control, n = 7) or were implanted for 10 days with the LHRH agonist deslorelin (n = 7). Bulls were castrated on Day 10 and testis tissues prepared for Western and Northern blotting. At castration, bulls implanted with deslorelin had greater plasma testosterone (5-fold) and testis content of testosterone (10-fold) compared with control bulls. Relative content (per μg total testis protein or RNA) of StAR protein, 3β-HSD, P450_scc, and mRNA for P450_17α in bulls treated with deslorelin ranged from 3- to 6-fold that of control bulls. In Experiment 2, bulls (20-mo-old) were left untreated (control, n = 6) or implanted with deslorelin (n = 12) for 120 days. On Day 120, bulls were castrated and right testis tissues prepared for morphology. Testis volume and weight were increased (P < 0.01) in bulls treated with deslorelin compared with control bulls. Stereological analysis revealed that this increase occurred in all compartments (seminiferous epithelium, lumen and interstitium) studied, but was significant (P < 0.01) only for the seminiferous epithelium. Absolute numbers of round spermatids per testis were increased (P < 0.05) in bulls treated with deslorelin compared with control bulls. Increased testosterone secretion in bulls treated with deslorelin was associated with increased testicular StAR protein and steroidogenic enzymes. Bulls treated long-term with deslorelin had a faster rate of testis growth and increased daily sperm production at the end of the experiment.     

GnRH和LHR基因多态性和牛精液品质性状的相关分析

本试验采用PCR—RFLP方法分析了GnRH基因外显子2和LHR基因内含子9在144头中国荷斯坦牛和79头河南地方肉牛品种中的多态性,利用最小二乘法分析多态位点不同基因型与精液品质性状的关系。研究结果表明,2～3岁荷斯坦牛的鲜精活力显著高于4岁以上的牛,而畸形率显著低于7岁以上的牛。对2～4岁荷斯坦牛不同精液品质性状的简单相关分析表明,畸形率与顶体完整率和冻精活力呈显著的负相关（相关系数r分别为-0．736和-0．500）。不同基因型与精液品质性状的关联分析结果表明,144头中国荷斯坦牛所研究位点不同基因型对精液品质性状没有显著影响。而河南地方肉牛GnRH基因外显子2的A883G位点GG基因型的精子密度显著低于AA和AG基因型．LHR基因G51656T位点的TT基因型精子密度显著高于GT基因型,未检测到GG基因型。并且发现随着年龄的增长,种公牛的精液品质逐渐变差。GnRH和LHR基因可作为影u向肉牛精液品质性状的候选基因。     

The Correlation between Age,Body Weight and Testicular Parameters in Murrah Buffalo Bulls Raised in Brazil

Buffalo are an economically important source for meat and milk production, especially in Brazil. However, important aspects of their biology remain unknown thus far. Herein, we describe the reproductive characteristics of male Murrah buffalo (Bubalus bubalis) raised under extensive management conditions by applying biometrics associated with testicular weight. We analyzed seven males, divided into two groups: G1, which consisted of four 18-month-old animals, and G2, which consisted of three 24-month-old animals. Testicular development occurs slowly in Murrah buffalo, suggesting a delay of sexual maturity. The biometric testicular parameters analyzed were scrotal circumference, testicular weight, testicular length, testicular width, testicular thickness and testicular circumference. Our data indicate strong correlations between SC, age and body weight, and additional significant relationships were identified between body weight, age and other testicular parameters. Thus, these parameters are suitable indicators when selecting bulls for breeding purposes.     

转型升级期中国奶业发展新形势

作者阐述了当前转型升级期中国奶业在生产、监管、政策、技术推广和交流合作等方面面临的形势,分析了这些形势的具体表现,旨在对研究奶业发展规律、行业走向、产业定位等提供参考。     

Influence of Body Condition on Serum Metabolic Indicators of Lipid Mobilization and Oxidative Stress in Dairy Cows During the Transition Period

The objectives of this study were to examine the influence of body condition of cows on metabolic and antioxidative status, as well as to investigate the relationship between metabolic indicators of lipid mobilization and oxidative stress during transition period. The study was conducted on 24 Holstein‐Friesian dairy cows divided into 2 groups according to their body condition score (BCS) as optimal (n = 12; BCS from 3.25 to 3.75) or adipose (n = 12; BCS ≥4). Metabolic status (glucose, triglycerides, total cholesterol, HDL cholesterol, NEFA and BHB), paraoxonase‐1 (PON1) and apolipoprotein A‐I (ApoA‐I) were analysed in sera taken on days ?30, ?10, ?2, 0, 5, 12, 19, 26 and 60 relative to parturition. Adipose cows had significantly higher glucose concentration at parturition being significantly decreased after parturition on days 12 and 19. Total cholesterol and HDL‐C concentrations were the lowest at parturition and significantly higher on days 26 and 60 after parturition in both groups of cows. Both investigated groups had significantly higher NEFA concentration from parturition until day 19 after parturition, indicating energy deficit and an increased lipid mobilization after calving. There were no significant differences in BHB concentration during transition period in both groups. No significant differences were found in PON1 activity and ApoA‐I concentration during transition period in both groups of cows. However, in adipose cows, although not significantly different, PON1 was decreased from calving until day 19 after parturition indicating a disturbance in antioxidative status in adipose cows. PON1 significantly positively correlated with total cholesterol and HDL‐C concentrations and negatively with NEFA indicating a strong relationship of PON1 with lipid metabolism. Significant positive correlation between NEFA and BHB in both groups of cows points out on energy deficit during transition period that cows tend to overcome by lipid mobilization providing alternative source of energy needed for parturition and lactation.     

莱芜猪脂肪代谢酶活性的发育性变化及其对肌内脂肪沉积的影响

以40~90 kg 6个体重阶段莱芜猪和新莱芜猪共72头为试验对象,研究了不同组织中脂肪代谢酶活性的发育性变化规律及其与肌内脂肪含量、背膘厚的关系。结果表明:(1)在生长期随着体重的增大,肌肉组织中脂肪合成酶异柠檬酸脱氢酶(ICDH)活性显著高于苹果酸脱氢酶(MDH)活性(P<0.01);ICDH活性在60~70 kg时达到峰值,而后开始下降,MDH活性规律不明显;脂肪分解酶激素敏感脂酶(HSL)的活性先降后升,70~80 kg时活性最高。(2)背膘中合成酶MDH活性显著高于ICDH活性(P<0.01);MDH和ICDH活性都是先降后升,但总体升降幅度不大;HSL活性40~50 kg基本稳定,而后逐步增强。(3)肝脏组织中合成酶ICDH活性显著高于MDH活性(P<0.01);ICDH、MDH活性逐渐升高,至60 kg以后其活性趋于稳定,脂肪分解酶HSL活性的发育性变化规律不明显。(4)肌肉组织中的MDH、HSL活性与肌内脂肪含量呈极显著相关(P<0.01);肝脏组织中的MDHI、CDH与肌内脂肪含量呈显著正相关,ICDH还与背膘厚呈极显著正相关;背膘组织中的MDH、HSL与背膘厚呈极显著相关(P<0.01)。研究结果提示:肌内脂肪的沉积与背膘脂肪的沉积既存在一定的内在联系(通过肝脏),又具有一定的独立性,通过选择肌肉组织中脂肪代谢酶活性,在不显著影响皮下脂肪沉积量的前提下可望提高肌内脂肪的沉积量。     

菜芜猪脂肪代谢酶活性的发育性变化及其对肌内脂肪沉积的影响

以40-90kg6个体重阶段莱芜猪和新莱芜猪共72头为试验对象，研究了不同组织中脂肪代谢酶活性的发育性变化规律及其与肌内脂肪含量、背膘厚的关系。结果表明：（1）在生长期随着体重的增大，肌肉组织中脂肪合成酶异柠檬酸脱氢酶（ICDH）活性显著高于苹果酸脱氢酶（MDH）活性（P〈0．01）；ICDH活性在60-70kg时达到峰值，而后开始下降，MDH活性规律不明显；脂肪分解酶激素敏感脂酶（HSL）的活性先降后升，70～80kg时活性最高。（2）背膘中合成酶MDH活性显著高于ICDH活性（P〈0．01）；MDH和ICDH活性都是先降后升，但总体升降幅度不大；HSL活性40～50kg基本稳定，而后逐步增强。（3）肝脏组织中合成酶ICDH活性显著高于MDH活性（P〈0．01）；ICDH、MDH活性逐渐升高，至60kg以后其活性趋于稳定，脂肪分解酶HSL活性的发育性变化规律不明显。（4）肌肉组织中的MDH、HSL活性与肌内脂肪含量呈极显著相关（P〈0．01）；肝脏组织中的MDH、ICDH与肌内脂肪含量呈显著正相关，ICDH还与背膘厚呈极显著正相关；背膘组织中的MDH、HSL与背膘厚呈极显著相关（P〈0．01）。研究结果提示：肌内脂肪的沉积与背膘脂肪的沉积既存在一定的内在联系（通过肝脏），又具有一定的独立性，通过选择肌肉组织中脂肪代谢酶活性，在不显著影响皮下脂肪沉积量的前提下可望提高肌内脂肪的沉积量。     

莱芜猪和鲁菜黑猪肌纤维发育规律及其对肉质特性的影响

本研究以40～90kg6个体重阶段的莱芜猪和鲁莱黑猪为试验对象,每个阶段每组各6头猪,采用组织化学切片染色技术进行组织学观察,探讨猪肌纤维的发育规律及其对肉质特性的影响。结果表明：①随着体重的增加,莱芜猪与鲁莱黑猪肌纤维的发育较为明显,但发育特点明显不同,莱芜猪40～70kg体重时肌纤维生长较慢,直径和面积变化不明显,70kg后肌纤维生长发育明显加快（P〈0．05）;而鲁莱黑猪则是40～60kg体重时肌纤维生长较快,60奴后肌纤维生长发育变慢（P〈0．05）。（爹琥珀酸脱氢酶（sDH）组织化学处理显示,肌肉肌纤维是由红肌纤维、中间型肌纤维和白肌纤维这3种类型肌纤维构成,并以白肌纤维占优势。莱芜猪与鲁莱黑猪在肌纤维类型的组成和不同类型肌纤维直径上具有不同的发育性变化模式,总体上莱芜猪红肌纤维含量有高于鲁莱黑猪的变化趋势。在不同类型肌纤维直径方面,莱芜猪与鲁莱黑猪具有基本相同的发育性变化模式。③相关性分析表明,肌肉的肌纤维尤其是红肌纤维的生长发育,对肌肉的干物质、肌内脂肪及系水力等肉质性状具有有利的影响,但白肌纤维的生长发育对肌肉的系水力具有不利的影响。研究结果提示：在肌肉组织中肌纤维的发育方面,莱芜猪比鲁莱黑猪较为晚熟;在肌纤维类型的组成方面。红肌纤维更有利于优良肉质特性的形成。     

荷斯坦公牛X和Y精子核形态差异及其影响因素分析

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半胱胺与金霉素对肉鸭的促生长效果及相关代谢激素水平影响的比较

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