Leptin and ghrelin levels in colostrum,milk and blood plasma of sows and pig neonates during the first week of lactation

Radioimmunology was used to determine leptin and ghrelin levels in sow colostrum and milk in relation to those in sow and neonatal pig blood plasma and to the body weight of piglets during the first week of lactation. The highest concentration of leptin was found in colostrum on the second day of lactation (69.3 ± 6.3 ng/mL). Leptin concentrations in sow plasma were significantly lower than in colostrum/milk (2.19 ± 0.9 ng/mL, P = 0.7692) and were stable in the first 7 days of lactation. Total and active ghrelin concentrations in colostrum/milk were stable in the measured time points (6734 ± 261 pg/mL, P = 0.3397; 831 ± 242 pg/mL, P = 0.3988, respectively). Total ghrelin concentrations in sow plasma were lower than in colostrum/milk. These results indicate that pigs follow a unique species‐specific pattern of leptin and ghrelin synthesis, release and existence, and that the mammary gland is an important source of leptin and ghrelin contained in colostrum/milk.     

合作猪HMOX1基因过表达载体构建及组织表达分析

为了构建合作猪HMOX1基因过表达载体,并分析其组织表达特征,本研究通过PCR扩增获取合作猪HMOX1基因完整CDS区序列,将其插入到pcDNA3.1(+)过表达载体中,构建pcDNA3.1-HMOX1过表达载体;并通过实时荧光定量PCR检测HMOX1基因在合作猪心、肝、脾、肺、肾、胃、十二指肠和背最长肌中的表达情况。结果显示,成功扩增出合作猪HMOX1基因924 bp的完整CDS区,通过双酶切和测序鉴定,HMOX1基因成功连接到pcDNA3.1(+)过表达载体中。组织表达结果显示,HMOX1基因在合作猪组织中表达量最高是脾脏,显著高于其它组织(P<0.05),其次是肝脏、肺脏、肾脏和心脏,在十二指肠中的表达量最低。研究结果为进一步研究HMOX1基因在合作猪高海拔低氧适应过程中的功能提供了重要参考。     

Model averaging for genome‐enabled prediction with reproducing kernel Hilbert spaces: a case study with pig litter size and wheat yield

Predictive ability of yet‐to‐be observed litter size (pig) grain yield (wheat) records of several reproducing kernel Hilbert spaces (RKHS) regression models combining different number of Gaussian or t kernels was evaluated. Predictive performance was assessed as the average (over 50 replicates) predictive correlation in the testing set. Predictions from these models were combined using three different types of model averaging: (i) mean of predicted phenotypes obtained in each model, (ii) weighted average using mean squared error as weight or (iii) using the marginal likelihood as weight. (ii) and (iii) were obtained in a validation set with 5% of the data. Phenotypes consisted of 2598, 1604 and 1879 average litter size records from three commercial pig lines and wheat grain yield of 599 lines evaluated in four macro‐environments. SNPs from the PorcineSNP60 BeadChip and 1447 DArT markers were used as predictors for the pig and wheat data analyses, respectively. Gaussian and univariate t kernels led to same predictive performance. Multikernel RKHS regression models overcame shortcomings of single kernel models (increasing the predictive correlation of RKHS models by 0.05 where 3 Gaussian or t kernels were fitted in the RKHS models simultaneously). None of the proposed averaging strategies improved the predictive correlations attained with single models using multiple kernel fitting.     

Changes of K+ channels of outer hair cells in guinea pig cochlea with streptomycin ototoxicity

AIM:To study the changes of K⁺ channels of outer hair cells in guinea pig cochlea with streptomycin ototoxicity. METHODS:Auditory brainstem responses (ABR) and whole-cell patch clamp techniques were used.RESULTS:(1) The body weight of guinea pigs with streptomycin ototoxicity decreased significantly; (2) The ABR threshold markedly increased in streptomycin group (Ⅱ,Ⅲ);(3)The number of dissociated outer hair cells of guinea pigs (Ⅱ,Ⅲ) was lower than that of control (Ⅰ); (4) Streptomycin decreased the Ca²⁺-sensitive K⁺ currents and delayed outward K⁺ currents distinctly; (5) There was no significant difference of K⁺ currents between Ⅰ and Ⅱ/Ⅲ. CONCLUSION:These results suggest that the inhibition of K⁺ channels is the basis of streptomycin ototoxicity, but not the direct reason for cell death.     

Serovar profiling of Haemophilus parasuis on Australian farms by sampling live pigs

Objective Investigate the diversity of serovars of Haemophilus parasuis (Hps) present in Australian pig herds. Design Nasal swabs were used to obtain multiple isolates of Hps, which were grouped first by genotyping and then by serotyping representative isolates. Procedure Swabs were taken from the nasal cavity of just-weaned healthy pigs from multiparous sows on 12 farms and from post-weaned pigs of multiparous sows on 1 farm. On 5 of the 13 farms, nasal swabs were also obtained from pigs showing clinical signs suggestive of Glässer's disease. On a further 7 farms, nasal swabs were obtained only from pigs with clinical signs suggestive of Glässer's disease. Results A total of 556 Hps isolates were genotyped, and 150 isolates were serotyped. Hps was detected on 19 of the 20 farms, including 2 farms with a long history of freedom from Glässer's disease. Isolates of Hps belonging to serovars regarded as potentially pathogenic were obtained from healthy pigs at weaning on 8 of the 10 farms with a history of Glässer's disease outbreaks. Sampling 213 sick pigs yielded 115 isolates of Hps, 99 of which belonged to serovars that were either potentially pathogenic or of unknown pathogenicity. Only 16 isolates from these 213 sick pigs were of a serovar known to be non-pathogenic. Conclusion Healthy pigs contain a range of Hps serovars, even on farms free of Glässer's disease. Nasal swabbing of both healthy and sick pigs seems a useful method of serovar profiling of farms.     

Dietary supplementation with Moringa oleifera and mulberry leaf affects pork quality from finishing pigs

Moringa oleifera and Morus alba leaves are nutritious non-traditional feed ingredients containing bioactive substances. This study was to evaluate the potential application of dietary Moringa and Morus leaf powder on the growth traits, carcass characteristics and meat quality of finishing pigs. Moringa did not alter growth performance or carcass characteristics, but it decreased meat b* value, increased MyHCIIa and decreased MyHCIIx mRNA levels, and increased CP and concentrations of Ala, Thr, Ile, Lys and Pro in longissimus thoracis. Morus increased final BW, ADFI and ADG, decreased F/G ratio, improved slaughter weight, carcass weight, carcass yield and meat a* value, and decreased shear force, drip loss, MyHCIIx and MyHCIIb mRNA levels, and increased MyHCI and MyHCIIa mRNA levels. Morus also increased CP, Glu, Gly, Ala, Arg, Ile, Phe, Pro, Ser, Tyr and Asp, and C16:1, C18:1n9c, C20:4n6, C18:3n3, C20:3n3, C22:1n9 and n-3 PUFA, but decreased C12:0 and C16:0. In summary, Morus improved the parameters and held great potential as an unconventional feed crop.     

小型猪特异性麻醉颉颃剂对大鼠脑NO/cGMP信号转导系统的动态影响

为探讨NO/cGMP信号转导系统对小型猪特异性麻醉颉颃剂催醒分子机理的调控,144只Wistar大鼠随机分为对照组和试验组,对照组和试验组再分为早期催醒组、中期催醒组和晚期催醒组。用分光光度法测定脑NOS活性和NO产量,ELISA测定脑cGMP含量。结果显示,小型猪特异性麻醉颉颃剂能明显地激活大鼠相关脑区的NOS活性和NO及cGMP产量,并且大鼠不同脑区NOS活性、NO产量和cGMP含量的变化趋势不仅与大鼠行为学变化相平行,还与不同时期表现出的催醒效果基本吻合。这表明小型猪特异性麻醉颉颃剂的催醒可能与激活特定脑区的NO/cGMP信号转导系统相关。     

低蛋白质氨基酸平衡日粮对高温环境下肥育猪生长性能、血清指标和蛋白质表观消化率的影响

探讨高温环境下低蛋白质氨基酸平衡日粮对肥育猪生长性能、血清指标和蛋白质表观消化率的影响。90头平均体重为（65．90±3．37）kg 的杜长大三元杂交猪随机分为3个组,每组3个重复,每个重复10头猪（5头公,5头母）,1组为对照组,粗蛋白质水平为16．02％,2组、3组为试验组,日粮粗蛋白质水平分别为14．08％和12．05％。试验期40 d。结果表明,在日平均温度为29．53～31．16℃条件下,2组、3组平均日增重分别比1组提高2．49％和1．81％,差异不显著（P ＞0．05）,平均日采食量、料重比组间差异不显著（P ＞0．05）;血清皮质醇（F）、T3、T4浓度组间差异均不显著（P ＞0．05）;血清尿素氮（BUN）浓度 2组、3组分别比1组降低10．45％和19．13％,差异均显著（P ＜0．05）;氮表观消化率组间差异不显著（P ＞0．05）,粪氮排泄量2组、3组分别比1组降低10．48％和25．64％,差异均显著（P ＜0．05）。由此可见,在高温环境条件下,低蛋白质氨基酸平衡日粮未能缓解热应激对肥育猪生长性能、血清指标和蛋白质表观消化率的影响。     

左旋咪唑擦剂的研制及其驱虫试验

用自制氮酮作透皮剂研制的１５％盐酸左旋咪唑擦剂，经ＨＰＬＣ法进行离体鼠皮透皮吸收率测定，结果表明氮酮含量在３％时左旋咪唑透皮吸收效果最佳。家兔血药浓度检测结果表明，左旋咪唑擦剂透皮吸收血药浓度与肌主左旋咪唑血药浓工相近。驱虫试验表明，猪按０．１ｍｌ／ｋｇ涂药对猪蛔虫的驱虫率和虫卵减少率远达１００％。