正交试验法优化普抗合剂制备工艺

以干浸膏得率和黄芩苷提取率为考核指标,采用正交试验法对普抗合剂水提取醇沉淀制备工艺进行考察.普抗合剂最佳制备工艺方案为加水量10倍,提取2次,每次1 h,55%的乙醇沉淀杂质 .该工艺科学合理,适合于大规模工业生产.     

Effects of Dietary Supplementation of β‐hydroxy‐β‐methylbutyrate on Sow Performance and mRNA Expression of Myogenic Markers in Skeletal Muscle of Neonatal Piglets

The effects of dietary β‐hydroxy‐β‐methylbutyrate (HMB) supplementation during gestation on reproductive performance of sows and the mRNA expression of myogenic markers in skeletal muscle of neonatal pigs were determined. At day 35 of gestation, a total of 20 sows (Landrace × Yorkshire, at third parity) were randomly assigned to two groups, with each group receiving either a basal diet or the same diet supplemented with 4 g/day β‐hydroxy‐β‐methylbutyrate calcium (HMB‐Ca) until parturition. At parturition, the total and live litter size were not markedly different between treatments, however, the sows fed HMB diet had a decreased rate of stillborn piglets compared with the sows fed the control (CON) diets (p < 0.05). In addition, piglets from the sows fed HMB diet tended to have an increased birth weight (p = 0.08), and a reduced rate of low birth weight piglets (p = 0.05) compared with piglets from the CON sows. Nevertheless, lower feed intake during lactation was observed in the sows fed the HMB diet compared with those on the CON diet (p < 0.01). The relative weights of the longissimus dorsi (LD) and semitendinosus (ST) muscle were higher (p < 0.05) in neonatal pigs from the HMB than the CON sows. Furthermore, maternal HMB treatment increased the mRNA levels of the myogenic genes, including muscle regulatory factor‐4 (MRF4, p < 0.05), myogenic differentiation factor (MyoD) and insulin‐like growth factor‐1 (IGF‐1, p < 0.01). In conclusion, dietary HMB supplementation to sows at 4 g/day from day 35 of gestation to term significantly improves pregnancy outcomes and increases the expression of myogenic genes in skeletal muscle of neonatal piglets, but reduces feed intake of sows during lactation.     

Effect of Dietary N‐Carbamylglutamate Levels on Reproductive Performance of Gilts

The effect of dietary N‐carbamylglutamate (NCG) supplementation during the entire gestation on reproductive performance of gilts was determined. At the initial day of gestation, forty‐five cross‐bred (Landrace × Large white) gilts were randomly assigned to five groups receiving a basal diet (control group) and basal diet supplemented with 0.05%, 0.10%, 0.15% and 0.20% NCG until parturition, respectively. At parturition, total litter size, live litter size and rate of stillbirth were not markedly affected by NCG supplementation. However, gilts in 0.05% NCG‐supplemented group had more pigs born alive than gilts in control group (+1.11 pigs, p = 0.12), and live litter weight was increased (+12.13–19.17%, p < 0.05) in 0.05%, 0.10% and 0.15% NCG‐supplemented groups relative to control group. And also, average birthweight of piglets born alive was higher (+6.57%, p < 0.05) in 0.05% NCG‐supplemented group than in control group. Furthermore, on days 30, 60, 90 and 110 of gestation, concentrations of arginine and ornithine in plasma were higher (p < 0.05) in 0.05%, 0.10%, 0.15% and 0.20% NCG‐supplemented groups than in control group, respectively. In addition, the chorioallantois gene expression of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor A (VEGF‐A), placental growth factor (PLGF) and angiopoietin‐2 (ANG‐2) was all increased (p < 0.05) in 0.05%, 0.10% and 0.15% NCG‐supplemented groups than in control group. In conclusion, dietary supplementation with 500 mg/kg NCG during the entire gestation significantly improves pregnancy outcomes in gilts, which may be associated with the improved concentrations of arginine in plasma and placental angiogenic factors gene expression of gilts.     

Molecular Cloning and Characterization of CD9 cDNA from Sheep and Cashmere Goat

CD9 is a glycoprotein of the transmembrane 4 superfamily (TM4SF) and is involved in various cellular processes. Some CD9 cDNA have been cloned in mammals and certain fish genera in recent years, but goat and sheep counterparts of cattle, human and mouse have not been identified. To facilitate the studies, we cloned the cDNA encoding for CD9 of cashmere goat (Capra hircus) and sheep (Ovis aries), and expressed sheep CD9 in Escherichia coli cells. Structural analysis indicated for both goat and sheep that a 1123 bp cDNA spanned an open reading frame of 681 bp which predicted a protein of 226 amino acids with a typical TM4SF structure, including four highly conserved transmembrane domains, two extracellular domains and a CCG motif, which is a hallmark of the TM4SF. The predicted amino acid sequences were highly homologous to those of cattle, mouse and human CD9. Molecular phylogenetic analysis based on CD9 cDNA sequences indicated that goat and sheep CD9 were closely related to CD9 of cattle, which is in agreement with their morphological taxonomy.     

高温胁迫对温州蜜柑蛋白质合成的影响

一年生兴津温州蜜柑经不同高温处理,均发生部分叶片脱落及细胞质膜系统相对透性增加;基因表达改变,合成5种与热激有关的多肽,分子量分别为108、105、60、27及22kDa;离区蛋白质合成也发生改变;逐级升温有利于柑桔叶片及离区可溶性蛋白质的积累和耐热性的提高,而这种耐热性的提高可能类似于低温驯化下柑桔耐寒性增强的过程。     

鸡胚成纤维细胞制备工艺改进试验

在制备鸡胚成纤维细胞过程中,对用连续消化法与玻璃珠分散法两种方法进行比较,结果表明:用玻璃珠分散法制备细胞,易使死亡细胞数大幅增加,在生产中加大成本,并在旋转培养中,影响活细胞的贴壁及生长;而采用胰酶连续消化法制备的细胞,贴壁较好、成活率高,但比前者工作量大;结合两者优点,找出了制备鸡胚成纤维细胞最佳的方法。     

Effects of Inulin Supplementation in Low‐ or High‐Fat Diets on Reproductive Performance of Sows and Antioxidant Defence Capacity in Sows and Offspring

This experiment was conducted to investigate the effects of inulin supplementation in low‐ or high‐fat diets on both the reproductive performance of sow and the antioxidant defence capacity in sows and offspring. Sixty Landrace × Yorkshire sows were randomly allocated to four treatments with low‐fat diet (L), low‐fat diet containing 1.5% inulin (LI), high‐fat diet (H) and high‐fat diet containing 1.5% inulin (HI). Inulin‐rich diets lowered the within‐litter birth weight coefficient of variation (CV, p = 0.05) of piglets, increased the proportion of piglets weighing 1.0–1.5 kg at farrowing (p < 0.01), reduced the loss of body weight (BW) and backfat thickness (BF) during lactation (p < 0.05) and decreased the duration of farrowing as well as improved sow constipation (p < 0.05). Sows fed fat‐rich diets gained more BW during gestation (p < 0.01), farrowed a greater number of total (+1.65 pigs, p < 0.05) and alive (+1.52 pigs p < 0.05) piglets and had a heavier (+2.06 kg, p < 0.05) litter weight at birth as well as a decreased weaning‐to‐oestrous interval (WEI, p < 0.01) compared with sows fed low‐fat diets. However, it is worth noting that the H diet significantly decreased the serum activities of superoxide dismutase (T‐SOD) and glutathione peroxidase (GSH‐Px) and increased the serum malondialdehyde (MDA) levels in sows and piglets (p < 0.05). In contrast, HI diet enhanced the activities of T‐SOD and GSH‐Px and decreased the serum MDA concentrations (p < 0.05) in sows and piglets. In summary, the fat‐rich diets fed to sows during gestation had beneficial effects on reproductive performance, but aggravated the oxidative stress in sow and piglets. Inulin‐rich diets fed to sow during gestation had beneficial effects on within‐litter uniformity of piglet birthweight and enhanced the antioxidant defence capacity of sows and piglets.     

棉花黄萎病菌毒素的分离提纯及致萎活性测定

经超滤,Con.A—Scpharosc 4B亲和层析,从棉花黄萎病菌的Czapck′s培养液中,分离纯化致萎毒素。成分分析和致萎活性测定结果表明:棉花黄萎病菌产生的毒素是一种致萎力极强的糖蛋白。其含糖量为14.74％,蛋白质量为85.26％,其致萎活力是半纯化液的10～15倍,活力回收为76％。     

鸡传染性法氏囊病（B87株）组织毒液生产工艺探讨

通过计算ELD50,将已知效价的鸡传染性法氏囊病(B87株)生产种毒分几个滴度进行稀释,分别接种SPF鸡胚,结果各组鸡胚随病毒接种量的提高,高峰期死亡时间逐渐靠前,高峰期死亡率也逐渐增加,抗原效价也逐渐提高,抗原产量也有明显变化,病毒滴度以102.0 ELD50/0.1mL接种鸡胚更合适.