No easy solution for the fractionation of faecal nitrogen in captive wild herbivores: results of a pilot study

Faecal nitrogen (FN) concentration is used as a marker for habitat quality and digestive efficiency in free‐ranging herbivores. In herbivores, FN can be separated into undigested plant N (analysed as the N concentration of the neutral detergent residue) and metabolic faecal N (MFN). It has been suggested that by differential analysis of the faecal fibre‐bound N, the MFN fraction can be further split into a bacterial N and an endogenous N fraction [Hesta et al., Br. J. Nutr. 90 (2003) 1007]. We applied these methods to 96 faecal samples of 48 mammalian herbivore species from zoos. Species were grouped into coprophageous and non‐coprophageous hindgut fermenters and ruminating and non‐ruminating foregut fermenters. Diet was not controlled. The FN decreased with body mass, possibly reflecting higher proportions of concentrates in diets of smaller animals. The proportion of MFN increased with FN, indicating that higher quality food might enhance the gastrointestinal bacterial flora. The only outlier to this pattern was the lesser panda (Ailurus fulgens), confirming the low relevance of fermentative digestion in this herbivorous ‘carnivore’. No relevant differences between the four digestion types were noted. The proportion of endogenous faecal N (32–80% of FN) was always higher than that of bacterial faecal N (7–30%), which contradicts basal understanding of herbivore digestive physiology. Thus, the method of Hesta et al. (2003) does not appear applicable to herbivores. While the results do not exclude the possibility that detailed differences might occur between digestion types, they indicate a high degree of similarity between herbivores that rely on bacterial fermentation, regardless of their digestion type, with respect to metabolic faecal losses.     

固态发酵复方中药防治奶牛乳房炎的效果及对生产性能的影响

本研究采用枯草芽胞杆菌和产朊假丝酵母按等比例制作固态发酵复方中药,并对复方中药发酵前后对奶牛乳房炎及生产性能的影响进行了对比分析.结果表明,与空白组相比,复方中药发酵前后均可显著降低奶牛乳房炎的发病率(P＜0.05),可提高牛奶的乳蛋白率(P＞0.05)和乳脂率(P＞0.05),可显著提高奶牛产奶量(P＜0.05),添加复方中药制剂组和发酵的复方中药制剂组的产奶量分别较空白组提高了0.72kg/d和2.64kg/d;经发酵后的复方中药制剂在降低奶牛乳房炎发病率、改善乳品质和增加产奶量等方面的效果均优于未发酵的复方中药制剂(即普通中药制剂);复方中药经发酵后,有利于提高中药的利用率及药理活性.     

补饲对湘东黑山羊血液生化指标的影响

采用32只3～4月龄的湘东黑山羊,研究三种不同补饲水平对其血液生化指标的影响.设1个对照组与3个试验组,试验组平均补饲量依次按100 g/d、200 g/d、300 g/d.结果表明:肥育羔羊的血清尿素氮、钙、无机磷与总蛋白含量在各组间的变化范围依次是:19.77 mg/dL～20.98 mg/dL、8.28 mg/dL～10.52 mg/dL、4.14 mg/dL～4.80 mg/dL、72.53 g/L～81.33 g/L.     

A recombinant-based ELISA evaluating the efficacy of netobimin and albendazole in ruminants with naturally acquired fascioliasis

The therapeutic efficacy of albendazole and netobimin in ruminants with naturally occurring fascioliasis was investigated using a recombinant-based ELISA. The variation in the IgG response against a 2.9-kDa recombinant protein (FhrAPS), termed efficacy index (EI) 1, and the egg-output changes, termed EI 2, were used to evaluate drug efficacy.The values of EI 1 ranged between 0% and 50% in sheep, and between 0% and 30% in cattle after treatment with albendazole and netobimin. Similar EI 2 values were observed in sheep receiving albendazole or netobimin, but the highest values were found in cattle treated with netobimin. The significant reduction in the IgG response to FhrAPS found in this study shows promise in terms of developing alternative methods for evaluating the efficacy of chemotherapy against Fasciola hepatica in grazing ruminants.     

家蚕表皮蛋白基因的生物信息学分析

家蚕的表皮蛋白(cuticular protein)是家蚕重要的结构蛋白,与几丁质一同作为家蚕表皮的重要组成部分。运用生物信息学的方法对家蚕表皮蛋白进行了广泛分析。通过保守的基序检索家蚕基因组,得到163条候选的表皮蛋白序列,包括RR、Tweedle、CPF&CPFL等家族,并且发现具有确定的保守基序的表皮蛋白基因在染色体上都是以串联集群形式分布。氨基酸组成分析表明,这些表皮蛋白富含甘氨酸、丙氨酸、亮氨酸、组氨酸等。运用Sig-nalP server预测这部分蛋白质有85%都具有信号肽。进化分析显示,负选择是家蚕表皮蛋白基因进化的主要驱动力。采用TFSEARCH等在线服务软件分析发现,在70%含有RR基序的家蚕表皮蛋白基因的核心启动子区具有通用的TATAAA序列。     

Effects of oocyte-derived growth factors on the growth of porcine oocytes and oocyte–cumulus cell complexes in vitro

During oocyte growth and follicle development, oocytes closely communicate with cumulus cells. We examined the effects of oocyte-derived growth factors, growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), on the growth and acquisition of meiotic competence of porcine oocytes collected from early antral follicles (1.2–1.5 mm). First, we confirmed that GDF9 and BMP15 mRNAs were expressed almost exclusively in the oocytes. Oocyte–cumulus cell complexes (OCCs) collected from early antral follicles were cultured in growth medium supplemented with 0–100 ng/ml of GDF9 or BMP15 for 5 days. GDF9 dose-dependently increased the OCC diameter, while BMP15 did not. GDF9 and BMP15 had no significant effects on oocyte growth (P > 0.05). When OCCs that had been cultured with 50 and 100 ng/ml BMP15 were subjected to a subsequent maturation culture, they expanded fully by gonadotropic stimulation and 49% and 61% of oocytes matured to metaphase II (MII), respectively. In contrast, GDF9 did not promote cumulus expansion, and < 10% of oocytes matured to MII. Based on the difference in cumulus expansion, we compared the expression of luteinizing hormone/choriogonadotropin receptor (LHCGR) and follicle stimulating hormone receptor (FSHR) mRNAs in cumulus cells. The level of LHCGR mRNA was increased in cumulus cells of the BMP15 group, although there were no significant differences in FSHR mRNA levels among the groups. These results suggest that GDF9 promotes the growth of OCCs and that BMP15 promotes LHCGR mRNA expression in cumulus cells during oocyte growth culture, which may contribute to cumulus expansion and oocyte maturation.     

The effect of different food types and rations on the liver and muscle of cod (Gadus morhua L.)

In a short time feeding experiment it was shown that the liver weight of cod was significantly reduced in prawn-fed cod compared to sand-eel-fed cod. The dry weight and the protein content of the muscle were not significantly reduced. It is concluded that short time energy deprivation of cod primarily affects the liver. The results futher support the view that the food type and ration of cod can produce anomalous effects in field studies of e.g. parasite induced liver weight decrease in cod.     

甘南生态经济建设支撑体系研究(三)--生态产业的选择与培育

生态产业的选择与培育是甘南生态经济建设的关键。通过分析以生态产业替代传统的生态破坏型产业来保证甘南区域可持续发展的背景和意义，提出了生态产业选择的原则，构建了甘南生态产业体系，并对该产业体系整体功能发挥和各自产业的效益回收所需的保障机制作了深入研究。     

Characterisation of transthyretin and retinol-binding protein in plasma and cerebrospinal fluid of dogs

The aim of this study was to investigate differences in concentrations of vitamin A, transthyretin (TTR) and retinol-binding protein (RBP) between plasma and cerebrospinal fluid (CSF) in dogs. RBP was detected using ELISA, and both RBP and TTR by Western blot analysis after separation on SDS-PAGE. Vitamin A was determined by high performance liquid chromatography. RBP and TTR as well as vitamin A were detected in all samples but at substantially lower concentrations in CSF compared to plasma. RBP in dog plasma showed a similar molecular mass to that of humans, whereas canine TTR had a lower molecular mass. Comparison between plasma and CSF showed that both RBP and TTR were of lower molecular mass in CSF. In CSF, RBP and retinol were present at 10-100-fold lower concentrations compared to plasma. Retinyl esters were present only in minute amounts in 5/17 samples. In conclusion, the CSF of dogs compared to humans is significantly different in terms of both quality and quantity of transport proteins for vitamin A.