In vitro phagocytic activity of milk neutrophils during lactation cycle in Murrah buffaloes of different parity

Milk samples were collected from 34 lactating Murrah buffaloes on days 0, 5, 15, 30, 45, 60, 90, 120, 150, 180, 210, 240, 270 and day 300 after calving. Milk somatic cell counts (SCC) were highest in multiparous buffaloes . Milk SCC were significantly lower in buffaloes of third and fourth parity during early lactation and than increased significantly (p < 0.01) by the end of lactation. Milk neutrophils were significantly lower in all the buffaloes during early lactation, but increased significantly (p < 0.01) afterwards. Milk lymphocytes were significantly higher during early lactation, but decreased significantly (p < 0.01) by the end of lactation. Phagocytic activity (PA) was highest in day 1 colostrum and then decreased significantly (p < 0.01) by the fourth milking in buffaloes of second, third and fourth parity . Phagocytic index (PI) was also highest in colostrums of primiparous buffaloes. Irrespective of parity, maximum PA and PI was observed during mid lactation. In terms of in vitro phagocytic activity, early lactation is the most critical period followed by late and mid lactation.     

饲料水分活度及其应用

饲料的水分活度(Aw),是指在相同温度下的密闭容器中,饲料的水蒸汽压与纯水蒸汽压之比。本文综述了饲料中水分活度及其应用的研究进展。     

叶下珠提取物体外抗氧化和保肝作用

采用叶下珠水提取物、75%乙醇提取物、95%乙醇提取物体外对羟自由基(·OH)、超氧阴离子(O2-)的清除和抑制H2O2诱导小鼠红细胞氧化溶血性等方法来研究叶下珠的抗氧化活性。以体外培养法获取罗非鱼的原代肝细胞,用CCl4对肝细胞建立体外损伤模型,研究叶下珠水提取物、75%乙醇提取物、95%乙醇提取物对丙氨酸转氨酶(Alanine aminitransperase,ALT)、天冬氨酸转氨酶(Aspartate aminotransferase,AST)活力的影响。叶下珠水提取物对羟自由基(·OH)、超氧阴离子(O2-)的清除和抑制H2O2诱导小鼠红细胞氧化溶血性最强。加药组丙氨酸转氨酶、天冬氨酸转氨酶活性显著低于损伤组,差异极显著(P<0.01)。叶下珠提取物具有明显的体外抗氧化和保肝作用。     

蜂粮酿制过程中花粉粒活力和水活度的测定

测定手采花粉、新鲜蜂花粉、1日蜂粮、2日蜂粮、3日蜂粮、4日蜂粮、5日蜂粮样品中花粉粒活力分别为31.4%、35.6%、18.1%、16.4%、7.8%、1.3%、0，5日以后花粉粒丧失活力。测定新鲜蜂花粉、晒干花粉、1日、5日、10日、15日、21日、60日蜂粮的水活度分别是0.651、0.208、0.809、0.605、0.602、0.598、0.607、0.600。     

牛初乳中活性物质IgG含量分析

通过对产犊后前四天内牛初乳活性物质(IgG)含量的检测，分析牛初乳中活性物质的变化规律及冻结、巴氏杀菌对其影响。     

Evaluation of a digitally integrated accelerometer-based activity monitor for the measurement of activity in cats

OBJECTIVE: To assess the correlation between data generated by an accelerometer-based activity monitor and the distance moved in cats. STUDY DESIGN: Prospective experimental study. ANIMALS: Three, four-year-old, male, purpose-bred research cats, weighing between 5.1 and 5.9 kg. METHODS: Part I: Collar and harness mounted accelerometers were evaluated in three cats, comparing simultaneously collected accelerometer data with movement data from computer-analyzed video. Part II: Cats wore collar and harness mounted accelerometers, and data were recorded for 4 weeks to evaluate day-to-day and week-to-week variation in activity. RESULTS: Part I: 432 hours of simultaneous video and accelerometer data were collected. The correlation between accelerometer counts and distance moved was 0.82 overall. Agreement between collar and harness mounted accelerometers was excellent with only 6% of the differences in measurements lying outside the mean difference +/- 2 standard deviations. The adjusted R(2) for harness accelerometer output and 6% mobility was 0.75; for movement 0.84; and for mean velocity 0.83. Evaluation of video indicated eating, grooming and scratching created high accelerometer counts with little effect on movement. Part II: There was a significant effect of day on harness (p < 0.001) and collar (p < 0.002) counts, with counts being lowest at the weekend. There was a significant effect of week on harness-mounted accelerometer counts (p < 0.034), but not on collar-mounted accelerometer counts. Harness accelerometer counts were lowest in week 1. CONCLUSION: Output from an acceleration-based digitally integrated accelerometer correlated well with distance moved and mobility in freely moving cats provided the mobility threshold in the analysis software was > or = 6%. CLINICAL RELEVANCE: Acceleration-based activity monitors may allow for objective measurement of improved mobility following analgesic treatment for conditions such as osteoarthritis.     

水溶性甲壳胺体外抑菌活性的试验研究

用二倍稀释法测定 6种甲壳胺样品的最低抑菌浓度 (MIC) ,并根据MIC制作含有甲壳胺的普通琼脂培养基和药敏试纸片。结果表明 :编号为 1 #、 3 #、 4 #、 6 #甲壳胺在一定浓度时对大肠杆菌、金黄色葡萄球菌、沙门氏菌、巴氏杆菌均有不同的抑制作用 ;2 #、 5 #在试验所用浓度下抑菌效果不明显。用与MIC相同浓度配制的甲壳胺琼脂的抑菌作用与试管MIC法相同 ,而甲壳胺试纸片则需要 8个MIC才有抑菌作用。     

2种紫花苜蓿氮代谢及其关键酶(NR、GS)活性差异研究

为探究不同紫花苜蓿氮代谢差异及氮代谢差异的生理机制,采用盆栽砂培法,通过对2个具有典型特征的紫花苜蓿品种(LW6010和陇东苜蓿)在2个氮素水平及3个生育时期下其氮代谢产物及氮代谢酶活性差异进行研究,探讨氮代谢产物与氮代谢酶活性的相互关系。结果表明:LW6010和陇东苜蓿在N210水平下其干物质重、氮含量、氮积累量及硝酸还原酶(NR)、谷氨酰胺合成酶(GS)活性均高于N21。在2个氮水平下,LW6010的干物质重、NR和GS活性均显著大于陇东苜蓿,而LW6010的氮含量显著低于陇东苜蓿。其中,LW6010的NR活性比陇东苜蓿在N210和N21下分别高24%和15%(苗期)、31%和40%(现蕾期)、20%和11%(盛花期);GS活性分别高30%和29%(苗期)、33%和20%(现蕾期)、7%和14%(盛花期)。在苗期和盛花期时,LW6010的氮积累量显著大于陇东苜蓿,而在现蕾期差异不显著。LW6010的氮积累量在N210下各生育期分别比陇东苜蓿高25%,3%和16%,而在N21下LW6010的氮积累量在苗期和盛花期下比陇东苜蓿高45%和12%。同时,紫花苜蓿干物质重、氮积累量、NR活性与GS活性呈极显著正相关关系。综上分析,紫花苜蓿的不同品种在不同氮素水平下其氮代谢能力不同,不同紫花苜蓿品种间氮代谢具有差异;LW6010较陇东苜蓿具有较好的氮代谢能力;NR和GS活性可为不同紫花苜蓿氮代谢差异评价提供参考。     

原料奶生产良好卫生规范(GMP)的实施效果

随着乳品工业的迅速发展,长效奶、学生奶等的兴起,乳品企业对原料奶的卫生要求也随之提高。而原料奶中的细菌数和体细胞数的含量又取决于牧场的卫生条件、牛体的健康状况、挤奶方式、储藏条件、储藏时间以及运输条件。本试验对实施牧场GMP(Good Manufacturing Practice)前后原料奶的卫生质量进行了比较。结果发现,GMP规范的实施有效地降低了原料奶中的细菌总数和体细胞数。     

Photic and non-photic entrainment on daily rhythm of locomotor activity in goats

We studied the photic (L/D cycle) and non-photic (restricted feeding) entrainment on the patterns of daily rhythm of total locomotor activity in goats. Six female Maltese goats were subjected to three different artificial L/D cycles: 12/12 L/D, 12/12 D/L and constant light. During the 12/12 L/D and 12/12 D/L, food and water were available ad libitum . During constant light, animals were subjected to a restricted feeding treatment. Total activity was recorded by means of an actigraphy-based data logger (Actiwatch-Mini^®). Our results showed that goats exhibited clear daily rhythms of activity in 12/12 L/D cycle, 12/12 D/L cycle and constant light, although they showed FAA prior the feeding time during the restricted feeding treatment. Goats were diurnal, with activity consistently beginning promptly following the onset of light. Even when the L/D cycle was delayed by 12 h on some days, to the daily rhythm was re-established. During the constant light period, the onset of activity was linked to the time of food administration. Our study evidences two factors for the rhythm of total locomotor activity in goats: light stimuli (photic) and food access (non photic), strongly coupled to permit organisms the adaptive temporal coordination of behaviour with stable and unstable environmental periodicities.     

Correlates of objectively measured physical activity in dogs

To increase physical activity (PA) levels in dogs and to better evaluate their energy requirements, there is a need to understand which factors or correlates are associated with PA and/or sedentary behaviour. Improving our understanding of these correlates also has implications for prescribed energy requirements in dogs. PA was measured using accelerometry in 62 dogs from two common breeds (Labrador retrievers and Cocker spaniels). Five potential correlates (age, sex, breed, neuter status, body condition score) were tested for associations with total volume of PA, light-moderate intensity PA, vigorous intensity PA and sedentary behaviour. Age and breed were associated with total volume of PA, light-moderate intensity PA and sedentary behaviour in the final models. Age was associated with vigorous intensity PA. The final models explained 60%, 40%, 63% and 44% of variance in total volume of PA, light-moderate intensity PA, vigorous intensity PA and sedentary behaviour, respectively. These results should improve understanding of the variation in energy requirements of dogs, as well as the development of age and breed-specific diets and the prevention and treatment of canine obesity.     

饲用中性蛋白酶酶活测定的影响因子的研究

本文介绍了福林酚法测定中性蛋白酶的原理、步骤,并重点研究了福林法测定中性蛋白酶在实际应用中的一些问题。研究表明,无论何种来源的固体蛋白酶都可以用0.3mol/L氯化钠作为浸提剂,浸提时间为30min;酶促反应的时间为5min,显色反应为20min;酶液合适的稀释倍数为最后测定酶活时OD值不超过0.5;不同厂家生产的酪素底物对测定结果有影响,底物浓度应保持在1%;酶促反应的温度和pH分别为40℃和7.0。     

黄芩多糖体外抗氧化活性研究

目的:探讨黄芩多糖的体外抗氧化活性。方法:从还原力,清除DPPH自由基、超氧阴离子自由基和羟基自由基4个方面研究黄芩多糖的体外抗氧化活性,并与VC进行比较。结果:黄芩多糖对上述自由基均有不同程度清除作用,其还原力较低;清除DPPH自由基的能力略低于VC;对超氧阴离子清除能力强于VC,EC50为0.261 mg/mL;对羟自由基的清除能力弱于VC,EC50为0.724 mg/mL。结论:黄芩多糖具有一定的体外抗氧化能力。     

龙葵抗肿瘤活性研究进展

龙葵在我国大部分地区均有分布。龙葵全草含有多种化学成分,最重要的是生物碱类和多糖,具有抗肿瘤、抗炎、抗过敏、抗菌等作用,尤其在抗肿瘤方面的作用成为近年来研究的热点。笔者等对龙葵的抗肿瘤作用方面的研究进行综述。     

骨保护素对破骨细胞活性的影响

旨在探讨骨保护素(osteoprotegerin,OPG)对破骨细胞(osteoclast,OC)活性的影响.采用小鼠原代OC模型,在体外培养的基础上添加不同浓度OPG,通过TRAP阳性细胞计数、细胞骨架F-actin染色、骨吸收功能检测等手段,观察OPG对体外培养OC的作用.结果发现,OPG能够直接作用于OC,减少其数量,破坏其F-actin环,减弱其骨吸收活性,且随OPG浓度的增加,对OC的影响更加明显.结果表明,OPG能够减少OC数量并抑制其骨吸收活性,呈现剂量效应.     

Obidoxime reactivation of organophosphate-inhibited cholinesterase activity in pigs

The ability of obidoxime to reactivate organophosphate-inhibited cholinesterases was studied in pigs treated with either trichlorfon, dichlorvos or coumaphos. In 6 pigs Cholinesterase activity was measured in the blood samples both before and after in vitro reactivation with obidoxime. Three pigs were treated with obidoxime 6 h after administration of the organophosphates in order to study the possibility of in vivo reactivation.The results show a close correlation between the ability of obidoxime to reactivate the inhibited cholinesterases in vitro and in vivo. However, there was a marked difference in the possibility of reactivation between the 3 organophosphates. Thus no reactivation was possible after treatment with dichlorvos, while reactivation could be achieved for at least 6 h after administration of trichlorfon. After coumaphos treatment reactivation with obidoxime was possible for more than 24 h.     

伴大豆球蛋白酶解肽抑菌活性研究

建立伴大豆球蛋白酶解产生抑菌肽的最适条件,对酶解产物进行分离纯化后进一步测定其抑菌活性。采用复合风味蛋白酶水解伴大豆球蛋白,测定不同时间的酶解液对大肠杆菌和金黄色葡萄球菌的抑菌活性。结果显示:2 h水解产生的酶解肽具有抑菌活性,其对大肠杆菌和金黄色葡萄球菌的最小抑菌浓度分别是2.6和3.2 mg/mL。2 h水解液经Sephadex-G15分离纯化,采用平板计数法鉴定各组分。结果显示:CP2组分对大肠杆菌具有显著的抑制作用(P<0.05)。本研究证明伴大豆球蛋白的复合风味蛋白酶酶解肽具有一定的抑菌活性。     

夏枯草提取物的抗氧化活性

对夏枯草（Prunella vulgaris）不同溶剂提取物体外抗氧化活性进行评价,为进一步开发利用夏枯草提供参考。采用70%乙醇超声波提取,然后用等体积的乙酸乙酯、正丁醇和水萃取,得到乙酸乙酯、正丁醇和水提取物,并以BHT为对照,研究不同溶剂提取物的抗氧化活性。结果表明,夏枯草提取物具有良好的抗氧化性。不同溶剂提取物及BHT清除DPPH·的能力高低次序为乙酸乙酯提取物＞正丁醇提取物＞BHT＞水提物,清除·OH的能力高低次序为BHT＞乙酸乙酯提取物＞正丁醇提取物＞水提物,清除O-2·的能力高低次序为乙酸乙酯提取物＞水提物＞BHT＞正丁醇提取物,还原力高低次序为BHT＞乙酸乙酯提取物＞正丁醇提取物＞水提物。夏枯草乙酸乙酯提取物具有较强的抗氧化活性。     

天祝天然草地3种有毒植物提取物对粘虫的生物活性

测定了3种有毒植物露蕊乌头,铁棒槌和马先蒿的4种溶剂的提取物对粘虫的杀虫活性。结果表明：露蕊乌头甲醇、乙醇提取物对粘虫均具有一定的触杀活性,LC50分别为3．63、5．79g／L;露蕊乌头甲醇提取物,马先蒿丙酮提取物和铁棒槌甲醇提取物对粘虫的胃毒活性表现较强,杀虫活性LC50分别为2．13,2．82和3．22g／L,马先蒿和铁棒槌的石油醚提取物对粘虫无胃毒活性。3种植物的4种溶剂的提取物对粘虫均表现出一定的拒食活性,其中甲醇提取物的拒食活性都较高,露蕊乌头甲醇提取物对粘虫的拒食活性明显高于其他提取物,当质量浓度达到0．2g／mL时,拒食率为97．6％。而3种植物石油醚提取物的拒食活性均较差。