甘肃玛曲高寒草甸土壤微生物季节变化特性的研究

选取甘肃玛曲高寒草甸6个样地，对各样地的土壤微生物季节动态及其与土壤理化因子的关系进行了分析。结果表明，在土壤微生物中细菌数量占绝对优势，季节变化对土壤微生物有较大的影响，土壤微生物与土壤肥力有较为密切的关系。细菌在4月出现高峰；放线菌数量春季到秋季数量逐渐减少；真菌数量春季到秋季变化不明显，冬季略有增加；氨化菌、硝化...     

基于Logistic模型探究西藏巨柏播种苗生长规律

运用Logistic模型和二维有序样品聚类法分析了西藏巨柏播种苗生长过程,并建立了苗高和地径、生长时间与苗高之间的拟线性回归模型。分析结果显示：各个回归模型的相关系数都达到了显著水平。为科学培育巨柏优质苗木提供了理论依据。     

营销人的五项修炼

在中国,营销无疑是最具挑战性的职业之一,充满了辛酸和劳苦,同时营销也是让个人最容易突破自己,快速成长的职业.作为一名营销人,你应该为自己的选择而庆幸,因为你已经走上了一条通往成功的快捷之路,如果希望将来成为一名营销精英,甚至做中国最优秀的职业经理人,那么请参照下面的五项修炼.     

Efficiency of soil-applied 67Zn-enriched fertiliser across three consecutive crops

A very small amount of applied zinc (Zn) is taken up by crops, resulting in low recovery by plants. Adding elemental sulphur to zinc oxide (ZnO) fertiliser could improve Zn solubilisation and exert a higher residual effect on crops than soluble Zn sources. We produced an isotopically labelled Zn-elemental sulphur fertiliser and evaluated its performance in comparison to traditional Zn sources during sequential crop cultivation. Three ⁶⁷Zn-labelled fertilisers, ZnO, zinc sulphate (ZnSO₄), and ZnO co-granulated with elemental sulphur (ZnOS⁰), were soil applied, and their contributions to the uptake of Zn by three consecutive crops, wheat, ryegrass, and corn, were assessed in a 294-d pot experiment. The contributions of Zn fertilisers followed the order:ZnSO₄ > ZnO=ZnOS⁰. The relative contributions of Zn fertilisers were lower in the first crop than in the subsequent crops. The overall recovery of applied Zn by the three crops was higher for ZnSO₄ than for ZnO and ZnOS⁰, reaching 1.56%, 0.45%, and 0.33% of the applied Zn, respectively. Zinc recovery by plants was very low, regardless of the source of Zn. Adding elemental sulphur to ZnO did not increase its effectiveness up to 294 d after application. Fertiliser contribution was higher for the subsequent crops than for the initial crop, indicating the importance of assessing the residual effects of Zn fertilisers.     

Effects of a topically applied anaesthetic on the behaviour,pain sensitivity and weight gain of dairy calves following thermocautery disbudding with a local anaesthetic

ABSTRACT

Aims: To compare the effect of a topically applied anaesthetic to no pain relief or meloxicam on the behavioural responses, pain sensitivity and weight gain of calves following disbudding with or without sedation.

Methods: A total of 364, 2–6 week-old calves from three commercial farms were systematically allocated to one of six treatment groups. All calves received a cornual nerve block prior to disbudding, with half restrained in a crate and half sedated with xylazine. Within these groups one third received no further treatment (control), one third were treated with meloxicam >10?minutes prior to disbudding and one third received a topical anaesthetic applied to the horn bud wounds following disbudding. The frequency of ear flicks, head shakes, head scratches and pain sensitivity of the wound were recorded on up to eight occasions over 24 hours after disbudding. Calves were weighed before, and 7 and 28 days after, disbudding to determine average daily weight gain (ADG).

Results: Compared to calves in the crate-control group, all other groups had reduced ear flicks at all times following disbudding (p?<?0.01). Treatment with meloxicam and topical anaesthesia in addition to sedation reduced head scratches compared to calves in the crate-control group (p?≤?0.013). At 22 hours after disbudding head shakes were reduced in sedated calves treated with topical anaesthetic compared to calves in the crate-control group (p?<?0.001). Pain sensitivity was lower in all sedated calves than unsedated calves (p?<?0.001). The ADG between Days 0–7 was 0.14 (95% CI?=?0.015–0.274) kg/day greater in sedated calves treated with meloxicam than calves in the crate-control group (p?=?0.03), and the ADG between Days 0–28 tended to be 0.06 (95% CI=?0.01–0.13) kg/day greater in sedated calves treated with topical anaesthetic than calves in the crate-control group (p?=?0.09).

Conclusion and clinical relevance: Sedation of calves for disbudding reduced the pain experienced in the following 24 hours. There was a benefit to providing calves with topical anaesthetic following disbudding on behavioural responses and pain sensitivity, which was similar to that of treating calves with meloxicam.     

Advances in pasture management for animal productivity and health

A wide range of management techniques is available to enhance quantity and quality of forage supply to grazing animals throughout the annual production cycle. Within broad limits, dry matter (DM) production is relatively insensitive to management of defoliation frequency, severity and duration. However defoliation management has effects on feed quality which can be enhanced, in particular, by control of pasture growth in the spring through maintenance of relatively low average pasture masses. Treading damage can have significant immediate and ongoing effects on pasture production and farmers can use a range of management techniques to minimise these.

Fertiliser application practices have a potent influence on pasture production and seasonality of that production. Available soil nitrogen is the primary nutrient deficiency limiting production in New Zealand's characteristically grass-dominant pastures. Nitrogen fertiliser usage has increased markedly in recent years, particularly to grow substantially greater amounts of forage during the cool season, and this trend looks set to continue. However, the use of nitrogen fertiliser has important environmental implications.

Pasture renewal and forage crop use has also increased in recent years. Care needs to be taken in conducting cost-benefit analyses, selecting the options that best meet the needs, and in establishment and subsequent management practices. Ryegrass (perennial and hybrids) and white clover remain the primary choice for permanent pasture renewal, the availability of safe endophytes having largely alleviated effects of endophyte toxicosis. Special-purpose mixtures are used, especially in dry environments. Italian ryegrasses, brassicas and chicory are common choices for forage crops. A range of management techniques can be used to alleviate deleterious effects of some forages, including ryegrass endophyte toxicosis, facial eczema, and toxins associated with Fusarium fungi. Generally these techniques are not totally effective. More research is required to increase our understanding of these disorders, and in order to develop more effective and reliable management practices.     

我国利用蕃麻皂素合成生产地塞米松的现状及需研究的重点

蕃麻皂素即海柯吉宁 ,是一种具开发潜力合成生产地塞米松药物的原料。在论述国内外利用海柯吉宁研究及生产地塞米松现状的基础上 ,指出了国内合成生产存在的问题 ,针对国内用海柯吉宁合成生产地塞米松收率低的问题 ,提出把优化工艺作为合成生产的研究重点 ,且从 3个方面进行研究 ,可将其收率从现在的 6 0 3%提高到 10 %以上     

Pregnancy diagnosis in dairy goats and cows using progesterone assay kits

Early pregnancy diagnosis in dairy goats and cows was studied using enzyme immunoassays (EIA) to measure progesterone concentrations in whole milk samples collected approximately 3 weeks after mating. Two qualitative on-farm assay kits and 2 quantitative assay kits, all designed for use in the dairy cow, were tested for their accuracy with goats milk samples. Accuracy of diagnosis of goat pregnancy ranged from 83 to 88%, and of non-pregnancy from 80 to 100%. Pregnancy diagnosis with samples of cows milk using 2 quantitative kits gave accuracies of 66 to 68% for pregnancy, and 90 to 91% for non-pregnancy. Possible causes of error in the early diagnosis of pregnancy with milk samples are discussed.