Absorption,distribution and residue evaluation of active substances used as feed additives

Summary

Administration of feed additives is based on the necessity of satisfying a need in human nutrition. Oral feed additive intake results in an equilibration level which is followed by a steady state after absorption. The equilibrium point of the blood (tissue) level can be calculated mathematically. 70 Per cent of the plateau of the steady state is reached within four times the half‐life.

Some compounds give rise to an ‘initial peak’ with higher concentrations than the expected plateau level (phase of adaptation). For residue evaluation these effects have to be considered. The relevance of different metabolic processes and the impact on a traditional monofactorial evaluation, neglecting the incidence of combination, is mentioned. Commonly used residue assessment is discussed and the safety margin of a toxicological threshold elucidated.     

Relationships between workplace well-being,job demands and resources in a sample of veterinary nurses in New Zealand

AIM: To use a job demands-resources model to examine the associations among perceived job demands, job resources, family-to-work enrichment, positive team relationships, work engagement, emotional exhaustion, cynicism and intention to leave, in a sample of New Zealand veterinary nurses.

METHODS: Data were collected by means of a self-reported online survey, with the help of eight New Zealand tertiary education providers and the New Zealand Veterinary Nurses’ Association. Nine measures or variables were assessed using questions or statements with responses categorised on a linear scale. Measurement models for each of the variables in the study were assessed to establish whether the variables represented the respective item-level data. Structural equation modelling was then used to test the hypothesised interrelationships among study variables.

RESULTS: There were 253 respondents; 17.1% of individuals who classified themselves as veterinary nurses in the 2013 New Zealand census. In the final structural model job demands were associated with emotional exhaustion (standardised regression coefficient β=0.57), which was related to cynicism (β=0.52) and intention to leave (β=0.56). Job resources were negatively related to emotional exhaustion (β=?0.32). Higher work engagement was associated with lower emotional exhaustion (β=?0.29) and lower intention to leave (β=?0.30). Job resources were associated with work-to-family enrichment (β=0.69), which was related to work engagement (β=0.57); and job resources were associated with positive team relationships (β=0.79).

CONCLUSION: It is important that job resources are available to help deal with demanding work. Without resources, demanding work is associated with exhaustion, cynicism and increased intention to leave, while positive spill over between work and family life are related to higher work engagement.     

兽医影像诊断学开展病例讨论教学的问卷调查思考

问卷调查是以提出问题进行资料搜集的一种方法.笔者研究在兽医影像诊断学课程实施病例讨论的教学方法,通过问卷调查的方式,对学生选择选修课的动机和态度、教学方法和效果,以及考核方式进行调查.结果显示:病例讨论的教学方法可以增强学生对知识点的掌握,培养学生应用理论知识进行疾病诊断的思路.该教学方法受到学生广泛的欢迎和认可.     

Surgical hand antisepsis in veterinary practice: evaluation of soap scrubs and alcohol based rub techniques

Recent studies have shown that hydro-alcoholic solutions are more efficient than traditional medicated soaps in the pre-surgical hand antisepsis of human surgeons but there is little veterinary literature on the subject. The aim of this study was to compare the efficiency of medicated soaps and a hydro-alcoholic solution prior to surgery using an in-use testing method in a veterinary setting. A preliminary trial was performed that compared the mean log₁₀ number of bacterial colony forming units (CFU) and the reduction factors (RF) between two 5-min hand-scrubbing sessions using different soaps, namely, povidone iodine (PVP) and chlorhexidine gluconate (CHX), and the 1.5-min application of a hydro-alcoholic rub.A clinical in-use trial was then used to compare the hydro-alcoholic rub and CHX in a surgical setting. Sampling was performed using finger printing on agar plates. The hydro-alcoholic rub and CHX had a similar immediate effect, although the sustained effect was significantly better for the hydro-alcoholic rub, while PVP had a significantly lower immediate and sustained effect. The hydro-alcoholic rub showed good efficiency in the clinical trial and could be considered as a useful alternative method for veterinary surgical hand antisepsis.     

兽用B超在母猪早期妊娠监测中的临床应用及效益分析

超声波扫描技术具有无损伤、无放射性危害、诊断准确率高、重复性好、安全无副作用、易操作等特点。本文探讨了超声波扫描在母猪早期妊娠监测中的应用、探测方法、诊断标准及效益分析。结果表明：超声探查技术能够直接对妊娠动物的妊娠诊断、胎龄判定、胎儿活力、胎儿数目及胚胎早期死亡或流产做出直观、准确的诊断,相对传统诊断技术具有明显优势。