Drivers,challenges and opportunities of forage technology adoption by smallholder cattle households in Cambodia

Forage technology has been successfully introduced into smallholder cattle systems in Cambodia as an alternative feed source to the traditional rice straw and native pastures, improving animal nutrition and reducing labour requirements of feeding cattle. Previous research has highlighted the positive impacts of forage technology including improved growth rates of cattle and household time savings. However, further research is required to understand the drivers, challenges and opportunities of forage technology for smallholder cattle households in Cambodia to facilitate widespread adoption and identify areas for further improvement. A survey of forage-growing households (n = 40) in July–September 2016 examined forage technology adoption experiences, including reasons for forage establishment, use of inputs and labour requirements of forage plot maintenance and use of forages (feeding, fattening, sale of grass or seedlings and silage). Time savings was reported as the main driver of forage adoption with household members spending approximately 1 h per day maintaining forages and feeding it to cattle. Water availability was reported as the main challenge to this activity. A small number of households also reported lack of labour, lack of fencing, competition from natural grasses, cost of irrigation and lack of experience as challenges to forage growing. Cattle fattening and sale of cut forage grass and seedlings was not found to be a widespread activity by interviewed households, with 25 and 10% of households reporting use of forages for these activities, respectively. Currently, opportunities exist for these households to better utilise forages through expansion of forage plots and cattle activities, although assistance is required to support these households in addressing current constraints, particularly availability of water, if the sustainability of this feed technology for smallholder cattle household is to be established in Cambodia.     

Studies on equine lipid metabolism. 2. Lipolytic activities of plasma and tissue lipases in large horses and ponies

The enzymatic fundamentals of lipid metabolism of equine have not been thoroughly investigated at this point in time. It is still unclear why ponies in contrast to horses may become hyperlipaemic when coming negative energy balance. In this study, the activities of the triglyceride-cleaving key enzymes of ponies are large bred horses were investigated in order to obtain insight into the aetiology of the syndrome. The objective of the study was to measure the activities of hormone-sensitive lipase (HSL), lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) in ponies and horses in ex vivo in vitro assays. Norepinephrine (NE) stimulated pony adipocytes to release FFA in a linear fashion (4.57 +/- 2.09 nmol FFA.10(5) cells-1.min-1). This was not observed in horses. Lipolysis was significantly higher in fat cells of ponies than in horses when adenosine deaminase (ADA) and NE were added (12.71 +/- 3.12 vs. 1.96 +/- 1.22 nmol FFA.10(5) cells-1.min-1). Relative inhibition of lipolysis by the action of insulin was comparable in adipocytes of horses and ponies. However, absolute FFA release in pony fat cells was as high as the maximal NE and ADA stimulated lipolysis in horse adipocytes. Postheparin plasma lipase activities in ponies and horses did not differ between the sub-species. This finding was supported by the results obtained from measurement of LPL activity in adipose and muscle tissue showing only a tendency of increased activities in pony explants when compared to horse tissue incubations. This study further supports the hypothesis that differences in regulation of TG release from fat stores rather than clearance of TG from plasma is causative for the development of hyperlipaemia in ponies. Abbreviations used: ADA, adenosine deaminase; BW, body weight; FFA, free fatty acid; HSL, hormone-sensitive lipase; HTGL, hepatic triglyceride lipase; LPL, lipoprotein lipase; NE, norepinephrine; SDS, sodium dodecyl sulfate; TG, triglyceride; VLDL, very low density lipoprotein.     

南极半岛海洋气候区的土壤Ⅲ.冻-融作用与水分状况

自由水活动在南极海洋性气候区土壤形成与演化过程中发挥极为重要的作用。本文对土壤自由水的来源、冻-融作用、永冻层和活动层动态以及自由水参与下的物质迁移过程等几个方面进行了论述,讨论了上述不同过程的影响因素以及土壤发生学意义,指出以土壤水形态转化和自由水活动为基础的土壤过程具有显著的微域性特点,是决定本区土壤发生类型与分布模式的重要因素之一。     

"Tubules-Within-a-Tubule" Hierarchical Order of Mesoporous Molecular Sieves in MCM-41

The recently discovered mesoporous aluminosilicate MCM-41 consists of hexagonal arrays of nanometer-sized cylindrical pores. It is shown that this material can be synthesized by cooperative condensation of silicate and cylindrical cationic micelles. Careful control of the surfactant-water content and the rate of condensation of silica at high alkalinity resulted in hollow tubules 0.3 to 3 micrometers in diameter. The wall of the tubules consisted of coaxial cylindrical pores, nanometers in size, that are characteristic of those of MCM-41. The formation of this higher order structure may take place through a liquid crystal phase transformation mechanism involving an anisotropic membrane-to-tubule phase change. The hierarchical organization of this "tubules-within-a-tubule" particle texture is similar to that of the frustules of marine diatoms.     

Protein synthesis changes in the liver of piglets infected with Strongyloides ransomi

In piglets infected with Strongyloides ransomi, the incorporation of ¹⁴C-L-amino acid into liver protein was increased on days 7 and 14 post inoculation (PI), while on day 21 PI it was distinctly below the initial values.There was an increase of reduced glutathione (GSH) on day 7 PI and a decrease on day 14 PI. At day 21 PI the values were still below those of the controls.The concentration of plasma Cl, Na, K, Ca, Mg, Fe, Cu and Zn decreased from day 13 PI. The plasma levels of Na, K, Fe and chloride returned to normal on day 23 or 29 PI, but the other electrolytes had not regained their normal values at the end of the experiment (29 day PI).There was no change in electrolyte concentrations in heart, kidney and skeletal muscle. In the liver the concentrations of Ca, Fe and Cu increased. In the spleen the contents of Ca and Cu increased, whereas the fat content distinctly decreased.The enzymes GOT, GPT, LDH, LAP, ICDH, ALD, AP, SP and γ-GT were measured in blood plasma. Only alkaline phosphatase (AP) decreased markedly.     

The evaluation of hormone and metabolite profiles after the infusion of glucose, propionate and butyrate in cattle

Lactational performance in high-yielding dairy cows has its limits in metabolic processes. Energy metabolism is maintained by mobilization of body reserves via hormonal regulation, resulting in lipolysis and sometimes ketoacidosis. For characterization of such conditions the intraruminal and intravascular application of glucose and volatile fatty acids was used in ruminant physiology. On the other hand the results of such experiments were correlated to actual and potential milk yield. For this investigation pairs of monozygous Holstein Friesian twins were tested as heifers and as cows by intravenous infusion of glucose, propionate and butyrate after 18 hours of feed withdrawal. Insulin, growth hormone, glucose, free fatty acids and beta-hydroxybutyrate were measured before, during and up to 4 hours after infusion of substrates. Each substrate caused a transient change in plasma concentrations of metabolites and hormones. Differences between heifers and cows are discussed with the time series of the mean concentrations. The reaction profile of each animal was characterized by different parameters. Analysis of these parameters revealed a close relation between hormones and metabolites even under the conditions of the load-test.     

Die Wirkung einer Vitamin-A-Zulage auf die Konzentration einzelner antioxidativer Komponenten und die Antioxidative Kapazität im Serum von Ponys

Einleitung
Das Plasma enthält wenige antioxidative Enzyme, ist aber reich an anderen hoch- und niedermolekularen antioxidativen Molekülen. Hier sind die Plasma-Proteine mit ihren Thiolgruppen, allen voran Albumin, zu nennen. Von den niedermolekularen Verbindungen haben Urat, Ascorbat, Thiole, Bilirubin und α-Tocopherol eine Bedeutung. Als Parameter für die oxidative Homöostase des Organismus kann die Bestimmung der antioxidativen Kapazität des Plasmas und anderer biologischer Flüssigkeiten herangezogen werden (L ewin and P opov 1994). In den letzten Jahren wurde eine Vielzahl von Methoden zur Bestimmung der Antioxidativen Kapazität von Einzelsubstanzen und biologischem Material entwickelt. Die Generation freier Radikale geschah photochemisch (P opov and L ewin 1994), chemisch oder chemisch-enzymatisch (P ascual and R omay 1992). Die antioxidative Wirkung wurde dann über Radikal-Spintrapping (S oriani et al. 1994), Fluoreszens (R-Phycoerythrin) oder Chemilumineszenz (Luminol) ermittelt.
Die genannten Verfahren haben bisher kaum Eingang in die Tiermedizin gefunden, obwohl eine Reihe metabolischer Dysfunktionen bei Haustieren mit Störungen des peroxidativen Stoffwechsels in Zusammenhang gebracht werden (F uhrmann et al. 1996; M udron et al. 1997; S allmann 1998).
Ein weiterer Aspekt der Antioxidativen Kapazität ist die bei einigen Spezies beschriebene verminderte Vitamin E-Retention bei hohen Gaben von Vitamin A (Huhn: C ombs 1976; F rigg and B roz 1983; Ratte: J enkins and M itchell 1986; Schwein: H oppe and S ch & ouml ; ner 1993). Demzufolge erhob sich die Frage, ob auch beim Pony eine überhöhte Gabe von Vitamin A die Tocopherolgehalte und damit den antioxidativen Stoffwechsel negativ beeinflußt. Dazu wurden neben einzelnen antioxidativen Komponenten die Antioxidative Kapazität des Serums mit zwei unterschiedlichen Methoden bestimmt.     

Investigations on manifestations of vitamin E and selenium deficiency in sheep and goats]

In a prospective study from 1991-1998 plasma concentrations of alpha-Tocopherole (VitE) and Selenium (Se) were analysed in 125 sheep and 32 goats with generalised motor disturbances or elevated plasma-activities of Creatine-Kinase (CK). VitE-values < 1.0 mg/l and Se-values < 0.08 mg/l were regarded as deficiency. Diagnosis of pathological manifestations was based on blood enzyme values. CK-values in plasma > 300 U/l or Aspatate-Amino-Transferase (ASAT) > 150 U/l were regarded as myopathy, Glutamat-Dehydrogenase-values > 25 U/l indicated a hepatopathy. 92 (74%) sheep and 10 (31%) goats showed VitE and/or Se deficiency. There were no principal differences in the frequencies of myopathies (67%) and hepatopathies (46%) between pure VitE deficiencies or pure Se deficiencies or combinations of both deficiencies. In VitE deficiency and in the combinations of VitE and Se deficiency the elevations of the enzyme activities were more pronounced than in Se deficiency. The lethality was significantly higher in combined VitE + Se deficiencies (73%) than in pure VitE or Se deficiencies (35%). Combined VitE + Se deficiencies occurred more frequent in lambs (53%) and was often accompanied by anaemia (29%) and hypoproteinaemia (32%). The diagnostic reliability of ASAT and GLDH for the detection of VitE and Se deficiency was better than CK. Diagnostic and therapeutic strategies in flock diseases are discussed.