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.     

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.     

Long base line interferometry: a new technique

The technique of using magnetic-tape recorders and atomic frequency standards to operate two widely separated radio telescopes as a phase-coherent interferometer when the stations have no radio-frequency connecting link has been successfully tested at the National Research Council of Canada's Algonquin Radio Observatory.     

A comparison of the feeding behaviour of young broiler and layer males

The feeding patterns of young broilers were compared with those of young layers to see if any differences might explain the faster growth rate of broilers. During 5 d of observation, the broilers ate almost twice as much as the layers and gained twice as much weight. However, the broilers also converted their food more efficiently and it was thought that this accounted for their faster growth rate. Since there was no difference in the ability of the two strains to digest their food, and since any differences in basal metabolic rate between the strains were likely to be small, it was suggested that the layer strain probably expended more energy on various behavioural responses. The broilers spent half as much time feeding as the layers but ate more meals which were larger and of shorter duration than those of the layers. Although both strains showed the same daily pattern of food consumption, their patterns of feeding activity differed markedly and in general feeding activity bore little relation to food intake.     

The effect of egg formation and laying on the food and water intake of brown leghorn hens

Food and water intakes of four caged Brown Leghorn hens were studied on a daily and hourly basis in relation to egg formation. In addition the food intake of two similar hens was studied using a Skinner box which provided a more detailed record of ingestive behaviour in a non‐social situation in which social interactions might not mask the relationship between food intake and physiological needs. Food intake was greater on days on which ovulation occurred than on days during which there was neither ovulation nor oviposition. Water intake was greater on days during which ovulation occurred than on days with oviposition but no ovulation. On this latter type of day (laying day) food intake was greater than on days without ovulation and oviposition (resting day). Both food and water intakes were depressed for 1 to 2 h before oviposition, but ingestion increased during the hour of laying and remained high for 1 to 2 h.     

The rate of egg loss through internal laying

Sixty‐six Brown Leghorn pullets with laying rates of 50 to 89 per cent were found on occasion to nest without laying. A further population of 39 birds was examined for signs of ovulation after nesting‐without‐laying and 92.5 per cent of these nestings were found to have an associated ovulation. This suggests that the first population had lost about 11.6 per cent of its potential eggs through internal laying. A small number of birds derived from a commercial strain showed similar results.     

The potential of Vachellia kosiensis (Acacia kosiensis) as a dryland forestry species in terms of its water use,growth rates and resultant water-use efficiency§

The potential of the country’s numerous indigenous tree species to address challenges facing the commercial forestry industry in South Africa is under-explored. Relevant issues include the rising demand for timber and non-timber forest products due to population and economic growth, minimal available land for expanding traditional commercial forestry operations, and known streamflow reduction impacts associated with introduced plantation tree species. However, little is known about the water use and corresponding growth rates of indigenous tree species, and consequently their potential as an alternative form of forestry and sustainable resource use. In this study, the water use, growth rates and resultant water-use efficiency of Vachellia kosiensis (Acacia kosiensis) (dune sweet thorn) were quantified within a mature stand of these trees situated on rehabilitated dune mining land in the Richards Bay area of South Africa. Hourly sap flow rates were measured over a two-year period in five trees, and tree heights and stem circumferences were recorded periodically throughout the monitoring period, to derive biomass increments. Rates of growth and water use were used to calculate water-use efficiency, defined as mass of utilisable (stem) wood produced per unit of water transpired. Results were compared with similarly sampled data for introduced plantation species, including Eucalyptus, Pinus and Casuarina. Results showed that the indigenous V. kosiensis trees used less than half the water used by introduced plantation species. The growth rates of individual V. kosiensis trees were unable to compete with introduced species; however, their higher tree density nevertheless yielded a mean annual increment of 10.3 m³ ha^?1 y^?1 (7.2 t ha^?1 y^?1). Furthermore, their correspondingly low water-use rates indicated that the indigenous trees had similar biophysical water-use efficiency values compared with genetically improved introduced tree species and highlighted their potential as an attractive land-use option in appropriate locations within water-constrained or dryland areas.