Signal grass (Brachiaria decumbens) is a highly productive tropical grass that is widespread through South America, Australia, Indonesia, Vanuatu and Malaysia due to its adaptation to a wide range of soil types and environments. Animal production from these B. decumbens pastures is highly variable due to sporadic outbreaks of photosensitisation associated with low growth rates of young animals, anorexia and wasting. The identification of B. decumbens toxicity through clinical signs may grossly underestimate the impact and severity of the disease. Affected animals without clinical signs have elevated serum liver enzyme concentrations resulting from blockage of the bile ducts by birefringent crystals, identified as calcium salts of steroidal saponins found in leaves and stems. The concentrations of the steroidal saponins vary through the year and within the plant. Young, green leaves contain 5-10 times the saponin concentration of mature leaves indicating that B. decumbens pastures are likely to be more toxic during sprouting and early growth. Previous exposure, selective grazing, and avoiding toxic leaves may partly explain apparent resistance of some animals to B. decumbens toxicity. Further research is needed to define growing conditions that produce elevated saponin levels and to investigate the impact of B. decumbens on rumen function.

Wheat grain was given whole (W), cracked (C) or ammonia-treated (N) as the sole diet to six steers. In Expt 1, W, C and N were given at the rate of 2-1 kg per head per day. In Expt 2, W and N were given at the rate of 7-35 kg per head twice weekly; feeding of C had to be abandoned due to frequent bloat. Dry-matter digestibility was 0-79, 0-86 and 0-88 on W, C and N in Expt 1 and 0-75 and 0-83 on W and N in Expt 2.The digestibility of neutral detergent fibre was 0-37, 0-24 and 0-57 with diets W, C and N respectively in Expt 1 and 0-27 and 0-47 with diets W and N in Expt 2.The quantity of whole grain voided in faeces (g/kg grain fed) was 122, 3 and 31 with W, C and N in Expt 1 and 136 and 51 with W and N in Expt 2. Voided grains had a lower ratio of cr-glucose : neutral detergent fibre than grains fed, which indicated partial digestion of starch. Rates of nitrogen retention (g/day) were 6-6, 9-4 and 9-8 with W, C and N in Expt 1 and 7-2 and 12-2 with W and N in Expt 2.It was concluded that ammonia-treated whole wheat grain is utilized as efficiently as cracked wheat grain when given as a sole diet to cattle and results in fewer digestive disturbances than cracked wheat grain.

The metabolisable energy (ME) requirements for maintenance and growth of entire male Bali cattle (Bos javanicus) were determined by regressing liveweight change on ME intake. Cattle were fed either a diet (DM basis) of 52.5% urea-treated rice straw plus 47.5% fresh leucaena forage (Expt 1), or fresh leucaena forage alone (Expt 2). In each experiment, liveweight change and feed intake were measured over 4 weeks, after a 1-week introductory period, and feed constituent digestibilities were measured during the final week. In Expt 1, 10 bulls between 1.5 and 3 years of age and weighing 123.7 ± 11.79 kg (mean ± s.d.) were allocated to DM intakes estimated to provide 0.75, 1.0, 1.25, 1.5, 1.75, or 2.0 times the estimated ME requirement for maintenance (based on calculations made from published CSIRO equations for tropical cattle species other than B. javanicus), with either one or two bulls per treatment. In Expt 2, the bulls were given treatments estimated to provide 0.85, 1.0, 1.4, 1.8, or 2.2 times the ME requirement for maintenance, with two bulls allocated to each treatment. The measured ME requirements for maintenance were 0.42 ± 0.369 and 0.40 ± 0.153 MJ/kg LW0.75.day (coefficient ± standard error, Expts 1 and 2, respectively). The ME requirement for ‘production’ (i.e. positive liveweight change of male Bali cattle under the specific conditions of the experiment) was calculated to be 39.2 MJ/kg liveweight gain in Expt 2. The calculated efficiency of use of dietary ME for production in Expt 2, was 0.34

Maximising student employability on graduation by ensuring they have the discipline knowledge as well as the ‘soft skills’ required by employers is an important focus of university courses. Following completion of an Agribusiness or Agricultural Science degree, many students enter the workforce in industries where they are required to run their own field trials to test new products or varieties, or to research agronomic best practise. One of the approaches highlighted in this paper is to incorporate Work Integrated Learning (WIL), including authentic assessment, into unit learning outcomes where the practical component of a unit is focused on developing industry required skills, such as field trial management, data collection, analysis and report writing, as well as embedding core discipline knowledge. Students, working in small groups, are required to run their own research field trial over a semester, having been guided to develop their research question based on a current industry issue on a pre-sown crop, identify the measurements required to answer the question, and then plan their semester. At the end of the semester, the students present their work to the class and submit a conference-style research paper. Success is measured in relation to a clear hypothesis, measurements and analysis that addresses their hypothesis, and results related to the industry issue. Anecdotal feedback from students is that they enjoy the experience and responsibility of running their own trials, are able to add a skill to their curriculum vitae, and have increased confidence in their ability when entering the industry. The aim of this paper is to present an example of unit-level WIL, including authentic assessment that contains the application of discipline skills in crop science.

Graduates from agriculture/agribusiness courses need to understand the multidisciplinary nature of agriculture, to think critically and solve problems in the role of an agricultural advisor. Producers are being exposed to new technologies developed for integration into agricultural production systems. Producers require technical support from external sources such as advisors and consultants, to identify relevant technologies, identify potential constraints of the technology and to support adoption. Information from such technologies may not be relevant to the production system, potentially resulting in information that has limited relevance. It is important that students develop an understanding of the processes used to develop predictive relationships between data generated by technology and the production system. In this study, students worked as collaborative teams, to design and implement an investigation aimed at developing prediction equations for pasture biomass using NDVI and a range of measurable agronomic parameters. The investigation provided students with the opportunity to gain an understanding of the importance and relevance of information to build prediction equations, to develop critical evaluation skills, to identify limitations to the process, propose solutions, and to work as a team to achieve the desired outcomes.