Graded supplementation of chestnut tannins to dairy cows fed protein-rich spring pasture: effects on indicators of protein utilization

An on-farm experiment was conducted in order to evaluate effects of graded supplementation with chestnut tannin extract to cows in situations of excessive dietary protein supply on a low-input organic dairy farm. Respectively 10 Swiss Fleckvieh cows received twice per day 1 kg of experimental pellets containing either 0, 50 or 100 g/kg of chestnut extract (targeted at approximately 0, 5 and 10 g extract/kg of total dietary dry matter). Experimental feeding lasted for 21 days. Measurements and collection of milk, faeces and urine spot samples were performed in weeks 0 (baseline), 1 and 3. All cows were kept in one herd on pasture; fresh grass and grass hay were provided in the barn during night. Milk yield was recorded and cows wore sensor halters for recording chewing activity. In urine, total nitrogen and purine derivatives were measured; faeces were analyzed for protein, fibre and particle fractions; in milk, solid concentrations were determined. The data was analyzed with a general linear model. Cows did not show differences in general eating and rumination behaviour, but needed time to accept the tannin-containing pellets. Milk yield and composition were not affected by treatment, except for lactose content. No relevant differences between treatments were found for urinary and faecal parameters. In conclusion, although technically easy to supplement, pellets containing chestnut tannin extract were not readily accepted by the cows and effects on protein digestion and metabolism were not found. Successful on-farm application of chestnut extract in order to improve nitrogen efficiency therefore seems questionable

Western Canadian Coal Production Optimization and Risks Characterization

The coal mining industry is an important sector of Canada\u27s economy. The cost of mining and haulage of coal in Western Canada is a major focal point when compared to inexpensive coal from Australia. Spot coal price volatility affect contractual price arrangements and this creates pressure on companies\u27 profit margins and their competitive edge. In order to alleviate this pressure, companies may have to take short-term drastic measures that may hurt their strategic positions in the long-term. Companies must also create a mix of their products to ensure effective maintenance of profit margins given various quantity and quality constraints. In this paper the authors provide extensive analysis based on detailed probabilistic production systems for coal extraction and haulage in Western Canada. An optimization model is formulated for typical coal mining operations, processing and haulage from mine sites to the Vancouver Ports using linear programming algorithm. A stochastic model is also formulated to analyze the associated risks and uncertainties. These models are validated using data from five operating mines in Western Canada with varying quantity and quality products and uncertainties. The results show that the five mines studied have to produce between 180,000 and 2.10 million tonnes of metallurgical coal and between 70,000 and 2.16 million tonnes of thermal coal to enhance their profitability given the underlying constraints. The average expected probability of success associated with production capacities from these mines is about 66%. This results in a failure probability of 36%, which is extremely high under contractual arrangements. The results also show that management\u27s profit expectation of $83 million can be achieved at a zero percent failure probability. With a higher risk of failure of 10$100.3 million

Numerical Simulation of Surface Mine Production System Using Pit Shell Simulator

Surface mine production systems involve complex, multi-faceted and costly sequence of processes that must be planned, designed and evaluated to promote well-conditioned decision processes. Strategic and tactical mine plans are used to provide a long-term production vision and the resource requirements for meeting specific periodic mine and plant capacities. the schedule and sequence of material movement must respond quickly to changing technical, safety and economic constraints within the surface mining environment. Many production planning, scheduling and resource allocation methods are based on simplistic methodologies without rigorous technical and economic basis. These methods fail to consider the random processes governing critical production variables. with increasing demand for efficient schedules for low-cost bulk production requirements, the need for efficient tools is critical. in this study, the authors develop an innovative pit shell simulator to address these problems. Rigorous geometric formulations of the ellipsoidal approximations of the pit shells geometry, their planar expansions and vertical interactions are modeled to mimic material displacement dynamics in an open pit operation. Numerical simulation techniques are used to provide solutions to the time-dependent geometric models in random multivariate states. the pit shell simulator is used to solve the Pine Valley open pit mine production schedule for the first three years of production. the simulator provides the schedule and sequence of all the cuts from various quadrants in the four pit shells within the optimised pit layout. the simulator results show that, in order to maximize the mine value, the mine must produce 304,000, 180,000 and 140,000 tonnes of ore respectively for years 1, 2 and 3. the total materials within this period also include 72,000, 80,000 and 190,000 tonnes of stockpiles and 30,000, 80,000 and 30,000 tonnes of waste materials respectively for years 1, 2 and 3. This results in a maximum NPV of $27,000 at a discount rate of 12 percent over the 3-year duration. Keywords: Surface mine production, shovel excavation, kinematics and kinetics, dynamic simulator, numerical modeling

Graded supplementation of chestnut tannins to dairy cows fed protein-rich spring pasture: effects on indicators of protein utilization

An on-farm experiment was conducted in order to evaluate effects of graded supplementation with chestnut tannin extract to cows in situations of excessive dietary protein supply on a low-input organic dairy farm. Respectively 10 Swiss Fleckvieh cows received twice per day 1 kg of experimental pellets containing either 0, 50 or 100 g/kg of chestnut extract (targeted at approximately 0, 5 and 10 g extract/kg of total dietary dry matter). Experimental feeding lasted for 21 days. Measurements and collection of milk, faeces and urine spot samples were performed in weeks 0 (baseline), 1 and 3. All cows were kept in one herd on pasture; fresh grass and grass hay were provided in the barn during night. Milk yield was recorded and cows wore sensor halters for recording chewing activity. In urine, total nitrogen and purine derivatives were measured; faeces were analyzed for protein, fibre and particle fractions; in milk, solid concentrations were determined. The data was analyzed with a general linear model. Cows did not show differences in general eating and rumination behaviour, but needed time to accept the tannin-containing pellets. Milk yield and composition were not affected by treatment, except for lactose content. No relevant differences between treatments were found for urinary and faecal parameters. In conclusion, although technically easy to supplement, pellets containing chestnut tannin extract were not readily accepted by the cows and effects on protein digestion and metabolism were not found. Successful on-farm application of chestnut extract in order to improve nitrogen efficiency therefore seems questionable.ISSN:1230-138