Nutrient density of beverages in relation to climate impact

The food chain contributes to a substantial part of greenhouse gas (GHG) emissions and growing evidence points to the urgent need to reduce GHGs emissions worldwide. Among suggestions were proposals to alter food consumption patterns by replacing animal foods with more plant-based foods. However, the nutritional dimensions of changing consumption patterns to lower GHG emissions still remains relatively unexplored. This study is the first to estimate the composite nutrient density, expressed as percentage of Nordic Nutrition Recommendations (NNR) for 21 essential nutrients, in relation to cost in GHG emissions of the production from a life cycle perspective, expressed in grams of CO2-equivalents, using an index called the Nutrient Density to Climate Impact (NDCI) index. The NDCI index was calculated for milk, soft drink, orange juice, beer, wine, bottled carbonated water, soy drink, and oat drink. Due to low-nutrient density, the NDCI index was 0 for carbonated water, soft drink, and beer and below 0.1 for red wine and oat drink. The NDCI index was similar for orange juice (0.28) and soy drink (0.25). Due to a very high-nutrient density, the NDCI index for milk was substantially higher (0.54) than for the other beverages. Future discussion on how changes in food consumption patterns might help avert climate change need to take both GHG emission and nutrient density of foods and beverages into account

Simulation of Phosphorus, Zinc and Cadmium Mass Flow in Dairy Farming Systems

A simulation model, FARMFLOW, was developed for the calculation of phosphorus (P), zinc (Zn) and cadmium (Cd) stocks, flows and balances in different parts of a dairy farming system. The simulated continuous change in element stocks within the farming system enables evaluation of the long-term effects of management practices. The FARMFLOW model reproduces feedback mechanisms of the internal cycling of nutrients and trace elements between crops and animals on the dairy farm in feed and manure. In addition, FARMFLOW reproduces the balancing feedbacks in the system, consisting of export of elements in milk, crops and animals as well as losses from the soil system. Field data from a case study at the Swedish experimental farm Öjebyn were used to parameterise FARMFLOW. At Öjebyn, organic and conventional management practices were run in parallel over 12 years. Simulations were made over 6 crop rotations, i.e. 36 years. The simulated effects of the management practices on the stocks, flows and balances of P, Zn and Cd are presented for the organic farming system (OFS) and for the conventional farming system (CFS) at Öjebyn. The simulated field-specific element accumulation rates were mainly governed by the difference in manure application rate between the fields, arising from differences in field size, and by differences in losses between the fields, arising from differences in the initial elemental content of the fields. Simulations with increasing animal density in the two management systems showed that FARMFLOW is useful in predicting the impact of intensification on, e.g. the manure P application rates. Annual variations in mass flows, e.g. yields, and element concentrations were observed at the Öjebyn farm. In order to evaluate the impact on the element stocks, flows and balances of variations in the system, FARMFLOW was parameterised with input data including these variations. For P, the variations generated moderate variations in the farm gate P balances, and the variations did not cause a shift in the balances around the policy target of zero. For Zn, it was shown that even the highest simulated accumulation rates of the two systems did not cause soil Zn concentrations risking adverse effects on soil fertility in a 36 year perspective. For Cd, the variations can lead to up to 20% higher removal of Cd in harvested crops than average values

FARMFLOW - A dynamic model for phosphorus mass flow, simulating conventional and organic management of a Swedish dairy farm

A farm systems mass-balance calculation model, FARMFLOW, was applied to a case study comparing organic and conventional management of a Swedish experimental dairy farm, Ojebyn. Parameterisation of the model is implemented using detailed field data from the Ojebyn farm where the two management systems have been run parallel for more than 11 years. Simulations were made to compare the stocks, flows and resulting balances of phosphorus (P) in the two systems during six crop rotations (36 years). In addition, a maximum animal density scenario was tested, in order to analyse the effects of increased production intensity. Results show that FARMFLOW can be a useful tool for analysing the impact of management oil internal farm P dynamics, as well as imports and exports. The organic management results in a higher proportion of internal P flows whereas the conventional system relies more on imports of P in feed and mineral fertilisers. In both management systems, the crop rotation cause large temporal and spatial variation ill the application of manure P to the soil system. The resulting field specific soil P accumulation can indicate which fields to target with changed fertilisation management. In the maximum animal density scenario, both management systems led to an application rate of manure P ill excess of crop demands. (C) 2006 Elsevier Ltd. All rights reserved

Protein efficiency in intensive dairy production : A Swedish example

BACKGROUND: Animal agriculture has been criticised in terms of its sustainability from several perspectives. Ruminants such as dairy cows can transform inedible, low-quality protein in roughage and by-products from the food industry into the high-quality protein found in milk and meat. Evaluation of the protein conversion efficiency of dairy production from a sustainability and resource perspective must be based on the proportion of the animal feed edible to humans. A relevant metric is thus edible feed protein conversion ratio (eFPCR), i.e. human-edible protein output in cow's milk per unit human-edible protein input in feed. In this study, eFPCR was calculated for five regionally adapted and realistic feed rations fed to Swedish dairy cows producing different annual milk yields typical for high-yielding, intensive dairy production. RESULTS: All scenarios except one showed a protein efficiency ratio of >1 for human-edible protein. Thus, depending on the composition of their diet, most Swedish dairy cows can convert human-inedible protein into edible, high-value protein. However, higher milk yield led to a decrease in eFPCR, regardless of diet. CONCLUSION: Dairy cows in high-yielding, intensive production systems such as those used in Sweden have the capacity to convert low-value inedible protein into high-value edible protein. However, a minor part of the dairy cow diet is edible for humans and this fraction must be minimised to justify dairy production. These results are in line with previous findings on protein conversion efficiency and add scientific input to the debate on sustainable food systems and sustainable diets