Energy Consumption on Dairy Farms: A Review of Monitoring, Prediction Modelling, and Analyses

peer-reviewedThe global consumption of dairy produce is forecasted to increase by 19% per person by 2050. However, milk production is an intense energy consuming process. Coupled with concerns related to global greenhouse gas emissions from agriculture, increasing the production of milk must be met with the sustainable use of energy resources, to ensure the future monetary and environmental sustainability of the dairy industry. This body of work focused on summarizing and reviewing dairy energy research from the monitoring, prediction modelling and analyses point of view. Total primary energy consumption values in literature ranged from 2.7 MJ kg−1 Energy Corrected Milk on organic dairy farming systems to 4.2 MJ kg−1 Energy Corrected Milk on conventional dairy farming systems. Variances in total primary energy requirements were further assessed according to whether confinement or pasture-based systems were employed. Overall, a 35% energy reduction was seen across literature due to employing a pasture-based dairy system. Compared to standard regression methods, increased prediction accuracy has been demonstrated in energy literature due to employing various machine-learning algorithms. Dairy energy prediction models have been frequently utilized throughout literature to conduct dairy energy analyses, for estimating the impact of changes to infrastructural equipment and managerial practice

Grasdrogen (een energiedienst en meer eiwit van eigen land)

A large amount of grass is produced in the Netherlands and is dried using fossil fuels such as coal. The goal of a fossil-free future with energy transition can be realized, while interest in home-grown feed sources in livestock farming is increasing. In this report, the factors affecting quality of grass and losses, energy issues, CO2-footprint and the possibilities of grass drying are discussed at two levels: i) farm scale (decentralised) and ii) regional scale (centralised). Conclusions are drawn about future gras dryers running on green energy

Dynamic energy efficiency assessment of dairy farming system in Iran : Application of window data envelopment analysis

Livestock production systems, such as dairy farming, are one of the most important contributors to resource use and if not managed well, it can be environmentally detrimental. Iranian livestock sector faces a variety of the challenges such as high costs of energy and environmental legislations as well as an increasing demand for dairy products to respond the growing population. This paper aims to contribute to the discussion on technical efficiency as a key indicator of energy use within dairy farming systems. A Window Data Envelopment Analysis (W-DEA) with energy use as inputs and milk production as output was modelled with data from 25 provinces during the last 22 years (1994–2016) in Iran. In addition, the Slack-Based Model (SBM) was used to compare the radial DEA model with non-radial SBM, both in a dynamic environment (window analysis). The average efficiency score of Iranian dairy farming production system was estimated at approximately 0.85. Through the years, three provinces including Zanjan, Ardabil and Hormozgan had the highest technical efficiencies. Window analysis represented that provinces are distinctive in terms of their technical efficiencies and energy consumption over the years. Applying the SBM model improved the accuracy of the estimated efficiency scores compared to the radial (DEA) model. Further analysis represented a significant difference between the technical efficiency of different milk production levels. Provinces that produced higher volumes of milk had lower technical efficiencies. Based on the results it can be concluded that there is a substantial space for upgrading the technical efficiency of dairy farming in Iran by improving resource use efficiency which leads to an optimized energy consumption. It is recommended to reform Iranian livestock farming policies by applying mechanized systems, optimal strategies for water, electricity and fossil fuel consumption, use of renewable energy and better feed management while enhancing milk productivity and technical efficiency. In this respect, it is suggested that policy makers consider different indicators such as energy use efficiency and environmental impacts when allocating subsidies and resources to different provinces and farms

Technical, environmental and cost-benefit assessment of manure management chain: A case study of large scale dairy farming

Improper management of livestock manure has resulted in loss of nutrients and organic matter available in manure in addition to negative environmental impacts. This study developed and compared eight manure management scenarios across their entire life cycles, rom excretion to transport to land, considering technical, environmental and economic aspects. The scenarios based on combinations of collection, sand separation, solid/liquid (S/L) separation, anaerobic digestion (AD), composting, and storage were compared. Mass balances, costs and benefits and greenhouse emissions were evaluated. The model framework was tested and validated for a large-scale dairy farm with 9000 heads of cattle and daily manure production of approximately 505 t in Iran. The study indicated that sand separation and S/L separation did not contribute to a change in manure nutrients or emissions but reduced sand, maintenance cost, and transport requirements. AD followed by separation achieved the highest emission reduction (27.7 kg CO2eq t−1) due to the avoided emissions from replacing fossil fuels by renewable energy. Composting method had the lowest costs; however it resulted in a low nutrient recovery efficiency and high nitrous oxide emission. The assessment revealed that AD is a promising management option yielding a high potential greenhouse gas savings, nutrients recovery and nitrogen availability in fertilizer for plants. In spite of the high investment costs of AD, it could be a profitable strategy due to the high subsidies paid to renewable energy projects in Iran. In conclusion, this study showed that the choice of manure treatment method has a strong influence on nutrients, profitability and greenhouse gas balances by performing sensitivity analysis. The results of this study and the application of this model further indicate the need to consider various significant impacts, farm specifications and local conditions to decide the best manure management options.</p

Composting dairy cattle feces at Indonesian small-scale dairy farmsa : results of a composting trial in Lembang Sub-District, West Java

The aim of this study was to evaluate effects of composting different ratios of fresh dairy cow feces and amendment material on the composition and the cost price of compost. To this end, mass balance, nutrients losses and the costs of composting were analysed in two composting trials with different ratios of cattle feces to dry amendment (‘postal’, i.e. broiler manure mixed with bedding material) in a practical farm and experimental farm in Lembang Sub-District, West Java, Indonesia. Results showed that composting reduced the weight of input materials and increased the dry matter content, thereby increasing the concentration of nutrients (total nitrogen (N) and phosphate (P)) in the final compost product compared to the initial mixture. Much N was lost during composting, particularly mineral N. Extending the composting period to eight weeks further increased the DM content and resulted in a more stable compost. Using more amendment material (postal) in the initial mixture or extending the composting period, however, led to a higher cost price of compost. It was concluded that reducing the amount of amendment material (postal) and shortening the length of the composting period can reduce the cost price of compost, but may affect the quality of the final compost product. Results showed larger differences between farms than between ratios of cow feces and amendment material, suggesting that compost management practices play an important role

Insights into the impact of manure on the environmental antibiotic residues and resistance pool.

The intensive use of antibiotics in the veterinary sector, linked to the application of manure-derived amendments in agriculture, translates into increased environmental levels of chemical residues, AR bacteria (ARB) and antibiotic resistance genes (ARG). The aim of this review was to evaluate the current evidence regarding the impact of animal farming and manure application on the antibiotic resistance pool in the environment. Several studies reported correlations between the prevalence of clinically relevant ARB and the amount and classes of antibiotics used in animal farming (high resistance rates being reported for medically important antibiotics such as penicillins, tetracyclines, sulfonamides and fluoroquinolones). However, the results are difficult to compare, due to the diversity of the used antimicrobials quantification techniques and to the different amounts and types of antibiotics, exhibiting various degradation times, given in animal feed in different countries. The soils fertilized with manure-derived products harbor a higher and chronic abundance of ARB, multiple ARG and an enriched associated mobilome, which is also sometimes seen in the crops grown on the amended soils. Different manure processing techniques have various efficiencies in the removal of antibiotic residues, ARB and ARGs, but there is only a small amount of data from commercial farms. The efficiency of sludge anaerobic digestion appears to be dependent on the microbial communities composition, the ARB/ARG and operating temperature (mesophilic vs. thermophilic conditions). Composting seems to reduce or eliminate most of antibiotics residues, enteric bacteria, ARB and different representative ARG in manure more rapidly and effectively than lagoon storage. Our review highlights that despite the body of research accumulated in the last years, there are still important knowledge gaps regarding the contribution of manure to the AMR emergence, accumulation, spread and risk of human exposure in countries with high clinical resistance rates. Land microbiome before and after manure application, efficiency of different manure treatment techniques in decreasing the AMR levels in the natural environments and along the food chain must be investigated in depth, covering different geographical regions and countries and using harmonized methodologies. The support of stakeholders is required for the development of specific best practices for prudent – cautious use of antibiotics on farm animals. The use of human reserve antibiotics in veterinary medicine and of unprescribed animal antimicrobials should be stopped and the use of antibiotics on farms must be limited. This integrated approach is needed to determine the optimal conditions for the removal of antibiotic residues, ARB and ARG, to formulate specific recommendations for livestock manure treatment, storage and handling procedures and to translate them into practical on-farm management decisions, to ultimately prevent exposure of human population