Detection of Methane Eructation Peaks in Dairy Cows at a Robotic Milking Station Using Signal Processing

SIMPLE SUMMARY: The objective of this study was to investigate the use of signal processing to detect eructation peaks in methane (CH(4)) released by dairy cows during robotic milking using three gas analysers. This study showed that signal processing can be used to detect CH(4) eructations and extract spot measurements from individual cows whilst being milked. There was a reasonable correlation between the gas analysers studied. Measurement of eructations using a signal processing approach can provide a repeatable and accurate measurement of enteric CH(4) emissions from cows with different gas analysers. ABSTRACT: The aim of this study was to investigate the use of signal processing to detect eructation peaks in CH(4) released by cows during robotic milking, and to compare recordings from three gas analysers (Guardian SP and NG, and IRMAX) differing in volume of air sampled and response time. To allow comparison of gas analysers using the signal processing approach, CH(4) in air (parts per million) was measured by each analyser at the same time and continuously every second from the feed bin of a robotic milking station. Peak analysis software was used to extract maximum CH(4) amplitude (ppm) from the concentration signal during each milking. A total of 5512 CH(4) spot measurements were recorded from 65 cows during three consecutive sampling periods. Data were analysed with a linear mixed model including analyser × period, parity, and days in milk as fixed effects, and cow ID as a random effect. In period one, air sampling volume and recorded CH(4) concentration were the same for all analysers. In periods two and three, air sampling volume was increased for IRMAX, resulting in higher CH(4) concentrations recorded by IRMAX and lower concentrations recorded by Guardian SP (p < 0.001), particularly in period three, but no change in average concentrations measured by Guardian NG across periods. Measurements by Guardian SP and IRMAX had the highest correlation; Guardian SP and NG produced similar repeatability and detected more variation among cows compared with IRMAX. The findings show that signal processing can provide a reliable and accurate means to detect CH(4) eructations from animals when using different gas analysers

Reducing the Environmental Impact of Animal Production

La demanda mundial de alimentos aumentará en los próximos 30 años para satisfacer las necesidades de la creciente población. Es probable que la demanda de productos de origen animal (carne, leche y huevos) aumente a un ritmo más rápido que la demanda de cereales. Hay presión para reducir los impactos ambientales de los sistemas pecuarios, en particular las emisiones de gases de efecto invernadero (GEI) y la excreción de nitrógeno y fósforo. El principal impulsor del impacto ambiental en los sistemas animales es la eficiencia de la producción, es decir, la producción de leche, carne, huevos o contaminantes por unidad de insumo. La eficiencia de producción está relacionada con el rendimiento por animal, la tasa de reproducción y la tasa de reemplazo. Una mayor eficiencia de producción significa que se necesitan menos animales por unidad de producto, de modo que las emisiones y excreciones "improductivas" asociadas con el mantenimiento y la fase de crianza se distribuyen en más unidades de producto. La nutrición puede reducir las emisiones y las excreciones por animal. Las emisiones de metano de los rumiantes están relacionadas con la cantidad de forraje digerido, por lo que aumentar las proporciones de la dieta de los concentrados y aumentar el contenido de almidón o grasa a expensas de la fibra, reducirá el metano por unidad de producto. La selección genética para bajas emisiones de metano solo debe considerarse junto con la eficiencia de la alimentación. Las excreciones de nitrógeno y fósforo están relacionadas con el contenido de nitrógeno y fósforo en la dieta, particularmente con exceso de suministros. La formulación precisa de la dieta, el uso de requisitos proteicos degradables e indestructibles del rumen en los rumiantes y los requisitos de aminoácidos digestibles en los no rumiantes, puede reducir la excreción de nitrógeno. La reducción del contenido de fósforo en las dietas y las enzimas fitasas en las dietas no rumiantes pueden reducir la excreción de fósforo. En conclusión, la principal estrategia para reducir la huella ambiental de los sistemas pecuarios debe ser reducir el desperdicio de animales reproductores mediante el sacrificio prematuro de fertilidad y enfermedades. Esto también mejorará la rentabilidad. Por lo tanto, se necesita un enfoque de todo el sistema que considere el costo ambiental de la formulación de la dieta, así como el costo económico.Global food demand will increase in the next 30 years to meet the needs of the increasing population. Demand for animal products (meat, milk and eggs) is likely to increase at a faster rate than the demand for cereals. There is pressure to reduce the environmental impacts of livestock systems, particularly greenhouse gas emissions (GHG) and excretion of nitrogen and phosphorus. The main driver of environmental impact in animal systems is production efficiency, i.e. output of milk, meat, eggs or pollutants per unit of input. Production efficiency is related to performance per animal, reproductive rate and replacement rate. Higher production efficiency means that fewer animals are needed per unit of the product so that ‘unproductive’ emissions and excretions associated with maintenance and the rearing phase are spread over more units of product. Nutrition can reduce emissions and excretions per animal. Methane emissions by ruminants are related to the quantity of forage digested, so increasing dietary proportions of concentrates, and increasing starch or fat content at the expense of fibre will reduce methane per unit of product. Genetic selection for low methane emissions should only be considered alongside feed efficiency. Nitrogen and phosphorus excretions are related to dietary nitrogen and phosphorus contents, particularly with excess supplies. Precise diet formulation, using rumen degradable and undegradable protein requirements in ruminants, and digestible amino acid requirements in non-ruminants, can reduce nitrogen excretion. Reducing phosphorus content of diets, and phytase enzymes in non-ruminant diets can reduce phosphorus excretion. In conclusion, the main strategy for reducing the environmental footprint of livestock systems must be to reduce wastage of breeding animals through premature culling for fertility and diseases. This will also improve profitability. Therefore, a whole-system approach is needed which considers the environmental cost of diet formulation as well as economic cost

Variation in carbon footprint of milk due to management differences between Swedish dairy farms

To identify mitigation options to reduce greenhouse gas (GHG) emissions from milk production (i.e. the carbon footprint (CF) of milk), this study examined the variation in GHG emissions among dairy farms using data from previous CF studies on Swedish milk. Variation between farms in these production data, which were found to have a strong influence on milk CF were obtained from existing databases of e.g. 1051 dairy farms in Sweden in 2005. Monte Carlo analysis was used to analyse the impact of variations in seven important parameters on milk CF concerning milk yield (energy corrected milk (ECM) produced and delivered), feed dry matter intake (DMI), enteric methane emissions, N content in feed DMI, N-fertiliser rate and diesel used on farm. The largest between farm variation among the analysed production data were N-fertiliser rate (kg/ha) and diesel used (l/ha) on farm (coefficient of variation (CV) 31-38%). For the parameters concerning milk yield and feed DMI the CV was approx. 11 and 8%, respectively. The smallest variation in production data was found for N content in feed DMI. According to the Monte Carlo analysis, these variations in production data led to a variation in milk CF of between 0.94 and 1.33 kg CO2 equivalents (CO2e) per kg ECM, with an average value of 1.13 kg/CO2e kg ECM. We consider that this variation of ±17% that was found based on the used farm data would be even greater if all Swedish dairy farms were included, as the sample of farms in this study was not totally unbiased. The variation identified in milk CF indicates that a potential exists to reduce GHG emissions from milk production on both national and farm level through changes in management. As milk yield and feed DMI are two of the most influential parameters for milk CF, feed conversion efficiency (i.e. units ECM produced per unit DMI) can be used as a rough key performance indicator for predicting CF reductions. However, it must be borne in mind that feeds have different CF due to where and how they are produced

Spectroscopy of 50^{50}Sc and ab initio calculations of B(M3)B(M3) strengths

The GRIFFIN spectrometer at TRIUMF-ISAC has been used to study excited states and transitions in $^{50}$Sc following the $\beta$-decay of $^{50}$Ca. Branching ratios were determined from the measured $\gamma$-ray intensities, and angular correlations of $\gamma$ rays have been used to firmly assign the spins of excited states. The presence of an isomeric state that decays by an $M3$ transition with a $B(M3)$ strength of 13.6(7)\,W.u. has been confirmed. We compare with the first {\it ab initio} calculations of $B(M3$) strengths in light and medium-mass nuclei from the valence-space in-medium similarity renormalization group approach, using consistently derived effective Hamiltonians and $M3$ operator. The experimental data are well reproduced for isoscalar $M3$ transitions when using bare $g$-factors, but the strength of isovector $M3$ transitions are found to be underestimated by an order of magnitude

Review: More effective linkages between science and policy are needed to minimize the negative environmental impacts of livestock production

Animals form an integral part of our planetary ecosystem but balance is critical to effective ecosystem functioning as demand for livestock products has increased, greater numbers of domesticated livestock have created an imbalance and hence had a negative impact on a number of ecosystem services which means that life as we know it will become unsustainable. Policies and technology advances have helped to manage the impact but more needs to be done. The aim of this paper is to highlight ways in which better knowledge of animal science, and other disciplines, can both harness technology and inform policy to work towards a sustainable balance between livestock and the environment. Effective policies require simple, quantifiable indicators against which to set targets and monitor progress. Indicators are clear for water pollution, but more complex for biodiversity. Hence, more progress has been made with the former. It is not yet possible to measure the impacts of changes in livestock management on greenhouse gas emissions per se at a farm level and progress has been slower, although new technologies are emerging. With respect to land use, the simple indicator of area has been used, but total area is oversimplistic. Our analysis of land suitability and use highlights a relatively overlooked role of livestock in acting as a ‘buffer’ to use by-products and grains which do not meet the standards for processing by industry during years of inclement weather, which in the past has provided an ‘insurance policy’ for farmers. Since extreme weather events are increasing in frequency with climate change, this role for livestock may be more important in future. The conclusions of the review with respect to strengthening the links between research and policy are i) to encourage animal scientists to identify the relevant environmental indicators, work with the cutting edge experts developing technologies to measure these cost-effectively and across a range of relevant livestock systems and ii) to work with the feed industry to optimize diets not just in terms of least cost financially but also least ‘cost’ in terms of global carbon flux and engage in dialogue with the food industry and policy makers on regulations for grain quality

Effect of different exogenous fatty acids on the cytosolic triacylglycerol content in bovine mammary cells

The objective of this study was to determine how cytosolic triacylglycerols (TAG) are stored in mammary cells and whether this depends on the individual chemical configuration of fatty acids (FA). This objective was accomplished by addition of different FA to a FA-free medium used to culture mammary alveolar cells-large T antigen cells (MAC-T). Treatments consisted of adding FA (palmitate, stearate, oleate, linoleate, rumenic acid [CLA], elaidate and vaccinate) solutions to the medium at 100, 200, 300 and 400 mmol/L concentrations for a 24-h incubation period. At the end of each incubation period, cytosolic TAG, DNA and protein contents were measured. Palmitate, vaccenate, linoleate and CLA increased (P < 0.05) cytosolic TAG (μg/mg protein). Palmitate and CLA increased (P < 0.05) cytosolic TAG adjusted for DNA content. Overall, effects on cytosolic TAG accumulation depended on individual FA structure (chain length, degree of saturation, and number and orientation of FA double bonds). In addition, the long-chain FA used in this study did not have a detrimental effect on MAC-T cells as indicated by cytosolic protein and DNA contents reflecting their biological role in lipid accumulation