Introduction; Science And Mathematics Of Greenfeed - C-lock GreenFeed Instruction Manual

1. Introduction

1.1.

Science and Mathematics of GreenFeed

GreenFeed (TM, Patent Pending) is a system to monitor the metabolic gas composition of
animals in a cost-effective, non-intrusive way. Its design and measurement capabilities have
been initially tailored to the measurement of metabolic gases emitted from ruminants. The
system is optimized to quantitatively capture the breath of cattle and to analyze the emitted
gases for trace constituents, including methane (CH ), carbon dioxide (CO ), and
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water-vapor.
GreenFeed is an important tool for research scientists as well as for those responsible for
the husbandry of animals, especially ruminants, because it provides new data that allows
scientists and producers to monitor trace gas emissions with a high time-resolution in
near-real time, remotely from a large number of individual animals in a cost-effective and
non-intrusive way. The trace gas composition and flux rates are important because they can
reflect changes in the animal's physical and biological condition. This can lead to improved
animal health, higher feed efficiency, lower greenhouse gas (GHG) emissions, increased
production and lower costs to operators and to society.
The purpose is to attract animals to a specific location periodically throughout the day for at
least five minutes so that emitted gases can be measured at the location without interfering
with an animal's normal routine. For this purpose, an automated feeder has been developed
which will attract the animals. While the animals are at the station, air is drawn past the
animal's nose and into a collection pipe. The concentrations are analyzed in the pipe
second-by-second using a non-dispersive infrared analyzer. A flow meter is also used to
measure the pipe flow. In addition, a number of strategies have been implemented to
ensure that a uniform flow measurement and mixed sampling measurement are
obtained. Once the methane concentrations and air flow rates are known, it is possible to
calculate a mass emissions rate from the animal while it is visiting the feeder.
The mass flux of CH and CO is calculated by multiplying the measured increase in
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concentrations from ambient levels related to the animal, by the measured airflow rate, and
then applying the ideal gas laws. Also, a "capture" rate adjustment factor, as discussed
below, is applied. The correct dimensional conversion factors are also used.