Up until recently, dairy farmers have been hindered in quickly detecting possible reasons for a reduction in milk production among their herd. One such reason is sub-clinical ketosis (SCK) when an affected cow appears to be well but only becomes observably under stress when SCK becomes full ketosis affecting major organs, or it could be other metabolic diseases. The only true method of detecting these abnormalities was by taking vials of the affected cow’s blood and sending samples to a lab for diagnosis. However, Bionanolab of the School of Engineering has advanced this procedure by putting the ability to diagnose a cow’s health in the hands of farmers themselves, thereby saving crucial time in detecting certain bovine metabolic irregularities, and thereby providing earlier treatment.
By detecting certain enzymes in blood, the newly developed device can pick out these biomarkers present in miniscule amounts and help identify diseases. A combination of the device’s unique composition of electrodes, a plant enzyme, and the correct amount of electric current were discovered by the Bionano research team to be the winning formula used collectively in the device known as a “Gryphsens”.
A New Tool on the Farm
Through the implementation of a hand held sensor, a dairy farmer can rapidly detect whether a cow has sub-clinical ketosis or other metabolic diseases through a small amount of blood being taken and having the sample analyzed in real-time through interfacing with the Internet by a smart phone. Such technology not only allows a dairy farmer to rapidly determine a cause for a reduction in milk production, but it also allows early detection of metabolic diseases that can then be treated, facilitating a cow to return to its normal milk volume levels in a shorter period of time. The cost saving of such early detection is substantial for small and larger dairy herds.
In the case of larger dairy herds, this Canadian invention that uses a unique electrochemical measurement of samples can be engineered for use with in-line robotic milking machines to monitor a herd individually, yet collectively, to avoid the repetitive and time-consuming method of testing each cow separately. The sensor, developed at Guelph’s Bionano laboratory of the School of Engineering by a team headed by Dr. Suresh Neethirajan is able to detect minute electrochemical activity in biological fluids that indicate biomarkers for certain irregularities and diseases. These markers flag slightly elevated levels of non-esterified fatty acids (NEFA), and a ketone prevalent in cows, β-hydroxybutyrate (BHBA), that at higher levels can both signal the early onset of ketosis and other metabolic diseases.
A Critical Time Line
Historically, the calving period is a stressful time for cows, described as a time of negative energy balance (NEB), when the onset of ketosis or other metabolic diseases are most prominent. Although the levels of NEFA and BHBA are miniscule at the beginning, early detection can reduce complications and a faster recuperation period, otherwise a later detection could lead to fatty liver, ketosis, displaced abomasum (twisted stomach), and inflammation of the uterus or a retained placenta. Dairy farmers are highly cognizant that charting a cow’s NEFA and BHBA levels is the litmus test for the animal’s overall health. One of the great advantages of testing for on-farm dairy cow diseases using our developed biosensor is that it not only significantly reduces the stress on the animals due to relying on a drop of blood instead of vials sent, but also provides instant test results.
The Lab Comes to the Barn
Traditionally, these levels are determined through expensive and lengthy tests performed in laboratories. Through electrochemistry and nanotechnology the University of Guelph’s Bionano team has made it possible for dairy farmers from all scales of operation to ascertain for themselves their herd’s health. Although humans have similar devices for measuring glucose levels for diabetes, the cow’s organism presents a further challenge by having 11 major blood groups versus four. The challenge was developing the sensor’s electrode that could simultaneously detect both NEFA and BHBA in variable metabolic conditions that can include a number of interfering components, which could alter the test results. Ability to detect multiple disease biomarkers from just a droplet of blood sample that could be used by untrained farmers is unique.
A Plant with the Answer
An issue the University of Guelph team had to surmount was the insulating property of GO that hindered the electrochemical function crucial for the biosensor. A particular enzyme from the soybean plant was integral in solving this problem and was incorporated into the dual electrodes. Although lipoxygenase is found in animal and plant species, using soybean lipoxygenase-1 (SLO) was itself a first for catalyzing direct electrochemical oxidation of NEFA in conjunction with graphene oxide nanomaterial. The result is a biosensor that has a dual function of detecting NEFA and BHBA in less than a minute on-site by the dairy farmer using a small sample of whole blood. Dairy cattle are an investment that must be kept in prime condition to maintain optimal production levels, and the Canadian biosensor is the latest tool for dairy farmers and large scale operations to monitor the health of their herds. The dual sensor can be an important part of routine screening used by farmers in the dairy barn.