@conference {41278,
	title = {CowTrakker technology for improved heat detection},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {61},
	year = {2001},
	month = {Jan},
	pages = {172-175},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Devices designed to detect motion (CowTrakker{\texttrademark}, Bou-Matic, USA) were attached to Holstein-Friesian cows of either NZ or overseas origin. Animals of each strain either grazed pasture or were fed a total mixed ration. Milk samples were collected twice weekly and progesterone content analysed to identify ovulation events. Cows had tail paint applied from 2 weeks after calving, and were observed twice daily at milking for oestrous activity. Recording continued until 6 weeks after the planned start of mating (PSM). Cows were artificially inseminated following a progesterone-based synchrony programme at PSM. CowTrakker{\texttrademark} data were analysed using four algorithms (T3/1, T3/3, T10/1 and T10/3), which varied according to the period of the rolling average used (3 or 10 days) and the standard deviations from that average (1 or 3). These measurements were related to behavioural observations and the occurrence of ovulation. There was a significant number of false positive events detected by the CowTrakker with all algorithms (sensitivity: 12.3, 46.9, 62.3 and 81.5\%; specificity: 67.1, 88.4, 95.4 and 99.0\%, for T3/1, T3/3, T10/1 and T10/3, respectively) as compared to behavioural observations alone (sensitivity: 71.6\%; specificity: 99.6\%). The CowTrakker{\texttrademark} was a useful heat detection aid, but must be used in conjunction with careful behavioural observations in order to interpret the high proportion of false positive events that are recorded.},
	issn = {1176-5283},
	author = {Verkerk GA and Claycomb RW and Taufa VK and Copeman P and Napper A and Kolver E}
}
@conference {41149,
	title = {Analysis of milk constituents by near infrared and visible light},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {60},
	year = {2000},
	month = {Jan},
	pages = {19-20},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Hamilton},
	abstract = {Herd testing, in which individual cow{\textquoteright}s production performance is measured, is infrequently carried out in New Zealand with at least a month between tests. A composite sample is collected from each cow and is analysed for fat, protein, and somatic cell count (SCC). The process is time consuming, and provides only a snapshot of these components. To create a more frequent, automated, on-farm system, sensors need to be developed that measure fat, protein, SCC, and other milk components inexpensively and easily. One potential measurement method which could be used in these devices is visible to near infrared (NIR) spectroscopy.
The industry currently uses a range of sophisticated machines (Fossomatic, Foss, Hedehusene Denmark) for the determination of milk constituents. These machines homogenise milk and use infrared (IR) spectroscopy in the wavelength range 3500-9600 nm to determine fat, protein, and lactose concentrations. SCC is determined by an integrated flow cytometer. The NIR region (1000-2500 nm) has also been successfully used to determine constituents of milk and milk products (Rudzik \& W{\"u}st, 1998). Any inexpensive, on-line sensor based on NIR spectroscopy should function without the requirement for homogenisation and use low-cost silicon photodetectors, which are sensitive from 400-1100 nm. },
	issn = {1176-5283},
	author = {Whyte DS and Kunnemeyer R and Claycomb RW}
}
