More detailed information can be retrieved from scientific papers.
As noted by Nasirahmadi et al. (2017), machine vision techniques based
on two-dimensional or three-dimensional cameras are increasingly applied to monitor cattle or pig feeding, locomotion, and aggressive or
reproductive behaviours. Specifically, as discussed by Rosell-Polo et al.
(2015), there is an interesting trend in the use of a commercial 3D
camera developed as a game interface, the Microsoft Kinect, for agricultural and livestock applications. Spoliansky et al. (2016) reported
the quantification of body condition scoring after the application of
three-dimensional cameras on cows; Kongsro (2014) reported weight
estimation results from two different pig breeds (Landrace and Duroc)
in the 20–140 kg interval based on volume information, and Jiao et al.
(2016) took advantage of the three-dimensional depth information to
enhance the collection of thermal images from pigs. Kulikov et al.
(2014) and Lee et al. (2016) reported on the application of the same
Kinect camera for tracking pigs and the automatic recognition of aggressive behaviours in commercial pigpens.