Conditionability of 'voluntary' and 'reflexive-like' behaviors, with special reference to elimination behavior: It seems promising to promote studies on latrine training in cattle

Conditionability of 'voluntary' and 'reflexive-like' behaviors, with special reference to elimination behavior in cattle. Neele Dirksen. Neuroscience & Biobehavioral Reviews. May 24 2020. https://doi.org/10.1016/j.neubiorev.2020.05.006

Highlights
• Indiscriminate excretion by cattle is a source of environmental pollution.
• No successful toilet training in cattle yet.
• Various brain centres, the ANS and the SNS are involved in the control of elimination.
• Toilet training of cattle should be possible using operant conditioning techniques.

Abstract: Typically, cattle urinate and defecate with little or no control over time and place. The resulting excreta contributes to a range of adverse effects on the environment and the animals themselves. These adverse effects could be substantially ameliorated if livestock could be toilet trained. Toilet training requires an animal to suppress impending voiding (a reflexive-like behavior), move to a latrine (voluntary behavior) and reinitiate voiding. Here, we review the neurophysiological processes and learning mechanisms regulating toileting. The suppression and initiation of voiding occur primarily via the coordinated activity of smooth and striated anal and urinary sphincter muscles. The autonomic and somatic nervous systems, along with central processes, regulate these muscles. In several mammalian species, voluntary control of the sphincters has been demonstrated using classical and/or operant conditioning. In this review, we demonstrate that the neurophysiological and behavioral regulation of voiding in cattle is likely to be similarly conditionable. The management of excreta deposition in cattle could have major benefits for reducing livestock greenhouse gas emissions and improving animal health/welfare.

Keywords: Neurophysiological control of eliminationtoilet trainingcattleclassical conditioningoperant conditioning

6. Summarizing conclusion and practical outlook

We have described the neurophysiology of voiding reflexes and have shown that there are both voluntary and involuntary responses involved in initiation and control of voiding. Regarding the conditionability of voiding, we have described how operant methodologies are mainly applicable to modifying voluntary behavior and classical methodologies are mainly applicable to changing involuntary behavior although there is potential for these to crossover. Further, we have argued that because many voluntary behaviors need to be trained in successful toileting and because involuntary behavior is also susceptible to operant conditioning, operant conditioning is likely to be the main tool for training latrine use in cattle.

For successful latrine training, animals must learn to recognize the impending need to void (Element a), withhold urination/defecation until reaching the latrine, void (Element b) and then leave the toilet.

It is well known that cattle must learn many tasks in farming systems, and these are often self-taught (or by social learning) or trained with little input from the animal carers. For example, cattle learn autonomously the location of essential resources in the living environment, and how to operate equipment such as automatic feeders, water dispensers and entry to automatic milking systems (Wechsler and Lea, 2007). Furthermore, various studies have shown that it is possible to use operant conditioning to teach cows to move reliably to a certain place after prompting with visual (Kiley-Worthington and Savage, 1978), acoustic (Kiley-Worthington and Savage, 1978; Wredle et al., 2004, 2006) or vibrational signal (Seo et al., 2002) that serve as discriminative stimuli.

Therefore, cattle have a ready propensity to learn to move to specific locations, which is an important element in training latrine use. Cattle appear to be able to learn to associate urination with a specific location (Vaughan et al., 2014a), and another study found that cattle appear to have an awareness of an association between their elimination behavior and rewards (Whistance et al., 2009). These observations mean that the second part of latrine training (voiding in a specific location) should also be achievable. In practical situations, it would be important for an animal to leave the latrine area after voiding. Leaving the toileting area is an operant response, and, therefore, it should be readily trainable, as for movement into the latrine. Although reflexes are often classically conditioned, the results with other species suggest that latrine training with operant conditioning would seem to be more promising. As continence is controlled not only by the detrusor muscle and internal (smooth muscle) urethral sphincter of the urinary bladder (both under involuntary control) but also by the external urogenital sphincter (striated muscles), which is under voluntary control (Arya and Weissbart, 2017), it is likely that operant rather than classical conditioning procedures will be more useful for latrine training. Therefore, it seems promising to promote studies on latrine training in cattle, particularly using operant conditioning methodology.

This review is mainly concerned with the feasibility of latrine training of cattle from a neurophysiological and learning theory point of view. The next obvious steps are to test the ability of cattle to learn the full latrine training process and the potential for practical implementation. To ensure ready applicability of latrine training on farms, ideally, the training should be undertaken with minimal input from the animal caretakers. One possibility would be to link remotely-detected signs of voiding initiation (e.g., changes in tail position), movement toward a latrine and voiding in a latrine with remotely activated reward presentation. A number of technologies could be utilized for such purposes including thermal imaging, machine vision and machine learning which have been used, for example, in the automated detection of parturient and other behaviors in a range of species including cattle (Miller et al. 2020; Wurtz et al., 2019) and for the automated training of rodents (e.g., Poddar et al., 2013).

If feces and urine were voided into latrines, the alleys and cubicles in the barn would much less soiled, which means that the hooves and udder would have reduced exposure to high levels of bacteria on the floor surfaces, thereby contributing to improved animal health (Santman-Berends et al., 2016; Sarjokari et al., 2013). In addition, alleys would no longer need to be cleaned as much, providing labor and cost savings (Brantas, 1968; Chapinal et al., 2013; Somers et al., 2005). Furthermore, the environmental aspect of this approach should not be forgotten. The use of latrines would help to mitigate the emission of greenhouse gases such as N2O and NH3 by making it possible to collect and separate feces and urine (van Dixhoorn et al., 2017).

We have provided solid evidence that toilet training is within the learning capacities of cattle. Our motivation for writing the review is to provide a resource to inspire researchers to explore innovative methods to reduce some of the deleterious effects of cattle farming on climate change and animal health and welfare.