Nonparametric analysis of noncognitive determinants of response type, intensity, mood, and learning in donkeys (Equus asinus)

Operant conditioning and quantitative and Qualitative Behavioral Assessment synergism can provide valuable information about animals' extinction/learning and emotional status. In this study, we tested operant conditioning with 300 donkeys using six different reinforcers. Simultaneously, we studied the effects 15 animal-inherent, environment and location, and test-related factors had on the response type and intensity, mood, and extinction/learning ability variables. We sought to test three hypotheses using nonparametric categorical analyses. First, we studied which of the 15 noncognitive factors could explain the variability of the 4 behavioral variables and their explanatory power. Second, we assessed the frontal and lateral ear positions donkeys displayed when each reinforcement treatment was implemented to study the correlations between the ear position and twelve mood Qualitative Behavioral Assessment categories. Third, we assessed which reinforcement treatment was more suitable to promote donkeys' learning and welfare, studying their success rate at completing the operant conditioning test and welfare-related behavioral signs, respectively. Almost all noncognitive factors significantly affected four variables (P < 0.001), although some were not linearly correlated. Our results show that body language is as an efficient tool to report translatable information on the donkey's mood and that neutral or luring/positive reinforcement techniques promote learning and are welfare-friendly methods to modified behaviors in donkeys.