Repeatability and Predictability of Calf Feeding Behaviors—Quantifying Between- and Within-Individual Variation for Precision Livestock Farming

Abstract

Individual calves show substantial between- and within-individual variation in their feeding behavior, the existence and extent of which are not fully researched. In this study, 57,196 feeding records, collected by a computerized milk feeder from 48 pre-weaned calves over 5 weeks, were collated and analyzed for individual differences in three different feeding behaviors using a multi-level modeling approach. For each feeding behavior, we quantified behavioral variation by calculating repeatability and the coefficient of variation in predictability. Our results indicate that calves differed from each other in their average behavioral expression (behavioral type) and in their residual, within individual variation around their behavioral type (predictability). Feeding rate and total meals had the highest repeatability (>0.4) indicating that substantial, temporally stable between-individual differences exist for these behaviors. Additionally, for some behaviors (e.g., feeding rate) calves varied from more to less predictable whereas for other behaviors (e.g., meal size) calves were more homogenous in their within-individual variation around their behavioral type. Finally, we show that for individual calves, behavioral types for feeding rate and total meals were positively correlated which may suggest the existence of an underlying factor responsible for driving the (co)expression of these two behaviors. Our results highlight how the application of methods from the behavioral ecology literature can assist in improving our understanding of individual differences in calf feeding behavior. Furthermore, by uncovering consistencies between individual behavioral differences in calves, our results indicate that animal personality may play a role in driving variability in calf feeding behavior.

Personality and predictability in farmed calves using movement and space-use behaviours quantified by ultra-wideband sensors

“…For decades predictability has been considered a part of the human personality framework since it was discovered that individuals display distinct patterns of intra-individual variation in behaviours [ 29 , 53 ]. Our results add to the existing evidence that predictability is a characteristic of animal behaviour [ 18 , 19 , 28 ]. On a biological level, the variation in predictability can affect the fitness of the individuals in different ways [ 19 ].…”

“…As such, animal personality research in a farm setting conducted to date may not be widely generalizable [ 25 ], and is still lacking any analysis and quantification of rIIV. In recent years precision livestock farming—the use of sensors to gather data on the animal or in its environment—has allowed monitoring of large numbers of animals in detail and for extended periods of time [ 12 , 26 – 28 ]. This type of data provides the granularity required for the analysis of inter- and intra-individual variability in behaviour and provides the opportunity to achieve a reliable and objective measures of animal personality and predictability [ 19 , 29 ].…”

Indication of a personality trait in dairy calves and its link to weight gain through automatically collected feeding behaviours

“…A more detailed description of the farm management and protocols can be found in Carslake et al 2022 23 . For the first two days from birth, calves were fed colostrum followed by transition milk in line with farm protocols.…”

“…A meal criterion was used to group visits by the individual that were close time into the same meal 24 . In this study we used a meal criterion of 100 s for both the pair and the group housing periods as detailed in Carslake et al (2022) 23 (also see supplementary material). Therefore, if two visits to the feeder by the same calf were separated by 100 s or less, they were grouped into the same meal.…”

“…The present study examined between-individual differences of two distinct feeding behaviours, feeding rate and meal frequency, over two different contexts in 76 pre-weaned dairy calves. We chose to study feeding rate and meal frequency as these behaviours are mathematically distinct (i.e., the calculation of meal frequency is independent of feeding rate) and our previous research indicates that these behaviours are repeatable and related in pre-weaned calves 23 . The two contexts studied here were pair housing (where each pair had access to a milk feeding station) and group housing (where one milk feeding station was shared between sixteen calves).…”