Tasty straw pellets – Exploration of flavoured rooting material by pigs

Kauselmann K, Schrader L, Glitz B, Gallmann E, Schrade H, Krause T. Tasty straw pellets – Exploration of flavoured rooting material by pigs. Animal. 2021;15(6): 100239.Tail biting is a common problem in pigs kept in conventional fully slatted pens. Suitable enrichment materials can help to prevent the occurrence of this behavioural disorder by encouraging pigs to increase exploration behaviour. We investigated whether additional flavours can increase exploration behaviour in undocked pigs. Therefore, we offered straw pellets flavoured with either fried onion (FO), strawberry (SB), ginger, almond (AL), vanilla or without flavour (control) during rearing (eight groups in total) and fattening (16 groups in total). Flavoured pellets were offered in an altering order during intervals of 1 week in material dispensers. Exploration duration at the material dispensers was continuously recorded via an ultra-high-frequency radio-frequency identification system. Pigs were weighed weekly and their tail lengths and tail injuries were scored in four categories. For analysis, changes in tail length scores compared to the previous week were calculated as Δ-tail length. The different flavours affected pigs’ exploration durations in both rearing (factor flavour, P < 0.0001) and fattening (factor flavour, P < 0.0001). Highest exploration durations during rearing were recorded when straw pellets were flavoured with FO and AL compared to all others. During fattening, exploration duration was highest towards controls without significant difference to SB. Exploration durations additionally were affected by temporal effects, i.e. week and day during rearing (both factors: P < 0.0001) and fattening (both factors: P < 0.0001). During rearing, highest exploration durations were recorded in the first week and on the first day within week after changing the flavour of the straw pellets. During fattening, exploration durations varied between weeks and within weeks. The highest durations were recorded at the end of weeks, i.e. on the fifth and seventh days after material change. During rearing, tail injuries were affected by week (P < 0.0001). From the fourth week of rearing, the prevalence of tail injuries significantly increased. During the fattening period, tail injuries were affected by flavour (P < 0.05). Fattening pigs had fewest tail injuries after straw pellets flavoured with AL were offered. Altogether, based on the exploration durations, rearing pigs showed different preferences for the flavoured straw pellets but highly explored flavours differed between rearing and fattening pigs. Despite a weekly change of the flavour of straw pellets, exploration durations decreased during rearing but increased again in the transition between rearing and fattening. Thus, straw pellets with alternating flavours are a suitable possibility to provide environmental enrichment to pigs but will not prevent tail biting

Effect of plant-based enrichment materials on exploration in rearing and fattening pigs (Sus scrofa domesticus)

Kauselmann K, Krause T, Glitz B, Gallmann E, Schrade H, Schrader L. Effect of plant-based enrichment materials on exploration in rearing and fattening pigs (Sus scrofa domesticus). Applied Animal Behaviour Science. 2021;236: 105261.When pigs cannot perform innate species-specific behaviours (e.g. rooting or chewing), behavioural disorders, like tail biting, can occur. However, it seems that various enrichment materials enhance the pigs to perform exploration behaviour and therefore can help to reduce and prevent tail biting. The aim of this study was to identify such highly explored plant-based enrichment material for undocked pigs during rearing and fattening. Furthermore, we evaluated the impact of the offered enrichment materials on tail length and injuries. Therefore, we continuously recorded the individuals’ exploration durations in 20 groups by using an ultra-high-frequency radio-frequency identification system, installed at material dispensers. Lucerne pellets (LP), straw pellets (SP), chopped hay (CH) and chopped straw (CS) were offered in a systematically alternating order for two-week sections, respectively. At weaning and at days of material change (i.e. eight times in total), animals were weighed and scored for tail length losses and tail injuries. For analysis, the changes in tail length compared to the previous section were calculated as Δ-tail-length losses. Our study revealed that the different offered plant-based enrichment materials affected the duration of exploration behaviour (e.g. rooting, nosing or chewing) during rearing (4 groups, LME, p < 0.0001) and fattening (16 groups, LME, p < 0.0001). In piglets, exploration duration was higher for pelletized materials (LP, SP) than for chopped materials. Fattening pigs explored materials of hay (CH) more often compared to straw-based materials (CS, SP). Daily weight gains of rearing pigs were affected by the type of enrichment material offered in the respective section (LME, p < 0.0001). The highest daily weight gains were achieved when CH was offered. Exploration duration during rearing and fattening was affected by section (LME, both p < 0.0001 for rearing and fattening). Exploration duration during rearing was highest in section 4 and continuously increased from the first section to the last section during fattening. During rearing, the plant-based enrichment materials affected tail injuries (GLMM, p < 0.0001) and Δ-tail-length losses tended to be affected (GLMM, p = 0.057). Fewest tail injuries and Δ-tail-length losses occurred when SP was offered. During fattening, section affected tail injuries (GLMM, p = 0.01). Most injuries occurred during sections 1 and 2. Our results show that pigs of different ages seem to prefer different plant-based enrichment materials. High exploration durations do not necessarily maintain intact tails if material is changed biweekly. However, exploration durations can be maintained at high levels from rearing through fattening period by regularly alternating the provided plant-based enrichment materials

Short-term choice of fattening pigs for additional plant-based materials

Kauselmann K, Krause T, Glitz B, Gallmann E, Schrade H, Schrader L. Short-term choice of fattening pigs for additional plant-based materials. Applied Animal Behaviour Science. 2020: 104975