Epsilon Archive for Student Projects

Abstract

Behaviour at feeding and performance of pigs can be influenced by the design of the feeding area. Resources allocated in restricted space cause a disruption in communicative behaviour and even pigs in established hierarchies compete for feed. Therefore, a substantial amount of agonistic behaviour happens at feeders. This study investigates the effect of different numbers of feeding places on pigs’ behaviour at feeding and performance at an organic farm. Four behavioural sessions were carried out on growing-finishing pigs in groups of 130, 153, 148 and 128 from April to July 2020. Two numbers of feeding places were tested: 8 for control and 10 for treatment groups. Less agonistic behaviour and better performance were expected in the treatment groups. Seventeen types of behaviour were observed and recorded in a protocol using continuous registration at a group level and scan sampling method in 1-minute intervals. The observational area consisted of a DOMINO Pig Sort feeding system that sorts pigs according to weight to different pens as programmed. Pigs were fed ad libitum and had unlimited access to pasture. Performance and carcass data were obtained from an online database. The results showed 6.78±2.68 (SD) pigs (range 2-13) and up to 15.70±8.51 (SD) pigs (range 1-34) located in the feeding pens for the control and treatment groups, respectively. More agonistic behaviour with a significant difference in pressing (p=0.000) and pressing + bite (p=0.000) occurred in the treatment groups. Denser feeding pen occupancy and a higher frequency of lying in the treatment groups (p=0.000) resulted in crowding. Vocalization was higher (p=0.028) in the control group. Fewer pigs in the feeding pens with a combination of vocalization used as a communication tool to avoid the conflict can explain the lower occurrence of agonistic behaviour in the control group. The control group was, furthermore, more engaged in positive social interactions, such as nosing (p=0.018), tail/anal sniffing (p=0.000) and pen sniffing (p=0.000). Finally, the total space provided to each pig in the feeding area might have had a greater effect on the expressed behaviour than the number of feeding places. No significant differences were seen in the growth rate and feed efficiency despite the varying frequency of agonistic behaviour. The treatment group consumed more feed (p=0.021) and its carcass quality (lean meat percentage) improved (p=0.025). The treatment group spent more time grazing which might have diminished the effect of higher feed consumption on the growth rate. Moreover, an elevated level of exercise could have enhanced the deposition of lean muscles. Yet, studied literatures offer little support for this assumption, thus, more feeding places afforded the treatment group could have affected the carcass quality. Additionally, a theoretical calculation based on the time needed for a pig to consume the amount of daily feed showed that even 10 feeding places might not be enough to provide sufficient access to all pigs. The limited data (only two batches studied), confounding variables and small sample sizes in performance and carcass data make it difficult to draw any strong conclusions from this study. Considering the complexity of the DOMINO Pig Sort feeding system, the change of one attribute neither mitigated the expression of agonistic behaviour at the feeders nor improved overall performance. Additional research over a longer time with larger sample size is needed to confirm the proposed assumptions.