Does Location Matter? Investigating the Impact of Environmental Enrichment Location on the Welfare, Behavior, and Performance of Sows and Piglets in Farrowing Crates
Creators: name: Klassen, Katherine E
name: Pempek, Jessica A.
name: Erasmus, Marisa A.
name: Richert, Brian
name: Stewart, Kara
name: Horback, Kristina M.
Publisher: name: Purdue University Graduate School
Year: 2024
Subjects: classificationCode: 300306
subject: Animal welfare

description: To meet the growing demands for pork products, lactating sows are often housed in farrowing crates to reduce piglet crushing. However, the public has raised welfare concerns about farrowing crate systems due to the confinement and barren environment, which can impair social interactions between sow and piglets, change their activity levels, and alter how sows and piglets satisfy their motivated behaviors to chew and explore by oral manipulation of pen and pen mates. Barren and confined environments can result in skin abrasions caused by oral manipulations and fighting, physiological stress, inactivity, and abnormal behaviors, which can have an impact on sows’ and piglets’ welfare, productivity, and behavior. Previous work on environmental enrichments has shown promise to improve average daily gain, activity levels, stress, and behavioral repertoire. However, the majority of studies on pig environmental enrichments take place after weaning and research investigating the impact enrichments have during lactation is limited. In addition, research on maximizing the use of environmental enrichments based on the location inside the farrowing crate systems has not been conducted. To address the knowledge gaps concerning the impact of the location of environmental enrichments on the welfare, behavior, and productivity of sows and piglets in farrowing crate systems and to provide educational material on pig enrichment, this dissertation consists of two parts: Chapters 2 and 3 examine the effects of the location of environmental enrichments in farrowing crate systems on sows’ and piglet’s welfare, productivity, and behavior. Chapter 5 is an extension article on the different types of environmental enrichments and the best strategies for implementing enrichment in swine operations.In Chapter 2, sows (n = 37) and focal piglets (n = 148) were assigned to three treatment groups: SPE (both sows and piglets had access to enrichment objects), PE (only piglets had access to enrichment objects), and CON (control group with no enrichment) blocked by sow parity and genetics. Sow posture and piglet behavior during the lactation and nursery phases were observed at various times after birth and weaning. Environmental enrichments significantly influenced the behaviors of suckling piglets, reducing pig-directed and agonistic behaviors. Piglets with enrichments tended to explore the pen less and engage in more social behaviors. The location of enrichments also impacted behaviors, with higher nursing behavior observed during mid-lactation for piglets with access to enrichments (PE) and increased interaction with enrichments when they were accessible to both sows and piglets (SPE). Treatment did not affect sow postural changes or most nursery behaviors, except for walking, which increased in SPE nursery piglets compared to CON piglets. Overall, the study demonstrated positive effects of environmental enrichments on suckling piglets in farrowing crate systems, highlighting the importance of enrichment placement on nursing behaviors and enrichment interaction.In Chapter 3, the same sows and piglets were used to investigate the effects of enrichment location on the welfare (skin lesions, pressure sores, salivary cortisol, and tear stains) and performance (average daily gain and piglet crushing) of the sows and piglets. This study used the same animals that were assigned the treatment group, housing, and management practices from Chapter 2. Salivary cortisol samples were collected from sows at four time points: 24 hours after moving into farrowing crates, 24 hours after treatment group assignment, midway between moving into crates and weaning, and on the day of weaning. Pressure sores of sows were scored on days 1, 4, 7, 10, 14, and 17 after farrowing. For suckling piglets, tear stains and skin lesions were assessed on the same days, and their average daily gain (ADG) was analyzed weekly during lactation. In the nursery phase, salivary cortisol was collected from piglets on the day of weaning and days 1, 7, and 14 post-weaning, with tear stains and skin lesions measured on those days as well. Nursery ADG was analyzed from weaning to day 14 post-weaning. Results indicated that control (CON) sows were less likely to have no pressure sores compared to sows with shared (SPE) enrichments, while piglets in the enriched treatment groups (PE and SPE) had smaller tear stain areas than those in the CON group. Treatment influenced skin lesions in suckling piglets, with enriched piglets having fewer lesions in the ear and front body regions. There was no treatment effect on salivary cortisol for both sows and nursery piglets, nor did treatment affect ADG, piglet crushing, or nursery skin lesions. The provision of environmental enrichments in farrowing crates reduced pressure sores of sows, skin lesions of suckling piglets and tear stains of suckling and nursery piglets.Overall, providing environmental enrichments to suckling piglets reduced aggression, as evidenced by fewer agonistic and pig-directed behaviors, and resulted in fewer skin lesions compared to piglets without enrichments. This suggests potentially reduced stress levels in enriched piglets, indicated by smaller tear stain areas. While most behaviors and skin lesion scores showed no significant differences during the nursery phase, enriched piglets continued to have smaller tear stains. Enrichment location influenced the following: sows had fewer pressure sores, and suckling piglets interacted more with enrichments and exhibited fewer pig-directed behaviors when enrichments were accessible to both sows and piglets compared to the only piglet enriched treatment group. Piglets with access only to enrichments also performed more nursing behaviors during mid-lactation compared to the control group. Overall, the study highlights the benefits of environmental enrichments in farrowing crate systems, particularly the positive impact of enrichment location on the welfare and behavior of sows and piglets.Lastly, in Chapter 5, the extension article discusses the definition of environmental enrichment and its impact on pigs’ welfare. The article also delves into the five types of environmental enrichments (nutritional, occupational, physical, sensory, and social), providing examples of each. Additionally, the article offers five practical tips for efficiently and successfully implementing environmental enrichments in swine herds.