BEHAVIOURAL RESPONSE OF GROWING PIGS TO ENVIRONMENTALLY ENRICHED STY

Abstract

Pigs in their natural habitat exhibit explorative habits from which they are restricted by the modern housing systems. Environmental enrichment through provision of rootable or hanging objects for exploratory activities could improve the welfare of pigs in confinement. Information on behavioural response of growing pigs to Hanging Play Enrichment (HPE) is scanty. Therefore, effects of HPE on behavioural response of growing pigs wereassessed. Blue, knotted, open ended polyester rope and soft wood, hung at the shoulder height of pigs were used as HPE. Seven treatments: T1 (control, without enrichment), T2 (1 rope, 12 mm), T3 (2 ropes), T4 (3 ropes), T5 (1 Small Wood-SW: 40.0x4.0x4.5 cm), T6 (2 SW) and T7 (3 SW). Large White X Landrace weaner pigs (n=63) weighing 10.28±0.35 kg was allotted to the treatments, each in triplicate in a augmented factorial arrangement (2 x 3) +1 for eight weeks. Another 60 grower pigs weighing 19.14±0.35 kg was randomly allotted to five treatments: control, Large Wood (LW: 70.0x6.0x4.5 cm), Medium Wood (MW: 55x5.0x4.5 cm), SW and Composite-Wood CW: (LW+MW+SW) replicated three times and raised for six weeks. Response to Alternation and Continuous Presentation (ACP) of HPE materials (rope and MW) were evaluated using 45 matured pigs (35.02±0.40 kg) randomly allotted to five treatments: control, Rope Continuous (RC), Wood Continuous (WC), Rope+Wood Continuous (R+WC) and Rope/Wood Alternation (R/WA) for eight weeks. Behaviours were monitored hourly from 09:00-12:00 and 15:00-18:00 in three days/week using CCTV. Parameters measured were Pen-Mate Manipulation (PMM), Pen Component Manipulation (PCM) and Enrichment Use (EU) using standard procedures. Performance indices measured were Weight Gain-WG (kg) and Feed Conversion Ratio (FCR). Data were analysed using descriptive statistics, t-test and ANOVA atα0.05. The PMM ranged from 11.8±0.0% (T7) to 29.9±0.0% (T1), PCM from 13.7±0.0% (T7) to 41.1±0.1% (T1) and EU from 11.90±0.1% (T2) to 50.8±0.1% (T7). The EU was lower between 09:00-12:00 (22.9±0.0%) compared to 15:00-18:00 (24.8±0.1%). The PMM (21.1±0.1%) and PCM (28.4±0.03%) were higher between 09:00-12:00 compared to 20.9±0.2% and 26.0±0.3%, respectively at 15:00-18:00. The WG of 9.6±0.2 (T6) was significantlyhigherthan9.0±0.1(T1),7.9±0.2(T2),8.8±0.3(T3),8.8±0.2(T4),8.9±0.3(T5) and 8.8±0.2 (T7). The PMM and PCM in control were significantly higher across the treatments, while CW (33.3±0.1%) was highest for EU. The PMM (8.8±0.1%) and PCM (42.9±0.1%) were significantly higher at 09:00-12:00 hours than at 15:00-18:00 hours (7.7±0.1% and 42.0±0.0%, respectively). The WG of 9.1±0.2 (control) and 9.2±0.3 (SW)were

significantly lower than 10.5±0.2 (LW), 10.5±0.3 (MW) and 10.6±0.4 (CW). Pigs on SW (3.3±0.14) recorded highest FCR. During ACP of HPE, PMM ranged from 8.5±0.1% (R/WA) to 29.9±0.1% (control), while EUwas 0(control), 45.4±0.1% (RC), 50.5±0.1% (WC), 55.9±0.1%(R+WC)and58.5±0.1%(R/WA).At09:00-12:00and15:00-18:00hours,PMM was 15.4±0.4% and 14.3±0.0%, respectively. The WG ranged from 11.4±0.4 (RC) to 18.9±0.2 (R/WA), while FCR ranged from 3.2±0.3 (R/WA) to 4.3±0.3 (RC). Enrichment of sty with three pieces of wood, combination of different wood sizes and alternation of wood and rope reduced adverse behaviour of growing pigs.