Comparison of two housing systems on behaviour and performance of fattening pigs

Figures & data

Figure 1. Construction plan for the DL pen (A) and the PG pen (B).

Table 1. Description of behaviours recorded over the study period.

Behaviour	Description
Inactive behaviours
Lie-resting	Trunk is contact with ground and no weight is supported by any limb.
Sit-resting	Body is in an upright position, with hindquarters and two forefeet contact with ground. Weight is supported by hindquarters and two forelegs.
Stand-resting	Weight is supported by four limps. No movement.
Active behaviours
Running	A rapid four-beat gait with forward movement. Lasting longer than 1 s.
Walking	A slow four-beat gait with forward movement. Lasting longer than 2 s.
Playing	Pig jumps in the air or runs back and forth in the pen doing buckjumps.
Exploring pens	Pig’s snout approaches (less than 5 cm) or digs any part of the pen. Lasting longer than 2 s.
Drinking	Pig manipulates the nipple drinker.
Elimination	Pig defaecates or urinates.
Comfort	Rolling, rubbing body on the wall or the floor, stretching body, shaking body, or yawning.
Giving social activity	Rubbing or snout-touching another pig’s body in the same pen.
Giving aggressive activity	A pig aggressively rams or thrusts other pigs with head or snout.
Abnormal behaviours
Stereotyped behaviour	Chewing with nothing in its mouth, opening its mouth to hold or bite bars of the fence, or walking back and forth in a fixed route. Lasting longer than 3 s with rhythm.
Mouth-holding/biting tail	Mouth-holding or biting another pig’s tail.
Mouth-holding/biting ear	Mouth-holding or biting another pig’s ear.

Table 2. Behaviours for pigs housed in deep litter (DL) system or playground (PG) system during the observation period (mean ± SEM).

Behaviour	DL	PG	SE
Inactive behaviour (% of total time)
Lie-resting	87.0	85.3	1.3
Sit-resting	1.6c	0.7d	1.6
Stand-resting	0.9a	1.4b	0.1
Total inactive behaviour	89.5	87.3	0.5
Active behaviour (time for each pig spent in one hour)
Running (s)	1.4	1.5	0.3
Walking (s)	58.1	46.7	3.1
Playing (s)	0.1a	0.9b	0.1
Exploring pens (s)	231.0c	178.0d	12.0
Drinking (s)	25.1a	19.2b	1.5
Elimination (s)	21.0	19.7	1.2
Comfort (s)	22.7	17.5	3.2
Giving social activity (s)	21.2c	60.4d	2.7
Giving aggressive activity (s)	0.4c	6.6d	0.4
Total active behaviour (s)	380.9	349.6	14.0
Abnormal behaviour (time for each pig spent in one hour)
Stereotyped behaviour (s)	0.1c	8.0d	0.9
Mouth-holding/biting tail (s)	0.9c	9.5d	0.6
Mouth-holding/biting ear (s)	2.3	2.6	0.5
Total abnormal behaviour (s)	3.2c	20.0d	1.5

Note: Within a row, means with different letters of ‘a’ and ‘b’ are statistically different (P < .05), while means with different letters of ‘c’ and ‘d’ are significantly different (P < .01).

Figure 2. The posture of pen exploration behaviour for pigs housed in DL pens or PG pens. The symbols of ‘*’ and ‘**’ represent P < .05 and P < .01, respectively.

Table 3. Performance of pigs housed in deep litter (DL) system or playground (PG) system during the experimental period (100–200 days of age; mean ± SEM).

Item	DL	PG
Initial body weight (kg)	20.06 ± 1.25	20.00 ± 0.81
Final body weight (kg)	77.56 ± 2.03	76.85 ± 1.71
Average daily feed intake (g/d)	1495 ± 27.20	1421 ± 37.20
Average daily gain (g/d)	573 ± 8.05	569 ± 13.20
Feed conversion efficiency	2.60 ± 0.02	2.50 ± 0.08