Colostrum intake from birth to 24 h after the onset of parturition (T24) was estimated for 526 piglets from 40 litters. Plasma concentrations of immunoglobulin G (IgG), lactate, glucose and cortisol were determined at T24 for six piglets per litter. Plasma IgG concentration was also assayed at weaning (28 days) on the same piglets. Rectal temperature was measured at T24 on all piglets. Mortality was recorded until weaning and comparisons were made between piglets that died before weaning and those that were still alive at weaning. The piglets that died before weaning had lower birth weight, lower colostrum intake, lower weight gain between birth and T24, and had a lower rectal temperature, higher plasma cortisol concentration and lower plasma IgG and glucose concentrations at T24 than piglets still alive at weaning. In addition, a higher proportion of piglets that died before weaning had difficulty taking their first breath after birth and were affected by splayleg. Considering all piglets, colostrum intake was positively related to rectal temperature and plasma glucose concentration and negatively related to plasma cortisol concentration at T24. Plasma IgG concentration at T24 was explained by colostrum intake, IgG concentration in the ingested colostrum, birth weight and birth rank (P<0.0001). Plasma IgG concentration at weaning was related to plasma IgG concentration at T24 (r=0.54; P<0.0001) and to colostrum intake (r=0.32; P<0.0001). Finally, body weight was explained by colostrum intake, birth weight and age until 6 weeks of age (P<0.0001). These results show that colostrum intake is the main determinant of piglet survival through provision of energy and immune protection and has potential long-term effects on piglet growth and immunity.

Lameness in sows has an economic impact on pig production and is a major welfare concern. The aim of the present project was to develop methods to evaluate and quantify lameness in breeding sows. Five methods to study lameness were compared between themselves and with visual gait scoring used as a reference: footprint analysis, kinematics, accelerometers, lying-to-standing transition and foot lesion observation. Fifty sows of various parities and stages of gestation were selected using visual gait scoring and distributed into three groups: lame (L), mildly lame (ML) and non-lame (NL). They were then tested using each method. Kinematics showed that L sows had a lower walking speed than NL sows (L: 0.83 ± 0.04, NL: 0.96 ± 0.03 m/s; P < 0.05), a shorter stride length than ML sows (L: 93.0 ± 2.6, ML: 101.2 ± 1.5 cm; P < 0.05) and a longer stance time than ML and NL sows (L: 0.83 ± 0.03, ML: 0.70 ± 0.03, NL: 0.69 ± 0.02 s; P < 0.01). Accelerometer measurements revealed that L sows spent less time standing over a 24-h period (L: 6.3 ± 1.3, ML: 13.7 ± 2.4, NL: 14.5 ± 2.4%; P < 0.01), lay down earlier after feeding (L: 33.4 ± 4.6, ML: 41.7 ± 3.1, NL: 48.6 ± 2.9 min; P < 0.05) and tended to step more often during the hour following feeding (L: 10.1 ± 2.0, ML: 6.1 ± 0.5, NL: 5.4 ± 0.4 step/min standing; P = 0.06) than NL sows, with the ML sows having intermediate values. Visual observation of back posture showed that 64% of L sows had an arched back, compared with only 14% in NL sows (P = 0.02). Finally, footprint analysis and observation of lying-to-standing transition and foot lesions were not successful in detecting significant differences between L, ML and NL sows. In conclusion, several quantitative variables obtained from kinematics and accelerometers proved to be successful in identifying reliable indicators of lameness in sows. Further work is needed to relate these indicators with causes of lameness and to develop methods that can be implemented on the farm.

The emotional state can influence decision-making under ambiguity. Cognitive bias tests (CBT) proved to be a promising indicator of the affective valence of animals in a context of farm animal welfare. Although it is well-known that humans can influence the intensity of fear and reactions of animals, research on cognitive bias often focusses on housing and management conditions and neglects the role of humans on emotional states of animals. The present study aimed at investigating whether humans can modulate the emotional state of weaned piglets. Fifty-four piglets received a chronic experience with humans: gentle (GEN), rough (ROU) or minimal contact (MIN). Simultaneously, they were individually trained on a go/no-go task to discriminate a positive auditory cue, associated with food reward in a trough, from a negative one, associated with punishments (e.g. water spray). Independently of the treatment (P = 0.82), 59% of piglets completed the training. Successfully trained piglets were then subjected to CBT, including ambiguous cues in presence or absence of a human observer. As hypothesized, GEN piglets showed a positive judgement bias, as shown by their higher percentage of go responses following an ambiguous cue compared to ROU (P = 0.03) and MIN (P = 0.02) piglets, whereas ROU and MIN piglets did not differ (P > 0.10). The presence of an observer during CBT did not modulate the percentage of go responses following an ambiguous cue (P > 0.10). However, regardless of the treatment, piglets spent less time in contact with the trough following positive cues during CBT in which the observer was present than absent (P < 0.0001). This study originally demonstrates that the nature of a chronic experience with humans can induce a judgement bias indicating that the emotional state of farm animals such as piglets can be affected by the way humans interact with them.

This study aimed at validating the anatomical sites for the measurement of infrared (IR) body surface temperature as a tool to monitor the pigs’ response to handling and transport stress. The selected anatomical sites were the neck (infrared neck temperature—IRNT), rump (infrared rump temperature—IRRT), orbital (infrared orbital temperature—IROT) and behind ears (infrared behind ears temperature—IRBET) regions. A total of 120 pigs were handled from the finishing pen to the loading dock through a handling test course. Two handling types (gentle vs. rough) and number of laps (1 vs. 3) were applied according to a 2 × 2 factorial design. After loading, pigs were transported for 40 min and returned to their home pens. Animal behavior, heart rate, rectal temperature and salivary cortisol concentration were measured for validation. Increased IR body temperature, heart rate and salivary cortisol levels were observed in response to rough handling and longer distance walk (P < 0.05 for all). The greatest correlations were found between IROT and IRBET temperatures and salivary cortisol concentration at the end of the handling test (r = 0.49 and r = 0.50, respectively; P < 0.001 for both). Therefore, IR pig’s head surface temperature may be useful for a comprehensive assessment of the physiological response to handling and transport stress.

The objective was to assess sows' lameness by measuring weight distribution on limbs using a force plate made up of 4 individual platforms each resting on 4 single-ended beam load cells. The weight was recorded at an average rate of 14 readings per s over a 15 min period. Ten sows (5 lame sows and 5 sound sows) were weighed twice on 2 different days to assess the repeatability of the measure. Sixty-one sows were then selected in 2 different sites and visually scored for lameness, using a 3-point scoring system (0 = normal gait; 1 = abnormal gait, and/or stiffness; and 2 = shortened stride, and/or the sow puts less weight or avoids putting weight on 1 leg). Various measures were recorded from each sow using the force plate (percentage of weight, the ratio between the weights applied by contralateral legs, weight shifting, and amplitude of weight bearing and weight removing), kinematics (speed, stride length, swing time, stance time, foot height, and carpal and tarsal joints angle average and amplitude), and accelerometers (time spent standing during 24 h, frequency of stepping behavior during feeding, and latency to lie down after feed delivery). The within-sow CV for each measure taken from the force plate were lower than 15%, which reflects a good repeatability. Among force plate measures, only the weight shifting frequency and the ratio between the weights applied by contralateral legs differed between lameness scores. Sows that scored 2 had a higher frequency of weight shifting for fore legs (P = 0.0003) and hind legs (P = 0.0007) than sows scored 0 and 1. The ratio between the weights applied by contralateral legs decreased with the increase of lameness score for the hind limbs (P = 0.014). However, these measures also differed between sites (P < 0.01). These differences may be due to various reasons, including but not limited to genetics and housing systems. Nevertheless, the results suggest that force plate measures such as the asymmetry in the weight applied between a pair of legs and weight shifting are good indicators of lameness. Multivariate analysis on fore and hind legs showed independency between variables related to animals in movement (measures from kinematics) and variables related to static animals (measures from the force plate and accelerometers). Therefore, both static and dynamic methods need to be used to detect various lame sows.