Lameness and fertility of sows and gilts in randomly selected loose‐housed herds in Finland

Most gait-scoring scales for pigs have a limited number of categories, supposedly to improve repeatability. However, reducing the number of categories could lead to loss of information if the observers' discriminative capacities are underused. With a recently estimated withinherd prevalence of sow lameness of 8.8% to 16.9% in the European Union and the associated losses, the availability of reliable tools for the timely detection of initial cases warrants attention. This study investigated the intra-and inter-observer repeatability (intra-OR and inter-OR) of three gait-scoring scales for sows: a continuous 'tagged' visual analogue scale (tVAS, measured in mm), a 5-point and a 2-point ordinal scale (5P and 2P), all with the same descriptors. Veterinary medicine students (n = 108) were trained to use the scales and then asked to score 90 videos (30 per scale) of sows with normal and abnormal gait. Thirty-six videos were shown once and 18 were randomly shown three times, of which one mirrored horizontally. The students' opinions on the scales were also collected. Intra-and inter-OR were higher with the tVAS than the 2P scale (inter-OR: 0.73 v. 0.60; P < 0.05. Intra-OR: 0.80 v. 0.67; P < 0.05). Intra-OR was higher with the 5P (0.81) than the 2P scale (0.67; P < 0.05). For all three scales, repeatabilities were lower ( P < 0.05) for non-lame sows (gait score of ⩽45 mm on the tVAS) than for sows showing some signs of lameness (gait score > 45 mm). Video order (first 45 v. last 45 clips), mirroring, users' opinions on the scales, and previous declared experience in handling pigs or scoring lameness in other species had no effect on repeatabilities. Correlations between the students' and experts' scores were high (tVAS = 0.92; 5P = 0.91; 2P = 0.88) but the association for the 2P was not linear and the frequency distribution showed lower correlations for a group of students. This study confirms recent evidence that it is possible to design high-resolution gait-scoring scales that do not reduce observer repeatability. Visual gait-scoring scales with fewer than five categories are likely to entail loss of information on lameness in individual sows.

Section: Discussionmentioning

confidence: 95%

“…Recent studies estimated the prevalence of sow lameness between 8.8% and 16.9% in the European Union (Heinonen et al, 2006;KilBride et al, 2009;Heinonen et al, 2013). Sow lameness is associated with economic losses, both in terms of early removal of sows from the herd and treatment costs.…”

Section: Introductionmentioning

confidence: 99%

Comparison of the inter- and intra-observer repeatability of three gait-scoring scales for sows

Nalon

Maes

Dongen³

et al. 2014

“…Leg disorders are important problems of reproductive females all over their life and are one of the major causes for culling, especially in gilts and primiparous sows (Lucia et al, 2000). The reasons for lameness have been studied, and in many reports, OCD is the most important cause (Dewey et al, 1993;Heinonen et al, 2006). For example, about 10% of gilts and primiparous sows and 7% of multiparous sows were diagnosed lame in loose-housed herds and the clinical reason for lameness was estimated to be OCD/osteoarthritis in half of the animals (Heinonen et al, 2006).…”

Section: Reproductive Sows and Suckling Pigletsmentioning

confidence: 99%

“…The reasons for lameness have been studied, and in many reports, OCD is the most important cause (Dewey et al, 1993;Heinonen et al, 2006). For example, about 10% of gilts and primiparous sows and 7% of multiparous sows were diagnosed lame in loose-housed herds and the clinical reason for lameness was estimated to be OCD/osteoarthritis in half of the animals (Heinonen et al, 2006). Fast growth rate and local overloading in the joints may be implicated in the development of leg weakness, especially OCD (c.f.…”

Section: Reproductive Sows and Suckling Pigletsmentioning

confidence: 99%

High physiological demands in intensively raised pigs: impact on health and welfare

Prunier

Heinonen

Quesnel

2010

Self Cite

102

Genetic selection and better control of the environment of the pigs have resulted in increased production levels concerning both reproduction and growth. Such high performances imply high physiological demands that may deteriorate health and welfare. The aims of this paper are to review the physiological challenges that pigs are facing, to identify possible consequences on health and welfare, to propose ways of detecting and correcting problems whenever possible. At weaning, piglets are submitted to abrupt changes in food supply, housing and social environment. Behavioural changes and efficient adaptations of the digestive tract are critical for their health and welfare. Physiological demands to support these adaptations and risks of failure are inversely related to the age of the pigs. During fattening, modern pigs have high daily weight gain especially of lean tissue as well as elevated feed conversion rate. These high growth performances are suspected to favour stress and disease susceptibility, undesirable behaviours as well as leg weakness, but further experimental data are necessary to validate these effects and find their origin. In reproductive females, high prolificacy generates elevated foetal demands for nutrients and space that are not fully met as shown by an increased number of light piglets having difficulties to adapt successfully to the neonatal life. During lactation, sows with high milk production have high nutrient requirements leading to intense catabolism that may affect their health, welfare and future reproductive abilities.

“…In addition, lameness has an economic impact as it decreases reproduction performance, longevity, human workload and veterinary costs (Anil et al, 2005;Ringgenberg et al, 2010;Pluym et al, 2013a). The importance of lameness as a welfare and economic problem is shown by its high prevalence: 8% to 15% of sows in group housing is estimated to be lame (Heinonen et al, 2006;Kilbride et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Effect of locomotion score on sows’ performances in a feed reward collection test

Bos

Nalon

Maes

et al. 2015

Sows housed in groups have to move through their pen to fulfil their behavioural and physiological needs such as feeding and resting. In addition to causing pain and discomfort, lameness may restrict the ability of sows to fulfil such needs. The aim of our study was to investigate the extent to which the mobility of sows is affected by different degrees of lameness. Mobility was measured as the sow's willingness or capability to cover distances. Feed-restricted hybrid sows with different gait scores were subjected to a feed reward collection test in which they had to walk distances to obtain subsequent rewards. In all, 29 grouphoused sows at similar gestation stage (day 96.6 ± 7 s.d.) were visually recorded for gait and classified as non-lame, mildly lame, moderately lame or severely lame. All sows received 2.6 kg of standard commercial gestation feed per day. The test arena consisted of two feeding locations separated from each other by a Y-shaped middle barrier. Feed rewards were presented at the two feeders in turn, using both light and sound cues to signal the availability of a new feed reward. Sows were individually trained during 5 non-consecutive days for 10 min/day with increasing barrier length (range: 0 to 3.5 m) each day. After training, sows were individually tested once per day on 3 non-consecutive days with the maximum barrier length such that they had to cover 9.3 m to walk from one feeder to the other. The outcome variable was the number of rewards collected in a 15-min time span. Non-lame and mildly lame sows obtained more rewards than moderately lame and severely lame sows ( P < 0.01). However, no significant difference was found between non-lame and mildly lame sows ( P = 0.69), nor between moderately lame and severely lame sows ( P = 1.00). This feed reward collection test indicates that both moderately lame and severely lame sows are limited in their combined ability and willingness to walk, but did not reveal an effect of mild lameness on mobility. These findings suggest that moderately and more severely lame sows, but not mildly lame sows, might suffer from reduced access to valuable resources in group housing systems.