Factors influencing claw lesion scoring in sows.

Claw lesions have a multifactorial origin and may affect sow welfare and farm profitability. However, estimating the precise impact is hampered by several factors that interfere with the accuracy of claw lesion assessment. The objective of this study was to determine the impact of observer, scoring condition and claw cleanliness on claw lesion scoring in sows. The first experiment evaluated the impact of observer by calculating the inter- and intra-observer reliability during three test sessions using photographs. The second experiment evaluated the impact of observer, scoring condition (Feet First© chute of Zinpro Corp., "sow chute" vs. Mobile Claw Scoring Device, "MCSD"), and claw cleanliness (clean or soiled claws) on claw lesion scoring. For this experiment, 20 hybrid mid-gestating sows were hoisted up using the sow chute in which the MCSD was positioned. Lateral and medial claw digits of both hind claws were scored for heel horn erosion and separations along the heel/sole junction and white line. Scores were given by drawing a vertical bar on a 160 mm tagged visual analogue scale (tVAS); the severity of a claw lesion type was determined by measuring the distance from 0 mm. Four scores per sow were collected and analysed: clean claws × MCSD video recordings, soiled claws × MCSD video recordings, clean claws × visual scoring in a sow chute, and soiled claws × visual scoring in a sow chute. In both experiments, observer had an impact on the claw lesion scores. The inter-observer reliability was highest for overgrown dewclaws and lowest for the horizontal wall cracks (0.84 and 0.35, resp.). The highest intra-observer reliability was found for overgrown dewclaws and heel horn erosion (0.89) and lowest for vertical wall cracks (0.64). Furthermore, scoring condition and claw cleanliness influenced the scores in the second experiment and the limits of agreements were high (23.5-58.9 mm). The improved concordance correlation coefficient (iCCC) was highest for the heel horn erosion scores. In conclusion, the impact of observer seemed less relevant for claw lesion scoring; however, claw cleanliness and scoring condition were important and cannot be used interchangeably.

On-Farm Claw Scoring in Sows Using a Novel Mobile Device.

Claw lesions and lameness in sows are important problems in the industry as they impair sow welfare and result in economic losses. Available scoring techniques to detect claw lesions are all limited in terms of collecting data during all reproductive phases and recording all claws. The Mobile Claw Scoring Device (MCSD) was designed to address these limitations. After considering different practical situations and a design phase, two prototypes were constructed and tested. Improvements were incorporated into a final aluminium apparatus, consisting of two cameras with light-emitting diode (LED) lights mounted in a two-segment aluminium box and covered with laminated tempered glass plates. The operating system slides underneath the claws and takes video images. This final prototype was optimised and validated in an experiment with 20 hybrid sows, comparing scores for soiled claws using the MCSD against scores for clean claws using the Feet First© sow chute (as gold standard). Fifty percent of the scores differed between both scoring tools, with mainly medial claw digits deviating, but this seemed biologically irrelevant. The MCSD seems to be an appropriate alternative for on-farm claw scoring and is distinguishable from other claw scoring techniques; however, it needs further optimisation to improve the similarity between the two techniques.

Risk factors for development of lameness in gestating sows within the first days after moving to group housing.

Lameness in sows is an important welfare issue that is affected by housing conditions and is thought to be influenced by hierarchical fights within the first days after mixing sows in groups. A longitudinal study in 15 randomly selected herds was performed to investigate the incidence of sow lameness and possible risk factors within the first days of group housing. Each herd was visited just before and again 3-5 days after the sows were moved to group housing. The floor characteristics and dimensions of the group housing facilities were assessed. Locomotion ability, body condition, skin lesions and degree of faecal soiling were recorded for all sows. Additional information on housing and management was obtained using a questionnaire. Amongst the 810 sows included in the study, the mean lameness incidence was 13.1% (95% confidence interval 10.9-15.6%). Following binomial logistic regression analysis, sows with >10% of the body covered with faeces had an increased risk for development of lameness (odds ratio, OR = 2.33, P = 0.001). An increase in space allowance from 1.7 m2 to 3.0 m2 (OR = 0.40, P = 0.03) and of herd size from 144 to 750 sows per herd (OR = 0.71, P = 0.02) decreased the risk of development of lameness. Neither the degree of aggression, indicated by skin lesions, nor the floor characteristics influenced the development of lameness. These results indicate that sows can benefit from a larger floor area.

Impact of group housing of pregnant sows on health.

Group housing of sows during gestation is mandatory in the EU since 2013. Compared to housing in individual crates, group housing allows the animals to express normal activity and behavior. The present paper discusses the impact of group housing on health, with emphasis on lameness, aggression and possible spread of infectious diseases. The prevalence of lameness is generally higher in sows housed in group than in sows housed individually. Floor space per sow, group size, pen design and flooring are the main factors of group housing involved in lameness development. Especially floor characteristics are important, and particular attention should be paid to the type, building material and quality of the floor, hygiene and the use of bedding such as straw or rubber mats. Aggression between sows is another critical issue in group housing systems. It occurs predominantly because of competition for access to a limited resource, or to establish a social hierarchy. Key factors to prevent aggression in group housing include gradual familiarization of unfamiliar animals, sufficient space and pen structure during initial mixing, minimizing opportunities for dominant sows to steal food from subordinates, provision of a good quality floor, environmental enrichment and use of straw bedding. Very scarce evidence-based information is available on the relationship between group housing and infectious disease. Compared to individual housing, sows in group housing have more nose-to-nose contact, and they have more oral contact with feces and urine. These factors could contribute to a higher or faster transmission of pathogens, but so far, there is no evidence showing more disease problems in group housing systems. In conclusion, in group housing systems, particular attention should be paid to prevention of lameness and aggression. Management is crucial but also feeding strategies, floor and bedding, and design of housing are very important as relatively minor adjustments may exert major effects on the animals.

Lameness Detection in Dairy Cows: Part 1. How to Distinguish between Non-Lame and Lame Cows Based on Differences in Locomotion or Behavior.

Due to its detrimental effect on cow welfare, health and production, lameness in dairy cows has received quite a lot of attention in the last few decades-not only in terms of prevention and treatment of lameness but also in terms of detection, as early treatment might decrease the number of severely lame cows in the herds as well as decrease the direct and indirect costs associated with lameness cases. Generally, lame cows are detected by the herdsman, hoof trimmer or veterinarian based on abnormal locomotion, abnormal behavior or the presence of hoof lesions during routine trimming. In the scientific literature, several guidelines are proposed to detect lame cows based on visual interpretation of the locomotion of individual cows (i.e., locomotion scoring systems). Researchers and the industry have focused on automating such observations to support the farmer in finding the lame cows in their herds, but until now, such automated systems have rarely been used in commercial herds. This review starts with the description of normal locomotion of cows in order to define 'abnormal' locomotion caused by lameness. Cow locomotion (gait and posture) and behavioral features that change when a cow becomes lame are described and linked to the existing visual scoring systems. In addition, the lack of information of normal cow gait and a clear description of 'abnormal' gait are discussed. Finally, the different set-ups used during locomotion scoring and their influence on the resulting locomotion scores are evaluated.