Characterisation of footpad lesions in organic and conventional broilers.

Recent data suggest that organic broilers often score worse on footpad lesions than conventional broilers but also that the current scoring of organic broiler feet may be misleading. In order to characterise footpad lesions in organic broilers, this study assessed and compared footpad lesions in a sample of 2987 conventional and 3578 organic broiler feet obtained from a large Danish abattoir during summer and winter. The feet were scored according to two scoring systems: the modified Danish surveillance scoring system and a histopathology-based new scoring system specifically developed to target the ability to differentiate between broiler feet with hyperkeratosis and ulcers. For both systems, all broiler feet with visible lesions were cross-sectionally incised. Significant differences between the two production systems were found for both scoring systems (χ2 = 710; P < 0.001 and χ2 = 247; P < 0.001 for the new and the surveillance systems, respectively), showing that a larger proportion of the organic feet compared to conventional feet - summer and winter - exhibited signs of hyperkeratosis. In addition, a smaller fraction of the organic feet than of the conventional feet were given the outermost scores, that is, normal or ulcerated; 13.4% v. 25.3% broiler feet were given score 0 for organic v. conventional production systems, respectively (χ2 = 152; P < 0.001), and 18.4% v. 23.8% feet were given score 4 for organic v. conventional production systems, respectively (χ2 = 308; P < 0.001). Thus, the results suggest that surveillance scoring systems such as the one used in Denmark are useful for the examination of footpad lesions in broilers from both types of production systems. However, the results have also raised attention to a typical characteristic of the feet of organic broilers, that is, profound hyperkeratosis, which may underlie potential misclassifications in surveillance scoring systems like the one used in Denmark. Among the possible solutions to this challenge to the correctness and fairness of the scoring system are improved procedures (such as mandatory incision), training of technicians and calibration of results (especially for the organic footpads).

Sow level risk factors for early piglet mortality and crushing in organic outdoor production.

Piglet mortality is a major problem in organic pig production affecting both farm economy and animal welfare. Knowledge is scarce on the risk factors of piglet mortality in Danish commercial organic pig production. The objectives of this study were to evaluate season, litter size, parity, sow body condition and stillborn littermates as risk factors for early piglet mortality and crushing of liveborn piglets from parturition until castration at day 3 to 5 postpartum (pp). The study was conducted over a 1-year period in nine commercial Danish organic pig herds practicing outdoor farrowing all year round. Data included recordings on 3393 farrowings with 50 284 liveborn piglets of which 14.8% died before castration. A subset of the dead piglets were collected and necropsied to identify crushed piglets. The average number of liveborn piglets per litter was 14.8 (SD=3.7) and the average time from parturition until castration was 4.1 (SD=1.7) days. A negative binomial regression analysis was used to model the effect of the predictive variables on the early piglet mortality accounting for different time periods from parturition to castration. An increase in maternal body condition score (BCS) and parity significantly increased the risk of dying between parturition and castration. Early mortality was found to be lowest during spring (March to May) and highest during summer (June to August). Being born into a litter with one or more stillborn littermates increased the risk of early mortality. The risk factors for crushing of piglets were evaluated using a logistic analysis. A significant effect of parity and litter size was found where the odds of at least one piglet in a litter with mortality was diagnosed as crushed increased with increasing parity and litter size. In conclusion, being born during summer (June to August), high parity and maternal BCS and stillborn littermates were found to be risk factors for piglet mortality between parturition and castration. In addition, parity and increasing litter size were found to be risk factors for crushing of piglets in litters with mortality.

Sow-level risk factors for stillbirth of piglets in organic sow herds.

In Danish organic pig production, one-third of total born piglets die before weaning, and stillbirth has previously crudely been estimated to account for 27% of the total preweaning mortality. The objective of this study was to evaluate season, litter size, parity and body condition of the sow as risk factors for stillbirth in nine commercial Danish organic pig herds. The study was conducted over a 1-year period, and the data included registrations on 5170 farrowings with 82 906 total born piglets. The average number of total born piglets per litter was 16.0, and the number of stillborn piglets per litter was 1.1. A significant effect of season was seen with an odds ratio for stillbirth of 1.15 during summer (May to August) compared with the remaining part of the year. A non-linear effect of litter size was seen where an increase in litter size from 11 to 16 resulted in an odds ratio of stillbirth of 1.11. An increase in litter size from 16 to 21 resulted in an odds ratio of stillbirth of 1.45. A significant interaction between body condition and parity was present. In first parity sows, an increase in body condition score from 2 (thin) to 3 (moderate) and from 3 to 4 (fat) increased the probability of stillbirth with an odds ratio of 1.23 and 1.36, respectively. In sows with parity above 4, an increase in body condition score from 2 to 3 and from 3 to 4 decreases the probability of stillbirth with an odds ratio of 0.68 and 0.79, respectively. In conclusion, increasing litter size and being born during the summer months of May to August were found to be risk factors for stillbirth. Furthermore, an interaction between body condition and parity showed that thin sows with parity above 4 had a substantially increased risk of stillbirth compared with normal and fat sows with parity above 4. In contrast, for parity 1 sows risk of stillbirth was increased in fat sows.