LAUSR

The aim of the current study was to verify the applicability of an automatic weighting method based on the support of the front legs of the pigs compared to a traditional scale. A total of 1,320 males and females crossbreed pigs [Pietrain x (Landrace x Large White)] from 110 sows were studied. Feed was offered ad libitum. All pigs were allotted to growing-fattening pens (13 pigs/pen) and individually identified by electronic ear tags. A scale with a platform to put the front legs (FLS), also equipped with an antenna to read the ear tags, was placed in each pen assembled with the feeder, weighing the pig automatically each time approached for feed. All pigs were also manually weighed with a regular scale (RS) on d 64 (entry to the fattening unit), d 90, d 111, d 140 and d 159, respectively, to compare both weighting methods. The relationship between the BW obtained by FLS and RS was analyzed by using the CORR procedure of SAS. Thereafter, a simple linear model was adjusted by using the REG procedure of SAS to predict the BW of the animals from the FLS method. The results showed a high correlation (r = 0.99; P < .0001) between the two weighting methods. Moreover, the linear model fitted (RS = -1.6799 + 1.7413 x FLS; P < .0001) presented a high R2 (0.99), low CV (4.29%) and low RMSE (2.641). Results suggest that the FLS is a good method to weight individually and automatically all the pigs of a growing-fattening unit allowing farmers to monitor the growth of their animals and to implement feeding strategies for pigs that are growing below the average (e.g. precision feeding). The benefits of animal welfare by reducing the stress associated to the over manipulation of pigs should also be considered.