A comparison of two genotypes of finishing pig housed in outdoor paddocks straw yards and fully-slatted pens

Abstract

In a companion paper reporting on ‘indoor’ and ‘outdoor’ genotypes of finishing pigs housed in outdoor paddocks, straw yards and fully-slatted pens, materials and methods are detailed along with performance results. The aim of this experiment was to assess the welfare of progeny from both genotypes in these three finishing systems.For the 6 treatments (2 genotypes x 3 finishing systems), the welfare of each group of 20 growing-finishing pigs was measured using a combination of objective and subjective means. i)Behaviour observations - recording the numbers of animals engaged in each of 5 behaviours at 5 minute intervals for a total of 6 hours (1.5 hours per day for 4 consecutive days). This value of pig minutes was then expressed as a proportion of the total time budget.ii)Mortality / Morbidity records - recording the number of pigs that died or were noted as being diseased or injured following daily inspection, and expressing this as a mean group score.iii)Body Damage scores - at the start and end of the experiment, each animal was restrained within a weighcrate for a few moments to determine levels of body damage (cuts, bruises and scratches) and hind leg bruising of the hock region (bursitis). Using scoring systems adapted from de Koning (1985), and Smith and Smith (1990), a mean injury score was subsequently calculated for each group of animals.iv)Stomach Damage scores - the number and severity of lesions and ulcers in the pars oesophagea region of the stomach were recorded following slaughter and translated into a mean pen score using a graded scoring system (Potkins et al 1989), where 1 = normal and 6 = ulcer.