Pathological lesions in swine at slaughter. VI. The relation between some mainly non-environmental factors, diseases, weight gain and carcass quality.

The influence of some diseases (lesions at slaughter) on daily weight gain and the relation between some mainly non-environmental factors and diseases, weight gain and carcass quality were studied in 12 herds running an all in/all out fattener production. The material consisted of 9800 baconers slaughtered in the period 1975–1977. The piglets were purchased when about 10 weeks old. The number of batches was 60. The investigation showed that 6 of the 12 diseases included in the analyses had a statistically significant influence on daily weight gain: pyaemia, atrophic rhinitis, severe and moderate pneumonia, tail lesion and scabies. The effect varied from a calculated reduction of 60 g in daily weight gain in pigs having atrophic rhinitis to a positive influence of 5 g/day in animals with recorded scabies lesions. It was also found that an increase in weight of marketing piglets would reduce the risk of contracting many diseases and accordingly increase the frequency of healthy animals. It also seemed possible to increase the frequencies of healthy animals by buying quality piglets. Further, quality piglets had a positive relation to weight gain and best paid carcasses (highest quality). Analyses of flock based antiparasitic treatment were inconclusive with regard to weight gain, parasitic hepatitis and scabies.