FACTORS INFLUENCING THE WEIGHT GAIN OF PIGLETS DURING THE NURSING PERIOD: PRELIMINARY RESULTS M. Johansen, L. Alban, H. D. Kjærsgaard and P. Bækbo

In intensive pig production the weight of the weaned piglet has significant influence on the pig's later performance. The objective of this study is to estimate the relative impact of genetics, feeding, housing, and health factors on the weight gain during the nursing period. The study was performed as a cohort study in 3 farrow-to-finish herds. A technician visited the herds weekly and collected information on: laying behaviour of sows and piglets, hygiene in the pen, number of functional teats, adjustment of farrowing rail, capacity of water supply for sows and piglets, leg position of sows, as well as presence of inflammations, wounds, ulcers or lesions on the body or on the legs/hoofs of the sows, and forelimb skin abrasions in piglets. The observations were made in the 1st and 3rd week after farrowing for each litter. The farmer recorded: boar id, sow id, date of transfer, sow weight when entering the farrowing pen, farrowing date, sow weight at weaning, individual piglet weight at birth and at weaning, sow feed consumption in farrowing pens and on the weaning day, cross fostering, piglets weak at birth, and disease treatments of sows and piglets. Average daily weight gain (ADG) for the individual pig was used as response in a linear mixed model, where sow, pen and farrowing date were included as random effects. The significant factors were tested for interaction at sow and pig level, respectively. A total of 8,231 piglets were included in the analysis.