Factors Influencing the Weight Gain of Piglets During the Nursing Period: Preliminary Results

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.

The results show that constitution and feed consumption of sows, birth weight; sex, and health of piglets as well as the random effect terms (sow, pen*farrowing date, and farrowing month) were significantly associated with the ADG during the nursing period (Table 1). However, as the data originate from 3 herds only, generalisation should be made with caution. The effect of genetics (boars) was not significant (NS) when month was included in the model. As age of sows and capacity of water supply for sows were not recorded for all sows, these factors were not included in the model. The effect of sow age was NS, but was confounded with the effect of weak pasterns. The effect of litter size and sow feed consumption in farrowing pens were explained by other variables in the model. There was no effect of herd on the ADG, probably because most of the variation between herds was explained by the random effect terms. This study indicates that the farmer may influence the ADG in particular by: 1) Ensuring the health of sows and piglets, 2) Maximising the feed intake in sows during lactation.

Table 1 Factors^a associated with average daily gain in the nursing period.