lexicon
FREN

Modelling post-farrowing body weight in sows from gestation and litter data

2026 · IFIP · eng

Regular weighing of sows during the reproductive cycle is useful to assess the relevance of feeding management. When available in commercial farms, manual scales are used when sows are moved between gestation and lactations rooms, while automatic scales are installed in collective pens in the gestation unit. Thus, body weight at farrowing usually corresponds to data collected at the latest a few days before farrowing (stage G, days after the first insemination) and provides the total BW of the sow, including reproductive compartments. In this study, modelling was considered to estimate the sow’s weight after farrowing (BWAF). Based on the literature that describes the growth of reproductive compartments, two nested models were built. The dynamic mechanistic approach allows the BWAF to be calculated from the total body weight at stage G by subtracting and adding the estimated reproductive compartments (i.e., uterus, placentas, fluids, foetuses, and mammary glands) at each stage to reflect their changes between stage G and farrowing. The first model (MOD1) estimated BWAF without accounting for maternal energy balance between stage G and farrowing, whereas the second model (MOD2) included body energy variation in maternal tissues, assuming an energy content of 8.37 MJ per kg of BW (the lowest value found in the literature for Large White x Landrace sows). The inputs were stage G, total body weight at stage G (BWG), gestation length, litter size and weight at birth, and, for MOD2, metabolizable energy (ME) supplied between stage G and farrowing calculated from the ME content of the feed and the daily ration. Models were evaluated using data collected in a demonstration farm from 1,067 sows weighed between 90 and 94 days of gestation and again within 24 hours after farrowing. Mean observed BWAF was 274 ± 40 kg. Predicted BWAF averaged 244 ± 37 kg with MOD1 and 270 ± 33 kg with MOD2. Including energy balance markedly reduced the prediction bias from 30 to 4 kg, the root mean square error of prediction from 33 to 15 kg, and the mean absolute error from 30 to 12 kg. With a 5% margin of error, the model MOD2 is accurate enough to estimate BW dynamics at herd level and support interpretation of routine BW measurements on commercial farms. However, its accuracy remains too low to allow for individual characterisation of sows in research contexts. Given genetic changes in prolificacy and body composition of sows, accuracy could be improved by updating knowledge on the growth of the reproductive compartments and on the maternal energy retention.

JSON

Source : Plateforme R&D Agricole (ACTA) — CC BY-NC-SA 4.0. Usage non commercial uniquement.