Assessing liveweight dynamics and production responses to nutritional level in Sarda dairy ewes through walk-over-weighing technology

In Mediterranean dairy sheep systems, seasonal feed shortages often result in periods of undernutrition, negatively affect-ing animal performance and welfare [1], particularly during lactation. Liveweight (LW) is a practical indicator of nutri-tional status and body reserve dynamics; however, conventional weighing is labour-intensive and usually performed at low frequency. Walk-over-weighing (WoW) systems integrated with electronic identification (EID) allow frequent, low-labour monitoring of individual animals and may improve the detection of nutritionally driven LW changes [2].This study evaluated the sensitivity of a WoW system to detect moderate LW changes associated with contrasting nutri-tional levels in Sarda dairy ewes managed indoors or at pasture. Two experiments were conducted: (i) non-lactating ewes housed indoors and subjected to a short-term nutritional challenge; and (ii) lactating ewes managed on pasture with dif-ferent daily access times and supplemented with hay and concentrate. In both experiments, ewes exposed to the lower nutritional level showed reduced LW, and the WoW system consistently detected these differences over time. Under grazing conditions during lactation, nutritional differences were also reflected in milk production indicators.Overall, automated LW monitoring through WoW technology represents a feasible approach to track LW trajectories in dairy ewes under contrasting management conditions. Integrating LW data with routinely collected production traits (e.g. milk yield and composition) may support earlier identification of nutritional shortfalls and improve decision-making in welfare-oriented management.[1] Morgan-Davies, C., Tesnière, G., Gautier, J.M., Jørgensen, G.H.M., González-García, E., Patsios, S.I., Sossidou, E.N., Keady, T.W.J., McClearn, B., Kenyon, F., Caja, G., Grøva, L., Decandia, M., Cziszter, L., Halachmi, I., Dwyer, C.M., 2024. Review: Exploring the use of preci-sion livestock farming for small ruminant welfare management. Animal 18(S2), 101233. https://doi.org/10.1016/j.animal.2024.101233A[2] González-García, E., Alhamada, M., Nascimento, H., Portes, D., Bonnafe, G., Allain, C., Llach, I., Hassoun, P., Gautier, J.M., Parisot, S., 2021. Measuring liveweight changes in lactating dairy ewes by using an automated walk-over-weighing system. Journal of Dairy Science 104, 5675–5688. https://doi.org/10.3168/jds.2020-19075