Abstract

GreenFeed (GF) emission monitoring units have been extensively used in cattle, but few studies have been conducted using sheep in pastoral grazing situations. This study aimed to investigate ewe visiting behaviour in the presence of GF units and the successful collection of methane (CH₄) measurements. Commercial sheep pellets were introduced to 156 naïve two-tooth Romney ewes at an allocation of 130 g/ewe/day. From those, 76 frequent pellet consumers were selected for introduction to three GF units. Out of those, 22 (28.9%) exhibited daily visits and a good stay duration (≥2 minutes) per visit at the GF units, allowing for valid CH₄ mass flow calculations. In total, the GF units were visited an average of 42.8 ± 14.9 times daily, making 4.6 ± 1.12 visits/ewe/day by the 22 frequent users. The average duration of successful CH₄ emission measurement was 5:32 ± 3:21 minutes/visit. The calculated average total CH₄ emissions were 30.02±5.52 g/d. The study provided valuable insights into the behavioural variability and engagement levels of ewes with GF units, along with functionality and feeding aspects of the three GF units. Further, the study highlighted key challenges in training ewes and pellet consistency, which should help improve the understanding of measurement variability to support more reliable use of GF systems in grazing settings.

Weerasinghe, R.N.N., Almeida A.K., Horne D.J., Burkitt L., Kenyon P.R., and Cranston L.M.

Hamilton, Volume 85, Hamilton, 27-31, 2025