Enteric methane emission factors and intensity of small ruminants production systems in Fiji – improved tier 1 approach

Fiji has the largest population of small ruminants across the Pacific Island Countries with a total of 37,435 sheep and 143,853 goats. Small ruminant production occupies an important socioeconomic and cultural role within Fijian society, however low productivity levels raise concerns about high emissions intensity of this sector. In addition, there is no published information about the enteric emissions of small ruminants in Fiji and possible ways it could be minimized. This work aimed to utilize the Tier II framework to estimate the greenhouse gas inventory for small ruminant production in Fiji. Data on herd/flock dynamics and animal performance from 19 sheep (n=9) and goat (n=10) farms across the Northen and Western Division of Fiji were monitored for at least one full year. At the beginning of the monitoring, all small ruminants were registered and received a unique eartag ID. Participating farmers were provided a hanging scale as well as a records booklet. Farms were visited once a month by enumerators and data related to flock numbers, liveweight births, deaths, sales/household consumption/gifts recorded. Productivity parameters (e.g. liveweight gain, lambing/kidding rate and mortality rate) were all calculated based on the farm recordings. Enteric methane emission factors were indirectly calculated based on gross energy intake estimated based on animal activity data collected on farms following IPCC 2019 methodology. Liveweight gain of young animals was modelled using a quadratic linear mixed model including age, farm, species (i.e. goat or sheep), type of birth (i.e. single, twins or triplets) and sex as fixed factors and animal as a random term. Proportional productive parameters (e.g. lambing rate, missing rate, death rate) were all calculated and compared using a generalized mixed Poisson effect model. Using the available data and literature information, total metabolic energy requirements, daily enteric methane emissions per season, and annual emissions (emission factors) for different animal classes will be calculated. Additionally, animal performance indices for goats in the country will be documented. This pioneering study in Fiji will provide the first Tier 2 enteric methane values for sheep and goats production systems, as well as estimated emission intensities. The results will contribute to improved reporting of the national livestock inventory and the development of locally appropriate mitigation strategies. Data processing and analysis are currently ongoing and will be completed in time for the GGAA 2025 conference.