Provision of High-Quality Molasses Blocks to Improve Productivity and Address Greenhouse Gas Emissions from Smallholder Cattle and Buffalo: Studies from Lao PDR

SIMPLE SUMMARY: Urgent responses to the climate change crisis are required, with concerns that cattle and buffalo are contributing to greenhouse gas emissions, particularly in developing countries where large ruminant production is inefficient. Recent studies in Lao PDR demonstrated that ad libitum supplementation of smallholder large ruminants with high-quality molasses nutrient blocks (MNB, 20 kg) with and without anthelmintics and 8% or 10% urea, provided from Australia (Four Seasons Pty Ltd., Brisbane, Qld, Australia), significantly improved productivity, average daily gains and milk production for MNB-supplemented animals compared to controls. ‘Emissions control molasses blocks (n = 200) were then formulated and distributed to beef farmers (n = 60) and two institutional farms to obtain block consumption rates (156 g/day) and farmer acceptance data. Modelling of greenhouse gas emissions (GHGe) intensity using Intergovernmental Panel on Climate Change (IPCC) Inventory software model V 2.69 of the recently published data on use of molasses nutrient blocks demonstrated a conservative net abatement of 350 kg CO(2)e over a 200-day feeding period, whereas modelling of the Emissions control molasses blocks identified an abatement of 470 kg CO(2)e per block consumed. We conclude that provision of high-quality molasses blocks to smallholder large ruminants may achieve impressive productivity gains and inclusion of greenhouse gas reducing agents improves the likely abatement of greenhouse gases during rumen fermentation. ABSTRACT: Large ruminant production in developing countries is inefficient with low growth rates and likely high greenhouse gas emissions per unit of meat or milk produced. Trials conducted in Lao PDR from 2017 to 2020, studied ad libitum supplementation for 12 weeks with 20 kg high-quality molasses nutrient blocks (Four Seasons Pty Ltd., Brisbane, Australia), that were either non-medicated; fenbendazole-medicated (Panacur100(®), Coopers Australia, 5 g/kg); triclabendazole-medicated (Fasinex(®), Novartis Australia, 5 g/kg or 10 g/kg, respectively); or formulated with urea (8% or 10% urea, respectively). Average daily gains were determined for access to all molasses blocks and compared with access to control blocks, no supplementation, or previously determined free-grazing baseline average daily gains (55–84 g in cattle; 92–106 g in buffalo). Productivity was significantly improved following access to all molasses blocks. Average daily gains following access to 8% urea and control blocks were calculated for three age cohorts of cattle: young calves <8 m (238–298 g), growing cattle (143–214 g) and lactating cows (179–191 g). Modelling using IPCC Inventory software model V 2.69 of published data demonstrated a conservative net abatement of 350 kg CO(2)e was achievable over a 200-day feeding period. An additional trial of Emissions control blocks (n = 200) distributed to farmers (n = 60) and two educational institutions were conducted. Consumption rates (156 g/day) and farmer and institutional acceptance of these blocks were similar to our published findings with other molasses blocks, confirming all formulations of blocks improved animal productivity and body condition score, with healthier animals that were easier to manage. Modelling of changes in greenhouse gas emissions intensity identified an abatement of 470 kg CO(2)e per Emissions control blocks consumed, delivering a total project emissions abatement of 94 t CO(2)e. Provision of high-quality molasses blocks significantly improved smallholder large ruminant productivity and addition of greenhouse gas reducing agents is likely to achieve impressive abatement of greenhouse gas emissions due to improved efficiency of rumen fermentation and productivity.