The carbon footprint of young-beef cattle finishing systems in the Eastern Plains of the Orinoco River Basin of Colombia

Abstract

IntroductionPrevious research has shown increased productivity amongst sown grass pastures compared to native savanna pastures by year-round grazing for fattening of adult and young Brahman (Bos indicus)-bred cattle in the well-drained native savanna ecosystem of the Colombian Orinoquía. But there is limited information on the carbon footprint (CF) of commercial young-Brahman heifers and steers reared throughout life on well-managed Brachiaria decumbens Stapf pastures.MethodsThe present study characterized growth, lifetime enteric methane (CH4) emissions, carcass carbon dioxide equivalent (CO2-eq) CH4 efficiency intensities (i.e., emissions per kg of product), and estimated the overall CF of young cattle grazing B. decumbens pastures subject to a range of daily liveweight gains (DLWGs; 0.428 – 0.516 kg) and fattening framework (405 – 574 kg). Weaning data from seven consecutive calving seasons in a commercial Brahman breeding herd continuously grazed on B. decumbens were integrated with a Microsoft Excel® dynamic greenhouse gas emission (GHGE) simulation of stockers-yearlings, and seven fattening, and processing scenarios.ResultsThe model predicted that heifers subject to low and high DLWGs (0.428 vs 0.516 kg) and steers (0.516 kg) may be successfully fattened without supplementation assuming that animals had access to a well-managed grass pasture. Depending on the fattening strategy, kg CO2-eq CH4/kg edible protein values ranged from 66.843 to 87.488 ± 0.497 for heifers and from 69.689 to 91.291 ± 0.446 for steers.DiscussionAssuming that forage on offer is at least 1,500-2,000 kg of dry matter/ha during the rainy season, all the simulated systems showed potential for C neutrality and net-zero C emission when considering GHGEs from the soil, pasture, and animal components vs the estimated soil C capture over seven seasons. However, under a more optimistic scenario, these beef systems could accomplish substantial net gains of soil C, over the period for which field data are available. Overall, this study projects the positive impact of the design of plausible fattening strategies on grasslands for improving cattle productivity and reducing emission intensities with concomitant increases in technical efficiency.

The carbon footprint of beef production from cull cows finished on sown pastures in the savannas of the Colombian Orinoquía

“…CH4 g/day = 16.176 (± 21.087) + 0.324 (± 0.057) LW (kg) r 2 = 0.663, P < 0.0001; CV = 16.78; r.s.d = 30.82; r = 0.814, P < 0.0001 Thus, predicted CH4 emissions are consistent with the estimations of Cottle and Eckard (2018) and are also consistent with recently published reports (Ramírez-Restrepo and Ramírez-Restrepo et al, 2019a, 2020a, 2023. As expected, this allows the present results also to be comparable with other tropical cattle system values (Ku- Vera et al, 2018).…”

“…The cumulative emissions (Table 2) would justify culling cows after the third weaning as emissions subsequently increase again. The effects of this practice might be an increased number of heifers (Vera-Infanzón and Ramírez-Restrepo, 2020) for earlier breeder replacement and specialized farming systems (Ramírez-Restrepo, et al, 2023) resulting in more stable temporal emissions. Culling of older mature breeding dams should result in more efficient cow-calf operations with lower environmental impact.…”

“…The Neotropical savannas environment of the Orinoco River Basin represents 30.4% of continental Colombia (Andrade et al, 2009), and it is generally considered a major, underutilized but fragile and biodiverse land resource (Romero-Ruiz et al, 2012). This socio-cultural-rich region (Navas Ríos, 1999;Romero-Ruiz et al, 2012) is also believed to have considerable potential to satisfy increased beef demand, stock turnover efficiency, and farm profitability Ramírez-Restrepo et al, 2023) based on year-round grazing on tropical pastures.…”

“…On this basis, the preservation, reuse, and repurposing of existing databases can address new demands on science (Griffin, 2015;Murdy et al, 2015;Wyborn et al, 2015). This also applies to environmental metrics of cattle and their relationship with soil organic C (SOC) accumulation at the system level (Rao et al, 2015;Ramírez-Restrepo et al, 2019a;Ramírez-Restrepo et al, 2023). To our knowledge, there are no studies using long-term individual legacy data of cull cows between birth and slaughter regarding land use, dry matter intake (DMI), methane (CH4) emissions, and animal performance to estimate the C footprint of cull cows at the system level.…”

A dynamic simulation model to assess farm-level effects of pasture intensification strategies on beef herd outputs and carbon footprints in acid soil savannas of Eastern Colombia

“…The beef production efficiency of native savanna, even when well-managed, does not exceed 10-20 kg of liveweight gain (LWG)/ha/year, one-quarter of the value that was observed even for a degraded B. decumbens Stapf (syn. U. decumbens) pasture (Vera and Hoyos, 2019), and much less than well-managed sown pastures (Rincón Castillo et al, 2010;Ramírez-Restrepo et al, 2023). Therefore, there is an economic incentive to replace native savanna vegetation whenever feasible.…”