Is the Grass Always Greener? Comparing the Environmental Impact of Conventional, Natural and Grass-Fed Beef Production Systems.

Judith L Capper

doi:10.3390/ani2020127

Abstract

Simple SummaryThe environmental impact of three beef production systems was assessed using a deterministic model. Conventional beef production (finished in feedlots with growth-enhancing technology) required the fewest animals, and least land, water and fossil fuels to produce a set quantity of beef. The carbon footprint of conventional beef production was lower than that of either natural (feedlot finished with no growth-enhancing technology) or grass-fed (forage-fed, no growth-enhancing technology) systems. All beef production systems are potentially sustainable; yet the environmental impacts of differing systems should be communicated to consumers to allow a scientific basis for dietary choices.This study compared the environmental impact of conventional, natural and grass-fed beef production systems. A deterministic model based on the metabolism and nutrient requirements of the beef population was used to quantify resource inputs and waste outputs per 1.0 × 109 kg of hot carcass weight beef in conventional (CON), natural (NAT) and grass-fed (GFD) production systems. Production systems were modeled using characteristic management practices, population dynamics and production data from U.S. beef production systems. Increased productivity (slaughter weight and growth rate) in the CON system reduced the cattle population size required to produce 1.0 × 109 kg of beef compared to the NAT or GFD system. The CON system required 56.3% of the animals, 24.8% of the water, 55.3% of the land and 71.4% of the fossil fuel energy required to produce 1.0 × 109 kg of beef compared to the GFD system. The carbon footprint per 1.0 × 109 kg of beef was lowest in the CON system (15,989 × 103 t), intermediate in the NAT system (18,772 × 103 t) and highest in the GFD system (26,785 × 103 t). The challenge to the U.S beef industry is to communicate differences in system environmental impacts to facilitate informed dietary choice.

Highlights

Sustainability is often defined as “meeting society’s present needs without compromising the ability of future generations to meet their own needs” and comprises three interlinked facets: environmental responsibility, economic viability and social acceptability [1]
The average time from birth to slaughter in the GFD system (679 d) is considered to be a conservative estimate as it is at the lower end of the range of finishing ages (671–915 d) quoted during personal communication with a grass-fed beef producer, Joel Salatin, Polyface Farm, Swoope, VA, USA, who is noted for a highly-successful forage-based system
Previous research has demonstrated that improving productivity demonstrably reduces the carbon footprint of beef production [5,47,57,58,59,60], which concurs with the results revealed by the 17.4%

Summary

Introduction

Sustainability is often defined as “meeting society’s present needs without compromising the ability of future generations to meet their own needs” and comprises three interlinked facets: environmental responsibility, economic viability and social acceptability [1] In this context, the sustainability of beef production comes under considerable scrutiny. The global beef industry will face a significant challenge in fulfilling consumer demand for meat products, using a finite resource base This issue is not confined to a future scenario—current concern over dwindling natural resources, climate change and the social acceptability of beef production practices leads to debate as to whether the U.S beef industry should continue to intensify and improve productivity to feed the increasing population, or adopt extensive production systems often perceived by consumers to have a lower environmental impact [4]

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