Reducing greenhouse gas emissions of New Zealand beef through better integration of dairy and beef production

Benjamin Van Selm,Imke J.M De Boer,Stewart F Ledgard,Corina E Van Middelaar

doi:10.1016/j.agsy.2020.102936

Benjamin Van Selm, Imke J.M De Boer + Show 2 more

Open Access

https://doi.org/10.1016/j.agsy.2020.102936

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Abstract

Integrating dairy and beef production offers opportunities to reduce greenhouse gas (GHG) emissions of beef production, which is dominated by emissions related to maintenance of the breeding cow. This study aims to quantify the GHG reduction potential of the New Zealand (NZ) beef sector when replacing beef breeding cows and their calves with dairy beef animals. To this end, we combined a cattle herd model of NZ beef and dairy production with GHG emission calculations of beef production. We computed GHG emissions (to farm-gate stage) of the current amount of beef produced, while increasing the number of dairy beef calves at the expense of the number of suckler-beef calves. GHG emissions were 29% lower per kg carcass weight for dairy beef animals compared to suckler-beef animals. The average emission intensity decreased from 21.3 to 16.7 kg CO2e per kg carcass weight (−22%) as the number of suckler-beef animals declined to zero and dairy beef animals increased. Integrating dairy and beef production would enable the NZ beef sector to reduce annual GHG emissions by nearly 2000 kt CO2e (i.e. 22% of the total sector's emissions), while the dairy sector would improve their social licence to operate by reducing the number of surplus dairy calves slaughtered from 4-days old.

Highlights

The beef sector in New Zealand (NZ) has an annual production volume of 677 kilotonne of carcass weight (CW) (1st of July 201730th of June 2018), of which 83% is exported
The beef sector has not set a target yet, mitigating greenhouse gas (GHG) emissions of beef production will play an important role in meeting national targets, while ensuring the long-term survival of the beef sector
Around 60% of beef produced in NZ originates from the traditional beef sector, while the other 40% comes from culled cows and slaugh tered surplus calves from the dairy industry (Ministry for Primary Industries, 2018)

Summary

Introduction

The beef sector in New Zealand (NZ) has an annual production volume of 677 kilotonne (kt) of carcass weight (CW) (1st of July 201730th of June 2018), of which 83% is exported. It is NZ's third most important agricultural industry in terms of export revenues (Ministry for Primary Industries, 2018, 2019; Beef + Lamb New Zealand Economic Service, 2018b). To maintain its central role as an export country and limit the effects of climate change, the government has set a target to reduce all GHG emissions (excluding biogenic methane) to net zero by 2050 and to reduce bio genic methane emissions (largely from animal enteric methane) by 24 to 47% relative to 2017 before 2050 (Ministry for the Environment, 2019). Beef calves of dairy origin have a significantly lower emission intensity (kg CO2 equivalent) compared to their suckler-beef counterparts, because emissions from suckler-beef are dominated by the maintenance of the breeding cow, while in the case of dairy-based beef, those emissions are mainly attributed to milk (de Vries et al, 2015)

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