Agricultural greenhouse gases & the New Zealand beef & sheep sectors

Quick facts

  • Forty-nine percent of New Zealand's greenhouse gas emissions come from agriculture.
  • At the same time, more than 38% of New Zealand's merchandisable exports come from agriculture. 
  • New Zealand's beef, wool and sheep meat industries contribute eight, 27 and 75% respectively, to their world marketplaces.

What's changed in the beef & sheep sectors since 1990 in on farm practices?

Beef

  • Reduction in breeding herd numbers
  • Increased number of finishing cattle - use of dairy origin animals for finishing
  • Feed management strategies
  • Pasture management strategies

Sheep

  • Breeding and flock testing for animals with improved genetic merit (gorwth, reproduction)
  • Use of pregnancy scanning
  • Hogget mating
  • Pasture management (growth quality)
  • Optimisation of stock numbers to pasture growth

What's the impact of these on farm changes on productivity?

Beef

  • Faster growth rates
  • Increased finished weight of animal
  • Increased meat yield per hectare (kg meat/ha) 

Sheep

  • Increased lambing percentage
  • Increased number of offspring per ewe
  • Increased finished weight of animal (lamb)
  • Increased meat yield per hectare (kg meat/ha)

What's the effect of these changes on emissions intensity? 

Emissions intensity of New Zealand beef and sheep sector is lower.  For the beef sector, a great proportion of feed goes to production rather than maintenance and for the sheep sector, a lower ewe population is producing the equivalent lamb meat.

What's the latest from industry?

Beef+Lamb New Zealand Read more

On farm practice change summary tables

Beef

On farm practice Effect on farm productivity Effect on emissions intensity (net)

Reduction in breeding herd numbers

 

Increased number of finishing cattle - use of dairy origin animals for finishing 

 

Feed management strategies

 

Pasture management strategies 

Faster growth rates

 

Increased finished weight of animal

 

Increased meat yield per hectare (kg meat/ha) 

Lower

 

* A greater proportion of feed going to production rather than maintenance *


Sheep

On farm practice Effect on farm productivity Effect on emissions intensity (net)

Breeding and flock testing for animals with improved genetic merit (gorwth, reproduction)

 

Use of pregnancy scanning

 

Hogget mating

 

Pasture management (growth quality)

 

Optimisation of stock numbers to pasture growth

Increased lambing percentage 

 

Increased number of offspring per ewe

 

Increased finished weight of animal (lamb)

 

Increased meat yield per hectare (kg meat/ha) 

 

Lower

 

* Lower ewe population needed to produce equivalent lamb meat *

 

What else is being done to lower emissions on farm?

The NZAGRC is working in partnership with the PGgRc to explore options to mitigate GHGs on New Zealand farms.  An overview publication is available for download

pdf NZAGRC_PGgRC_What are we doing_ed2.pdf (17.12MB)

or you can read about our research programme

More information

Heritability estimates of methane emissions from sheep

Pinares-Patiño, C. S., Hickey, S. M., Young, E. A., Dodds, K. G., MacLean, S., Molano, G., Sandoval, E., Kjestrup, H., Harland, R., Hunt, C., Pickering, N. K. and McEwan, J. C. (2013) “Heritability estimates of methane emissions from sheep,” animal. Cambridge University Press, 7(s2), pp. 316–321. doi: 10.1017/S1751731113000864.

The objective of this study was to determine the genetic parameters of methane (CH4) emissions and their genetic correlations with key production traits. The trial measured the CH4 emissions, at 5-min intervals, from 1225 sheep placed in respiration chambers for 2 days, with repeat measurements 2 weeks later for another 2 days. They were fed in the chambers, based on live weight, a pelleted lucerne ration at 2.0 times estimated maintenance requirements. Methane outputs were calculated for g CH4/day and g CH4/kg dry matter intake (DMI) for each of the 4 days. Single trait models were used to obtain estimates of heritability and repeatability. Heritability of g CH4/day was 0.29 ± 0.05, and for g CH4/kg DMI 0.13 ± 0.03. Repeatability between measurements 14 days apart were 0.55 ± 0.02 and 0.26 ± 0.02, for the two traits. The genetic and phenotypic correlations of CH4 outputs with various production traits (weaning weight, live weight at 8 months of age, dag score, muscle depth and fleece weight at 12 months of age) measured in the first year of life, were estimated using bivariate models. With the exception of fleece weight, correlations were weak and not significantly different from zero for the g CH4/kg DMI trait. For fleece weight the phenotypic and genetic correlation estimates were −0.08 ± 0.03 and −0.32 ± 0.11 suggesting a low economically favourable relationship. These results indicate that there is genetic variation between animals for CH4 emission traits even after adjustment for feed intake and that these traits are repeatable. Current work includes the establishment of selection lines from these animals to investigate the physiological, microbial and anatomical changes, coupled with investigations into shorter and alternative CH4 emission measurement and breeding value estimation techniques; including genomic selection.

Keywords: sheep, methane, heritability, genetic correlation, global warming

Acknowledgements

This work was funded by the Pastoral Greenhouse Gas Research Consortium, Sustainable Land Management and Climate Change and the New Zealand Agricultural Greenhouse Gas Research Centre. The animals themselves were part of the Ovita partnership and the related Central Progeny Test: both funded in part or whole by Beef+Lamb New Zealand. Thanks also to the Central Progeny Test collaborating organisations: AgResearch Woodlands especially Kevin Knowler, On Farm Research especially Paul Muir, Lincoln University especially Chris Logan and AbacusBio Ltd especially Neville Jopson. The New Zealand Government in support of the Livestock Research Group of the Global Research Alliance (GRA) on Agricultural Greenhouse Gases has funded Natalie Pickering's postdoctoral fellowship.

Read more (external link)


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