Assessing the climate change impact of pig farming is a much more complex question than merely taking feed conversion ratio (FCR) as the only indicator of environmental performance according to leading Dutch livestock scientist Theun Vellinga, writes Colin Ley.
Asked by Pig World for a view on the recent DEFRA report that England’s pig sector’s climate change status had ‘deteriorated’ in the last 10 years, with FCR as the heart of the decline, Dr Vellinga said it was too simple to focus only on FCR in relation to environmental performance.
“You have to look at both feed production and feed utilisation,” he said. “You also have to optimise the whole pig production chain, including feed, and not only the pig raising/fattening process.”
Based at Wageningen University, Dr Vellinga is an experienced climate change commentator, having been part of the study team behind last year’s 170-page FAO report on ‘Greenhouse gas emissions from pig and chicken supply chains’.
“One should keep in mind that GHG emissions from pigs are based 65–70% on emissions from the upstream feed production chain and only for one third on the pig production system itself,” he said. “This is clearly shown in the FAO report.
“It is possible that GHG emissions of the feed have reduced (in England) due to the fact that the percentage of soya has decreased, while the use of other co-products has increased. Where this leads to lower digestibility within the total ration, FCR will go down. However, you need to know the details concerning the overall effect on GHG emissions per kg of live weight. It is too simple therefore to only use FCR as the only indicator for environmental performance.
“For a final answer in this debate, you should look more at the replacement for soya and what the feed effect has been.”