AFBI Webinar presents research to support environmentally sustainable pig production

Date published: 12 November 2020

Area of Expertise:

In a recent webinar, hosted by the Agri-Food and Bioscience Institute (AFBI), research findings demonstrating the positive impact which diet can have on the nitrogen excretion and ammonia emissions for pig production were presented.

The webinar was delivered by the highly successful pig research consortium of AFBI, Devenish Nutrition Ltd, John Thompson and Sons Ltd and Preferred Capital Management. The Pig Research Consortium was first formed in 1996 and over the past 20 years it has significantly advanced our knowledge on practices to attain sustainable pig production.  It has also developed innovative solutions which have improved the efficiency of pig production while also reducing the impact of pig production on the environment.

The webinar, entitled “Nutritional Solutions to Environmental Challenges” was well attended by representatives from areas of government environmental policy and regulators as well as technical representatives from industry and advisory services.  The Webinar, and its complementary booklet, are now available on the AFBI website.

Dr Alistair Carson (DAERA Chief Scientific Advisor) introduced the webinar by providing some background to the various government policies and the environmental challenges facing Northern Ireland in terms of nitrogen loading, ammonia emissions and odour management. Dr Elizabeth Ball (AFBI’s lead pig nutrition research scientist) then overviewed the achievements of the consortium over the years to reduce nitrogen excretion through dietary means and highlighted the key questions which remained unanswered, but which would be addressed within the webinar.

The first half of the webinar focused on work investigating the impact of diet on ammonia and odour emissions.

Dr Linda Farmer (Head of Food Research in AFBI) outlined a project, co-funded between the Agri-Food Competence Centre and industry partners, on the effect of fat and fibre levels on pig odour and ammonia emissions. Linda commented that “changes in dietary fat content did not affect odour emissions from pigs or the volatile compounds that contribute to pig-house odour but that diets low in fibre content may increase some of these volatile compounds which contribute to offensive odours”. However, Dr Farmer concluded that “reducing odour is a complex problem and there is no simple solution as quite often reducing one aspect will increase another aspect associated with odour and its compounds”.

Mr Sam Smyth from John Thompson and Sons Ltd followed Linda and presented work which examined the relationship between dietary crude protein (CP) and ammonia emissions. Sam demonstrated that ammonia emissions were reduced by lowering dietary CP and for the first time, this has been quantified within the Northern Ireland context.  Sam concluded that “On average, the research supported the concept that there is a 10% reduction in ammonia emissions for every 1% unit reduction in dietary CP.  Furthermore, evidence suggested that there may be a relationship between ammonia and odour emissions, in that reducing ammonia appears to also reduce odour emissions, using the diets within the trials”.

The latter half of the webinar then focused on the implications of lower crude protein diets on pig performance. 

Dr Violet Beattie (representing Devenish Nutrition) and Dr Elizabeth Ball detailed the research findings on the balance between reducing dietary CP to reduce nitrogen excretion while also maintaining performance through the use of diet formulations  which focused on adequate levels of amino acids. Dr Beattie stressed that “Lowering dietary CP lowers nitrogen excretion but only when diets are balanced to meet the potential of the pigs”.  She continued “the separate feeding of boars and gilts on farms, with each being offered tailored diets, could achieve further reductions in nitrogen excretion”.  Dr Beattie explained that tailored diets were needed since boars have a higher potential for lean deposition than gilts and hence retain more nitrogen.

Dr Beattie and Dr Ball concluded that “for optimum performance and reduced nitrogen excretion, we recommend that boars should be offered diets containing 15% CP with balanced amino acids and gilts should be offered diets containing 13% CP with balanced amino acids from 60 kg to slaughter”.  However, looking to the future, research findings suggest that there is potential that all pigs over 60 kg could be offered 13% CP with balanced amino acids but careful consideration of the effect on performance is required.

Drs Beattie and Ball stressed that “as dietary CP is pushed down lower, a greater level of precision will be required with regard to raw material analysis as well as balancing and supplying amino acids within diets.  If this is not achieved there is real risk that on-farm growth rates will suffer which will in turn increases nitrogen excretion”. It was also concluded that diets should not be changed during the late finishing period (100kg and over) as changing diets (or phase feeding) can be detrimental to both performance and nitrogen excretion at this stage.

Dr Elizabeth Magowan, AFBI Director chaired the webinar and commented that “The research presented was a major step towards economically and environmentally sustainable pig production and I am confident that the findings of the work will be adopted widely and quickly within the industry locally, nationally and internationally due to the nature of the consortium and the publication of the results through this webinar and booklet.’  Dr Magowan also gratefully acknowledged the Department of Agriculture, Environment and Rural Affairs (DAERA) as the main funder of the work as well as the industry funders of John Thompson and Sons and Devenish Nutrition.

Notes to editors: 

AFBI is an arms-length body of DAERA delivering research and development, diagnostic and analytical testing, emergency response capability and expert scientific advice for DAERA and other government departments, public bodies and commercial companies in Northern Ireland, and further afield.

AFBI’s Vision is “Advancing the Local and Global Agri-Food Sectors Through Scientific Excellence”.

AFBI’s core areas:

  • Leading improvements in the agri-food industry;
  • Protecting animal, plant and human health;
  • Enhancing the natural and marine environment.

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