18th October

Algae as a new and sustainable resource in pig farming

Stefan Kraan, Ocean Harvest Technology

In 1986, Sweden imposed a general ban on the use of antibiotics in animal feed; the ban was followed in the EU in January 2006 and in the US in 2009.
 8.6aquacluture OHT edited-1

Earlier this year, the U.S. Food and Drug Administration finalised voluntary guidance for farmers on the judicious uses of antibiotics in agriculture, and asked veterinary drug makers to voluntarily phase out medically important drugs from being available over the counter Health advocates have not relented either in their call for stronger action on the issue

On 19 September 2012, a group of 150 US scientists, including the former commissioner of the FDA, issued a statement calling on the FDA and Congress to regulate the use of antibiotics in animal agriculture.

 Donald Kennedy, former FDA commissioner and president emeritus at Stanford University, said:

"There's no question that routinely administering non-therapeutic doses of antibiotics to food animals contributes to antibiotic resistance."

And he added that the FDA's current voluntary approach, which asks the animal drug industry to stop selling antibiotics that are medically important to human disease management as growth promoters in animal feed, was not enough.

The FDA’s own data shows that 80% of all anti-microbial drugs sold nationally are used in animal agriculture.  Standards for the uses of drugs and chemicals in food production, and common food-safety regulations for seafood are already high in all major import countries.

The global $80 billion shrimp industry is particularly well regulated. The EU market has strict regulations and a zero tolerance approach on residues of chemicals and antibiotics.  Increasing consumer interest in the origin and production of food and rising regulatory barriers around the word is expected to lead to significant opportunities for producers of alternative additives.

Ocean Harvest Technology has been looking at one such alternative — macroalgae or seaweed.

Antibiotic activity
Chemicals responsible for antibiotic activities are widespread in macroalgae. Interesting substances in particular are the halogenated compounds such as haloforms; halogenated alkanes and alkenes; alcohols; aldehydes; hydroquinones and ketones. The list of terpenoids with antibiotic qualities is especially long, and many of these are also halogenated.

Sterols and heterocyclic and phenolic compounds sometimes have antibiotic properties. A promising antibacterial agent is a halogenated furanone, or fimbrolide, from Delisea   — a common red alga found in the intertidal zone on the Irish coast, which has been examined for its effectiveness as an active ingredient in bacterial antifouling agents and as a possible treatment for chronic Pseudomonas aeruginosa infection.

Some common Irish brown seaweeds show strong antibacterial effects on Vibrio — a widespread bacterial infection in shrimp and fish farming. In general, seaweeds show antibacterial effects on many marine and terrestrial pathogens although the exact mechanism and possible synergies with other compounds is not understood yet.

OceanFeed-swine trials

In 2011, Ocean Harvest Technology commissioned an Irish swine research group to start feeding trials using OceanFeed-swine at different percentages of inclusion:  0.5 %, 2 %, and 5 %, and to compare the results against a reference diet using 240 pigs.

Due to current industry requirements, OHT was unable to fully replace all of the mineral and vitamin pre-mix in this particular trial. OceanFeed-swine was therefore fed in addition to conventional premixes by diluting the other ingredients. This first trial was to establish if seaweeds could be fed to pigs and what were the negative or positive effects of using seaweeds in the diet.

After a four-month trial from weaning stage to 100 kg pigs, the results showed a positive outcome of having OceanFeed incorporated at 5% in the diet on taste and intestinal health.

In respect of food conversion efficiency and weight gain, the lower inclusion level scored better than the control. 16 pigs were slaughtered at the end of the trial to examine taste and intestinal health.

In brief the following results were obtained:

  • higher weight gain (pigs fed with 0.5% at harvest were 5.5 kg heavier on average, and had a higher leaner meat percentage than control
  • FCE lower at 0.5% inclusion on average 0.06 lower in OceanFeed fed pig
  • significantly improved taste and texture of the meat at 5% inclusion while having a marginal impact on FCE and growth
  • improved observed health and alertness of animals
  • improved gut flora and morphology development
  • improved environmental record due to  non release of foreign synthetic matters in the feed

Commercial trials
With these results to hand, trials using OceanFeed-Pig were conducted in 2012 at a medium-sized pig operation in south-western Ontario that produces over 10,000 pigs per annum.

The early results showed an immediate change in the environment due to less ammonia.  Working conditions were improved for employees and stress levels in the pigs were reduced. Moreover, higher weight gain, shorter production cycles and lower mortality was also reported.

 Most significant however was that the inclusion of Oceanfeed in the diet eliminated the need for 2 out of the 4 antibiotics routinely used to maintain health.  The farm now plans to increase its usage of OceanFeed in the diet and to re-formulate all of the diets and replace all antibiotic use.  

With a global €200bn farming industry, the future looks bright for seaweed as an additive in pig diets.

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