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Because of an increasing world population, with more demanding consumers,
the demand for animal based protein is on the increase. To meet this increased
demand, alternative sources of animal based protein are required. When
compared to conventional production animals, insects are suggested to be an
interesting protein source because they have a high reproductive capacity, high
nutritional quality, and high feed conversion efficiency, they can use waste as feed
and are suggested to be produced more sustainably.
This thesis starts with a historical perspective on insects as food and feed,
and explains why insects are expected to be more suitable production animals.
In Chapter 2 the nutritional quality of insects is discussed based on a
variety of insects that are commonly used as feed or food. Additionally, various
environmental and dietary factors which are known to significantly affect insect
chemical composition are reviewed.
In Chapter 3 the direct production of greenhouse gases (GHG) and
ammonia, as well as carbon dioxide emission and average daily weight gain of
five insect species is quantified. Differences regarding the production of GHGs
(expressed as CO2 equivalents) between insect species were mainly due to the
production of methane. All species tested emitted lower amounts of GHG than
cattle, had a higher growth rate than cattle or pigs, and emitted lower amounts of
ammonia and either comparable or lower amounts of GHG than pigs.
Results from Chapter 3 were used in a Life Cycle Assessment conducted
in Chapter 4. For a mealworm production system total GHG production, energy
use, and land use were quantified and compared to conventional sources of
animal protein. This chapter shows that mealworms should be considered a more
sustainable source of edible protein, and that a large part of their environmental
impact is due to the feed they consume.
In Chapter 5 four diets composed from industrial organic by-products
were formulated such that they varied in protein and fat content. These diets were
offered to four insect species and their feed conversion efficiency was determined.
Diets used in large scale production systems were included and served as
controls. Diet composition affected feed conversion efficiency in all species. It
is concluded that the four investigated species are efficient production animals
and can therefore be considered interesting for the production of feed or food.
Furthermore, diet composition affected insect composition, indicating possibilities
to tailor the composition of these insects to best meet consumers’ needs.
In Chapter 6 the suitability of chicken, pig, and cow manure was compared
as feed for larvae of the Black Soldier Fly, which in turn could be used as feed for
conventional production animals. Newly hatched larvae were directly inoculated
on moistened manure. Whereas survival was high on all three tested substrates,
the development time was greatly prolonged compared to the control diet. On
pig manure, more nitrogen was utilised than on chicken and cow manure, while P
utilisation was highest on cow manure. A large proportion of manure nitrogen was
lost in all treatments, indicating that the production system would require a way
to prevent this in order to make it ecologically sound. Furthermore, to improve
economic viability, shorter development times would be required.
In Chapter 7 the suggestions why insects would make suitable production
animals are evaluated based on both literature data, and data gathered in this
thesis. Furthermore, prospects for insects as food or feed are put forward,
with emphasis on the knowledge and legislation requirements for the further
development of the insect production sector.
|Qualification||Doctor of Philosophy|
|Award date||6 Jan 2015|
|Place of Publication||Wageningen|
|Publication status||Published - 2015|
- insects as food
- food composition
- life cycle assessment
- environmental impact