January 27,
2005: High organic feed costs have led organic
livestock producers in many parts of the world to investigate
alternative feeding strategies. Among these strategies,
especially for those rearing organic pigs, is to source
feed components from organic food processors. As the
number and variety of processed organic food products
continues to grow, so too does the quantity of organic
food by-products. Use of these materials as organic
feed, however, seems to be limited by a lack of knowledge
of the feed value of various by-products, lack of communication
between processors and farmers, and transportation and
organizational constraints.
New research from Sonja Wlcek and Werner Zollitsch
at the University of Natural Resources and Applied Life
Sciences in Vienna, Austria (and funded by the Austrian
Federal Ministry of Agriculture, Forestry, Environment
and Water Management and by Bio Ernte Austria) examines
the quantity and quality of food processing by-products
for feeding to organic pigs. Although this research
was focused on Austria, Wlcek and Zollitsch's findings
should be relevant to organic pigs farmers in the United
States and elsewhere.
The researchers began by sending questionnaires to
321 Austrian organic food processors, including bakeries,
breweries, grain mills, and fruit and vegetable processors.
Questions centered on the types and amounts of products
generated, storage and handling methods, and perceived
market values. Seventy-eight organic pig farmers were
also surveyed concerning their current feeding practices
and interest in using by-products.
The processor survey turned up a wide range of potentially
useable organic by-products, from pumpkin seed cake
and buttermilk to brewers' yeast and okara (a by-product
of tofu production). Samples of all identified by-products
were then analyzed for a range of nutritional factors,
including dry matter, crude protein, crude fiber, metabolizable
energy and lysine.
Next, Wlcek and Zollitsch sought to compare the potential
supply of organic by-products to the total nutrient
needs of Austria's organic pig population, estimated
at 25,500 growing-fattening pigs and 3200 breeding sows
in 1999. (Little work has been done thus far, the authors
note, on the nutrient requirements of organic pigs as
opposed to conventional pigs; therefore, conventional
performance data--based on a farrowing interval of 171
days and 19 weaned pigs/year--were used.)
Not surprisingly, the available organic by-products
varied significantly in nutritive value for pigs--high-fiber
products like bran from small grains and sunflower oilcake,
for instance, are better fed to ruminants, the authors
note. Nevertheless, Wlcek and Zollitsch found that 42
percent of the crude protein, 31 percent of the lysine
and 37 percent of the metabolizable energy needs of
the 1999 Austrian pig population could theoretically
be met by using available organic by-products.
The researchers identified stale bread (509 metric
tons/year), feed-grade potatoes (11,100 t/yr), and whey
(12,900 t/yr) as the three primary underutilized sources
of organic pig feed in Austria. (Stale bread tested
out at 66.3 percent dry matter with 16.17 Megajoules
metabolizable energy per kilogram of dry matter (MJ
ME/kg DM). Crude protein was 11.2 percent of DM and
lysine was .33 percent of DM. Feed-grade potatoes were
18.4 percent DM, with 13.36 MJ ME/kg DM, crude protein
12.2 percent of DM and lysine .44 percent DM. Whey was
5 percent DM, 14.06 MJ ME/kg DM, crude protein 13.7
percent of DM and lysine 2.89 percent DM.)
Challenges to using stale bread as an organic feed
source include limited shelf-life and the dispersed
locations of bakeries. Potatoes are more nutritious
if cooked, but cooking requires additional labor and
energy. Large amounts of organic whey go unused in Austria
because organic pig farmers have yet to get established
in the areas where most large-scale organic milk processing
plants are located. The researchers calculated that
as many as 14,000 organic feeder pigs could be fed with
organic whey in their country.
In conclusion, despite the range and volume of available
materials, Wlcek and Zollitsch noted a deficiency in
high-value protein feed materials among organic by-products.
They therefore recommend increased efforts to include
additional legumes--such as lupins, lathyrus, or fava
beans--in organic crop rotations.
Citation: Sonja Wlcek and Werner Zollitsch, "Sustainable
pig nutrition in organic farming: By-products from food
processing as a feed resource." Renewable Agriculture
and Food Systems 19(3): 159-67.
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