AN ACRE A MEAL? - MEAT: A Benign Extravagance - page 32

On the other hand, cows and other ruminants are much more efficient than pigs and
poultry at consuming fibrous waste products. In third world countries, crop residues are
routinely fed to cows and goats which are hardier and better adapted to surviving on lowly
fare than European Holsteins and Limousins. Rice straw, millet and sorghum stovers, yam
peels, substandard roots and grains and so on are a significant component of third world
ruminant diets. Very fibrous materials such as bagasse (sugar cane straw) and wheat straw
are more easily fed after treatment with ammonia or alkali. In many cases, cows are folded
on the stubble of harvested crops, which helps dispose of it, manures the land and assists in
the sequestration of carbon. Nomadic herders sometimes make arrangements with sedent-
ary farmers to take some of their crop residues - for example Fulani (Peul) pastoralists in
Nigeria move out of their grazing areas in the dry season to feed their animals on cereal
straw. 40
According to the FAO, feeding rice straw to cattle is 'the most efficient way at present to
recover the energy of the straw. Straw nitrogen can also be effectively recovered if the dung
is subsequently fermented to produce gas'. 41 In 1999, Fadel calculated that the global crop
residues from wheat, rice, barley, maize and sugar cane (bagasse) alone totalled three-quar-
ters of a billion tonnes of dry matter, while a later study estimated that the same volume
was potentially available as animal feed in Asia alone. 42 Being mainly fibrous straws, these
are sometimes not fed to animals when better food is available or when they are needed for
some other purpose such as litter, thatch or fuel. In Bangladesh and Thailand over 70 per
of rice straw is fed to animals, whereas in South Korea the figure is only 15 per cent. 43 It
should be borne in mind that when crop residues are fed to animals the bulk of the organic
matter emerges at the tail end of the process in the form of manure, which either finds its
way back to the soil or is used for fuel or building material. In theory, according to Fadel's
calculations these residues provide enough energy to support the entire world's milk sup-
ply, and enough protein to support about a third of it.
In the UK there is a similar range of crop residues available for cows, such as apple
pomace, sugar beet pulp and various kinds of straw. As William Cobbett sourly observed,
almost the only major human food plant whose residue cannot be eaten by animals is the
potato: 'While the wheat straw is worth from three to five pounds an acre, the haulm of the
potatoes is not worth one single truss of that straw'. 44 But collectively these crop residues
provide a tiny amount of nutrition for the national cattle herd, partly because there is such
an abundance of higher grade feed around, and also because wheat and other crops have
been bred so that most of the goodness goes into the seed and very little into the straw. Oat
straw is a good deal more nutritious and palatable to livestock than wheat straw; but few
crops of oats are grown nowadays.
Happily, the most abundant fibrous material of all happens to be a food highly relished
by the cow, precisely because it has not been bred for seed production - namely grass.