THE DIGESTIBLE NUTRIENTS OF CERTAIN CEREAL GRAINS AS DETER-
MINED BY EXPERIMENTS ON INDIAN FOWLS
By R. MUKHERJEE and D. PARTHASARATHY, Poultry Research Section, Indian Veterinary Research
Institute, Izatnagar
(Received for publication on 26 August 1947)
I N the absence of information on the digestibility of certain Indian poultry feeds the authors
have determined the digestible nutrients of three comparatively cheap cereal grains cheena, jowar
(Sorghum vulgare) and ragi (Eleusine coracana). Experiments on two other grains, viz. barley and
bajra (Pennesetum typhoideum, bulrush millet), for which foreign data are available, have also been
conducted to see if the figures given by western workers hold good for similar Indian grains. Except
ragi, the grains studied are sparingly used for human consumption in India. An investigation of
their value as poultry-feeds is necessary since such staple cereals as rice and wheat are often in short
supply in this country and should be used sparingly in rations for livestock.
Katayama [1924] and Halnan [1926] for obvious reasons, used indirect methods of determining
digestibility coefficients of poultry feeds by analysing the mixed excreta and making use of certain
equations. These equations are given by Katayama (Loc. cit) and are based on data obtained on
only two birds, before and after operation. The formulae as reproduced in an article by Halnan
[1926] are as follow:
1. Dung Nitrogen=Excretory N-(Uric acid N-free ammonia N) 114.6 per cent/102.3 per cent
2. Urinary Nitrogen=Excretory N-Dung N
3. Urinary organic matter=Urinary N × 3.26
4. Urinary ether extract=Organic urinary matter × 108 per cent
This method of computation has been used in this study. Fraps [1920] has determined the
digestibility of a large number of feeds taking the urinary products as consisting entirely of uric
acid and ammonia. Though this method has been used by a number of other workers it is undoubtedly
less accurate.
EXPERIMENTAL
The cereal grains were fed singly, without the addition of any other feed to adult desi (indigenous)
cockerels between 1 and 1½ years of age. They were housed individually in roomy (16 × 12 × 16 in.)
metabolism cages with wire bottom. The mixed excreta were collected on polished glass-plates
placed under each cage. Food was provided in wooden boxes and water in triangular tins fastened
to the sides of the cages. The birds were kept in their respective cages for a few weeks before the
experiment so that they become used to the environment. Each metabolism experiment was preceded
by a preliminary period of five days with a collection period of seven to eight days. The birds were
weighed on two days, viz. at the commencement and end of the digestibility trial, the average weight
being used for calculation. During the metabolism experiment a weighed quantity of the test feed,
the amount of which was based on the consumption of each bird during the preliminary period was
offered to the cockerels. Any food left over was weighed. Every attempt was made to feed an
adequate amount of diet and to ensure an uniform intake throughout the period of observation.
The birds were given 1 gm. of common salt and 2 gm. of limestone-grit along with their daily diet
and water was always available to them. Every morning, the excreta were scraped and collected
in glass-stoppered bottles after mixing with 10 c.c. of 10 per cent acetic acid after collection. The
glass stoppered bottles were kept at 30°F to arrest fermentation. At the end of the experimental
period the pooled sample was rendered distinctly acidic by adding acetic acid, mixed thoroughly
and weighed. Suitable quantities were then weighed out into tared porcelain dishes and dried in
an electric oven at a temperature not exceeding 70°C. The dried material was ground finely, passed
through a sieve to remove any pieces of feather and stored in glass-stoppered bottles for subsequent
analysis.
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