THE MANGANESE CONTENT OF SOME COMMON POULTRY FEEDS
By D. PARTHASARATHY AND R. MUKHERJEE, Poultry Research Section, Indian Veterinary Research
Institute, Izatnagar
(Received for publication on 26 August 1947)
I N view of the importance of manganese in poultry nutrition, the manganese content of some poul-
try feeds, commonly used in India, was determined to see if rations compounded from them
are sufficient with respect to their manganese content. Though figures for some of these feeds used
in foreign countries are available, the Indian products have been examined for comparison in order
to find out if they show any variation. The manganese content of some Indian feeds have been
determined, in a different connection, by Rudra [1939] and Sundara Rao [1940]. We have included
in our list some feeds studied by these workers to see if any differences exist ascribable to soil variations.
MATERIALS AND TECHNIQUE
The cereals and their by-products were purchased locally except ragi which was obtained from
Madras. As far as possible only the portions of leafy vegetables which are not used for human consump-
tion have been used for the estimation. These and other grasses were obtained from the institute
farm.
The A.O.A.C. (1940) method using ammonium persulphate was employed in several cases. In
cases, however, where the concentration of chlorides was high, the method of Willard and Greathouse
[1917] with slight modifications was employed, as in our experience the latter method produced a
colour which was brighter and stable for longer periods, while the colour produced by the persulphate
method was somewhat dull and faded out quickly. The modified method of Willard and Greathouse
was as follows :
The sample was ashed in a silca crucible at dull-red heat. The ash was dissolved in a small
quantity of concentrated nitric acid, about 5 c.c. of syrupy phosphoric acid and sufficient quantity
of distilled water were added till the crucible was about three-fourths full. The solution was heated
for about 30 minutes on a water bath for complete extraction of the ash, then cooled, filtered and
washed. To the filtrate, in a 150 c.c beaker, about 0.3 g. of potassium periodate was added and the
beaker heated on water bath till the maximum colour developed. The solution was cooled and
compared in a colorimeter with a standard solution of manganous sulphate similarly treated. In
preliminary experiments to compare the above procedure with the A.O.A.C. [1940] method using
ammonium persulphate, agreement was found to be fairly close.
RESULTS AND DISCUSSION
The results of the determination are given in Table I which shows that certain cereal by-products
such as rice bran and wheat bran are excellent sources of manganese. Ragi used in South India by
human beings and for poultry is also a good source of this element. The low manganese in polished
rice may be due to milling. Bajra, cheena, jowar and barley are poor sources and when the ration
consists entirely of these, the inclusion of necessary supplements in the form of manganese sulphate
or other concentrates may be necessary to get the optimum level of manganese. The cakes of linseed,
groundnut and mustard seem to be moderate sources. Limestone is a good source but there is much
variation from sample to sample. Among the green feeds studied cowpeas appear to be a very good
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