REPORT OF THE KING INSTITUTE, GUINDY

33

below the standard fixed as the minimum percentage which is likely to occur in genuine milk,
points to the addition of water. Fat of course separates as cream on standing. A deficiency
of fat may accordingly, be due, either to watering which lowers the percentage of
fat as well as that of solids-not-fat, or to skimming, or, what comes to the same thing to the
addition of skimmed or separated milk. An analyst decides from the percentage of
solids-not-fat whether a sample of milk is watered, and when there is a deficiency of fat
exceeding that of the deficiency of solids-not-fat or when the latter is the only deficiency he
will certify that a sample is not genuine by reason of a portion of the cream having been
removed.

   A large number of samples (318) of milk taken from individual cows at the various
Madras Hospitals have been examined. Also numerous samples from the Agricultural Dairy
Farm at Coimbatore and from the Military Dairy at Bangalore.

   The only official standards in India are those of the Bengal Government who have
adopted standards of 3.5 per cent of fat and 8.5 per cent of solids-not-fat for cows milk. I
recommend that the English standards of 3.0 per cent of fat and 8.5 per cent of solids-not-
fat be adopted for Madras.

   Samples were taken before and after and during the monsoon (taken as the month of
November in 1924). The average figures obtained were:—

   These figures show that the average figure for solids-not-fat is remarkably steady.
This is brought out even more clearly in appendix B in which the averages have been calcu-
lated for morning and evening samples for the different periods. The lowest average
obtained was 8.92 for evening milk in the post-monsoon period (December—March) and the
highest for morning milk in the pre-monsoon period (August-September). During
the period (April—June), the milk of individual cows was not collected but samples from
the bulked milk of the General Hospital herd were examined periodically. These samples
were sufficient to show that there is no change in the composition of milk during these months,
as compared with the other dry months, a result which one would naturally expect.

   Of all the samples from individual cows examined, none gave a percentage of solids-not-
fat below 8.2 per cent.

   I consider that the 8.5 limit would be a very reasonable one. No authority would ever
be likely to take proceedings in connexion with a sample containing 8.3 or 8.4 per cent of
solids-not-fat, which would correspond to about 2 per cent of added water. The normal
procedure of the authority for whom I had the honour to work as Public Analyst in England,
was that vendors of samples giving 8.0—8.3 per cent of solids-not-fat were cautioned in the
first instance. Proceedings were only initiated forthwith in the case of samples containing
less than 8.0 per cent corresponding to over 5 per cent of added water. I would emphasise
here that a milk standard is not a rigid limit such that the vendors of samples giving lower
figures have no defence in case of proceedings. All the fixing of a standard does is to raise a
presumption of adulteration, transferring the onus of proof of genuineness to the defendant.

   The fixing of a fat limit for cow's milk is considerably more difficult. Unfortunately the
bulk of the milkers of Madras, allow the calf to take a portion of the milk, direct from the
cow, at each milking. If the calf is allowed to take the first portion of the yield only, this is
to the advantage of the purchaser, as fore-milk contains very much less fat than after-milk.
(There is very little difference in the figure for solids-not-fat.) Thus with a cow milked in
five portions, the first portion contained only 1.7 per cent of fat, while the last portion
contained 4.1 per cent. A very general practice appears to be to allow the calf to take the
first and last part of the milk, and I am of opinion that in most of the cases of low fat, the
explanation is that the calf has taken an undue proportion of after-milk. This practice of
allowing the calf to take a portion of the milk is quite unnecessary. At the Military Dairy
Farm at Bangalore which I visited in company with Major-General Symons, nearly all the
cows, and there are some hundreds are milked without the presence of a calf and the dairy
manager there informed me that if cows are trained from their first calf to yield their milk
without a calf, there is no difficulty whatever in getting a full yield. It is common knowl-
edge that the practice has been long abandoned in England, the calf being fed either with
a part of the mixed milk or with separated milk.

   The practice of allowing the calf to take a portion of the milk direct from the udder
is so strongly established in Madras, that I think it would probably be found impossible to