EFFECT OF FOUR TIMES MILKING AND HANDLING ON THE YIELD OF
MILK IN COWS OF THE THARPARKAR BREED
By C. H. PARR and S. SEN, Imperial Agricultural Research Institute, New Delhi
(Received for publication on 20 September 1946)
(With Plate II and three text figures)
THE frequency of milking has considerable effect on the secretion of milk in dairy cows. Ragsdale
et al. [1924] observed that the longer the interval between milkings, the less the speed of milk
secretion per unit of time. They found that if the amount of milk secreted during the first hour
were represented as 100 per cent, the amount secreted in each succeeding hour would be approximate-
ly 95 per cent of that secreted during the previous hour. Woodward [1931] held that relief from the
pressure of milk within the udder as a result of frequent milking allowed secretion to proceed more
freely. Hammond [1936] found that the retardation of the rate of secretion and the final cessation
of milk production were caused by the pressure created by the accumulated milk rather than the
chemical effect of its constituents within the udder. Ispe [1941] has stressed the necessity for in-
termittent periods of intramammary pressure in order to stimulate milk secretion and advocates
that the maximum milk production can be secured by frequent milking and thus preventing an
accumulation of milk in the udder. Ispe and Hammond are also of the opinion that the possibility
of milk or fat being secreted into the blood stream during periods of high intramammary pressure
appears improbable. Bartlett [1929] showed that the yields of milk and fat at morning milkings
after a long night interval, although greater in amount, were not in proportion to the interval of time
between the respective milkings. He attributed the cause to reabsorption of milk taking place during
the long night interval. To avoid this depression and to obtain optimum results he suggested the
shortening of the long night milking interval.
EXPERIMENT WITH THARPARKAR COWS
An experiment to compare four and two times milking on Tharparkar cows maintained at the
Karnal Sub-station of the Imperial Agricultural Research Institute was started in 1939. Twenty-
four cows were selected for this purpose. Most of the cows had completed their first lactations when
the experiment was started. As one cow died, data were available pertaining to eleven cows under
four times milking and twelve cows under two times milking. The cows under four times milking
were milked and 'handled', i.e., the udder was massaged before calving for about ten minutes every
day for a period of 15 to 20 days and regularly milked once a day as soon as milk secretion started,
following the practice introduced by Sayer [1934] in the Sahiwal herd at Pusa and subsequent
continued with the same herd at Delhi as a standard practice.
Rationing. Roughages were fed ad lib. in the form of bhusa (bruised oat and wheat straw),
green sorghum, green cowpeas, green berseem, sorghum silage and berseem hay to provide the nutri-
ents required for maintenance of animals of weights varying from 750 to 1,200 lb. Concentrates
were fed in the proportion of one pound concentrates for every two pounds of milk yield. The com-
position of the concentrate ration was generally as follows:—crushed oats 48 per cent, crushed gram
32 per cent, crushed groundnut cake 12 per cent and crushed linseed cake 8 per cent. To this mixture
was added sterilised bone meal and common salt each at the rate of 1½ lb. per 100 lb. of the mixture.
The above gives a concentrate ration which provides 68.00 per cent starch equivalent and 13.71 per
cent digestible protein, i.e., 0.34 lb. of starch equivalent and 0.068 lb. of digestible protein per pound
of milk against the standard requirement of 0.316 lb. of starch equivalent and 0.051 lb. of digestible
protein per pound of milk containing five per cent fat [Sen, 1938].
STATISTICAL ANALYSIS OF THE DATA
In their pre-experimental first lactations, eight cows were under two times milking, while another
set of eleven cows were under four times milking. Of the remaining four cows, three had completed
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