52
INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY
[VOL. XXIX, PART I
related to the depth of coloration in the fishmeal samples. It is concluded that as a result of
over-heating during manufacture, degradation of the proteins occurred, giving rise to toxic
products which in turn led to a high embryonic death-rate during the last four days of incu-
bation. The egg production in all groups of birds was high and it therefore seemed improbable
that over-heating had proceeded to the stage of materially damaging the essential amino-acid
contents of the meal. (S.B.)
Observations on the grazing habits of grade and zebu steers in a high altitude
temperate climate. G. H. LAMPKIN, J.QUARTERMAN and M. KIDNER (1958).
J. Agric. Sci., 50: 211-218.
Although several studies have been made comparing grazing habits of zebu cattle
and grades (indigenous cattle which have been graded up by several generations of crossing
with Europeans) in the tropics, such studies have not been done in temperate climates.
Mugugua, where the experiments were conducted is situated near the equator, at an
altitude of 6,500 to 7,000 feet. The climate is very mild and the mean temperature for any
month seldom fluctuates beyond 65 to 75°F.
Six home-bred zebu steers with an average weight of 537 lb. were considered compara-
ble to six purchased grade steers with an average weight of 680 lb. and slightly older in age.
The appearance of the grades suggested that they were 'high grades.'
The observations were carried out for 13 days in December 1955 and one week in June
1956, after the animals had been grazing for at least five weeks in each case. Animals were
observed every five minutes, during the day alone in the first experiment and during day and
night in the second. The various differences observed in grazing habits could be quantified
in terms of the time taken for the different operations and the significances of the differences
tested by analysis of variance.
It was observed that the maximum temperatures were within the comfort limits of both
kinds of cattle. The lower temperatures (below 55°F.), however, when accompanied by rain,
caused discomfort to the zebus, which remained standing instead of lying down and resting.
Both breeds tended to graze during day and rest and ruminate at night for about the same
length of time, thereby suggesting similarity in physiology. The grades, however, drank about
twice as much water as the zebus. The authors suggest that water consumption at lower
environmental temperatures (below 70°F.) might give some indication of the heat-tolerance
of the animals at higher temperatures. The abstracter is of opinion that this hypothesis on
water consumption can be tested easily in India. [P.G.N.]
A field-trial comparison of milk and egg-yolk citrate as semen dilutors. B. M.
KERRUISH (1956). 3rd Congr. on Animal Reproduction, 1956. Section 3, p. 65.
A comparison of milk and egg-yolk citrate as semen dilutors has been made on large
scale under field conditions. The homogenised milk dilutor and the skimmed milk dilutor
were prepared by heating them separately between 95 to 98°C. for 10 minutes inter-
mittent stirring. The dilutors were then cooled and stored at 5°C. in sterile bottles. The egg-
yolk citrate dilutor was prepared by adding one part fresh egg-yolk to two parts citrate solution
containing 0.3 per cent sulphanilamide. Streptomycin and penicillin were mixed with the
three dilutors as a routine (500 units of each per ml. dilutor). Sulphanilamide was not added
to milk dilutors. Semen samples were divided into two parts, one diluted with heat-treated
milk and the other with EYC. Calculation of conception rates was made on a 90 to 120 day
'non-return' basis on first insemination.
The results showed that EYC dilutor (5051 inseminations) was 1.1 per cent superior
to the homogenised milk dilutor (4637 inseminations). Whereas skimmed milk dilutor (6850
inseminations) was 1.6 per cent superior to the EYC dilutor (7978 inseminations). During
long-term storage the semen viability was reduced in the homogenised milk dilutor but storage
in skimmed milk produced best results of the three dilutors. [P. N. S.]