June, 1955] TULSA RAM AND RADHEY MOHAN SHARMA 103
microscope. Gruineapig inoculation and guineapig feeding trial also yielded nega-
tive results. These findings are in conformity with the results previously obtained
by Sahai and Dhanda [1944-45] who examined milk samples of 116 reacting cows of
all ages and condition by guineapig inoculation for the presence of tubercle bacilli
at this farm and found all the samples negative. Survey of tuberculosis carried
out by tuberculin test in different districts of the Punjab shows that the incidence
of infection is only 1-5 per cent under field conditions.
Liston and Soparkar [1917] and Soparkar [1926] studied the susceptibility of
several breeds of cattle and concluded that Indian breeds of cattle were more resistant
than European breeds. Carmichael [1939, 1941] obtained the most striking evidence
concerning the relative susceptibility of different breeds of cattle in Uganda. He
found the incidence of tuberculosis, judged on meat inspection figures, 16 per cent
in Ankole breed and 0.93 per cent in breeds originated from Zebu cattle and on
tuberculin testing 54.9 and 4.6 per cent respectively. Carmichael by experimental
inoculation of Zebu and Ankole calves observed that the disease in Zebu cattle was
not progressive but the lesions were only moderate to slight whereas the infection
proved fatal in Ankole calves within two to five months. He, therefore, concluded
from both epidemiological and experimental evidence that the Ankole cattle were
as susceptible as European cattle whereas the common Zebu cattle were much
more resistant. The observations recorded in this paper also point out that 80 per
cent cases of the disease examined post-mortem showed the infection localised in
lymph glands only and that clinical cases of the disease exhibiting involvement
of the udder and tubercle bacilli in the milk were not encountered. These findings
are indicative of the comparatively higher resistance of the Hariana-Hissar cattle
to the disease and appear to account for the non-significant differences in the breed-
ing efficiency and incidence of the infection in their progeny. The difference in the
average span of life is also not well marked.
SUMMARY
1. Records of over 300 tuberculin positive cows were examined to study the
effect of tuberculosis infection on (1) their span of life, (2) number of calves born
during their life time, and (3) the incidence of the disease in their progeny. These
results were compared with corresponding figures obtained from a similar study of
over 400 tuberculin negative cows of the same age group.
2. The average span of life of the reactor animals was 4690.73 days against
4781.16 days of the non-reactors. The difference in the average span of life in the
two groups is only 90.43 days which, however, is highly significant statistically.
3. The average number of calves born was 5.28 and 5.44 in the positive and
negative groups respectively. The difference of 0.16 is not significant statistically.
4. Twenty animals out of 441 progeny of reactor cows proved positive to tuber-
culin test as compared to 16 out of 508 produce of non-reactor cows. The difference
of 1.38 per cent is again non-significant statistically, indicating thereby that the
close contact of the progeny with their tuberculin positive dams for about six months
had no significant effect on the incidence of the disease in them.
141 AR/54
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