CHARACTERISATION AND EVALUATION OF THE DWARF CATTLE OF KERALA
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Date
1994
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COLLEGE OF VETERINARY AND ANIMAL SCIENCES-MANNUTHY,THRISSUR
Abstract
The native cattle of Kerala have been treated as non
descript animals always eventhough they possess some special
features. The dwarf cattle often called as Vechur were very
popular in Central Travancore until 35 years back. with the
emergence of the crossbred population of cattle the
traditionally reared local cattle have gradually suffered
genetic erosion. Under this circumstance, the present work
was undertaken to characterise and evaluate the germplasm of
local dwarf cattle of Kerala by studying (a) the karyotype and
morphology of chromosomes using G-banding (b) the population
structure by means of gene frequencies of different blood
proteins (c) the growth and production performance. The
characterisation and the evaluation would help in finding out the genetic differences of the dwarf cattle which will help in
deciding about the conservation of their germplasm as a
reserve for the future.
The dwarf cattle maintained under the ICAR scheme on
"Conservation of germplasm of Vechur cattle of the coastal
area and the dwarf cattle of the high ranges of Kerala" formed
the material for the study.
The characterisation and evaluation was carried out
through the cytogenetic, immunogenetic and polymorphism
studies as well as through the description of the growth and
production traits. Karyotype analysis was carried out using
peripheral blood leukocyte culture technique described by
Hainan (1977) and Hainan (1989) with suitable modifications.
G-banding of chromosomes were done by the method described by
Thiagarajan, ^19 9!^. Blood protein polymorphism systems^ such as
Haemoglobin and transferrin were studied by poly acrylamide
gel electrophoresis in horizontal dimension ' y(Cahne et al.
,1977) with suitable modifications. The statistical analysis
of the growth and production data were done as suggested by
Snedecor and Cochran (1967).
The diploid chromosome number of the dwarf cattle was
found to be 60, with 29 pairs of autosomes and one pair of
sex chromosomes. All the autosomes and the 'Y' chromosome
were acrocentric. The X chromosome was submetacentric. The
relative length of the autosomes ranged from 1.757 to 5.431
per cent. The relative length of the X and Y chromosomes were
found to be 5.591 per cent and 2.875 per cent respectively.
In the karyological array, the X chromosome occupied the first
position. The X chromosome was biarmed and the arm ratio and
centromere index obtained were 2.182 and 0.314 respectively.
The karyotype and morphometric measurements resembled the
finding in Bos indicus group of cattle. The G-banding pattern
of chromosomes revealed 72 regions and 314 G-bands. The Y
chromosome had 7 G-bands in the 'q' arm which resembled the
'q' arm of Bos taurus described in the international system
for cytogenetic nomenclature of domestic animals.
A B There were two haemoglobin variants Hb and Hb and
three phenotypes viz. Hb^^, Hb^® and Hb®^, in the population.
The heterozygocity was found to be 0.4815. The population was
found to be in genetic equilibrium with respect to the
Haemoglobin locus.
Six transferrin phenotypes controlled by three alleles
Tf^, Tf*^ and Tf^ were observed. The frequency of Tf^ (0.359)
allele in the dwarf cattle was as high as the frequency of the
allele reported in the zebu cattle. The absence of
F H N G transferrin variants like Tf , Tf , Tf and Tf and higher
frequency of Tf allele are probably indicative of the genetic
isolation of the population from exotic breeds. The absence
B F of Tf and Tf allele which is present in Gir, Hariana,
Kankrej, Kangayam, Ongole, Red Sindhi, Sahiwal and Tharparkar
also indicates that the dwarf cattle has not inherited genes
from the above cattle breeds.
The body weights and measurements of calves at birth
studied showed that the male calves had a higher body weight
(12.55 + 0.311 kg with a CV of 7.86 per cent) than female
calves (10.78 + 0.404 kg with a CV of 15.02 per cent). The
same trend was observed with regard to the birth body
measurements also. The heart girth measurement and body
weight showed a positive correlation from birth to the 24th
fortnight. There is a 100 per cent increase in the birth
weight by the 5th fortnight and a three-fold increase by the
10th fortnight. The average daily gain in weight for the four
periods i.e., fortnights 0-6, 7-12, 13-18 and 19-24 were 0.160
+ 0.011, 0.167 + 0.018, 0.212 + 0.011 and 0.139 + 0.015
respectively for female calves, and 0.188 + 0.023, 0.145 +
0.016, 0.116 ^ 0.025, 0.242 + 0.049%respectively in male
calves. During the period from birth to 6th fortnight the
growth rates in males and females were similar. The gain in
body weight per day during the periods from 7 to 12th and 13
to 18th fortnight was comparatively less for males but the
trend reversed during the period of fortnights for 19 to 24th.
The average body weights of adult females and males
were 126.90 + 3.56 kg (CV 16.39%) and 210 + 15.75 kg (CV
14.95%) respectively. The body measurements such as length,
heart girth and height (in cms) in females were 97.5 + 1.12
(CV 5.85%), 115.60 + 1.32 (CV 5.82%) and 87.53 + 0.82 (CV
4.82%) respectively. The corresponding figures in males were
111.5 + 3.77 (CV 6.76%), 146.0 + 2.92 (CV 3.99%) and 107.5 + 1.35 (CV 2.50%) respectively. The average body weights and
measurements were lesser than those reported in other Indian
breeds and crossbred cattle.
The total lactation milk production performance of the dwarf cattle was 471.68 + 38.72 kg (cv 45.29%) in an average
lactation length of 217 + 16.50 days (CV 32.20%). The average daily yield was 2.17 + 0.11. kg (cv 29.48%). • The dwarf cattle
attained a peak yield of 3.71 + 0.16 kg (cv 21.5%) in 23.23 +
1.703 days (CV 37.38%). The milk production performance
eventhough was lesser than crossbreds or some recognised
Indian breeds, the milk production in comparison with the body
size was reasonable.
Considering the morphology of the Y chromosome, the Hb
as well as Tf polymorphism and their allelic frequencies, it
is to be summarised that the stock of dwarf cattle of Kerala
maintained at Kerala Agricultural University is gehetically
isolated from the other cattle breeds of the country and
world. The body size and milk production of the cow indicates
its suitabMity for a farmer who requires milk just for home
consumption. The study strongly confirms the necessity of
conservation of the dwarf cattle of Kerala which is the
smallest variety available in India and perhaps in the world itself.
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