PHENOTYPICAL CHARACTERISTICS OF UDDER AND TEAT VIS-A-VIS MILK YIELD AND MILKING TRAITS IN GIR COWS
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Date
2012-03
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JAU,JUNAGADH
Abstract
An investigation was undertaken to study the variation
m the udder and teat shapes and dimensions, body measurements
and their relationship with the milk yield and milking traits in Gir
cows. The study is carried out on hundred Gir cows maintained at the
Cattle Breeding Farm, Junagadh Agricultural University, Junagadh,
Gujarat. The present investigation was carried out in four groups of
lactating Gir cows based on udder shape, teat shape, lactation
number and stage of lactation, over a period of three months from
01-11-2010 to 31-01-2011.
The results showed that among the different udder shapes
round shape was very common on the farm followed by trough
pendulous and bowl shapes and their occurrences were 35.0%,'
27.0/6, 23.0% and 15.0% resoectivelv ^itviii-. i Y- Similarly, cylindrical teats were
more common with a Hpceircceennttaaggee ootf ^35n.0 followejd l by pear, bottle and
funnel shaped of teats with 21%, 20% and 24% respectively.
The udder & teat measurements in Gir cows were low in bowl
shaped udders and high in pendulous shaped udders compared to
the other shapes of udders. Body measurements as body length,
height at withers and heart girth with different udder shapes were
found higher in pendulous shaped udders however, measurements
on body length were significant (P < 0.05) with respect to different
shapes of udder.
Gir cows with pendulous shaped udders were found to have
highest average daily milk yield followed by trough, round and bowl
udders. Similarly milking time and milk flow rate was higher in
pendulous shaped udders and lower in round shaped udders. The
maximum milk yielding capacity of pendulous udders might be due
to maximum udder, teat and body measurements. Bowl shaped
udders were low in all measurements showing low milk yielding
capacity.
According to different teat shapes in Gir cows, all udder, teat
and body measurements had higher means for cylindrical type teats
and low for pear type teats. Funnel shaped teats were found to have
higher daily milk yield followed by cylindrical, pear and bottle shaped
teats. Percent of Milk constituents as Fat, SNF and Protein were not
affected due to teat shapes. Milk flow rate and milking time were
found to be higher in funnel and cylindrical shaped teats respectively
Udder lengths were continuously increasing with parity
compare to udder width and udder depth which were highest in
third parity animals. Gir cows in third parity were found to have
higher average daily milk yield.
All udder measurements were high in second stage of lactation
(except udder length which is highest in first stage) and low in third
stage of lactation. The results of various milking traits were
significantly ( P < 0.05 ) higher for daily milk yield, milking time and
milk flow rate in first stage of lactation compared to second and third
stage of lactation. Percent milk constituents as Fat, SNF and Protein
were higher in third stage and lower in second stage of lactation.
A positive correlation was found between the udder
measurements and the daily milk yield, however, the correlation was
significant among udder length, udder width and daily milk yield
(P<0.05). A positive correlation existed between the average daily
milk yield and teat measurements but was significant (P<0.05) with
the teat diameter. Body measurements (except body height) were
positively and significantly correlated with udder and teat
measurements. Body measurements are not correlated with milking
traits and milk constituents. The correlation of milk flow rate with
daily milk yield and milking time was significantly positive (P < 0.01).
Regression analysis is positively and significantly (P < 0.05)
dependent on udder length and teat diameter, having the Coefficient
of Determination of 14% and 7.00% respectively. In comparison to
all, regression analysis of milking traits as milking time and milk flow
rate to average daily milk yield in Gir cows was found to be positively
and significantly (P < 0.01) higher. Multiple linear regression equation
has shown that maximum contribution to average daily milk yield
was due to udder width, milking time and milk flow rate. However,
value in Simple linear regressions for udder width, milking time and
milk flow rate to daily milk yield are found to be 8%, 47% and 31%
respectively. So the above regression study suggests that udder
width, milking time and milk flow rate are important factors deciding
that milking potential of Gir cattle.
Key Words: Gir cow, milk yield, teat dimensions, teat shape,
udder dimensions, udder shape, body dimensions, milking traits
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VETERINARY SCIENCE