Sheep - AgRIS

at 75 or 8-4 monthly intervals compared to six monthly interval will allow one clip with longer
staple length which could be processed onworsted system. The second clip utilized in semiworstedlwoollen
system for making knitting yarn.
Crossbreeding trials at Tal(H.P.), Dantiwada(Gujarat) and Sandynallah(T.N.) units where
Gaddi, Patanwadi and Nilgiri respectively were used as indigenous breeds with Soviet Merino
and Rambouillet as exotic breed, have also shown very encouraing results. The performance of
Gaddi and its halfbreds indicated that through crossbreeding in Gaddi there was not only
improvement in six monthly greasy fleece production but substantial improvement in wool
quality also. Similarly the performance of Patanwadi and its crossbreds revealed that through
crossbreeding the Patanwadi could be improved from 45.87 to 55 .79% in wool production and
7.0 to 13.39% in average fibre diameter and 18.48 to 36.32 in medullation. Performance of
Nilgiri and its crosses revealed that the 5/8th and 3/4th produced more than 2.5 kg of greasy
wool annually which was of excellent appearel quality. There was also improvement in the
body weight in crosses. The 5/8th were observed better than the indigenous and the F 1 s
particularly beyond 6 months of age. These results will be of con- siderable importance since
the improvement of fine wool production of local sheep will boost the profit accruing to the
sheep farmers.
A research project to evolve new wool breeds suitable for arid and semi-arid regions had
been in operation at the CSWRI, Avikanagar since 1964. It involved crossing of Rambouillet
with three diverse native type (Medium-fine carpet medium apparel type-Chokla, medium
carpet wool - Jaisalmeri and coarse hairy carpet wool - Malpura). Three levels of Rambouillet
inheritance, viz. 1/ 2,5/8 and 3/4 have been tested. Further halfbreds and 3/4th have been
interbred. The results available indicate that there is little to gain in body weight and greasy
wool production beyond 50% exotic fine wool inheritance, although further introduction does
improve wool quality. There is no serious decline in perforrnance of the progeny produced
from interbreeding of crossbreds. The halfbreds pose no serious management and disease
problems. Higher crosses do show lower adaptation to heat and prevelent disease and would not
be suitable except in temperate regions with better pastoral conditions. Rambouillet x Chokla
halfbreds produce about 2.5 kg of greasy wool per year of 585 to 645 quality which is suitable
for medium quality apparel. Economic gains from improvement in wool alone are around 33%
in Rambouillet x Chokla halfbreds over Chokla. One new strain 'Avivastra' has been evolved
through interbreeding and selection of Rambouillet x Chokla (halfbred and 5/ 8th) base. Annual
greasy fleece produced is 2.26 kg with staple length (six month growth) 3.82 cm, fibre diameter
23.60 p and medullation percentage 21.60. Average adult body weight for males is 36 kg and
for females 29 kg. The surviability in younger age as well as in adults ofthis breed is betterthan
either of its parents. The performance of these animals on reseeded cenchrus pasture with
density of 5 sheep per hectare along with their lambs upto weaning age (90 days) with daily
schedule of 12 hrs grazing and without any supplementary grain feeding has been extremely
satisfactory in terms of greasy fleece production, wool quality, lamb growth, survivability and
breeding efficiency. Higher percentage of hairy hetero-fi- bres however give rough feel to the
apparel. Elimination of this defect through selection is in progress. Rambouillet x Jaisalmeri
crosses though superior to Jaisalmeri in wool production and wool quality pose serious problem
due to black patches on the fleece which considerably reduce the return from the sale of wool.
At 3/4th level of exotic inheritance, the native types involved in crossing do not show any
serious differences.
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