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Genetic Analysis Of Growth Traits In Mecheri Sheep

KrishiKosh

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Title Genetic Analysis Of Growth Traits In Mecheri Sheep
 
Creator Jeichitra, V
 
Contributor Rahumathullah, P.S.
Rajendran, R
Thyagarajan, D
Karunanithi, K
 
Subject Sheep
Mecheri
Growth traits
Genetic parameters
 
Description The data on production and viability records of Mecheri sheep at Mecheri Sheep
Research Station, Pottaneri, Salem over a period of sixteen years from 1991 to 2006 and
breeding records of ewes from 1991 to 2005 were collected analysed. Traits analysed
were body weights at various ages viz., at birth, 3, 6, 9, 12 and 18 months of both males
and females. The absolute and relative growth rates during the growth period at different
age intervals were also estimated and included in the analysis. The effects of various
non-genetic factors viz., period of lambing, season of lambing, age of dam at mating and
sex of lamb on various growth traits were analysed. For pre- and post-weaning
(3-6 and 6-12 months) survivability, the effects of period and season of lambing, and sex
of lamb as non-genetic factors were included in the analysis. Age-specific reproduction
traits were estimated. Body weight records were also used to evaluate sires by threes
different methods viz., least-squares (LS), best linear unbiased prediction (BLUP) and
derivative free maximum likelihood (DFREML). The genetic and phenotypic trends
were estimated for body weight over a period of sixteen years.
The least-squares means (± S.E.) for body weights at birth, 3, 6, 9, 12 and
18 months of ages were 2.25 ± 0.01, 7.96 ± 0.06, 11.63 ± 0.08, 14.87 ± 0.11, 17.48 ± 0.14
and 21.49 ± 0.27 kg respectively. The overall least-squares means of AGR measures
over the age intervals birth-3, 3-6, 3-9, 3-12, 3-18, 6-9, 9-12 and 12-18 months
were 63.4 ± 0.58, 39.57 ± 0.57, 37.48 ± 0.44, 34.31 ± 0.42, 29.55 ± 0.52, 35.33 ± 0.60,
27.01 ± 0.65 and 22.53 ± 0.98 grams per day respectively. The overall least-squares
means of RGR for the same traits were 1.38 ± 0.007, 0.41 ± 0.006, 0.34 ± 0.004,
0.28 ± 0.003, 0.22 ± 0.004, 0.27 ± 0.004, 0.17 ± 0.004 and 0.11 ± 0.005 per cent
per day respectively.

Period and season of lambing, age of dam at mating and sex of lamb
had significant (P
 
Date 2016-05-17T15:37:19Z
2016-05-17T15:37:19Z
2009
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/66039
 
Language en
 
Format application/pdf
 
Publisher Tamil Nadu Veterinary and Animal Sciences University