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A STUDY ON PRODUCTIVE AND REPRODUCTIVE PERFORMANCE OF NELLORE BROWN SHEEP

KrishiKosh

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Title A STUDY ON PRODUCTIVE AND REPRODUCTIVE PERFORMANCE OF NELLORE BROWN SHEEP
 
Creator VISHNU VARDHAN REDDY D
 
Contributor Dr. D. SREENIVAS
 
Subject A study on productive and reproductive performance of Nellore Brown sheep
 
Description Data on body weights, growth and reproductive traits recorded on about 500 Nellore brown sheep maintained at Livestock Research Station of Sri P.V. Narsimha Rao Telangana State University for Veterinary, Animal and Fisheries Sciences located at Mamnoor, Warangal district was utilized for the present study.
The overall least squares means for body weight at birth, 3, 6, 9 and 12 months of age were 2.63 ± 0.01, 12.52 ± 0.03, 20.15 ± 0.03, 24.25 ± 0.03 and 27.06 ± 0.03 kg, respectively. The year of birth had significant (P≤0.05) effect on body weight at all ages except at six months of age. Males were significantly (P≤0.01) heavier than females at all ages. The season of birth significantly (P≤0.05) influenced the body weight at all ages except at 3 months of age. The lambs born in off season were heavier at all ages.
The overall least squares means for average daily gains during 0-3, 3-6, 6-9 and 9-12 months of ages were 109.90 ± 0.28, 84.80 ± 0.23, 45.53 ± 0.20 and 31.29 ± 0.25 g, respectively.
The overall least squares mean age at first service, age at first lambing, gestation period, service period and lambing interval were 593.55 ± 6.74, 742.53 ± 6.75, 149.13 ± 0.08, 155.03 ± 10.71 and 304.41 ± 10.71 days, respectively. Year of birth had shown highly significant (P≤0.01) effect on all the reproductive traits studied. The season of birth significantly (P≤0.01) influenced service period and lambing interval only. The parity of the ewe had significant (P≤0.05) effect on gestation period, service period and lambing interval.
Data adjusted for significant non-genetic effects was utilized to study genetic parameters. The estimates of heritabilities of body weights ranged from 0.01 ± 0.06 to 0.25 ± 0.12; of daily gains ranged from 0.02 ± 0.06 to 0.20 ± 0.11 while the heritabilities for reproductive traits ranged from 0.07 ± 0.16 to 0.26 ± 0.13.
The genetic, phenotypic and environmental correlations of body weights and average daily gains were low to high. The genetic, phenotypic and environmental correlations of reproductive traits were positive and ranged from low to medium in general.
Heritability estimates for 6 months body weight (0.13 ± 0.09) and 12 months body weight (0.25 ± 0.12) indicated the presence of moderate genetic variance, which could facilitate the improvement through selection coupled with optimum managerial practices. The estimates of heritabilities for reproductive traits indicated that non genetic factors play an important role and better feeding and management of ewes can help to improve these traits.
 
Date 2017-01-04T12:03:10Z
2017-01-04T12:03:10Z
2015-11-06
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/94369
 
Relation D;432
 
Format application/pdf
 
Publisher PVNR TVU