Please use this identifier to cite or link to this item: http://krishikosh.egranth.ac.in/handle/1/5810086480
Authors: Arthy, V
Venkataramanan, R
Sivaselvam, SN
Sreekumar, C
Balasubramanyam, D
TANUVAS
Title: Genetic evaluation of growth in farmers’ flocks of Madras Red sheep under long-term selection in a group breeding scheme
Other Titles: Tropical Animal Health and Production
Publisher: Akinik Publications
Language: en
Type: Article
Pages: 1463-1471
Volume: 50
Series/Report no.: ;7
Agrotags: Veterinary Science
Keywords: Long-termselection . Genetic parameters . Breeding value . Genetic trend . Response to selection
Abstract: The Network Project on Sheep Improvement (NWPSI)–Madras Red field unit is a group breeding scheme involving 198 farmers’ flocks of Madras Red sheep in which selection for growth traits and rotation of rams have been practised for over two decades. Growth data collected from these flocks were used to evaluate the performance and understand the direct and expected responses to selection based on genetic parameters. The body weight at birth (BW), weaning weight (WW), 6-month weight (6W), 9-month weight (9W), 12-month weight (YW), pre-weaning average daily gain (ADG1, birth to 3 months), post-weaning ADG2 (3– 6 months), ADG3 (6–9 months), ADG4 (9–12 months) and ADG5 (3–12 months) were 2.67, 10.05, 14.56, 18.36, 21.36, 80.13, 49.05, 43.00, 34.21 and 41.18 g, respectively. Univariate analyses were carried out using animal and sire models to estimate variance components. Heritability obtained from animal model for BWwas 0.36 and the values for other body weight traits were almost unity. Heritability estimate for pre-weaning ADG1 was 0.31. Very high genetic variability was observed in spite of long-term selection and this sustenance of variability is one of the main advantages of a group breeding scheme, combining several flocks of smaller size. An increasing genetic and phenotypic trend was noticed for almost all the traits studied. The expected responses calculated based on genetic parameters also indicated scope for improvement.
Description: TNV_TAHP_2018_50(7)1463-1471
Issue Date: 2018-04
Appears in Collections:Articles (1.Journal)

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