Brown, Chris and Brand, Z. and Cloete, S.W.P. and Malecki, I.A. (2009) Genetic Parameters for Ostrich Incubation Traits in South Africa. South African Journal of Animal Science , 39 (4). pp. 253-259.Full text not available from this repository. (Request a copy)
Data obtained from a pair-mated ostrich flock located at Oudtshoorn, South Africa, were used to estimate genetic parameters for egg weight (EWT), weight of day-old chicks (CWT), water loss to 21 (WL21) and 35 (WL35) days of incubation, and pipping time (PT) for between 13 806 and 19 913 artificially incubated ostrich eggs during the 2003 – 2006 production years. Data were initially analysed as single traits using ASREML. Covariance components and ratios were subsequently derived from two-trait analyses. Single-trait estimates of heritability (h2) were 0.46 ± 0.08 for EWT, 0.34 ± 0.07 for CWT, 0.34 ± 0.07 for WL21, 0.27 ± 0.06 for WL35 and 0.16 ± 0.04 for pipping time. Estimates of maternal genetic effects (m2) were 0.23 ± 0.12 for EWT and 0.29 ± 0.10 for CWT. A maternal permanent environmental effect amounted to 0.25 ± 0.10 for EWT, 0.12 ± 0.09 for CWT, 0.25 ± 0.04 for WL21 and 0.30 ± 0.04 for WL35. Genetic correlations with EWT amounted to -0.21 ± 0.13 for WL21 and to -0.12 ± 0.14 for WL35. Corresponding correlations with CWT were -0.43 ± 0.07 and -0.54 ± 0.11. Parameters indicate that it should be possible to alter evaporative water loss of ostrich eggs by genetic selection. A feasible selection strategy, however, needs to be devised as it is challenging to effect genetic change in a trait with an intermediate optimum.
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|Uncontrolled Keywords:||embryo, shell, albumen, water loss, egg membranes, air sac, development, regression|
|Subjects:||S Agriculture > S Agriculture (General)
Q Science > QH Natural history > QH301 Biology
|Divisions:||Academic Departments > Institute of Science and the Environment|
|Copyright Info:||The South African Journal of Animal Science is an Open Access journal.|
|Depositing User:||Chris Brown|
|Date Deposited:||13 May 2010 08:13|
|Last Modified:||06 Aug 2015 11:58|
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