Published in Scientific Papers. Series D. Animal Science, Vol. LXVI, Issue 2
Written by Osamah Mahmood Abdulzahra MURSHEDI, Horia GROSU, Petrut-Lucian PARASCHIVESCU
The purpose of this study is to estimate the heritability in Palas - Prolific Line Sheep, for milk and prolificacy. This objective was undertaken applying the BLUP methodology, to a random regression animal model, for milk yield and, also, to an ordinary animal model for the number of offsprings/ewe/lambing. For milk yield, the data set consisted of 4610 test day records from the first lactation of 485 ewes, with records, sired about 97 rams. Totally, there were 1049 animals, including the ancestors. The fixed effect in the model were fixed lactation curves and flock-test-date. The random effects of animal and permanent environmental effects were modelled using orthogonal polynomials of order three. The curve of daily heritabilities for milk yields were 0.216, 0.133, 0.151, 0.219, 0.280, 0.314, 0.318, 0.292, 0.243, 0.199 and 0.210 for 50, 64, 78, 92, 106, 120, 134, 148, 162, 176, 190 days in milk. For the number of offsprings/ewe/lambing (prolificacy) the heritability was estimated using an animal model. The fixed effect was the year and season of lambing. Random effects was represented by animals. The heritability of prolificacy was 0.177.
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