Estimation of Some Genetic Parameters of The Growth and Wool Characteristics of The Libyan Barbary Sheep

Authors

  • Abdulkarim Ahtash
  • Aiad Abo-Zakhar
  • Fathia Abousaq

DOI:

https://doi.org/10.51984/jopas.v20i1.1231

Keywords:

Birth weight, Weaning weight, Greasy fleece weight, Barbary sheep, Heritability, Repeatability

Abstract

Records on 306 Libyan Barbary lambs descended from 232 ewes sired by 25 rams were included during the period from 2004 - 2009. Analyses were used by ASREML to estimate (CO)Variance, Additive and maternal heritability and Correlations; fitting an animal model including maternal genetic for live weight traits. The objective was to evaluate the performance and previously mentioned genetic parameters in some traits of Barbary sheep in Libya. Mean birth weight (BW), weaning weight (WW) and adjusted weaning weights (adjWW) were 3.11±0.06, 21.11±0.08 and 21.62±0.02 kg respectively. Mean greasy fleece weight (GFW), staple length (SL) and number of crimps/2cm. was 1.98±0.67 kg., 9.67±1.64 cm. and 11.02±1.56 respectively. The additive heritability estimates for (BW), (WW) and (adj WW) were 0.11, 0.21 and 0.27 respectively. The maternal heritability estimates for (BW), (WW) and (adj WW) were 0.05, 0.11 and 0.25 respectively. These results indicate that selecting for improved maternal and for direct effects in Barbary sheep would generate slow genetic progress in BW trait. Direct and maternal genetic and phenotypic correlations among the lamb weights varied between 0.08 and 0.966.  The Repeatability estimates for (GFW), (SL) and crimps/2cm were 0.13, 0.03 and 0.03 respectively. The positive phenotypic correlation coefficient between the wool traits of the Libyan Barbary sheep ranged from 0.61 to 0.456. The negative correlation ranged from – 0.259 to – 0.036; It was the highest positive and significant correlation between number of fine and coarse crimps/2cm was 0.456, while the highest negative and significant correlation between number of crimps of fine fiber and coarse fiber ratio was 0.259. It concluded that Low estimates of additive and maternal heritability for live weights indicated the presence of less additive genetic variance and large environmental variance. Hence, improvement through selection may be limited in growth traits if the causes of environmental variation are not removed. Only year’s records can be trusted to predict performance in the wool traits when temporary environmental impacts are minimized.

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Published

2021-05-18

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Section

Articles