M.H. Khalil, K.A. Al-Sobayil, A.M. Al-Saef1, K.M. Mohamed1, and S.A. Salal1
Department of Animal Production and Breeding, College of Agriculture and Veterinary Medicine,
Al-Qassim University, Buriedah, P.O.Box 1482, Saudi Arabia.
1Range and Animal Development Research Centre (RADRC), Al Jouf, Saudi Arabia
ABSTRACT
A 269 lactation records for Saudi she-camels were genetically analysed and evaluated for lactation traits of milk yield of the first three months of lactation, annual milk yield, total milk yield, length of lactation period, monthly milk yield, and daily milk yield. Data were analysed using DFREML procedure to estimate direct additive effects (i.e. direct heritabilites), permanent environment and random errors. Breeding values of camels with and without records in this population were predicted for lactation traits using an animal model.
Heritabilities were moderate and ranged from 0.08 to 0.25. Ratios of permanent environment were also moderate and ranged from 0.16 to 0.22. The ranges in breeding values for the animals with and without records were moderate or high, e.g. 166.8 kg, 1312 kg, 1436 kg, 282 day, 121.2 kg, and 3.044 kg for 3-month milk yield, annual milk yield, total milk yield, lactation period, monthly milk yield, and daily milk yield, respectively. Accuracies of breeding values recorded for lactation traits were high and ranged 0.42 to 0.76. The percentage of animals that had positive estimates of breeding values for all traits were nearly similar and ranged 53.3 to 57.30%. The rates of selection responses predicted were moderate or high where these rates were ranged from 3.1 to 9.6 % relative to the actual mean of the trait.
Key words: Animal model, genetic evaluation, heritabilities, lactation, permanent environment, saudi camels
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