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 (3MMY), annual milk yield (AMY), total milk yield (TMY), length of lactation period (LP), monthly milk yield (MMY), and daily milk yield (DMY). Data were analyzed 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.
Phenotypic variations for most lactation traits in Saudi camels were moderate; ranging from 12.2 to 31.2%. Direct heritabilities (h2a) obtained for lactation traits were moderate and ranging from 0.08 to 0.25. Ratios of permanent environment for these traits were also moderate and ranging from 0.20 to 0.28. The ranges in breeding values for the animals with and without records genetically evaluated were moderate or high. These ranges were 166.8 kg, 1312 kg, 1436 kg, 282 day, 121.2 kg, and 3.044 kg for 3MMY, AMY, TMY, LP, MMY, and DMY, respectively. Accuracies of breeding values recorded for lactation traits were high and ranging from 0.42 to 0.76. The percentages of animals that have positive estimates of breeding values for 3MMY, AMY, TMY, LP, MMY, and DMY were 57.9, 57.3, 54.3, 56.3, 56.4, and 53.3%, respectively. The rates of selection responses predicted were moderate or high where the rates were ranging from 3.1 to 9.6 % relative to the actual means of the traits. |
