Osama yosef
General Commission of Scientific Agricultural Research-
GCSAR/ Jossih Al-Kharab
beFaculty OF Agriculture- Damascus University ,
2010
Abstract
A total of 2536 records of shami goat, collected during 2000-2008 at the scientific agricultural research station in Karahta, Syria, were used to determine the genetic parameters and factors affecting total milk yield (TMY) and lactation period (LP). Data were analyzed by the Least Squares Method and Maximum Likehood Function to determine the effects of some genetic and non-genetic factors affecting those traits. Harvey,1990 program was used to estimate some heritability, genetic and phenotypic correlations (rg, rp) on the studied traits of shami goat.
The least squares means of total milk yield was 488±22 kg. Sire, type, parity, year and the interaction between parity and year had highly significant effect on TMY. While the interaction between type and parity had no significant.
The least squares means of lactation period was 226±4 day. Year and the interaction between parity and year had highly significant. The Sire, parity had significant effect, while the type and the interaction between type and parity had no significant effect on LP.
Estimates of heritability were 0.20±0.05 and 0.083±0.04 TMY and LP, respectively. Also the prediction of genetic and phenotype correlation between the two studied traits were 0.529±0.18 and 0.59±,respectively.
The Repeatability for the two studied traits were 0.0549 and0.0546 respectively.
The result of selection response in deferent selection intense showed in the table:
| selection intense | 5% | 10% | 15% | 20% |
| selection response TMY | 42.8 | 36.5 | 31.2 | 27 |
| selection response LP | 5.6 | 4.8 | 4.1 | 3.5 |
Breeding value for total milk yield was ranged between (76 to 51- ), and Breeding value for lactation period was between (30 to 9-).
Milk yield curve was Corrected depending on the age, the result showed that the best yield was in the third parity.