This study was conducted at fedio dairy station belongs to the General organization
for cattle in Lattakia.. A total of 2534 production records of 1771 Holstein cattle were used
to study factors affecting the Days open (DO) during 1990 to 2013, and
to study the effects
of calving year, calving season, parity and interactions between studied factors on this trait.
Data were analyzed by the Least Square Means, and Duncan test was used to compare
means by SAS 9 program.
The overall mean for Days Open (DO) was 150.23 ± 1.44 days. and affected
significantly (P< .0..1) by calving year, calving season, parity and interaction (calving
year × calving season), (calving year × calving season) and (P<.0.5 ) by interaction
(calving year × calving season × parity) on the Days Open, but there was no significant
effect for interaction (calving year × parity).
Results suggested that better management, and improving the feeding status may
reduce Days Open to typical period (60 - 90 days), reduce interval calving, to get calf
every year, and increase reproductive and economic efficiency of dairy cattle at fedio
station.
This study was conducted at Kharabo Dairy Station belongs to the Faculty
of agriculture, University of Damascus. 553 records for 206 Holstein Friesian
cattle were used to study factors affecting the calving interval during 1982 to
2007. Data were
exposed eccording to GLM, and analysis of variance was used
to determine the calving interval (CI) and the effect of calving year, calving
season, parity and interactions on the calving interval, and Duncan test was
used to compare means by SPSS program. The overall mean for (CI) was
459.12±4.90 days. and affected significantly (0.001>P) by calving year, but
there was no significant effect for calving season, parity and interactions
between studied factors on the calving interval. These results suggested that
better management, and applaying more efficient administration practices as
well as to improving the feeding status may reduce calving interval to typical
period of 365 days and increase reproductive and economic efficiency of dairy
cattle at Kharabo station.
أدى استخدام عرق الهولشتاين فريزيان بشكل واسع في أعمال الخلط التربوي و الإنتاجي مع تحسين
العوامل البيئية إلى تحسين إنتاجية الأبقار من الحليب، إلا إنه قد سجل مع هذا التطور في إنتاج الحليـب
ازدياد في حالات أمراض التهاب الضرع Mastitis ، و قد أشارت المر
اجع العلمية في هذا السياق إلـى أن
الإصابة بأمراض التهاب الضرع يزداد احتماله مع ارتفاع إنتاجية الأبقـار مـن الحليـب، كمـا سـجلت اختلافات بين سلالات أو عروق الحليب بالنسبة لهذا المرض.
