معاملات تصحيح إنتاج الحليب و أوزان المواليد لبعض العوامل غير الوراثية في أغنام العواس

الملخص EN

Production records were corrected for some environmental effects to remove the variance, due to environment among animals before genetic evaluation.

Non-genetic factors effect on milk yield and weights at birth, and weaning, adjusted at 180 age day, 360 age day, and at 480 age day of Syrian Awassi sheep in both lines production (milk, meat) were determined for 6864, 10733 records of Awassi sheep for milk and weights traits, respectively.

Data were collected from the Scientific Agricultural Research Center in Salamia, Syria during 1987 and 2005 years.

Data were analyzed statistically using the least squares means, by SAS program (1(1996).

Line production (milk, meat), lambing month, and parity had high significant effects, while ewe age had significant effect on total milk yield.

The effects of birth type, sex of lamb had high significant on studied weights.

Polynomial equation was selected to describe lactation milk according to high R-squares (R2 = %99.5 - 89.7).

So polynomial equation was fitting in each parity.

Correction factors were calculated for bi-weekly daily milk yields, total milk yields according to parity and month of lambing.

Correction factors were calculated for twin birth of lambs to be compared with single lamb, also female lamb sex to compare male born for weights traits according to ewe age.

Correction factors of total milk yield in milk herd according to parity ranged 1.00 to 1111.63, while in meat herd ranged 1.00 to 1111.83.

Correction factors of total milk yield in milk herd according to lambing month ranged 1.00 to 8.04, while in meat herd ranged 1.00 to 6.52.

Correction factors of female lamb’s weights in milk herd according to ewe age (male lamb weights was taken as a comparison base) ranged 1.054 to 1.379, while in meat herd ranged 1.058 to 1.371.

Correction factors of twin’s weights in milk herd according to ewe age (single lamb weights were taken as a comparison base) ranged 1.051 to 1.328, while in meat herd ranged 1.038 to 1.362.

This study was concluded that, the polynomial equation was described for lactation milk production in Awassi sheep.

Month lambing, parity had affected total milk yield.

Also lambing type, gender kids affected weights traits.

So we estimated correction factors for them.

And it was recommended to application environmental correction factors before genetic evaluation for herd or traits, to be improved by genetic selection