Evaluation of some factors influencing the weight of lamb and placenta at lambing in local sheep under arid environment of Saudi Arabia

الملخص EN

Data of the present study were collected from 105 lambing from 7 breeding groups.

The sheep flocks were raised at Hada El- Sham Experimental Station of King Abdulaziz University, KSA.

The aim of the study was to evaluate the effect of breed, season of lambing, parity, weight of ewe and sex of lamb on lamb birth-weight and placental weight at lambing.

The average lamb birth weights (LBWT) of different breed groups were 3.01, 2.95, 2.77, 3.29, 2.82, 3.34 and 2.97 kg for Naeemi (NAE), Sawakni (SAW), Najdi (NAJ), Harri (HAR), and crosses of (HAR × NAJ), (HAR × SAW) and (HAR × NAE), respectively.

Difference between the two averages was significant.

The average placental weights (PWT) of the same breeds were 488, 507, 481, 447.94, 457.57, 491.25 and 527.21 g respectively.

Difference between the two averages was significant.

The average fluids weight (FWT) of the different groups were 2.12, 2.25, 2.31, 1.81, 2.05, 2.22 and 1.91 kg, respectively.

Differences between NAJ and HAR were significant (2.31 and 1.81 kg, respectively).

No consistent pattern was observed with regard to parity effects on LBWT, PWT.

LBWT was heavier for male lambs than for female lambs, however, PWT of female lambs was heavier than males.

Sex difference was found to have significant effect on LBWT and PWT.

Estimates of linear regression revealed that the increase in ewe weight was associated with an increase in LBWT, PWT and decrease in FWT.