Which is more important for reproduction of Egyptian ossimi ewes : body condition score or body weight?

الملخص EN

The present study was carried out using 171 of Ossimi ewes, related to a commercial sheep flock.

It is aimed to study which factor is more important for reproductive performance, ewe body condition score (BCS) at mating or ewe body weight.

Ewes were classified according to their body weights to 30-34 kg, 35-39 kg, 40-44 kg and ≥45 kg and to their body conditions to the scores ≤ 2, 2.5, 3 and > 3.

The traits were analyzed using chi square CATMOD procedure (SAS, 2004).

Body condition score of ewes at mating significantly affected 78 % of the studied reproductive traits, compared to only 11 % for their body weights.

In addition, the significance levels for the effect of BCS varied between P < 0.001 (Ewes conceived at the first two estruses per ewes joined to rams [CR1], Lambing rate, and Potential lambing rate), P < 0.01 (ewes showed estrus per ewes joined to rams [ESE / EJ] and kilograms born per ewes joined to rams [KgB / EJ]) and P < 0.05 (ewes needed 3 estruses or more to be conceived per ewes joined to rams [CR2] and ewes conceived at the whole breeding season per ewes joined to rams [CR3]).

While only CR1 was affected by body weight of ewes (P < 0.05), that refers to the importance of BCS of ewes at mating than their body weights.

Therefore, it is recommended to depend on BCS rather than body weight to assess the status of ewes before mating.

This choice will help holders of sheep flocks for making decisions to cull, keep or give ewes the proper regime to control their body conditions to the required scores.