ABSTRACT
The reproductive performance of 482 multiparous ewes, with growth characteristics of 585 lambs from Dorper rams and ewes: 3/4 Texel x 1/4 Corriedale (TXC, n = 68); 1/2 Romney Marsh x 1/2 Corriedale (RMC, n = 64); 3/4 Poll Dorset x 1/4 Corriedale (PDC, n = 68); 1/2 Finnish Landrace x Australian Merino (FLAM, n = 183) and Australian Merino pure ewes (AM, n = 202) and kg of lamb produced/kg of sheep used in the service (as an indicator of efficiency), grazing natural and sown pastures, were studied. The TXC and FLAM sheep had the highest lambing percentage (167.89 and 174.36%, respectively) compared to the rest of the other crosses, and did not differ from each other (121.43 and 125.49%, PDC and RMC respectively, P>0.05), but were higher than AM (88.99%), due to the greater number of lambs born / ewe calving rather than their higher fertility. The type of ewe also affected (P<0.0001) lamb growth until its sale at 41.6±6.7 kg to 206±7.25 days of age, showing mothers of TXC lambs, PDC and RMC had higher daily gains than the FLAM and these more than those of MA. However, in all crosses tested, only FLAM was more efficient than MA.
multiple crosses; Finnish Landrace sheep crosses; Australian Merino; lamb sold kg/kg sheep served
