Crossbred Lamb Production from Columbia and Suffolk Ewes II. Simulation of the Sheep Flock; Net Return Per Ewe

Net returns per ewe exposed to a ram and per hectare were estimated for Suffolk and Columbia-type range ewes producing crossbred lambs on western Oregon hill pastures. To estimate ewe and lamb feed requirements, a deterministic, discrete-step, grazing simulation model was run for the two ewe breeds for 1973 and 1974 production years. Results were compared to an independent grazing study conducted at the same time on similar pastures. At the start of mating, average weights of Suffolk and Columbia ewes were 71.2 and 57.4 kg, respectively. For 1973, Columbia ewes and their lambs consumed 378 kg dry matter (DM) of pasture and 209 kg DM of supplemental feed, while Suffolks consumed 434 kg DM of pasture and 240 kg DM of supplemental feed. For 1974, Columbias consumed 409 kg DM of pasture and 201 kg DM of supplemental feed, while Suffolks consumed 478 kg DM pasture and 228 kg DM supplemental feed. Lamb income was $27.14 for Columbias and $34.87 for Suffolks for 1973 and $17.94 and $25.27 for the two breeds, respectively, for 1974. Wool income was $6.75 for Columbias and $3.52 for Suffolks in 1973 and $6.34 and $3.19 for Columbias and Suffolks, respectively, in 1974. Return per ewe above feed costs was $11.95 for Columbias and $13.18 for Suffolks in 1973 and $2.11 for Columbias and $3.12 for Suffolks in 1974. Net return per ewe above feed and variable costs for labor, depreciation and interest was $8.09 for Columbias and $9.62 for Suffolks during 1973, and $−1.03 and $.46 for the two breeds, respectively, during 1974. Net return per hectacre was $94.65 for Columbias and $96.20 for Suffolks during 1973 and $−12.05 for Columbias and $4.60 for Suffolks during 1974. Copyright © 1978. American Society of Animal Science . Copyright 1978 by American Society of Animal Science.