Maximum herd efficiency in meat production III. Feeder - breeder dimorphism

Abstract

Feeder- breeder dimorphism is advantageous when large offspring for slaughter is obtained from small breeding animals. The effect of feeder- breeder dimorphism on herd efficiency is evaluated for terminal crossbreeding and growth modification by biotechnological or dietary means. Selection criteria for breeds or lines in terminal crossbreeding can be derived from economic weights relating to terd efficiency, i.e. from the value of the percentage relative gain in herd efficiency for a given percentage relative gain in a component.

Slagdier- teeldier-dimorfisme is voordelig wanneer groot nageslag vir verslagting verkry word vanaf kleiner teeldiere. Die effek van slagdier-teeldier-dimorfisme op kuddedoeltreff,~ndheid is geevalueer vir terminale kruisteelt en vir groeimanipulasie by wyse van biotegnologie of dieetmodifikasie. Seleksiekriteria vir rasse en lyne in terminale kruisteelt kan afgelei word van ekonomiese gewigte wat op verwan~skappemet kuddedoeltreffendheid beros, oftewel van die waarde van die persentasie relatiewe toename in kuddedoeltreffendheid vir 'n gegewe persentasie relatiewe