Variation in growth and efficiency in twin cattle with live weight and food intake controlled

Abstract
In an experiment to investigate the interrelationships of genetics and nutrition in the growth of cattle up to 2 years of age, five monozygotic and six dizygotic Ayrshire twin heifers were reared under close nutritional control on an all cubed diet.Two control systems were used. Some animals were fed similar amounts of food, and differences in growth rate and efficiency examined while others were made to grow alike and differences in food consumption and efficiency examined. Overall, similarly fed animals had similar growth rates and efficiencies and similarly grown animals similar food intakes and efficiencies. Variation in growth, food consumption and efficiency was much less than in an ad lib. feeding system.