Abstract: [Objective] The dietary nutrients apparent digestibility and daily gain of beef cattle at different growth stages were compared to provide references for ration formulation of beef cattle feeding. [Method] Two groups of Simmental crossbred cattle were randomly selected according to their age and weight. The light weight group comprised of ten 12- to 15-month-old cattle with weights of 250-300 kg. The heavy weight group comprised of ten 15- to 18-month-old cattle with weights of 350-500 kg. The diet was adjusted according to the weight change of beef cattle. The formal test period was divided into early and late test stages. Using ash insoluble in hydrochloric acid （AIA） as endogenous indicator, the apparent digestibility of dietary nutrients was determined by spot fecal collection method. [Result] The overall gain and average daily gain of the light weight group were significantly （P<0.05） different from those of the heavy weight group over the course of the experiment. In the early stage of the experiment, the apparent digestible amount of organic matter （OM）, crude protein （CP）, neutral detergent fiber （NDF）, acid detergent fiber （ADF）, starch, and energy in the diet of light weight group significantly （P<0.05） differed from that of heavy weight group. However there was no significant （P>0.05） difference in the apparent digestibility of OM, CP, NDF, ADF, starch, and energy between the two groups. [Conclusion] Under the conditions of the experimental diet composition, there was no significant difference in the apparent digestibility of dietary nutrients between the beef cattle at the two feeding stages, and the increasing digestible nutrient intake could increase the daily gain.

Key words: beef cattle, daily gain, nutrients, apparent digestibility