Metabolism and Nutrition: Feed Additives

A study was conducted to determine the clinical effects of 2% ractopamine hydrochloride (RAC) Type A Medicated Article on growth performance in tom finishing turkeys (576, Nicholas, Large White) during 3 different age periods: 15–17, 17–19, and 19–21 wks of age. After a one week acclimation period, turkey finisher toms were fed one of 2 treatments with and without RAC (4.6 g/ton) for the last 14 d before slaughter. The pen of turkeys (10 toms/pen) was the experimental unit and each treatment was replicated 8 times. Toms were allocated to pens one week before the start of the treatment based on body weight. Individual body weights were taken at the start and finish of the 14 d treatment phase. Feed intake was measured for the 2 week period. Data were analyzed using mixed model procedures (SAS). The model included diet treatment, age group and their interaction as a fixed effect with significant effects at P < 0.05. Turkeys fed RAC, on average, had 0.3 kg increased body weight. Average daily gain of turkeys fed Topmax was improved 9.2% (20.2 g/day) for all age groups. No differences were noted for feed intake among diet treatments. Feed efficiency (feed/gain) of turkeys fed RAC was improved by 6.75% (20 points) during the feeding period compared with the respective nonsupplemented control treatments. Feeding of RAC to finisher toms for 2 weeks improved gain and feed efficiency regardless of market age.