263 Effects of Programmed Compensatory Gain on Feedlot Steer Performance

Abstract

Abstract The objective was to determine the effects of programmed compensatory gain on feedlot steer growth performance. After a period of growth restriction, a return to ad libitum intake will result in compensatory gain as cattle convert feed more efficiently due to reduced maintenance costs. Simmental × Angus steers (n = 159; BW = 278 ± 49 kg) were blocked by BW, stratified by sire, and allotted to 10 pens. Each pen contained a 3.0 m-long bunk to allow 19 cm of linear bunk space per steer. Pens were randomly assigned to one of two treatments on d 0: control (CON) or programmed compensatory gain (PCG). To achieve programmed compensatory gain, previously growing animals were maintained at a constant BW by reducing the amount of feed offered by 3.29% daily for 10 consecutive d. Thus, on d 54, PCG steers were consuming 72% of original dry matter intake (DMI) and subsequently returned to ad libitum intake to facilitate a period of compensatory gain. Feed intake for CON pens was managed using slick bunk management for the entire experiment. Steers were fed a common diet consisting of 20% corn silage, 20% modified wet distillers grains, 25% high moisture corn, 25% dry rolled corn, and 10% supplement inclusion on a dry matter basis. Steers were feed twice daily at 0800 h and 1200 h. Data were analyzed using MIXED procedure of SAS 9.4 using a beta distribution. The model included fixed effects of treatment and block. From d 39 to 63, average daily gain (ADG) was greater (P = 0.03) for PCG steers compared with CON steers. No treatment effect (P = 0.36) for dry matter intake was observed from d 39 to 63 as PCG and CON steers were consuming 9.49 and 9.67 kg, respectively. Thus, PCG steers had a greater (P = 0.01) gain:feed (G:F) than CON steers from d 39 to 63. Body weight was not different (P = 0.38) on d 148. Also, ADG from d 0 to 148 was not different (P = 0.54) as PCG and CON steers gained 1.92 and 1.91 kg, respectively. From d 0 to 148, overall dry matter intake was not affected (P = 0.91) by treatment. However, programmed compensatory gain steers had a greater G:F (P = 0.01) compared with CON steers for the overall feeding period (0.216 vs 0.210, respectively). In conclusion, programmed compensatory gain improved G:F of feedlot steers over a 148 d-finishing phase without affecting final body weight. Effects of programmed compensatory gain should be further evaluated in a commercial setting with large feedlot pens.