Evaluation of a Self-feeding System with a Total Mixed Ration without Long Fiber to Lot-fed Beef Calves
An experiment was conducted to evaluate the effect of a feed delivery system on the performance and behavior of lot-fed growging cattle. Forty eight Hereford calves (148.3±25.8 kg, 272± 20 days old) were randomly allocated to 8 pens outdoors to receive 1 of 2 treatments, which consisted in an all-concentrate diet (CP: 16.2%, ME: 2.51 Mcal/kg) offered ad libitum, and delivered daily in three meals (DF) or using self-feeder troughs placed in each pen (SF). Self-feeders were filled weekly, and checked daily to ensure permanent feed availability. The experiment lasted eight weeks, being preceded by four weeks of introduction to the diet and experimental facilities. The experiment was analyzed as a completely randomized design with repeated measures. Calves in SF showed lower liveweight gain (LWG 1.362 vs. 1.516 kg/day; P < 0.05) and lower dry matter intake (DMI, 5.7 vs. 6.8 kg/day; P < 0.05) but tended to be more efficient in terms of feed to gain ratio (4.2:1 vs. 4.5:1; P = 0.08) compared to SD. Feed delivery system did not affect between-day variation in DMI (P > 0.1) but it determined a higher intake activity and a lower idling in SD (P < 0.05) and a more stable diurnal pattern of intake in SF. By the end of the feeding period DF calves were heavier (P < 0.05) but no differences were observed in fat deposition (P > 0.1). These results evidenced SF as a viable delivery system for the type of diet evaluated offered to lot-fed calves.