Abstract #T367
Section: Ruminant Nutrition
Session: Ruminant Nutrition: Beef II
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
Session: Ruminant Nutrition: Beef II
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
# T367
Effects of oscillating dietary crude protein on nutrient intake, digestibility, performance, and carcass traits of finishing crossbred bulls in feedlot.
Paloma de Melo Amaral*1,3, Stefanie Alvarenga Santos2, Laura Franco Prados1, Lays Mariz1,3, Lyvian Cardoso Alves1, Ana Clara Baiao Menezes1, Faider Alberto Castano Villadiego1, Flavia Adriane de Sales Silva1, Sebastiao Valadares Filho1, Antonio Faciola3, 1Federal University of Vicosa, Vicosa, MG, Brazil, 2School of Veterinary Medicine and Animal Science of the Federal University of Bahia (UFBA), Salvador, BA, Brazil, 3University of Nevada, Reno, NV.
Key Words: oscillating protein, beef cattle, feedlot
Effects of oscillating dietary crude protein on nutrient intake, digestibility, performance, and carcass traits of finishing crossbred bulls in feedlot.
Paloma de Melo Amaral*1,3, Stefanie Alvarenga Santos2, Laura Franco Prados1, Lays Mariz1,3, Lyvian Cardoso Alves1, Ana Clara Baiao Menezes1, Faider Alberto Castano Villadiego1, Flavia Adriane de Sales Silva1, Sebastiao Valadares Filho1, Antonio Faciola3, 1Federal University of Vicosa, Vicosa, MG, Brazil, 2School of Veterinary Medicine and Animal Science of the Federal University of Bahia (UFBA), Salvador, BA, Brazil, 3University of Nevada, Reno, NV.
Protein is a costly nutrient and excessive dietary N is an important environmental concern. The finishing period may offer the possibility of reducing dietary CP without negatively affecting beef-cattle production. This reduction may be achieved by oscillating dietary CP during the finishing period. Therefore, the goal of this study was to evaluate the effects of fixed or oscillating dietary CP on nutrient intake, digestibility, performance, and carcass traits of crossbred bulls in the finishing period. Twenty-four bulls (417 ± 54 kg of initial BW) were used in a complete randomized block design in a 2 × 2 factorial arrangement with 6 replications per treatment. The treatments were: Constant 11% CP (11–11), constant 13% CP (13–13), oscillating 11–13% CP (11–13), and oscillating 13–11% CP (13–11). The experiment lasted 72 d and oscillating treatments switched diets at d 37. Animals were housed and fed individually. Data were analyzed using the MIXED procedure in SAS and significance was declared at α = 0.05. Partial data are presented in Table 1. There were no interactions (P > 0.05) between fixed and oscillating CP level. There were no effects (P > 0.05) of CP levels on intakes of DM, OM, NFC, and TDN. There were no effects (P > 0.05) of CP levels on ADG or in carcass traits. We concluded that there were no benefits of oscillating dietary CP levels for crossbred bulls with ADG of approximately 2 kg/d in feedlots. There were no performance or carcass traits benefits of feeding more than 11% CP in the diets of crossbred bulls in feedlots.
Table 1. Effects of constant or oscillating CP levels on intake, performance, and carcass traits
1HCDP = hot carcass dressing percentage, SFT = subcutaneous fat thickness.
| Item | Dietary CP | SEM | P-value | |||||
| 11-11% | 11-13% | 13-11% | 13-13% | Pi | Pf | Pi × Pf | ||
| Intake, kg/d | ||||||||
| DM | 12.1 | 11.8 | 10.6 | 11.3 | 1.5 | 0.14 | 0.80 | 0.46 |
| OM | 11.5 | 11.2 | 10.1 | 10.8 | 1.4 | 0.14 | 0.80 | 0.46 |
| NFC | 6.0 | 5.9 | 5.4 | 5.7 | 0.8 | 0.16 | 0.81 | 0.46 |
| TDN | 8.6 | 8.3 | 7.7 | 8.4 | 1.0 | 0.36 | 0.63 | 0.52 |
| Performance, kg/d | ||||||||
| ADG | 2.1 | 2.0 | 1.9 | 2.0 | 0.3 | 0.85 | 0.89 | 0.59 |
| Carcass traits1 | ||||||||
| HCDP, % | 58.4 | 59.0 | 58.6 | 59.9 | 0.02 | 0.70 | 0.52 | 0.30 |
| SFT, mm | 2.9 | 3.1 | 2.8 | 3.1 | 1.12 | 0.86 | 0.86 | 0.66 |
Key Words: oscillating protein, beef cattle, feedlot
