Zebu cattle fed dry distiller's grain or cottonseed meal had greater nitrogen utilization efficiency than non-supplemented animals.

This study evaluated intake, apparent digestibility, ruminal parameters, nitrogen balance, and microbial protein synthesis in grazing beef cattle fed a mineral mix or combination of two coproducts (cottonseed meal and dried distiller's grains (DDG)) during the wet season. Urochloa brizantha cv. Marandu pastures were managed under continuous stocking to maintain a fixed grazing height of 25 cm using put-and-take methodology. Eight rumen cannulated Nellore steers were used to evaluate the different supplementation strategies. The experiment was composed of four treatments: (1) mineral mixed (MM; ad libitum); (2) energy-protein supplement using corn grain (energy) and cottonseed meal (protein; CS); (3) energy-protein supplement with 50% of the cottonseed meal replaced by DDG (50DDG); and (4) energy-protein supplement with 100% of the cottonseed meal replaced by DDG (100DDG). Except for MM, all supplements were supplied at a level of 0.3% of body weight (BW). A double Latin square was the experimental design performed, with eight cannulated animals, four treatments, across four experimental periods. There was a difference between dry matter and nutrient intake among treatments. The nitrogen balance was different between MM and the other treatments. There was a linear decrease in the rumen ammonia nitrogen levels under CS, 50DDG, and 100DDG. There were no treatment effects on the other parameters evaluated (P ≥ 0.10). Replacing the protein source in the supplement composition did not affect the metabolic parameters and the microbial protein synthesis. Supplementation at a rate of 0.3% BW, compared to MM supplementation, increased the nitrogen utilization efficiency in grazing cattle.

Does the Effect of Replacing Cottonseed Meal with Dried Distiller's Grains on Nellore Bulls Finishing Phase Vary between Pasture and Feedlot?

The study aimed to evaluate the effect of replacing cottonseed meal by dried distiller's grains (DDG) in terms of efficiency in the productive aspects of beef cattle finishing in pasture versus feedlot. The experiment was conducted in a completely randomized design in a 2 × 3 factorial arrangement, with two production systems (pasture versus feedlot) and three supplements: CM, conventional supplement with cottonseed meal (CM) as a protein source; 50DDG: supplement with 50% replacement of CM by DDG; and 100DDG: 100% replacement. The effect of replacing CM by DDG on dry matter and nutrients intake and nutrients digestibility depends on the finishing system (p < 0.05). While in the pasture system animal consumed more nutrients in the CM, a greater intake was observed in the 100DDG in feedlot. The nutrients digestibility was lower in the pasture (p < 0.05). Animal performance and final body weight were higher in the feedlot (p < 0.0001), with averages of 1.57 kg/d and 566 kg of final body weight (FBW) for feedlot, and 0.99 kg/d and 504 kg FBW for pasture. The use of DDG does not change the animal performance finished in pasture or feedlot, and it is a viable alternative to replace conventional supplements in finishing phase in both systems in tropical environment.

Organic additives used in beef cattle feedlot: Effects on metabolic parameters and animal performance.

Organic additives are recently being used in animal diets owing to their ability to control metabolic issues and result in better animal performance. Specifically, the organic additive Fator P® presents an additional advantage that is to cause a lesser greenhouse gas emission. This study evaluated whether Fator P® intake changes ruminal parameters or animal performance of beef cattle. Evaluations were carried out in a feedlot experiment divided into growing (46 days; two diets [control mix-CM and standard mix-SM] and finishing (lasted 83 days; four diets: CM, SM, Fator P® + virginiamycin, and Fator P® alone [FP]) trials. Animal performance study involved 48 animals allocated to 12 collective pens in completely randomized experimental design. Ruminal parameters were evaluated in separate metabolism study developed carried out using individual pen with four steers. During growing trial, FP diet resulted in higher (p < 0.05) dry matter intake (DMI) and ruminating time. In the finishing trial, diets containing Fator P® resulted in higher DMI than obtained with CM. Most of the ruminal parameters did not differ (p > 0.05) among dietary treatments. Therefore, Fator P® represents a viable and safe strategy for supplementation to beef cattle finished using high-concentrate diet in feedlot systems.