Feed intake, nutrient digestibility, and selected rumen parameters in feedlot bulls fed diets with different feed additives

• Published in: PloS one 2021-11, Vol.16 (11), p.e0259414
• Main Authors: Silva, Breno de Castro, Pacheco, Marcos Vinicius Carneiro, Godoi, Letícia Artuzo, de Souza, Gilyard Angelo Pinheiro, Trópia, Nathália Veloso, Pucetti, Pauliane, Silva, Flávia Adriane de Sales, Menezes, Ana Clara Baião, Rennó, Luciana Navajas, Paulino, Mário Fonseca, Schoonmaker, Jon Patrick, Valadares Filho, Sebastião de Campos
• Format: Article
• Language: English
• Subjects: Additives; Amylases; Animal Feed - analysis; Animal Nutritional Physiological Phenomena; Animal sciences; Animals; Antibiotics; Bicarbonate; Bicarbonates; Biology and Life Sciences; Cattle; Diet; Diet - veterinary; Dietary Supplements; Digestibility; Digestion - drug effects; Dilution; Dosage and administration; Dry matter; Eating; Efficiency; Environmental aspects; Enzymes; Experiments; Feed additives; Feedlots; Feeds; Food additives; Food and nutrition; Food intake; Growth; Health aspects; Lasalocid; Limonene; Linear alkyl sulfonates; Magnesium; Magnesium oxide; Maintenance and repair; Male; Medicine and Health Sciences; Metabolic disorders; Microbiology; Microorganisms; Monensin; Monensin - administration & dosage; Monensin - pharmacology; Nutrients; Nutrients - metabolism; Organic matter; Parameters; pH effects; Physical Sciences; Research and Analysis Methods; Rumen; Rumen - metabolism; Silage; Sodium; Starch; Superconductors (materials); Temperature effects; Virginiamycin; Zoology; α-Amylase
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0259414

An experiment was conducted to evaluate the feed intake, nutrient digestibility and selected rumen parameters in feedlot bulls fed diets containing different feed additives. Six rumen-cannulated Nellore bulls (age = 8 ± 1.0 months; initial BW = 225 ± 13.2 kg) were distributed in a 6 × 6 Latin square design. Six experimental diets based on 30% corn silage and 70% concentrate on a dry matter (DM) basis were evaluated. Diets differed in feed additive on a DM basis, as follows: 1.4% bicarbonate and magnesium oxide in 3:1 ratio (BOX); 36 ppm lasalocid sodium (LAS); 30 ppm monensin sodium (MON); 25 ppm virginiamycin (VIR); 30 ppm monensin sodium plus 25 ppm virginiamycin (MV); and 3.15% commercial mineral supplement containing D-limonene and exogenous α-amylase (EOA). The experiment lasted 144 d, with six periods of 24 d. Each period consisted of 14 d for dietary adaptation, 3 d for feces and urine collection, and 7 d for omasal and ruminal digesta collection. Bulls fed the BOX diet showed greater (P < 0.05) intake of DM, organic matter (OM), neutral detergent fiber (apNDF), crude protein (CP), and starch compared to the other diets. Diets with LAS, MON, VIR, MV, or EOA did not influence (P > 0.05) the DM, OM, apNDF, CP, or starch intake of feedlot bulls. Bulls fed the EOA diet showed greater (trend; P = 0.09) ruminal digestibility of starch compared to the other diets. The feed additives did not affect (P > 0.05) the intestinal or total tract digestibility of starch, rumen pH, microbial efficiency, total rumen fluid, dilution rate, rate of intake, rate of degradation, or passage rate of the DM, OM, apNDF, and starch. In conclusion, LAS, MON, VIR, MV, and EOA diets reduced nutrient intake compared to BOX. Although all feed additives presented similar effects on rumen pH, temperature, and kinetics the presence of exogenous α-amylase in the EOA diet may increase ruminal starch digestibility and apparent total tract digestibility of DM and OM.