In situ rumen degradation of kernels from short-season corn silage hybrids as affected by processing. Transl Anim Sci 2018;2:428-438. [PMID: 32704725 DOI: 10.1093/tas/txy084]

Effects of barley and corn as sources of silage and grain on dry matter intake, ruminal fermentation, and total-tract digestibility in growing beef heifers

The objective of this study was to evaluate the use of barley (BS) or corn (CS) silage when fed with dry-rolled barley grain (BG), corn grain (CG), or an equal blend (BCG) of BG and CG for backgrounding cattle. Ruminally cannulated heifers (n = 5) were assigned to an incomplete 6 × 6 Latin square design. Treatments contained either BS or CS in combination with BG, CG, or BCG. Samples were collected to determine dry matter intake, ruminal fermentation, total-tract nutrient digestibility, and nitrogen (N) balance. Interactions between cereal silage and cereal grain sources were detected for the molar proportions of propionate and butyrate where the magnitude of change with the type of cereal grain was increased in heifers fed CS relative to BS. Feeding CS increased estimated microbial N production (silage, P = 0.022) and fecal N excretion (silage, P = 0.042) over BS. Diets containing BG had greater dry matter, organic matter, starch, and gross energy digestibility values compared with CG, but values for BCG were not different (grain, P ≤ 0.043). Based on limited silage × grain interactions, use of CS in backgrounding diets may increase microbial N production relative to BS and dry-rolled CG may reduce apparent total-tract nutrient digestibility relative to dry-rolled BG.

Use of barley silage or corn silage with dry-rolled barley, corn, or a blend of barley and corn on predicted nutrient total tract digestibility and growth performance of backgrounding steers

The objective of this study was to determine the effects of feeding barley silage (BS) or corn silage (CS) with dry-rolled barley (BG), dry-rolled corn (CG), or a blend of barley and corn grain (BCG), on growth performance and nutrient digestibility, the latter predicted using near-infrared spectroscopy for backgrounding cattle. Steers (n = 288) were stratified by body weight (BW) into 24 pens and pens were randomly assigned to one of six treatments (n = 4) in a 2 × 3 factorial design. Main factors included BS or CS in combination with BG, CG, or BCG. There were no silage × grain interactions. Dry matter intake (DMI; P = 0.018) and final BW (P = 0.004) were greater for steers fed CS than BS, but average daily gain (1.01 kg d−1) and gain-to-feed ratio (0.10 kg kg−1) were not affected by silage or grain source. Steers fed CS also had greater dry matter, organic matter, crude protein (CP), acid detergent fiber (ADF), starch, and gross energy digestibility values (P < 0.01) than BS. Feeding BG increased starch, neutral detergent fiber, ADF, and CP digestibility values (P ≤ 0.01) over CG and BCG. Relative to BS, feeding CS increased DMI, final BW, and nutrient digestibility, whereas dry-rolled BG improved nutrient digestibility when compared with CG and BCG in backgrounding diets.