ABSTRACT:A feedlot growth performance experiment and 2 metabolism experiments were conducted to evaluate dietary roughage concentration and calcium magnesium carbonate in steers fed a high-grain diet. In Exp. 1, one hundred ninety-two crossbred yearling steers (320 ± 10 kg of initial BW) were fed diets based on steam-flaked corn with 0, 0.75, or 1.5% CaMg(CO 3 ) 2 . There were no effects (P ≥ 0.13) on ADG, DMI, G:F, or total water intake due to CaMg(CO 3 ) 2 . In Exp. 2, five ruminally and duodenally fistulated steers (263 ± 9 kg of initial BW) were used in a 5 × 5 Latin square design, with 5 dietary treatments arranged in a 2 × 2 + 1 factorial: 1) 3.8% dietary roughage and no CaMg(CO 3 ) 2 ; 2) 7.6% dietary roughage and no CaMg(CO 3 ) 2 ; 3) 11.4% dietary roughage and no CaMg(CO 3 ) 2 ; 4) 3.8% dietary roughage and 1.5% CaMg(CO 3 ) 2 ; and 5) 7.6% dietary roughage and 1.5% CaMg(CO 3 ) 2 . Water consumption was less (quadratic, P = 0.003) when 7.6% dietary roughage was fed compared with 3.8 or 11.4% dietary roughage. Intake of DM was not affected (P ≥ 0.16) by dietary roughage or by CaMg(CO 3 ) 2 . Poststomach and total tract starch digestion decreased (linear, P < 0.01) as dietary roughage increased. Ruminal pH tended (P = 0.08) to increase as dietary roughage increased but was not affected (P = 0.60) by CaMg(CO 3 ) 2 . In Exp. 3, DMI and ruminal pH were continuously monitored in a 6 × 6 Latin square design using 6 ruminally and duodenally fistulated Holstein steers (229 ± 10 kg of initial BW). A 3 × 2 factorial treatment structure was utilized, with factors consisting of dietary roughage concentration (4.5, 9.0, or 13.5%) and CaMg(CO 3 ) 2 inclusion (0 or 1.0%) to replace MgO and partially replace limestone. A dietary roughage × CaMg(CO 3 ) 2 interaction (P = 0.01) occurred as steers consuming 13.5% roughage, 1.0% CaMg(CO 3 ) 2 had greater DMI per meal than those consuming 4.5% dietary roughage, no CaMg(CO 3 ) 2 and 9.0% dietary roughage, 1.0% CaMg(CO 3 ) 2 . Steers consuming 13.5% dietary roughage, 1.0% CaMg(CO 3 ) 2 and 9.0% dietary roughage, no CaMg(CO 3 ) 2 had greater meal length (min/meal; P = 0.01) than steers consuming 4.5% dietary roughage, no CaMg(CO 3 ) 2 . Total tract OM digestibility decreased linearly (P = 0.01), and ruminal pH increased linearly (P = 0.01) with increasing dietary roughage concentration. Inclusion of CaMg(CO 3 ) 2 can replace limestone and MgO but did not produce ruminal pH responses similar to those observed by increasing dietary roughage in high-concentrate diets.

The 2015 Dietary Guidelines recommend legume consumption as part of a healthy diet, and consumer interest in non‐meat protein sources has increased. This study describes legume intakes across demographic groups in the U.S. and their association with nutrient intakes and body weight, using Day 1 24‐hour recalls from NHANES 2009–12 and the USDA Food Patterns Equivalent Database 2009–2012. In adults aged 19+ years, the prevalence of legume consumption differed by ethnicity, ranging from 14% among Non‐Hispanic (NH) Blacks (n=2399), to 18% in NH Whites (n=4710) to 31% among Hispanics (n=2671). Among legume consumers, mean intakes also varied by ethnicity, from 2.2 protein oz eq/d among NH White adults, to 2.8 oz eq/d in NH Blacks, to 3.2 oz eq/d among Hispanics. Similar trends were observed in children aged 4 to 18 years (n=5155). Nutrient intakes differed between legume consumers and non‐consumers. Both adults and children who consumed legumes had significantly higher intakes of key nutrients such as fiber, protein, folate, iron, calcium, magnesium and potassium. However, legume consumers also had higher sodium and total energy intakes. Overall, legume consumers exhibited healthier eating patterns. Those who ate legumes consumed a smaller percentage of their total energy from both total and added sugar and ate more oz eq/d of total protein foods. Adult legume consumers also ate more of encouraged food groups such as whole grains, fruit and vegetables. Body weight measures differed between legume consumers and non‐consumers. Adults who ate legumes had significantly lower body mass index (BMI) and waist circumferences than those who did not, despite consuming more total energy. Among children, those who ate legumes had smaller waist circumferences, a lower prevalence of obesity, and a non‐significant trend for lower BMI z‐scores than those who did not eat legumes. These findings suggest that people who eat legumes have healthier diets, and legumes contribute to favorable nutrient intakes in adults and children. In addition, legume consumption may be associated with healthier body weights.Support or Funding InformationFunded by the Bell Institute of Health and Nutrition, General Mills, Inc.