Does Beef Inclusion in a Modern Diet Influence Risk Factors for Obesity-Related Metabolic Disorders in a Swine Biomedical Model

Twenty-four Berkshire gilts were obtained at weaning and transported 1,480 km to the NDSU Animal Nutrition and Physiology Center (Fargo, ND). Upon reaching 18 kg, gilts were sorted, blocked by litter and weight, and penned individually. Gilts were assigned a treatment (TWD vs. GB) and provided feed at 3.7% of body weight (BW; 12 gilts/ treatment) for 91 d. A TWD was developed for swine using the 2007 to 2008 National Health and Nutrition Examination Survey with micronutrients corresponding to American intakes at the 50th percentile when adjusted for nutrient density (mass of nutrient/calorie). For GB, cooked ground beef (70:30 lean:fat) replaced sugar in TWD on a kcal for kcal basis. Blood samples were collected on d0 at start of treatment and then every 28 d. Weekly BW were taken and subcutaneous fat depth (FD) and longissimus muscle area (LMA) were measured at the 10th rib on d 42, 56, 70, and 91. Fat-free lean as a percentage of BW (FFL%) was calculated using FD, LMA, and live BW. Data were analyzed as repeated measures using the mixed procedure of SAS (SAS Inst. Inc., Cary, NC) with fixed effects of treatment, day, and treatment by day with pig as the repeated variable.