Acceptance of a Novel Cheese By-Product Powder By Young Ruminants

Acceptance of a novel cheese by-product powder was evaluated in yearling Holstein heifers through 2 feed preference trials performed at the University of Wisconsin-Platteville Pioneer Farm, Platteville, WI. The cheese by-product was provided by Agri Processing Services, LLC, (Carmel, IN). Each morning, heifers were attracted to headlocks and locked in place. Heifers were then offered 2 feeding trays (14 × 26 × 15 cm) of feedstuffs. Plywood dividers were positioned between heifers to insure heifers only had access to the assigned dietary treatment. Heifers were allowed 15 minutes to consume the offered feed after which feed trays were removed, orts collected, and heifers released. Heifers were offered hay ad libitum throughout the day and were fed a concentrate ration following the daily test period. During each 15-minute test period, heifers were digitally recorded and their eating habits observed. In both trials, heifers (n = 12) were used in a 2 × 2 Latin square design with 2 feedstuffs (trial 1: 500 g concentrate pellets vs 450 g concentrate pellet + 50 g cheese by-product powder, trial 2: 500 g corn silage vs 450 g corn silage + 50 g cheese by-product powder) offered in 2 locations (right or left side) over 4 days. Orts were dried in an oven at 75°C until stable dry matter mass was achieved and used to calculate dry matter intake and feed preference ratio (DMI of test diet × total DMI^-1). Digital recordings were viewed by trained individuals to measure time spent consuming each diet. Dry matter intake, time spent eating and feed preference were compared with significance being declared at P ≤ 0.05. Dry matter intake of pellets was greater than pellets supplemented with cheese by-product (341.6 vs 27.3 g P < 0.01). Dry matter intake of silage was also greater than silage supplemented with cheese by-product (77.3 vs 4.4 g P < 0.01). Time spent eating pellets or silage was greater than time spent eating pellets or silage supplemented with cheese by-product (P < 0.01) and there was a preference (P < 0.01) for feedstuffs without cheese by-product supplementation. Regardless of feedstuff offered, heifers consumed unsupplemented feedstuff first (Trial 1: 57.61 vs 42.39% P < 0.01; Trial 2: 57.29 vs 42.71% P < 0.01). In both trials, heifers would consume feed combined with cheese by-product, but there was a preference for feed offered without cheese by-product supplementation.