Preference of Carinata Meal Compared with Other Oilseed Meals and Distillers Dried Grains By Dairy Heifers.

Different oilseed meals contain different types and amounts of glucosinolates which may cause bitter tastes. Our objective was to determine if the type and content of glucosinolates in carinata meal affect dairy heifer preference and intake compared to other oilseed meals. Six Holstein heifers (7.2 ± 0.3 mo old; 234.7 ± 15.7 kg BW) were used in sequential elimination preference study to compare five different grain mixes containing 27.4 % (DM basis) of carinata meal (CRM), camelina meal (CAM), canola meal (CAN), linseed meal (LIN), and distillers dried grains with solubles (DDGS). Glucosinolates concentrations were 6.09, 3.24, 0.23, 0, and 0 g/kg of DM for CRM, CAM, CAN, LIN, and DDGS grain mixes, respectively. Heifers were kept in individual pens (3.7 × 4.5 m) with a row of 7 feed containers. Grain mixes were offered for 30 min in the morning and evening. At each feeding positions of grain mixes were randomized and the two end containers were left empty to nullify effects of placement. Grass hay was fed at 1.6% of BW throughout the day in a separate tub. During phase 1, all 5 grain mixes were offered for 5 d and the most preferred by each heifer was removed at the end. In the subsequent phases, days and number of grain mixes were reduced sequentially, until only 2 grain mixes were offered during 2 d. Preference ranking by heifer was based on intake amounts. Kendall’s coefficient of concordance (W) was calculated to evaluate the agreement of preference among heifers. Total DMI were 3.90 ± 1.74, 5.91 ± 1.39, 6.60 ± 1.47, and 6.49 ± 1.16 kg/d for phases 1, 2, 3, and 4, respectively. During phase 1, when all grain mixes were offered, grain mix DMI/d were 1.58 ± 0.57, 0.20 ± 0.43, 0.16 ± 0.17, 0.14 ± 0.57, and 0.07 ± 0.13 kg/d for DDGS, LIN, CRM, CAN, and CAM, respectively. Heifers preferred DDGS first, LIN second, CRM and CAN were tied for third, and CAM was fourth with W = 0.64 and P = 0.009 indicating agreement in preference rankings among heifers. Despite greater glucosinolate content, CRM was comparable to CAN for taste preference, had greater preference compared to CAM, and less preference compared to DDGS or LIN for dairy heifers.