Abstract #M277

# M277
Metabolic profile of Holstein heifers fed carinata meal compared with canola meal and a control diet.
Karla Rodriguez-Hernandez*1,2, Jill L. Anderson1, Jeffrey A. Clapper3, George A. Perry3, 1Dairy and Food Science Department, South Dakota State University, Brookings, SD, 2Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Matamoros, Coahuila, México, 3Animal Science Department, South Dakota State University, Brookings, SD.

Carinata meal is a developing oilseed meal that contains glucosinolates which may impair thyroid gland function and consequently metabolism and reproduction. Our objective was to compare the metabolic profile and onset of puberty of dairy heifers fed diets containing carinata meal, canola meal, or a control diet. A 16-wk randomized block design experiment with 36 Holstein heifers (6.3 ± 0.1 mo of age, and 207 ± 3 kg of BW) was conducted. Heifers were blocked by age. Treatments were (1) carinata meal (CRM), (2) canola meal (CAN), and (3) a control diet (CON) with most of the protein provided from soybean meal. Test meals were solvent extracted and included at 10% of diet DM. Diets were isocaloric and isonitrogenous and contained similar ingredients, other than the test feeds. Heifers were limit-fed rations at 2.4% of BW on DM basis using a Calan gate system. Jugular blood samples were collected 4 h post-feeding on 2 d during wk 0, 4, 8, 12, and 16 for metabolite and thyroid hormones analyses. To determine onset of puberty, blood samples were taken every 3 or 4 d for progesterone analysis. Data were analyzed using MIXED procedures with repeated measures in SAS 9.4. Puberty data were analyzed as binomial data (cycling or not cycling) and using repeated measures by 10-d and 10-kg intervals of age and BW. Significance was declared at P < 0.05. Glucose (75.9, 75.8, and 77.1 mg/dL; SEM = 1.65 for CRM, CAN and CON, respectively), cholesterol (81.7, 81.2, and 79.0 mg/dL; SEM = 2.95), triglycerides (23.4, 23.3, and 21.3 mg/dL; SEM = 1.13), plasma urea nitrogen (18.4, 18.0, and 17.2 mg/dL; SEM = 0.41), triiodothyronine (135.4, 140.7, and 141.6 ng/dL; SEM = 5.73), and thyroxine (4.7, 4.3, and 4.6 μg/dL; SEM = 0.17) concentrations were similar (P > 0.05). Age (297, 290, 294 d; SEM = 3.1) at puberty was similar among treatments. Heifers fed CRM and CON weighed less at puberty than heifers fed CAN (318 and 317 vs. 329 kg; SEM = 3.2; P = 0.02). Results demonstrate that heifers can be limit-fed diets with 10% CRM without negative effects on metabolic profile and onset of puberty, showing it is viable as a feed for heifers.

Key Words: carinata meal, metabolic profile, dairy heifer