Abstract #436

Section: Ruminant Nutrition
Session: Ruminant Nutrition V
Format: Oral
Day/Time: Tuesday 3:45 PM–4:00 PM
Location: 318
# 436
Metabolic profile of Holstein heifers fed carinata meal.
K. Rodriguez-Hernandez*1,2, J. Anderson1, J. Clapper3, 1Dairy and Food Science Department, South Dakota State University, Brookings, SD, 2CIRNOC-INIFAP, Torreon, Coahuila, Mexico, 3Department of Animal Science, South Dakota State University, Brookings, SD.

Carinata meal (CRM) is an oilseed meal that is a quality source of protein but contains high concentrations of glucosinolates, especially sinigrin. Glucosinolates limit dietary inclusion rates as they may cause issues with thyroid gland function which may negatively influence heifer growth performance; however, in previous results, we demonstrated growth performance was maintained when heifers were fed CRM. Therefore, our objective was to determine effects of feeding CRM compared with distillers dried grains with solubles (DDGS) to peripubertal dairy heifers on the metabolic profile. A 16-week randomized block design experiment with 24 Holstein heifers (6.6 ± 0.7 mo and 218 ± 27 kg of BW) was conducted. Heifers were blocked by age. Treatments diets were (1) 10% cold-pressed CRM (glucosinolates at 2.06 g/kg of diet DM), and (2) 10% DDGS on a DM basis. The remainder of the diets consisted of grass hay, ground corn, soybean meal and mineral mix, and diets were formulated to be isonitrogenous and isocaloric. Heifers were individually fed using a Calan gate feeding system, and the rations were limit-fed at 2.65% of BW on DM basis. Jugular blood samples were collected 3–4 h post-feeding on 2 d during wk 0, 4, 8, 12, and 16 for metabolite and metabolic hormone analyses. Data were analyzed using MIXED procedures with repeated measures in SAS 9.4, and wk 0 results were used as covariate terms for each parameter. Significance was declared at P < 0.05. There were no interactions of treatment by wk for any of the metabolites and metabolic hormones measured. Glucose (84.0, and 82.3 mg/ dL; SEM = 1.25 for CRM and DDGS, respectively), plasma urea nitrogen (19.8, and 19.77 mg/dL; SEM = 0.48), IGF-1 (117.1, and 105.0 ng/mL; SEM = 4.9), triiodothyronine (140.2, and 154.7 ng/dL; SEM = 5.3), and thyroxine (6.3, and 6.6 μg/dL; SEM = 0.23) concentrations were similar (P > 0.05) among treatments. Cholesterol concentration was greater (P < 0.05) in the CRM heifers than DDGS heifers (89.9, and 78.2 mg/dL; SEM = 2.6). These results demonstrate that growing heifers can be limit-fed diets with 10% CRM without negative effects on the thyroid hormones and metabolic status.

Key Words: carinata meal, glucosinolates, dairy heifer