Abstract #436

# 436
Growth performance of dairy heifers fed carinata meal compared with canola meal and a control diet.
Karla Rodriguez-Hernandez*1,2, Jill L. Anderson1, 1Dairy and Food Science Department, South Dakota State University, Brookings, SD, 2Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Matamoros, Coahuila, México.

Carinata meal is a developing oilseed meal and has similarities to canola meal. Our objective was to compare the growth performance of dairy heifers fed diets containing carinata meal, canola meal, or a control diet. A 16-wk randomized block design experiment with 32 Holstein heifers [6.3 ± 0.7 mo of age, and 207 ± 20 kg of body weight (BW)] was conducted. Heifers were blocked by age. Treatment diets were (1) carinata meal (CRM), (2) canola meal (CAN), both at 10% of diet dry matter (DM); and (3) control diet (CON) with most of the protein provided from soybean meal. All test meals were solvent extracted. The remainder of the diets were grass hay, distillers dried grains with solubles, ground corn, soybean hulls and mineral mix. Diets were isocaloric and isonitrogenous. Heifers were individually limit-fed rations at 2.4% of BW on DM basis using a Calan gate system. Frame sizes, BW, and BCS were measured at 4 h post feeding on 2 consecutive days during wk 0 and then every 2 wk throughout the feeding period. From all heifers rumen fluid was collected via esophageal tubing at the same time in wk 12 and 16 and during wk 16 fecal grab samples were collected for analysis of total-tract digestibility of nutrients (TTD) using acid detergent insoluble ash as an internal marker. Data were analyzed using MIXED procedures with repeated measures in SAS 9.4. Significance was declared at P < 0.05. The DMI (6.31, 6.16, and 6.05 kg/d, SEM = 0.114 for CRM, CAN, and CON, respectively), average daily gain (1.01, 1.02, and 1.03 kg/d, SEM = 0.033) and BCS (3.1, 3.1, and 3.1, SEM = 0.02) were similar (P > 0.05). There were no effects of treatment on withers heights (122.2, 122.6, and 122.4, SEM = 0.34) or other frame measurements. Rumen fermentation was not influenced as indicated by similar acetate to propionate ratios (2.6, 2.6, and 2.6, SEM = 0.04). The TTD of DM (71.6, 71.6, and 73.7, SEM = 2.30) was similar, as were individual nutrients. Feeding CRM at 10% of the diet, maintained intakes, growth performance, rumen fermentation, and TTD compared with CAN or CON. Therefore, CRM shows potential as a new feedstuff for growing dairy heifers.

Key Words: dairy heifer, carinata meal, growth