Growth Performance of Dairy Heifers Fed Carinata Meal.

Carinata meal is an oilseed meal that is a quality protein source but contains high concentrations of glucosinolates, especially sinigrin. Glucosinolates limit dietary inclusion rates of the meal as they may cause issues with thyroid gland function which consequently may cause growth issues. Our objective was to determine effects of feeding carinata meal compared to distillers dried grains with solubles to peripubertal dairy heifers on growth performance. 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 were: 1) cold-pressed carinata meal (CRM; with glucosinolates at 2.06 g/kg of diet DM) and 2) distillers dried grains with solubles (DDGS) at 10% of the diet on a DM basis. The remainder of the diets were comprised of grass hay, ground corn, soybean meal and mineral mix with the inclusion amounts of the corn and soybean meal varied slightly to meet nutrient requirements and have diets be similar in crude protein and energy content. Heifers were individually fed using a Calan gate feeding system and the rations were limit-fed at 2.65% of BW on DM basis. Frame sizes, BW, and body condition scores (BCS) were measured at 4 h post feeding on 2 consecutive d during wk 0 and then every 2 wk thereafter throughout the feeding period. Data were analyzed using MIXED procedures with repeated measures in SAS 9.4. Significance was declared at P < 0.05. There were no significant interactions of treatment by wk. Heifer DMI (6.55 and 6.42 kg/d; SEM = 0.16 for CRM and DDGS, respectively), BW (269.9 and 268.9 kg; SEM = 1.47), ADG (0.837 and 0.825 kg/d; SEM = 0.029), and gain:feed (0.131 and 0.130 kg/kg; SEM = 0.004) were similar (P > 0.05) between treatments. There were no differences (P > 0.05) in withers height (122.8 and 122.4 cm; SEM = 0.53), hip height (126.0 and 126.4 cm; SEM = 0.27), heart girth (145.6 and 145.2 cm; SEM = 0.53), hip width (37.98 and 38.26 cm; SEM = 0.28), and BCS (3.01 and 2.99; SEM = 0.01). This research demonstrates that carinata meal, despite the glucosinolate content, can be fed at the inclusion rate of 10% diet DM to growing dairy heifers and maintain DMI, ADG, and frame growth compared to DDGS.