Abstract #T275

# T275
Dairy heifer growth performance when fed hydroponically grown barley sprouts.
R. D. Lawrence*1, J. L. Anderson1, 1Dairy and Food Science Department, South Dakota State University, Brookings, SD.

Our objective was to determine the effects of feeding hydroponically grown barley sprouts (HydroGreen Inc., Renner, SD) to dairy heifers on growth and rumen fermentation. A 12-wk randomized complete block design study was conducted using 20 Holstein and 4 Brown Swiss heifers [215.1 ± 25 d of age; body weight (BW) 229.7 ± 39 kg]. Treatments were (1) control (CON) diet which was a total mixed ration (TMR) with grass hay, corn silage, and ground corn and soybean meal as major concentrate ingredients; and (2) a TMR with 14% (DM basis) hydroponic barley sprouts (HYD) replacing a portion of the concentrate mix. Diets were fed for ad libitum intakes and formulated to be isonitrogenous and isocaloric (DM basis), although the CON was 66% DM and HYD was 44% DM. Intakes were measured using the Calan gates. Frame sizes, BW, and body condition scores (BCS) were measured on 2 d during wk 0, 2, 4, 6, 8, 10, and 12. Rumen fluid was collected 4 h post feeding via esophogeal tube every 4 wk. Data were analyzed in MIXED procedures of SAS 9.4 with repeated measures. Heifer DMI was greater (P < 0.01) for HYD (7.5, and 8.0 kg/d for CON and HYD, respectively; SEM = 0.42). Heifer ADG tended (P = 0.07) to be greater for the CON treatment (1.2, and 1.0 kg/d; SEM = 0.06). Body weight (289.7, and 282.4 kg; SEM = 2.02) and gain: feed (0.16, and 0.13; SEM = 0.01) were greater (P < 0.01) for the CON treatment. Withers height (121.7 and 121.9 cm; SEM = 0.54) and hip width (37.3 and 37.1 cm; SEM = 0.57) and BCS (3.11, and 3.10; SEM = 0.02) were similar (P > 0.05), but heart girth was greater (P < 0.01) for the CON heifers (146.0 cm, and 145.0 cm; SEM = 0.62). Rumen ammonia-N (21.0, and 24.5 mg/dL; SEM = 2.15), pH (6.75, and 6.70; SEM = 0.06), total volatile fatty acids (95.0, and 98.0 mM; SEM = 2.32) and acetate to propionate ratio (3.4, and 3.3; SEM = 0.13) were similar. Results indicated that replacing ground corn and some soybean meal with hydroponic fresh barley sprouts maintained rumen fermentation and heifer body frame growth with slightly decreased gain:feed. The decreased gain:feed was most likely because of the overall high moisture content in the HYD TMR.

Key Words: hydroponic feed, dairy heifer, growth performance