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1416
A novel bm3 corn silage hybrid with floury kernel genetics improves lactational performance and feed efficiency in Holstein cows

Thursday, July 21, 2016: 2:15 PM
155 F (Salt Palace Convention Center)
Elizabeth M. Remick , William H. Miner Agricultural Research Institute, Chazy, NY
Shane M Fredin , William H. Miner Agricultural Research Institute, Chazy, NY
Kurt W. Cotanch , William H. Miner Agricultural Research Institute, Chazy, NY
Heather M. Dann , William H. Miner Agricultural Research Institute, Chazy, NY
Catherine S. Ballard , William H. Miner Agricultural Research Institute, Chazy, NY
John P Brouillette , Dow AgroSciences, Mycogen Seeds, Indianapolis, IN
Richard J. Grant , William H. Miner Agricultural Research Institute, Chazy, NY
Abstract Text:

Dry matter intake, lactation performance, feed efficiency and chewing behavior of multiparous Holstein cows (n=15) fed diets containing a novel bm3 corn silage (CS) hybrid with floury kernel genetics were compared to diets containing commercially available conventional and bm3 hybrids using a replicated 3 × 3 Latin square design with 28-d periods. Cows were housed in tie-stalls, milked 3x/d, and fed a diet containing (DM basis) 49.0% of 1 of 3 CS hybrids (Mycogen Seeds, Dow AgroSciences, LLC): 1) a conventional CS hybrid (CON); 2) a brown midrib hybrid (BMR); and 3) a bm3 hybrid with floury kernel genetics (BMRFL). All diets contained 6.3% hay crop silage and 44.7% concentrate. Diet nutrient composition averaged 14.8±0.3% CP, 2.7±0.5% NDF, and 26.3±0.5% starch. Dry matter intake and milk yield were measured on d 22-28. Milk composition was measured on d 25-26. Cow behavior was monitored for 48 h over d 24-26. Data were analyzed by ANOVA using the MIXED procedure in SAS. Dry matter intake was increased (P=0.01; SE=0.5) for cows fed BMR (28.0 kg/d) compared to CON (26.8 kg/d); DMI for cows fed BMRFL was intermediate (27.6 kg/d). Energy-corrected milk yield was increased (P<0.01; SE=1.5) for cows fed BMR (50.3 kg/d) and BMRFL (51.8 kg/d) compared to CON (47.2 kg/d). Milk fat yield was increased (P≤0.05; SE=0.06) for cows fed BMRFL (1.87 kg/d) compared to CON (1.74 kg/d) and BMR (1.80 kg/d). Milk protein yield was increased (P<0.01; SE=0.06) for cows fed BMR (1.49 kg/d) and BMRFL (1.54 kg/d) compared to CON (1.36 kg/d). Milk urea-N was reduced (P<0.01; SE=0.3) for cows fed BMR (11.61 mg/dL) and BMRFL (11.16 mg/dL) compared to CON (13.60 mg/dL). Feed efficiency (Energy Corrected Milk/DMI) was increased (P≤0.03; SE=0.04) for cows fed BMRFL (1.87) compared to CON (1.76) and BMR (1.79). Milk N efficiency (P=0.001; SE=1.2) was greatest for cows fed BMRFL (40.4%) followed by BMR (38.1%) and CON (35.3%). Cows fed CON chewed 5 min more per kg NDF consumed than cows consuming either bm3 hybrid (P<0.01).  Lactational performance was increased for cows fed diets containing both bm3 CS. Greater feed efficiency indicates that a bm3 CS hybrid containing floury kernel genetics improves lactational performance and energy utilization compared to bm3 and conventional CS. Additionally, improved milk N efficiency indicates greater ruminal carbohydrate fermentability can be achieved when feeding a BMRFL diet.

Keywords: Brown midrib, floury corn, feed efficiency