The present study investigated the effect of reduced lignin alfalfa on forage quality. A 2 × 3 factorial design was used. Two alfalfa cultivars (Roundup Ready (RR) and double stacked RR and Reduced Lignin (RR/RL)) were harvested at intervals of 28d, 33d, and 35d. All replicated plots were established in June and harvested for 2 regrowth periods in July and August in 2014. Four replicates were used. Statistical analysis was a 2-way ANOVA using SPSS 22. Crude Protein (CP), Neutral Detergent Fiber (aNDF), Lignin, NDF Digestibility in 48 h (NDFD48) were analyzed by NIRS (FOSS 6500 using NIRSC 2012 Alfalfa Hay Equation). CP content was not significantly different between RR and RR/RL (27.5 vs 28.0, P > 0.05) and declined with advancing maturity (P < 0.05). aNDF content of RR was significantly higher than RR/RL (31.6 vs 30.1), though differences among harvest intervals were not significant (30.8 vs 30.5 vs 31.1). Lignin content was not significantly different between RR and RR/RL (5.6 vs 5.5) or among harvest intervals (5.6 vs 5.6 vs 5.5). The NDFD48 of RR/RL was significantly higher than RR (52.2 vs 50.5). Indigestible NDF (iNDF), Rate of fiber digestion (K_d), and Total-tract NDF Digestibility (TTNDFD) had not been reported for the RL germplasm and were shown in the table below. The reduced lignin alfalfa tended to be lower in iNDF and higher in K_d though differences were not significant, but was significantly higher in TTNDFD. It appears that RR/RL reduced the aNDF content and improved NDFD48 and TTNDFD. Table 1. Comparison between RR and RR/RL in iNDF, Kd and TTNDFD

Item		RR	RR/RL	Average	P-value
Forage	Harvest interval	Forage × harvest interval
iNDF	28 d	34.1	29.9	31.7b	0.086	0.001	0.470
(%NDF)	33 d	42.1	37.0	39.9a
	35 d	39.3	39.2	39.2a
	average	38.7a	35.1a	36.8
Kd	28 d	7.8	7.1	7.4a	0.156	0.980	0.153
(%)	33 d	7.0	8.2	7.5a
	35 d	6.4	8.9	7.8a
	average	7.0a	8.0a	7.6
TTNDFD	28 d	53.0	56.3	54.9a	0.012	0.010	0.849
(%NDF)	33 d	46.3	51.9	48.7b
	35 d	46.8	51.1	49.2b
	average	48.6b	53.3a	51.0