Abstract #M163

Section: Forages and Pastures (posters)
Session: Forages and Pastures I
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Exhibit Hall A

# M163
Yield and nutritional value of forage sorghum varieties for dairy cattle.
E. E. Corea Guillén^*1, J. M. Flores Tensos¹, F. M. López Hernández¹, E. A. Martínez Aguilar¹, M. Mendoza¹, J. A. Elizondo Salazar², G. A. Broderick³, ¹Departamento de Zootecnia, Facultad de Ciencias Agronómicas, Universidad de El Salvador, San Salvador, El Salvador, ²Estación Experimental Alfredo Volio Mata, Facultad de Ciencias Agroalimentarias, Universidad de Costa Rica, Cartago, Costa Rica, ³Broderick Nutrition and Research LLC, Madison, WI.

Sorghum is an important forage source for dairy farms in warm and dry areas of the Pacific coast of Central American because of its tolerance to drought and pests. Its nutritional value is comparable to corn and management strategies including variety selection can affect its performance and feeding value. In this study 3 regional varieties of sorghum (Sorghum bicolor) from the Centro Nacional de Tecnología Agropecuaria of El Salvador (CENTA), RCV, BMR and S2, were compared. Sixteen replicates of each variety were planted in 10 × 6.4 m plots at a density of 125,000 plants/ha with 0.8 m between rows and 0.1 m between plants in 4 replicates during the rainy season. Yield of fresh matter was measured in 2.4 × 3 m area in each plot at 85 d after planting at the milky stage of the grain, and whole plant material was separated into leaves, stems, and panicles. Samples of fractions were dried, milled (1 mm screen) and analyzed for DM, CP, and NDF concentration; nutrient yield also was computed. Data were analyzed with Infostat using a completely random model. Greater DM and CP yield was found in RCV and S2 varieties compared with the BMR variety, while more CP in the leaves and less NDF in the panicle were found in the RCV variety (Table 1). Results of this study indicate that improved nutritional composition and greater yield make RCV a better forage sorghum variety for feeding dairy cattle. Table 1. Yield and nutritional composition of 3 varieties of forage sorghum (Sorghum bicolor)

Item	Variety			SEM	P > F
RCV	BMR	S2
% DM	19.0^b	21.2^a	20.7^a	0.65	<0.001
Yield, ton/ha
Green matter	54.3^a	31.1^b	51.6^a	5.68	<0.001
DM	10.30^a	6.57^b	10.39^a	1.05	<0.001
CP	0.88^a	0.49^b	0.77^a	0.10	0.001
CP, % DM
Whole plant	8.53	7.39	7.44	0.37	0.076
Stem	4.91	4.29	4.49	0.18	0.450
Leaves	16.3^a	13.8^b	14.9^b	0.73	< 0.001
Panicle	11.0	12.0	10.8	0.36	0.436
NDF, % DM
Whole plant	54.6	50.0	53.1	1.36	0.670
Stem	63.0	61.5	66.1	1.37	0.141
Leaves	52.5	50.8	50.7	0.57	0.645
Panicle	47.4^b	65.8^a	53.8^b	5.39	0.003

^a,bMeans with different superscripts differ (P < 0.05).

Key Words: yield, sorghum variety, nutritional composition