Claudio Rojas G.1 y Adrián Catrileo S.
Over a period of 84 days of the winter of 1996, 28 Hereford steers of 20 months of age and 342 kg live weight, were fattened in order to evaluate whole barley silage (Hordeum vulgare) at three cutting periods in comparison to maize silage (Zea mayz) in the Carillanca Regional Investigation Center of the National Agricultural Research Institute (INIA). Treatments were T1: maize silage; T2 : barley silage at the milky state ; T3 : barley silage at the starchy state; and T4 : barley silage at the hard starchy state. The silages were offered ad libitum and supplemented daily with concentrates equivalent to 0.9% of the animal live weight on a dry matter basis. The concentrates were formulated with oats, white lupin grains and commercial mineral salts in order to obtain isoproteic rations with 13% CP. The total dry matter intake was assumed to be equivalent to 2.5% of the live weight of the animals. The experimental design was a completely randomized block with 7 replicates. Daily live weight gains were 1.069a ; 0.883b; 1.024a and 0.742c kg day-1 (P<0.05), for treatments 1, 2, 3 and 4, respectively. Daily dry matter intakes were 8.5b ; 8.6ab ; 9.2a and 8.8ab kg animal-1 (P<0.05); feed conversion efficiency was 7.9c ; 9.7b ; 9.0b and 11.8a kg of dry matter kg-1 of live weight gain (P<0.05), for the same treatments, respectively. It was concluded that starchy whole barley silage could replace maize silage in rations for fattening steers without affecting productive performance.
Key words: barley silage, maize silage, steers, intake, live weight.
1 Instituto de Investigaciones Agropecuarias, Centro Regional de Investigación Carillanca, Correo 58– D, Temuco, Chile. E-mail: firstname.lastname@example.org; email@example.com.