Comparative yield and feeding value of barley, oat and triticale silages

Abstract

The yield and feeding value of barley (Hordeum vulgare 'Johnson'), oat (Avena sativa 'Calibre') and triticale(Triticosecale 'Carmen') silages were compared in a field study, a heifer growth trial (119 d in length, with four pens of eight Charolais cross heifers (average body weight 300 kg) per treatment), and a sheep digestibility trial (total fecal collection with eight sheep per treatment). The swathed and chopped plant material was ensiled in stack silos covered with plastic. Yields of dry matter (DM) and crude protein (CP) did not differ significantly (P > 0.05) among species. At harvest, oat and triticale had greater acid detergent fiber (ADF) levels than barley. After ensiling, triticale alone had greater neutral detergent fiber, ADF and acid detergent insoluble nitrogen levels than the other silages. The three silages did not otherwise differ in chemical composition. Heifer intakes of barley (6.06 kg d−1) and oat (5.70 kg d−1) silage DM were similar, and greater than for triticale (4.86 kg d−1). Average daily gain was greatest with barley (0.65 kg d−1), intermediate with oat (0.57 kg d−1) and least with triticale (0.49 kg d−1). Intake of silage DM by the sheep was greatest with barley silage (741 g d−1), intermediate with oat (617 g d−1) and least with triticale (434 g d−1), which appeared less palatable than the other silages. Dry matter and CP digestibilities were greatest for barley silage (64.2 and 71.6%, versus 58.3. and 61.1% for oat, and 58.8 and 65.4% for triticale, respectively). Oat silage had the lowest fiber digestibility. Sheep given triticale silage had lower rumen fluid volatile fatty acid concentrations, apparently due to low DM intake. Oat silage gave a greater molar proportion of acetate, a lower proportion of propionate, and a higher acetate to propionate ratio than either barley or triticale. Triticale silage produced a greater molar proportion of acetate and a lower proportion of butyrate than barley silage. Based on animal performance, it was concluded that barley silage was the preferred of the three cereal silages for growing cattle. Triticale produced a less acceptable silage due to poor palatability and low DM intake. Key words: Cattle, sheep, cereal silage, forage quality, digestibility