Effects of triticale (cv. Beaguelita) and barley-based concentrates on feed intake and milk yield by dairy cows

Abstract

Triticale (cv. Beaguelita) was compared with barley in concentrate mixes for lactating Holstein cows. Grains in the concentrate mixes were 100% barley (B), 57% barley and 43% triticale (BT) or 14% barley and 86% triticale (T). Alfalfa silage (15% crude protein (CP), 62.2% dry matter (DM) digestibility) was fed ad libitum and the concentrates were fed twice daily at 1 kg per 2.75 kg milk produced. Twenty-one lactating cows were allocated to the three diets for an 11-wk trial with three repeated measures of responses (periods). There were no linear or quadratic effects due to dietary treatments (P > 0.05) on mean dry matter consumption of concentrate and alfalfa silage by cows fed the three diets, with average daily intake of concentrate and forage (kg d−1), respectively being: B, 8.2 and 13.3; BT, 8.8 and 12.2; T, 8.3 and 12.2. Replacing barley with triticale also was not related to 4% fat-corrected milk yield (kg d−1) (P > 0.05) which was 23.6, 26.6 and 24.7 for diets B, BT and T, respectively. Similarly the fat, protein and lactose contents of the milk were not related to the proportions of barley and triticale in the diets. There was a linear reduction in body weight gain as triticale levels increased in the diets (P < 0.05). Rumen fluid pH and ammonia concentration were not affected by triticale levels in the diets. However, the molar concentrations of acetate, propionate, butyrate and valerate tended to increase linearly (P < 0.10) with triticale levels. The rates of disappearance of DM and CP of barley were faster than for triticale from nylon bags incubated in situ in the rumen but the solubilities of DM and CP at zero time of triticale were greater (P < 0.01). Concentrate mixes BT and T containing triticale were readily accepted by dairy cows and supported milk yields similar to one based on barley. However, body weight gain was reduced in cows fed triticale indicating that more of the productive energy was expressed in milk production. Key words: Triticale, barley, lactation