Effects of feeding triticale and wheat silages on feed intake, milk production and composition, and enteric methane production in lactating dairy cows

Abstract Text:

The objective of this experiment was to evaluate the production effects of replacing corn silage (serving as the control) with either triticale or wheat silage in a total mixed ration fed to lactating dairy cows. Twelve Holstein cows (days in milk 38 ± 5.6, BW 632 ± 101.6kg) were used in a replicated 3 × 3 Latin square design experiment with 3, 28 d periods. Feeding was ad libitum for 5 to 10% refusals. The control diet consisted of (DM basis): 44% corn silage, 8% alfalfa haylage, 5% hay/straw mixture, 9% ground corn, 8% canola meal, 7.5% whole roasted soybeans, 7% SoyPLUS, 4.5% molasses, 4% cottonseed hulls, and 3% mineral premix. For the triticale diet, 22.7% (DM basis) of the corn silage was replaced with triticale silage. Similarly, 22.7% of the corn silage in the wheat diet was replaced with wheat silage. Diets met or exceeded the MP and NE_l requirements of the cows. The triticale (Hyoctane) and wheat (Malabar) were harvested May 13 and 20, 2015, respectively, at the boot stage. The silages had DM of 30.7 and 40.7%, pH 4.48 and 4.46 and (DM basis):  lactic acid, 7.03 and 6.43%; NDF, 51.1 and 51.0%; and CP, 17.3 and 14.6%, respectively. Diet did not affect DMI (27.5 kg/d; SEM = 1.8, P = 0.37), enteric methane emission (470 g/d; SEM = 23.4, P = 0.16), or milk fat yield (1.55 kg/d; SEM = 0.11, P = 0.35). Milk yield was higher in control versus triticale or wheat diets (42.7, 41.2, and 41.4 kg/d, respectively; SEM = 5.2, P = 0.01). Energy corrected milk yield was also higher (P = 0.05) in control (40.9 kg/d) versus triticale (38.6 kg/d) or wheat (38.5 kg/d) diets. Triticale and wheat diets increased (P < 0.001) milk urea nitrogen concentration compared with the control (12.7 and 13.1 vs 10.8 mg/dL, respectively). Milk true protein and lactose yields were lower for both triticale and wheat diets compared with the control: 1.20, 1.20, and 1.27 kg/d (SEM = 0.096, P = 0.02) and 2.00, 1.98, and 2.14 kg/d (SEM = 0.173, P= 0.01), respectively. The results indicate that a 22.7% replacement of corn silage DM with either triticale or wheat silage in the diet of lactating dairy cows did not affect enteric methane emission or DMI, but decreased milk yield.

Keywords: triticale, wheat, silage