Title: Energy content of reduced-fat distillers grains for lactating dairy cows Authors
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: February 12, 2014
Publication Date: July 1, 2014
Citation: Foth, A.J., Gomez, G.G., Brown Brandl, T.M., Freetly, H.C., Kononoff, P.J. 2014. Energy content of reduced-fat distillers grains for lactating dairy cows [Abstract]. Journal of Animal Science. 92(E-Suppl. 2):171. Abstract #0345. Technical Abstract: Byproducts of ethanol production have become an important source of nutrients for dairy cows in recent years but accurate energy values have yet to be determined. Eight Holstein and 8 Jersey multiparous, lactating cows were used to complete 56 energy balances to determine the energy content of reduced-fat distillers grains with solubles (RFDDGS). A repeated switchback design was used to compare treatments with and without RFDDGS. Diets consisted of 24.2 % corn silage, 18.4 % alfalfa hay, 6.94 % brome hay with either 22.9 % rolled corn and 14.8 % soybean meal, or 4.51 % rolled corn, 14.5 % RFDDGS, and 0 % soybean meal (DM basis). On average the inclusion of RFDDGS increased DMI from 21.7 ± 0.70 kg/d to 23.3 ± 0.68 kg/d (P < 0.01) but did not affect milk production (29.8 ±1.46 and 30.9 ± 1.45 kg/d for control and RFDDGS diets, respectively; P = 0.11) or 3.5% FCM (33.0 ± 1.27 and 34.2 ± 1.25 kg/d for control and RFDDGS diets, respectively; P = 0.10). Milk energies were 1.44 ± 0.50 Mcal/d higher with RFDDGS (P = 0.01). Energy lost as methane was reduced (P = 0.01) by 0.28 Mcal/d with the addition of RFDDGS to the diet. Heat loss averaged 30.4 ± 0.55 Mcal/d and did not differ by diet (P = 0.94). Energy retained as tissue energy was found to be -0.22 ±1.48 Mcal/d for the control diet and 6.78 ± 1.43 Mcal/d for the RFDDGS diet (P < 0.01). Intake of digestible and metabolizable energies were lower (P < 0.01) for the control (2.70 and 2.36 ± 0.05 Mcal/kg DM, respectively) compared to RFDDGS (2.86 and 2.54 ± 0.05 Mcal/kg DM). There was also a treatment by breed interaction for digestible, metabolizable and lactational net energies (P < 0.01) with a greater difference between treatments with Holstein cows than Jersey cows. Differences between treatments in Holsteins were 12.0 ±2.09, 11.7 ± 1.98 and 11.3 ± 1.90 Mcal/d (P < 0.01), and Jerseys were 4.16 ± 2.14, 4.32 ± 2.04 and 5.47 ±1.96 Mcal/d (P = 0.06, 0.04 and 0.01), for digestible, metabolizable and lactational net energies, respectively. These energy estimates suggest higher energy content of diets containing RFDDGS than diets containing a mixture of corn and soybean meal in lactating dairy cows.