Date of this Version
Foth, A.J. "Energy Content of Reduced-Fat Dried Distillers Grains and Solubles for Lactating Dairy Cows and Effects on Energy and Nitrogen Balance" (2014). MS thesis, University of Nebraska.
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 and 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 (Control), or 8.95 % rolled corn, 28.8 % RFDDGS, and 0 % soybean meal (Co-P; DM basis). The inclusion of RFDDGS did not affect (P = 0.86) DMI averaging 21.4 ± 0.53 kg DM for all cows but milk production tended (P = 0.10) to increase from 29.8 to 30.9 ± 1.46 kg/d for Control and Co-P treatments. There was no difference between treatments in milk fat percentage or ECM (P = 0.81 and 0.22, respectively), averaging 4.33 ± 0.14 % and 34.1 kg/d, respectively. Milk protein was decreased (P < 0.01) by the Co-P treatment (3.56 and 3.41 ± 0.08 % for Control and Co-P treatments), but protein yield was not affected (P = 0.51). Milk energies were 1.40 Mcal/d higher with Co-P (P = 0.01). Energy lost as methane was reduced (P < 0.01) by 0.31 Mcal/d with the addition of RFDDGS to the diet. Heat loss averaged 29.9 ± 0.55 Mcal/d and was not different between diets (P = 0.49). Average energy retained as tissue energy was -2.99 ± 0.93 Mcal/d (P = 0.73). Intake of digestible and metabolizable energy were not significantly different (P = 0.16 and 0.14 for DE and ME, respectively) between the Control and Co-P treatments, averaging 2.68 and 2.31 Mcal/kg DM, respectively. Net energy of lactation values of Control and Co-P diets were calculated to be 1.43 and 1.47 Mcal/kg DM (P = 0.10), respectively.
Advisor: Paul J. Kononoff