Use of indirect calorimetry to evaluate utilization of energy in lactating Jersey dairy cattle consuming common coproducts

Authors: REYNOLDS, M - University Of Nebraska; Brown-Brandl, Tami; JUDY, J - University Of Nebraska; HERRICK, K - Poet; Hales Paxton, Kristin; WATSON, A - University Of Nebraska; KONONOFF, P - University Of Nebraska

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/4/2018
Publication Date: 1/2/2019
Publication URL: https://handle.nal.usda.gov/10113/6190792
Citation: Reynolds, M.A., Brown-Brandl, T.M., Judy, J.V., Herrick, K.J., Hales, K.E., Watson, A.K., Kononoff, P.J. 2019. Use of indirect calorimetry to evaluate utilization of energy in lactating Jersey dairy cattle consuming common coproducts. Journal of Dairy Science. 102(1):320-333. https://doi.org/10.3168/jds.2018-15471.
DOI: https://doi.org/10.3168/jds.2018-15471

Interpretive Summary: Feeding dairy cows coproducts such as canola meal and distillers grains and solubles is common practice. The supply of energy is affected by the type of byproduct but when within coproduct type. A study was conducted to evaluate the impact of fat content of different coproducts on milk production, intake, and heat production. The study used 12 lactating Jersey cows using 4 different diets: control diet with Low fat distillers grain diet (LFDG), high fat distillers grain (HFDG), and a lower fat canola meal diet (CanM). The fat content of the 4 diets were CON – 5.5%, LFDG – 5.8%, HFDG – 6.0%, and the canola meal diet – 5.7%. The cows ate similar amounts of feed and had similar milk yield regardless of diet. Across treatments, the concentration of metabolizable and net energy balance (milk plus tissue) was highest when feeding HFDG. These results indicate that high fat distillers grains supply more energy than canola meal and that the fat content of distillers grains is a major factor affecting this.

Technical Abstract: The use of coproducts as an alternative feed source is a common practice when formulating dairy rations. A study using 12 multiparous (79 ± 16 d in milk; mean ± standard deviation) lactating Jersey cows was conducted over 5 mo to evaluate the effects of dried distillers grains with solubles (DDGS) or canola meal on milk and gas production. A replicated 4 × 4 Latin square design was used to compare 4 dietary treatments. Treatments comprised a control (CON) containing no coproducts, a treatment diet containing 10% (dry matter basis) lowfat DDGS (LFDG), a treatment diet containing 10% high-fat DDGS (HFDG), and a 10% canola meal (CM) treatment. The crude fat content of the LFDG, HFDG, and CM treatments was 6.05 ± 0.379, 10.0 ± 0.134, and 3.46 ± 0.085%, respectively. Coproducts were included in partial replacement for corn and soybean meal. Indirect headbox-style calorimeters were used to estimate heat production. Dry matter intake and milk yield were similar between all treatments, averaging 17.4 ± 0.56 kg/d and 24.0 ± 0.80 kg, respectively. Milk urea N was affected by treatment and was highest in CON (20.6 mg/dL; 18.0, 19.9, and 18.1 ± 0.62 mg/dL in LFDG, CM, and HFDG, respectively). Heat production per unit of metabolic body weight tended to be affected by treatment and was lowest for CON, and diets containing coproducts were not different (192, 200, 215, and 204 ± 5.91 kcal/kg of metabolic body weight for CON, LFDG, CM, and HFDG, respectively). The concentration of metabolizable energy was affected by dietary treatment; specifically, HFDG did not differ from CON but was greater than LFDG and CM (2.58, 2.46, 2.29, and 2.27 ± 0.09 Mcal/kg for HFDG, CON, LFDG, and CM, respectively). The concentration of net energy balance (milk plus tissue) tended to be affected by dietary treatment; HFDG did not differ from either CON or LFDG, but it was higher than CM (1.38, 1.36, 1.14, and 1.06 ± 0.11 Mcal/kg for HFDG, CON, LFDG, and CM, respectively). Results of this study indicate that milk production and dry matter intake were not affected by feeding common coproducts and that differences may result in whole-animal energy use; fat content of DDGS is a major factor affecting this.