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

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.

Factors that affect heat production in lactating Jersey cows

“…Data from 9 research experiments conducted at the University of Nebraska-Lincoln's Dairy Metabolism Unit were used (Foth et al, 2015;Drehmel et al, 2018;Judy et al, 2018Judy et al, , 2019aKnoell et al, 2019;Reynolds et al, 2019;Morris et al, 2020a,b). Across these 9 experiments, data from 293 animal-periods were collected on 54 Jersey cows.…”

“…Cows were fed within the headboxes and allowed free access to water via a water bowl. Details for the specific methods used to quantify gas consumption and production can be found in individual publications (Foth et al, 2015;Drehmel et al, 2018;Judy et al, 2018Judy et al, , 2019aKnoell et al, 2019;Reynolds et al, 2019;Morris et al, 2020a,b). Heat production was estimated through calculation of observed O 2 consumption and CO 2 production with correction for CH 4 production and urinary N excretion according to Brouwer (1965) as follows:…”

“…for Foth et al (2015) and Reynolds et al (2019), where analyses were completed at the Ruminant Nutrition Laboratory of the University of Nebraska-Lincoln. Methods were similar across location and are described in individual publications (Foth et al, 2015;Drehmel et al, 2018;Judy et al, 2018Judy et al, , 2019aKnoell et al, 2019;Reynolds et al, 2019;Morris et al, 2020a,b). Crossover experimental designs were used in all 9 experiments.…”

“…According to the laws of thermodynamics, heat generated from reactions in the body is equal to the difference in chemical energy between all substrates and products in a reaction (Kleiber, 1975). In lactating Jersey cows, heat production (HP) accounts for 25 to 32% of the gross energy (GE) intake (Drehmel et al, 2018;Judy et al, 2018;Reynolds et al, 2019). Heat production can be categorized into NE M -the basal energy expenditure of an animaland heat increment (HI)-the HP that is associated with digestion and metabolism of food (NRC, 1981).…”

Evaluation of Mineral Contents in Milk of Dairy Cattle Fed Elephant Grass Planted at Ex-Coal Mining Land

“…The result agreed with Miller et al (2019) reporting that TM sources affected DMI. Additionally, DMI is influenced by the source roughage with its total mixed fiber (Maneerat et al, 2013) and forage particle size (Reynolds et al, 2018).…”