The influence of fat and hemicellulose on methane production and energy utilization in lactating Jersey cattle

Authors: DREHMEL, OLIVIA - UNIVERSITY OF NEBRASKA; BROWN-BRANDL, TAMI; JUDY, JARED - UNIVERSITY OF NEBRASKA; FERNANDO, SAMODHA - UNIVERSITY OF NEBRASKA; MILLER, PHIL - UNIVERSITY OF NEBRASKA; HALES PAXTON, KRISTIN; KONONOFF, PAUL - UNIVERSITY OF NEBRASKA

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/21/2018
Publication Date: 9/1/2018
Citation: Drehmel, O.R., Brown-Brandl, T.M., Judy, J.V., Fernando, S.C., Miller, P.S., Hales, K.E., Kononoff, P.J. 2018. The influence of fat and hemicellulose on methane production and energy utilization in lactating Jersey cattle. Journal of Dairy Science. 101(9):7892-7906. https://doi.org/10.3168/jds.2017-13822.
DOI: https://doi.org/10.3168/jds.2017-13822

Interpretive Summary: Increasing the fat content of diets in lactating dairy cows tended to reduce methane production, while increasing the hemicellulose content had no effect. Eight multiparous, lactating Jersey cows were used in a study to determine the effects of fat and hemicellulose on energy utilization and methane production. The diets included either 0 or 2% tallow and the concentration of hemicellulose was adjusted by manipulating the inclusion rate of corn silage, alfalfa hay, and soybean hulls. Neither fat nor hemicellulose affected dry matter intake, and treatments did not affect milk production or the energy in the milk. The inclusion of fat tended to reduce methane produced per kilogram of dry matter intake while hemicellulose did not.

Technical Abstract: Feeding fat to lactating dairy cows may reduce methane production. Relative to cellulose, fermentation of hemicellulose is believed to result in less methane; however, these factors have not been studied simultaneously. Eight multiparous, lactating Jersey cows averaging (±SD) 98 ± 30.8 d in milk and body weight of 439.3 ± 56.7 kg were used in a twice-replicated 4 × 4 Latin square to determine the effects of fat and hemi-cellulose on energy utilization and methane production using a headbox-type indirect calorimetry method. To manipulate the concentration of fat, porcine tallow was included at either 0 or 2% of the diet dry matter. The concentration of hemicellulose was adjusted by manipulating the inclusion rate of corn silage, alfalfa hay, and soybean hulls resulting in either 11.3 or 12.7% hemicellulose (dry matter basis). The resulting factorial arrangement of treatments were low fat low hemicellulose (LFLH), low fat high hemicellulose (LFHH), high fat low hemicellulose (HFLH), and high fat high hemicellulose (HFHH). Neither fat nor hemicellulose affected dry matter intake, averaging 16.2 ± 1.18 kg/d across treatments. Likewise, treatments did not affect milk production, averaging 23.0 ± 1.72 kg/d, or energy-corrected milk, averaging 30.1 ± 2.41 kg/d. The inclusion of fat tended to reduce methane produced per kilogram of dry matter intake from 24.9 to 23.1 ± 1.59 L/kg, whereas hemicellulose had no effect. Increasing hemicellulose increased neutral detergent fiber (NDF) digestibility from 43.0 to 51.1 ± 2.35%. Similarly, increasing hemicellulose concentration increased total intake of digestible NDF from 6.62 to 8.42 ± 0.89 kg/d, whereas fat had no effect. Methane per unit of digested NDF tended to decrease from 64.8 to 49.2 ± 9.60 L/kg with increasing hemicellulose, whereas fat had no effect. An interaction between hemicellulose and fat content on net energy balance (milk plus tissue energy) was observed. Specifically, increasing hemicellulose in low-fat diets tended to increase net energy balance, but this was not observed in high-fat diets. These results confirm that methane production may be reduced with the inclusion of fat, whereas energy utilization of lactating dairy cows is improved by increasing hemicellulose in low-fat diets.