Abstract

Data from six experiments (two with dry cows) were used to predict partitioning of gross energy to CH4 in Holstein cows using selected independent variables, some of which were intercorrelated, and a stepwise backward elimination regression procedure. Methane outputs ranged from 3.1 to 8.3% (mean 5.5) of gross energy intake for 134 dry cow balance trials and from 1.7 to 14.9% (mean 5.2) of gross energy intake for 358 lactating cow energy balance trials. This is equivalent to 176 and 300 g/d or 245 and 419 L/d of CH4 for dry and lactating Holstein cows, respectively. Digestibilities of hemicellulose and neutral detergent solubles were positive predictors, and cellulose digestibility was a negative predictor of CH4 output in dry cows fed all forage diets, but hemicellulose digestibility was not a significant variable for predicting CH4 production by lactating cows fed diets with concentrate and forages. Fiber digestibility generally remained in models to predict CH4 output. Except for one data set, regression equations accounted for 50 to 72% of the variation in percentage of gross energy partitioned to CH4 by Holstein cows. Results confirm that increased concentrate feeding reduces CH4 production. Supplementation of lactation diets with fat generally increases fat digestibility, and this trait was associated with reduced CH4 output. Results enable 1) estimation of CH4 output for calculation of metabolizable energy and 2) computation of the contribution from dairy cows to global warming.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.