Nitrogen partitioning, energy use efficiency and isotopic fractionation measurements from cows differing in genetic merit fed low-quality pasture in late lactation
dc.contributor.author | Cheng, L | |
dc.contributor.author | Woodward, SL | |
dc.contributor.author | Dewhurst, RJ | |
dc.contributor.author | Zhou, Huitong | |
dc.contributor.author | Edwards, GR | |
dc.date.accessioned | 2017-03-14T00:59:25Z | |
dc.date.available | 2014-08-19 | |
dc.date.issued | 2014 | |
dc.description.abstract | The study was carried out to evaluate energy and nitrogen (N) use efficiencies of high and low breeding worth (BW) cow groups relative to N isotopic fractionation (∆¹⁵N). Eight high- and eight low-BW cows (mean BW index ≤ 198 and 57, respectively) in late lactation were used to conduct an N balance study with all cows fed autumn pasture. Individual cow pasture DM intake, N intake and N outputs of milk, urine and faeces were quantified. Plasma sample from each cow was harvested. Feed, plasma, faeces, urine and milk samples were measured for δ¹⁵N and calculated for ∆¹⁵N. Urea N in milk and plasma, and urinary excretion of purine derivatives were also measured. The metabolisable energy (ME) intake, milk energy output, and energy and N use efficiencies of high-BW cows were greater on average than low-BW cows. Conversely, the ratios of urinary N excretion to faecal N excretion and urinary N excretion to N intake were greater for low-BW cows than high-BW cows. There was no effect of BW groups on manure N output, apparent N digestibility, retained N, purine derivatives excretion or ratio of purine derivatives excretion to ME intake. No relationships were found between N and energy efficiencies and δ¹⁵N measurements. Regression analysis with individual cow measurement showed plasma δ¹⁵N - feed δ¹⁵N was negatively correlated with DM intake. N use efficiency was positively correlated with BW. High genetic merit cows are more efficient in N and energy use than lower genetic merit cows when fed low quality pasture in late lactation. Plasma δ¹⁵N - feed δ¹⁵N was proved to be a potential indicator of DM intake for individual cows when identical feed was offered. BW may be used to predict N use efficiency for individual cows. © CSIRO 2014. | |
dc.format.extent | pp.1651-1656 | |
dc.identifier | https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=elements_prod&SrcAuth=WosAPI&KeyUT=WOS:000340723900019&DestLinkType=FullRecord&DestApp=WOS_CPL | |
dc.identifier.citation | Cheng, L., Woodward, S.L., Dewhurst, R.J., Zhou, H., & Edwards, G.R. (2014). Nitrogen partitioning, energy use efficiency and isotopic fractionation measurements from cows differing in genetic merit fed low-quality pasture in late lactation. Animal Production Science, 54, 1651-1656. doi: 10.1071/AN14171 | |
dc.identifier.doi | 10.1071/AN14171 | |
dc.identifier.eissn | 1836-5787 | |
dc.identifier.issn | 1836-0939 | |
dc.identifier.other | AN6RL (isidoc) | |
dc.identifier.uri | https://hdl.handle.net/10182/7876 | |
dc.language | en | |
dc.language.iso | en | |
dc.publisher | CSIRO Publishing | |
dc.relation | The original publication is available from CSIRO Publishing - https://doi.org/10.1071/AN14171 - http://www.publish.csiro.au/AN/AN14171 | |
dc.relation.isPartOf | Animal Production Science | |
dc.relation.uri | https://doi.org/10.1071/AN14171 | |
dc.rights | © CSIRO 2014 | |
dc.subject | isotopic discrimination | |
dc.subject | manure nitrogen | |
dc.subject | microbial energetic efficiency | |
dc.subject | microbial protein synthesis | |
dc.subject | sustainability | |
dc.subject.anzsrc | ANZSRC::070204 Animal Nutrition | |
dc.subject.anzsrc2020 | ANZSRC::30 Agricultural, veterinary and food sciences | |
dc.subject.anzsrc2020 | ANZSRC::31 Biological sciences | |
dc.subject.anzsrc2020 | ANZSRC::41 Environmental sciences | |
dc.title | Nitrogen partitioning, energy use efficiency and isotopic fractionation measurements from cows differing in genetic merit fed low-quality pasture in late lactation | |
dc.type | Journal Article | |
lu.contributor.unit | LU | |
lu.contributor.unit | LU|Agriculture and Life Sciences | |
lu.contributor.unit | LU|Agriculture and Life Sciences|AGSC | |
lu.contributor.unit | LU|Research Management Office | |
lu.contributor.unit | LU|Vice Chancellor's Office | |
lu.contributor.unit | LU|Research Management Office|OLD QE18 | |
lu.identifier.orcid | 0000-0001-7620-3160 | |
pubs.issue | 10 | |
pubs.notes | Accepted 16 Jun 2014 | |
pubs.publication-status | Published | |
pubs.publisher-url | http://www.publish.csiro.au/AN/AN14171 | |
pubs.volume | 54 |