English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The aim of the present study was to derive individual methane (    CH  4    ) emissions in ewes separated in    CH  4    respiration and eructation traits. The generated longitudinal    CH  4    data structure was used to estimate phenotypic and genetic relationships between ewe    CH  4    records and energy efficiency indicator traits from same ewes as well as from their lambs (intergenerational perspective). In this regard, we recorded    CH  4    emissions via mobile laser methane detector (LMD) technique, body weight (EBW), backfat thickness (BFT) and body condition score (BCS) from 330 ewes (253 Merinoland (ML), 77 Rhön sheep (RH)) and their 629 lambs (478 ML, 151 RH). The interval between repeated measurements (for ewe traits and lamb body weight (LBW)) was 3 weeks during lactation. For methane concentration (   µ   L L-  1    ) determinations in the exhaled air, we considered short time measurements (3 min). Afterwards,    CH  4    emissions were portioned into a respiration and eructation fraction, based on a double normal distribution. Data preparation enabled the following    CH  4    trait definitions: mean    CH  4    concentration during respiration and eructation (    CH    4   r  +  e), mean    CH  4    concentration during respiration (    CH    4  r), mean    CH  4    concentration during eructation (    CH    4  e), sum of    CH  4    concentrations per minute during respiration (    CH    4  rsum), sum of    CH  4    concentrations per minute during eructation (    CH    4  esum), maximal    CH  4    concentration during respiration (    CH    4  rmax), maximal    CH  4    concentration during eructation (    CH    4  emax), and eructation events per minute (    CH    4  event). Large levels of ewe    CH  4    emissions representing energy losses were significantly associated with lower LBW (   P  &lt;  0.05   ), lower EBW (   P  &lt;  0.01   ) and lower BFT (   P  &lt;  0.05   ). For genetic parameter estimations, we applied single- and multiple-trait animal models. Heritabilities and additive genetic variances for    CH  4    traits were small, i.e., heritabilities in the range from &lt;0.01 (    CH    4   r  +  e,    CH    4  r,    CH    4  rmax,    CH    4  esum) to 0.03 (    CH    4  rsum). We estimated negative genetic correlations between    CH  4    traits and EBW in the range from  -  0.44 (    CH    4   r  +  e) to  -  0.05 (    CH    4  rsum). Most of the    CH  4    traits were genetically negatively correlated with BCS (  -  0.81 for    CH    4  esum) and with BFT (  -  0.72 for    CH    4  emax), indicating same genetic mechanisms for    CH  4    output and energy efficiency indicators. Addressing the intergenerational aspect, genetic correlations between    CH  4    emissions from ewes and LBW ranged between  -  0.35 (    CH    4   r  +  e) and 0.01 (    CH    4  rsum,    CH    4  rmax), indicating that breeding on reduced    CH  4    emissions (especially eructation traits) contribute to genetic improvements in lamb weaning performance.

Assessment of methane emission traits in ewes using a laser methane detector: genetic parameters and impact on lamb weaning performance