Impact of breeding for reduced methane emissions in New Zealand sheep on maternal and health traits.

Autor: Hickey SM; Ruakura Research Centre, AgResearch Ltd., Hamilton, New Zealand., Bain WE; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand., Bilton TP; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand., Greer GJ; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand., Elmes S; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand., Bryson B; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand., Pinares-Patiño CS; Grasslands Research Centre, AgResearch Ltd., Palmerston North, New Zealand., Wing J; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand., Jonker A; Grasslands Research Centre, AgResearch Ltd., Palmerston North, New Zealand., Young EA; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand., Knowler K; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand., Pickering NK; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand., Dodds KG; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand., Janssen PH; Grasslands Research Centre, AgResearch Ltd., Palmerston North, New Zealand., McEwan JC; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand., Rowe SJ; Invermay Agricultural Centre, AgResearch Ltd., Mosgiel, New Zealand.
Jazyk: angličtina
Zdroj: Frontiers in genetics [Front Genet] 2022 Sep 30; Vol. 13, pp. 910413. Date of Electronic Publication: 2022 Sep 30 (Print Publication: 2022).
DOI: 10.3389/fgene.2022.910413
Abstrakt: Enteric methane emissions from ruminants account for ∼35% of New Zealand's greenhouse gas emissions. This poses a significant threat to the pastoral sector. Breeding has been shown to successfully lower methane emissions, and genomic prediction for lowered methane emissions has been introduced at the national level. The long-term genetic impacts of including low methane in ruminant breeding programs, however, are unknown. The success of the New Zealand sheep industry is currently heavily reliant on the prolificacy, fecundity and survival of adult ewes. The objective of this study was to determine genetic and phenotypic correlations between adult maternal ewe traits (live weight, body condition score, number of lambs born, litter survival to weaning, pregnancy scanning and fleece weight), faecal and Nematodirus egg counts and measures of methane in respiration chambers. More than 9,000 records for methane from over 2,200 sheep measured in respiration chambers were collected over 10 years. Sheep were fed on a restricted diet calculated as approximately twice the maintenance. Methane measures were converted to absolute daily emissions of methane measured in g per day (CH 4 /day). Two measures of methane yield were recorded: the ratio of CH 4 to dry matter intake (g CH 4 /kg DMI; CH 4 /DMI) and the ratio of CH 4 to total gas emissions (CH 4 /(CH 4 + CO 2 )). Ewes were maintained in the flocks for at least two parities. Non-methane trait data from over 8,000 female relatives were collated to estimate genetic correlations. Results suggest that breeding for low CH 4 /DMI is unlikely to negatively affect faecal egg counts, adult ewe fertility and litter survival traits, with no evidence for significant genetic correlations. Fleece weight was unfavourably (favourably) correlated with CH 4 /DMI (r g = -0.21 ± 0.09). Live weight (r g = 0.3 ± 0.1) and body condition score (r g = 0.2 ± 0.1) were positively correlated with methane yield. Comparing the two estimates of methane yield, CH 4 /DMI had lower heritability and repeatability. However, correlations of both measures with adult ewe traits were similar. This suggests that breeding is a suitable mitigation strategy for lowering methane yield, but wool, live weight and fat deposition traits may be affected over time and should be monitored.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2022 Hickey, Bain, Bilton, Greer, Elmes, Bryson, Pinares-Patiño, Wing, Jonker, Young, Knowler, Pickering, Dodds, Janssen, McEwan and Rowe.)
Databáze: MEDLINE
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