Plasma natural 15N abundance may predict both feed conversion efficiency and residual feed intake in beef cattle across different dietary conditions
Résumé
Cheap and rapid methods to predict between-animal variability of feed efficiency (FE) are
needed. We evaluated, by using a large dataset on beef cattle (n = 355) fed contrasting diets
(grass vs corn based diets), the potential of plasma natural 15N abundance (δ15N) as a
biomarker of between-animal variation in FE, measured either as feed conversion efficiency
(FCE) or residual feed intake (RFI). Data were analyzed by mixed models, with diet and δ15N
as a fixed effect and experimental farm, batch and pen as random effects. A negative and
significant correlation was found between FCE and δ15N within each contemporary group,
with a lower response (slope) however in grass vs corn diets (δ15N × diet interaction; P =
0.002). Likewise, we found a significant but positive relationship between δ15N and RFI, but
without the influence of diet or any tested random effect. Our results indicate that δ15N is a
promising biomarker of between-animal variation of feed efficiency (FCE and RFI) in
growing beef cattle.
Domaines
Sciences du Vivant [q-bio]Format | Poster |
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