Abstract

Simple Summary A polyphenolic-rich extract from radiata pine bark (PBE) has been demonstrated to reduce in vitro ammonia nitrogen concentration without detrimentally affecting diet digestibility or ruminal fermentation parameters, suggesting that PBE can improve dietary protein use efficiency by increasing the protein outflow to the intestine. This in vivo study evaluates the effects of a short-term (21-d) supplementation with PBE at three concentrations (0, 1, and 2% dry matter basis) on animal performance, blood parameters, and fatty acid (FA) profiles in finishing Suffolk lambs. The supplementation with PBE improved sheep FA profile by (i) reducing the saturated FA and the sigma n-6/sigma n-3 ratio, (ii) increasing unsaturated FA, and (iii) increasing FAs that are beneficial to human health. Additionally, PBE supplementation enhances relative growth rate and dietary protein conversion without affecting intake, growth performance, blood parameters, or carcass traits. The aim of this study was to evaluate the effects of a short-term supplementation with a polyphenol-rich extract from radiata pine bark (PBE) on animal performance, blood parameters, and fatty acid (FA) profiles in finishing lambs. Twenty-seven Suffolk lambs (4 months old) fed a finishing diet were randomly assigned to one of the following treatments: diet without PBE or diet supplemented with PBE on a 1 or 2% dry matter (DM) basis, for 35 d (14 d adaptation and 21 d of experimental period). Data were compared using Tukey's test and orthogonal and polynomial contrasts. The results indicated that the supplementation with PBE increased (p = 0.008) relative growth rate (RGR) and improved (p = 0.003) protein conversion (CPC), whereas weight gain, carcass characteristic, and blood parameters were unaffected (p >= 0.106). Total mono- and polyunsaturated FAs, conjugated linoleic acid (CLA), and vaccenic and oleic acids were linearly increased (p = 0.016) by PBE supplementation. In contrast, total saturated FAs (sigma SFA), sigma n-6/sigma n-3 ratio, atherogenicity index (AI), thrombogenic index (TI), and the proportion of elaidic acid were linearly decreased (p = 0.018). In conclusion, the supplementation with 1 or 2% DM of PBE improves subcutaneous FA profiles by increasing CLA and reducing sigma SFA, sigma n-6/sigma n-3 ratio, AI, and TI. Additionally, PBE supplementation has the potential to improve RGR and CPC, with unaffected intake, growth performance, blood parameters, or carcass characteristics.