Herbs, thyme essential oil and condensed tannin extracts as dietary supplements for broilers, and their effects on performance, digestibility, volatile fatty acids and organoleptic properties
Résumé
ABSTRACT 1. Herbs, thyme essential oil (EO) and condensed tannin (CT) extracts were compared for their effects as dietary supplements, on broiler growth performance, nutrient digestibility and volatile fatty acid (VFA) profiles in the gut. Cooked meat from the birds fed diets with 4 herbs and an EO extract was compared by a taste panel against those fed the control treatment, for organoleptic properties in the meat. 2. Female broiler chicks were fed wheat-soybean meal diets from 0-42 days of age. These chicks were fed either the basal ration (control), or the basal ration with one of rosemary, garlic or yarrow herbs, mimosa, cranberry or grapeseed CT's, or thyme EO supplements (8 treatments in total). Body mass (BM) and feed consumption (AFC) were measured (7, 21 and 42 days of age). 3. The garlic supplement tended (P>0.05) to improve growth rate over the first 7 days, while mimosa CT and thyme EO supplements reduced weight gains. The mimosa supplement in diets lowered (P<0.05) AFC up to study day 21. Meanwhile, the addition of a cranberry supplement reduced the digestibility of DM, OM and N, compared to the controls. Dietary thyme EO, yarrow, rosemary and garlic supplements modified caecal isovaleric and isobutyric acid proportions (Other VFA; P<0.05). Dietary herb supplements affected the intensity of meat flavour (P<0.001), and the potential of observing both garlic (P<0.001) and abnormal (P<0.001) flavours. There were large differences between the consumption of red and white meat samples, while meat temperature affected several flavour attributes. 4. Dietary garlic and grapeseed CT supplements maintained broiler performance and digestibility similarly to those birds fed the control diet, and these supplements appear suitable for dietary inclusion. Careful choices are necessary when selecting dietary plant extract supplements for broilers, but beneficial effects can be observed.
Domaines
Biologie animale
Origine : Fichiers produits par l'(les) auteur(s)
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