Original scientific paper
Increasing Dietary Energy with Starch and Soluble Fibre and Reducing ADF at Different Protein Levels for Growing Rabbits
Marco Tazzoli
; Department of Agronomy, Food, Natural Resources, Animal and Environment, University of Padova, Agripolis, I-35020 Legnaro, Padova, Italy
Marco Birolo
; Department of Agronomy, Food, Natural Resources, Animal and Environment, University of Padova, Agripolis, I-35020 Legnaro, Padova, Italy
Eirini Filiou
; Department of Agronomy, Food, Natural Resources, Animal and Environment, University of Padova, Agripolis, I-35020 Legnaro, Padova, Italy
Angela Trocino
; Department of Comparative Biomedicine and Food Science, University of Padova, Agripolis, I-35020 Legnaro, Padova, Italy
Andrea Zuffellato
; Veronesi Verona S.p.A., I-37142, Quinto di Valpantena, Verona, Italy
Gerolamo Xiccato
; Department of Agronomy, Food, Natural Resources, Animal and Environment, University of Padova, Agripolis, I-35020 Legnaro, Padova, Italy
Abstract
The effect of increasing dietary energy by increasing both starch (14% to 20%) and soluble fibre (9.6% to 11.6%) and decreasing ADF content (21% to 13%) at two crude protein levels (14% and 15%) was assessed on health, growth performance, caecal fermentative activity, gut mucosa traits, and carcass and meat quality of growing rabbits reared from 34 to 76 days of age. At weaning, 306 rabbits were divided into six groups and fed ad libitum six diets formulated according to a bi-factorial arrangement with 3 (starch+soluble fibre)/ADF ratio (L=1.2; M=1.8; H=2.8) x 2 protein levels. The contemporary increase of dietary starch and soluble fibre and the reduction of ADF linearly increased the digestibility of dry matter, energy and all nutrients, decreased feed intake and improved feed conversion (3.65 to 2.76 in rabbits fed diets L and H; P<0.001); it increased morbidity (P=0.09) but did not affect mortality due to epizootic rabbit enteropathy; at caecum, VFA production raised (52.1 to 61.9 mmol/L) and pH (5.90 to 5.67) and N ammonia lowered (4.85 to 1.93 mmol/L); the villi/crypts ratio (4.42 vs. 3.81 and 3.95 in rabbits fed diets L, M and H) decreased in a non linear mode. The decrease of the protein level did not affect growth performance, but nearly halved mortality (28.9% vs. 16.3%; P=0.01) and increased caecal pH (5.70 to 5.87; P=0.05). Weak effects of the dietary treatments were measured on carcass traits and meat quality.
Keywords
starch; soluble fibre; insoluble fibre; protein; growing rabbits
Hrčak ID:
106912
URI
Publication date:
4.9.2013.
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