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To evaluate how dietary inclusion of distillers dried grains and solubles (DDGS) could affect the performance and caecal environment of growing rabbits, four experimental diets were formulated from a control diet without DDGS (C), including 20% barley DDGS (Db 20 ), 20% wheat DDGS (Dw 20 ) and 20 (Dc 20 ) or 40% (Dc 40 ) corn DDGS. Animals had free access to medicated versions of the diets until 49 d, and then to unmedicated diets until 59 d of age. The performance trial was done using 475 three-way crossbred weaned rabbits of 28 d of age, individually housed in 5 batches. Caecal fermentation traits were determined in 20 animals per diet and at 42 d and at 59 d of age. No significant effect of the growing diet on mortality, morbidity or sanitary risk index was observed. In the whole period and compared to the control group, animals fed with Db 20 showed higher dry matter (DM) and digestible energy (DE) intake (+6 and +12%, respectively; P<0.05), but similar daily weight gain (DWG) and increased feed conversion ratio (+9%; P<0.05). Similarly, and regardless of its inclusion level, the increase in DE intake of animals fed with corn DDGS (+9, respectively; P<0.05) did not increase DWG. In contrast, higher DM and DE intake of animals fed with Dw 20 (+8; P<0.05) resulted in a higher DWG (+2.8 g/d; P<0.05) than those fed with C. Although inclusion of DDGS at 20% did not affect main caecal parameters recorded at 42 d, caecum of animals fed with the diet Dc 40 was characterised by greater N-NH 3 and valeric acid and lower total volatile fatty acids and acetic acid concentrations than the average of the other groups (on av. +5.2±1.7 mmol/L, +0.29±0.07 mol/100 mol, -17.17±4.41 µmol/L and -2.60±0.99 mol/100 mol, respectively; P<0.05). At 59 d of age, higher caecal DM, and propionic and valeric acid concentration and lower values of total volatile fatty acids and acetic/propionic rate were observed for DDGS inclusion at 20% compared to the control (+1.6±0.5%, +0.95±0.44 mol/100 mol, -9.3±4.3 µmol/L and -2.7±1.2, respectively; P<0.05). Linear inclusion of corn DDGS increased caecal DM, propionic acid proportion and total volatile fatty acids concentration and reduced acetate/propionic rate (+4.0±0.4%, +2.27±0.41 mol/100 mol, -21.27±3.9 µmol/L and -5.6±1.1, respectively for Dc 40 compared to C; P<0.05). Rabbits given Dc 40 were also characterised for a greater caecum N-NH3 content than the other groups (on av. -8.7±1.7 mmol/L; P<0.05) at 59 d of age. The results of the present work reveal that inclusion of DDGS up to 20%, independently of the grain source (barley, wheat or corn), could be an interesting alternative in balanced diets for growing rabbits.

Elsevier Alagón, G.; Arce-Cabrera, ON.; Martinez-Paredes, E.; Ródenas Martínez, L.; Moya, V.; Blas Ferrer, E.; Cervera Fras, MC.... (2016). Nutritive value of distillers dried grains with solubles from barley, corn and wheat for growing rabbits. Animal Feed Science and Technology. 222:217-226. doi:10.1016/j.anifeedsci.2016.10.024 Nutritive value of distillers dried grains with solubles from barley, corn and wheat for 1 growing rabbits 2 (on av. +70 g kg -1 DM). DDGS' protein was richer in proline, phenylalanine, valine and 27 arginine for barley DDGS (107, 55, 54 and 51 g kg -1 CP, respectively), in leucine, alanine and 28 histidine for corn DDGS (114, 75 and 27 g kg -1 CP, respectively), and in glutamic acid for 29 wheat DDGS (290 g kg -1 CP). Barley DDGS was richer in saturated (236 g kg -1 total fatty 30 acids), corn DDGS in monounsaturated (278 g kg -1 total fatty acids) and wheat DDGS in 31 polyunsaturated fatty acids (615 g kg -1 total fatty acids). Barley DDGS was characterized by the 32 lowest nutritive value traits of DDGS evaluated (11.9 MJ digestible energy (DE) and 168 g 33 digestible protein (DP) kg -1 DM). In spite of higher protein and lower fibre content of the 34 Brazilian corn (+1.7 g CP and −31 g neutral detergent fibre kg -1 DM), no significant differences 35 for the nutritive value of both corn DDGS were observed (on av. 15.3 MJ DE and 208 g DP kg -1 36 DM). Wheat DDGS might be considered as the DDGS with the highest nutritive value of those 37 evaluated (15.7 MJ DE and 263 g DP kg -1 DM). 38 39

To evaluate the effect of dietary level of beet pulp, with or without molasses, on growth performance, a total of 470 28-day-old rabbits were used (614 ± 6 g). Animals were randomly allocated into five dietary treatment groups: Control, without beet pulp; BP20, and BP40 with 20 and 40% of beet pulp without molasses, respectively; and BPM20 and BPM40, with 20 and 40% of beet pulp with molasses, respectively. Daily feed intake (DFI) and average daily gain (ADG) were controlled at 28, 49, and 59 days of age. Carcass and digestive tract traits were also determined at 59 days of age. Mortality and morbidity were controlled daily. Mortality during the growing period was higher in BPM than in BP groups (+9.2%; p < 0.05). The higher the inclusion of beet pulp, the lower the DFI and ADG of animals (5.5 and 4.6% for every 20% inclusion, respectively; p < 0.001), as well as the dressing out percentage, the liver proportion, and the dissectible fat percentage of their carcasses. However, the best feed efficiency during the last 10 days was obtained with the BPM40 group. The higher the inclusion of beet pulp, the higher the weight of the empty gastrointestinal tract and cecum (+2.4 and +3.0 percentage points for every 20% inclusion, respectively; p < 0.001). In fact, a higher inclusion of beet pulp decreased the pH and dry matter and decreased the total volatile fatty acids content of cecum richer in acetic acid but poorer in propionic, isobutiric, isovaleric, and valeric acids. Stomach weight was lower, and the capric acid content in the cecum was higher in the BPM than in the BP group. The inclusion of beet pulp in the feed reduced the growth performance and carcass yield of growing rabbits, and an even higher incidence of digestive disorders was observed when beet pulp included molasses.