AbstrAct:The nutritive value and potential use of sundried sulla hay [(Hedysarum flexuosum), g/kg as feed: 885 dry matter, 438 neutral detergent fibre (NDF), 337 acid detergent fibre, 80 acid detergent lignin and 147 crude protein (CP)] for growing rabbits was studied by comparing 3 diets containing an increasing inclusion rate of sulla hay (S): 0% (control, S0), 15% (S15) and 30% (S30) in substitution for control diet (294 g NDF and 179 g CP/ kg). Three groups of 30 rabbits (individually caged) were fed ad libitum the 3 diets from weaning (35 d, mean weight: 572±93 g) to 84 d of age. Faecal digestibility of the diets was measured between 42 and 46 d of age on 10 rabbits per group. The digestible energy (DE) concentration of sulla hay estimated by regression was 8.96±0.57 MJ/kg DM, thus 7% higher than standard alfalfa meal, which would account for its high NDF digestibility (54.9%). Digestibility of crude sulla protein was estimated at 42.8%, corresponding to a digestible crude protein concentration of 71.1±8.9 g/kg DM. Even at a high incorporation rate in the feed (30%), sulla hay did not cause adverse effects on the animal growth (mean 36.0 g/d), feed intake (mean 119 g/d) or health. Feed conversion was better for a moderate rate of sulla inclusion in the diet (about 15%) than for a higher inclusion rate (3.14 vs. 3.36, P<0.001). Health status and slaughter traits were not affected by the sulla incorporation rate. Sun-dried sulla hay (Hedysarum flexuosum) could thus be considered as a good fibre source for the rabbit as a substitute for alfalfa meal.

The nutritive value and potential use of sun-dried common reed (<em>Phragmites australis</em>) leaves (CRL), for growing rabbits was studied by comparing 3 diets (regression method) containing an increasing incorporation rate of CRL: 0% (control, CRL0), 15% (CRL15) and 30% (CRL30) in substitution for the control diet (356 g neutral detergent fibre (NDF) and 197 g crude protein (CP)/kg). Three groups of 37 rabbits (individually caged) were fed the 3 diets <em>ad libitum</em> from weaning (35 d, mean weight: 722±142 g) to 77 d of age. The faecal digestibility of the diets was measured between 42 and 46 d of age in 10 rabbits per group. CRL can be considered high-fibre roughage, as it contained 64% of NDF (38% of ADF and 10% ADL) and 10.2% of CP. The digestible energy (DE) content of CRL calculated by regression was null (–1.8±0.29 MJ/kg as fed). CP digestibility reached 29%, corresponding to a digestible crude protein concentration of 29.0±5.6 g/kg as fed basis. The fibre digestibility was reduced with CRL incorporation. Dietary incorporation of CRL impaired the rabbit growth (34.2 vs. 31.5 g/d during the period 35-77 d without CRL or with CRL (CRL15 and CRL30), respectively; P=0.002). Consequently, feed conversion was impaired with the high incorporation rate in feed (30%). Health status or main slaughter traits were not affected by CRL incorporation rate. Thus, the sun-dried common reed leaves had a poor nutritive value for growing rabbits and it can be considered a high-fibre feedstuff, interesting to supply low digested fibres (cellulose) and lignin.

ABSTRACT:The aim of this study was to characterize the growth of rabbits of a local Algerian population (Kabylian) from birth to weaning at 28 days. A total of 216 litters from 82 females of the local population were regularly weighed between birth and weaning (28 d) in the experimental rabbitry of the Tizi-Ouzou University (100 km east of Algiers). The average weight of young rabbits at birth was 51 g. During the first three weeks of nursing, the young rabbit's weight increased from 119 g at the end of the first week to 308 g at the end of the third week. At weaning the average weight of kits was 475 g. The 0-28 d daily weight gain (DWG) was modest (15.7g/d). DWG was significantly lower in summer (12.6 g/d) than during the three other seasons (15.9 to 16.9 g/d) mainly as a consequence of a reduced growth rate during the fourth week. There was no significant effect of season on growth rate until the age of three weeks, which implies that there was no significant effect of season on milk production of the does. The birth weight decreased from 62.1 g for kits born in litters of 1-4, to 43.0 g for those born in litters with 9 or more born alive. Similarly the DWG was reduced from 18 to 12 g/day. Individual kit's birth weight was the smallest for primiparous does (44.2 g) when compared to multiparous does (52.7 g), but at weaning, differences were not significant (438 to 496 g for kits born from does in parity class 1 to 4 or more). These results confirm the low growth rate of this local population, but also the good resistance of does to hot summer conditions.

The nutritive value of 2 types of sun-dried olive cake (OC), extracted traditionally (COC) or with a 3-phase olive cake (TPOC), was studied for the growing rabbit. Four diets containing 10 or 20% of COC (COC10 and COC20) or of TPOC (TPOC10 and TPOC20) in substitution for a basal diet were compared to a control diet without OC (OC0). Five groups of 12 rabbits were fed one of the 5 diets ad libitum from weaning (35 d) to 46 d of age. The faecal digestibility was individually measured between 42 and 46 d of age. COC and TPOC are high fibre and lignin sources, with 707 and 787 g/kg dry matter (DM) of neutral detergent fibre, 530 and 554 g/kg DM of acid detergent fibre, 242 and 243 g/kg DM of acid detergent lignin, respectively. Replacing 20% of basal diet by COC sharply reduced (P<0.001) the digestibility of energy and crude protein from 0.67 to 0.54, but that of protein only moderately (from 0.80 to 0.76). The same effect was observed with the incorporation of 20% of TPOC. The digestible energy (DE) content of COC and TPOC were calculated by regression and were 3.24±0.41 and 2.94±0.52 MJ DE/kg DM respectively, corresponding to an apparent faecal digestibility of the gross energy of 0.14 (COC) and 0.13 (TPOC). The apparent faecal digestibility of the crude protein of COC was 7 units higher than TPOC (0.44 vs. 0.37) and the digestible protein (DP) content was 20% higher (27.9±4.2 g vs.22.4±6 g DP/kg DM). Olive cake could be considered as a high fibre source with a low protein and energy content for the growing rabbit.

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