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.

A total of 287 females of a local Kabylian population of rabbits were studied at the University of Tizi-Ouzou (Algeria) over 6 years. The females were mated for the first time at the age of 4.5 months and remated 10-12 days after parturition. The females were characterized by a medium to small adult weight (2.81±0.38 kg) and a rather low prolificacy at birth and weaning (7.2±2.5 total born, 6.1±3.0 born alive and 5.4±2.3 weaned). Based on the registration of 1377 mating attempts, acceptance of mating and conception rates were 74.3±3.8% of presented does and 73.3±4.3% of mated does respectively. The Algerian hot summer season did not seem to affect parameters of practical importance such as fertility or litter size at weaning. The only significant effect (P<0.01) was a reduction of litter weight at weaning (-13%) compared with the average of the 3 other seasons (2070 vs 2368 g at 28 days). Acceptance and conception rates were not significantly affected by mating number. At first parturition, total number of kits (6.6/litter) was significantly lower than that of multiparous does (7.3 to 7.4), and individual birth weight of first litter kits was 10% lower than that observed for subsequent litters (51.4 g on average). On the other hand, it must be emphasised that for this sample of the Kabylian population, the kit's individual weight at weaning did not vary significantly with parturition number. Birth to weaning mortality was the lowest for parturition of rank 4 and more (9.8% vs 14.4 to 16.9% for previous ones).

Eighty one rabbits were used to study the utilisation of hard wheat by-products on the growth of rabbits from a local Algerian population. At weaning (28 d, 501±99 g), the animals were individually caged and received ad libitum one of the three experimental diets for 49 d. The control diet included 26% wheat bran (W26: control diet), alfalfa, barley and soybean meal. The two other diets were formulated by substituting barley and soybean meal with hard wheat by-products, and contained 60% (W60) or 67% (W67) of these by-products (50 or 57% bran and 10% middling). On average, diets contained 11.8% crude fi bre and crude protein decreased from 18.3 (W26) to 16.1% (W67). Growth traits and slaughter performances were recorded. Another group of thirty animals was used to determine dietary nutrient digestibility from 42 to 46 d of age. Dry matter digestibility and digestible energy content were lower in the W60 and W67 diets than in the control diet (W26) (71.3 and 71.5% vs. 74.9%, and 11.9 and 11.9 vs. 12.5 MJ/kg, respectively; P<0.01). In contrast, crude fi bre digestibility was lower in W26 (21.9%) than in the other two diets (29.6 and 32.2% for W60 and W67, respectively; P<0.01). The growth rates were similar for all three groups (28.0, 27.1 and 26.0 g/d for W26, W60 and W67) as were the feed conversion ratios (3.14, 3.17 and 3.10, respectively). Dressing out percentage (66.4±2.0% on average for the cold carcass) was not affected by the amount of wheat by-products in the diet. The total mortality rate was high (23%), probably corresponding to the low crude fi bre content of the three experimental diets, but was not connected to the amount of wheat by-products.

Abstract:In order to characterize the does of a local Kabylian rabbit population raised in Algeria, a study of their milk production was carried out in the experimental rabbitry of the Tizi-Ouzou University. Milk production of does was measured every day during the 21 days following 299 parturitions by weighing each litter before and after the single daily suckling. The calculated parameters were the quantity of milk produced per day, per week and the total quantity produced in 21 days, as well as the intake of milk per young rabbit. The analysis concerned the effects of the parity order (4 classes: 1 to 4-and-more) and of the average number of young rabbits suckled per litter (7 classes: from 2-3 kits to more-than-8). During the 21 days of controlled lactation, the average litter size was 5.6 ± 2.3. The rabbit does of the local Kabylian population produced on average 2180 ± 719 g in 21 days, which is 104 g of milk/day. The milk intake of young rabbits increased from 12.6 g/day/kit during the 1 st week, to 27.2 g/day during the 3 rd week of lactation. The number of young per litter influenced the does' milk production very significantly: 62.8 g/d for 2 to 3 young per litter, and up to 127-131 g/day for more than 6 young, although milk production available per kit and per day decreased linearly with the number of kits in the litter for each of the 3 weeks considered. On the other hand, the average milk production expressed as quantity available per kit and per day was not significantly affected by the parity order: 20-21 g /kit /day on average for the 0-21 day period.

Specific knowledge of the nutritive value of raw materials is fundamental to formulate balanced diets for rabbits and allows greater use of by-products and non-conventional feedstuffs. This paper examines the feeding value of sun-dried brewers' grain and maize silage (whole plant) for fattening rabbits. Twentyfour individually caged 8-wk-old rabbits were used to determine the digestibility. Both wet products were sun-dried and ground before being incorporated into a basal diet. The inclusion level at the expense of all basal ingredients amounted to 30%. Basal diet and both experimental diets were fed ad libitum to 8 rabbits during the 4-d balance trial. The determined digestibility of protein, fat, crude fibre and neutral detergent fibre digestibility amounted to 76.2 and 77.2%; 86.5 and 99.1%; 8.1 and 8.3% and 28.0 and 13.5%, respectively, for brewers' grain and maize silage. The digestible energy content amounted to 11.66 MJ/kg dry matter (DM) (brewers' grain) and 11.10 MJ/kg DM (maize silage). Both by-products have potential as alternative feedstuff in rabbit diets. However, further experiments are necessary to determine the effect of ensilaging the whole maize plant, as a significantly lower (P<0.001) feed intake was observed.

The aim of the trial was to study the effects of replacement of a soybean meal-alfalfa-maize based diet by a mixture of field bean (g/kg as fed: 257 crude protein [CP], 139 neutral detergent fibre [NDF]) or pea (g/kg as fed: 203 CP, 122 NDF) combined with hard wheat bran (g/kg as fed: 140 CP, 396 NDF) and without supplementation of synthetic DL-methionine, on diet digestibility, growth and slaughter traits of growing rabbits. Three diets were formulated: a control diet mainly consisting of 15% of soybean meal, alfalfa and maize (SBM15 diet; g/kg as fed: 161 CP and 267 NDF) and 2 experimental diets based on 26% of field bean (FB26 diet; g/kg as fed: 167 CP and 250 NDF) or 30% of pea (P30 diet; g/kg as fed: 167 CP and 255 NDF) as main protein source, and completed with hard wheat bran (34 and 40%, respectively for FB26 and P30 diets) partly replacing alfalfa and maize. Diets were distributed ad libitum to 3 groups of 40 mixed-sex growing rabbits of Algerian white population, placed in collective cages (4 rabbits/cage) from weaning (28 d, mean weight: 614±112 g) until 77 d of age (slaughter). Faecal digestibility was measured between 42 and 46 d of age in 7 rabbits/group. Gross energy and crude protein digestibility coefficients were similar for SBM15 and FB26 diets (78.6 and 86.4%, respectively) and lower for P30 diet (75.1 and 83.6%, respectively; P≤0.03). Treatments had no effect (P=0.12) on mortality rate, which was on av. 9.2%. Treatments did not affect growth performance from 28 to 77 d of age (30.8 g/d) or feed intake (mean 94.6 g/d), but feed conversion ratio was higher for rabbits fed FB26 and P30 diets compared to those fed SBM15 diet (3.13 vs. 2.94; P=0.006). The dressing out percentages (mean 66.6%) and the muscle/bone ratio (6.8) were similar for the 3 groups of rabbits. In conclusion, the substitution of soybean meal-alfalfa-maize by a combination of field bean or pea with hard wheat bran, without methionine supplementation, does not seem to affect growth, nor the slaughter performances of the local growing rabbits. However, digestion of pea diet was reduced and feed efficiency of FB26 and P30 diets was impaired.

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.

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