1. A common reference procedure adopted by several European laboratories to determine apparent metabolisable energy corrected to zero-nitrogen balance (AMEn) is described. 2. Reproducibility has been estimated by comparing results from 4 diets measured in 7 laboratories. The standard deviations between laboratories of dry matter, gross energy, Kjeldahl nitrogen and AMEn were respectively, on average, 11.29 g/kg, 0.242 MJ/kg, 1.56 g/kg and 0.380 MJ/kg dry matter; the corresponding coefficients of variation between laboratories were 1.27, 1.29, 4.39 and 2.92%. 3. Effect of food intake was tested by comparing AMEn from birds fed either 0.90 or 0.45 of ad libitum: the amount of food intake had a negligible effect on AMEn values. Endogenous energy losses corrected (EELn) or not (EEL) to zero nitrogen balance were estimated either by regression between excreted energy and ingested energy or in fasted and glucose-fed cockerels. EELn estimated by regression was, on average, 8.7 kJ/bird/d.; it was independent of diet composition. EEL and EELn determined in fasted or glucose-fed birds were higher than those determined by regression. 4. AMEn values measured by individual laboratory procedures were very close to those obtained by the reference method, except from laboratories using a tube feeding procedure, where deviations were probably a consequence of overestimated EEL.

The nutritional value of different categories of peas was measured in mash or pelleted diets using adult cockerels. Twenty-five round and white-flowered peas (feed peas), 12 round and coloured-flowered peas and five wrinkled and white-flowered peas were used in mash diets. From the same batches, 11 feed peas, five coloured peas and four wrinkled peas were tested in pelleted diets.Mean apparent metabolizable energy (AME) values were 12·02, 11·35 and 10·50 MJ/kg dry matter (DM) for feed peas, coloured peas and wrinkled peas respectively in mash diets and 13·18, 12·72 and 11·63 MJ/kg DM for the same categories in pelleted diets.Mean starch digestibility was 0·905, 0·887 and 0·802 for feed peas, coloured peas and wrinkled peas respectively in mash diets and 0·985, 0·984 and 0·840 for these categories in pelleted diets.Mean protein digestibility was 0·788, 0·643 and 0·798 for feed peas, coloured peas and wrinkled peas respectively in mash diets and corresponding values for peas in pelleted diets were 0·855, 0·743 and 0·853.Pelleting thus had a positive effect on the nutritional value of peas and this improvement was all the more important because the AME and protein digestibility of the pea in mash diets was low.The nutritional value of feed peas for cockerels was not strongly correlated with chemical composition or to digestibility data obtained in the pig.

1. Apparent metabolisable energy corrected to zero-nitrogen retention (AMEn) was measured using the European reference procedure in 9 European laboratories. Seven pelleted diets were evaluated. AMEn was measured with adult cockerels and young birds. 2. Between-laboratory standard deviations were for dry matter (DM) 12.5 g/kg, gross energy 0.085 MJ/kg DM, Kjeldahl nitrogen 0.768 g/kg DM, AMEn (adults) 0.256 MJ/kg DM, and AMEn (young) 0.337 MJ/kg DM. Corresponding coefficients of variation between laboratories were 1.42, 0.45, 2.15, 1.88 and 2.60% respectively. 3. AMEn values of experimental diets were always significantly lower when measured with young birds. This effect was more pronounced when diets contained added fat. 4. Tallow or soyabean oil were incorporated into two basal diets at 40 g/kg inclusion rate. No significant differences were observed between AMEn values of either diet with adults or young birds, suggesting that AMEn energy values of these fats are indistinguishable at this inclusion rate. 5. Similar AMEn values were obtained in young birds by estimating nitrogen accretion, either by the difference between intake and excreta nitrogen or by measuring body weight gain. Determined AMEn values were very similar to those predicted using three different regression equations.

-The effects of the level of dietary starch on growth performance and mortality were studied in six experimental sites on 2 328 growing rabbits (582 per diet). Four iso-lignocellulosic (ADF) diets (A12, A16, A20, A24) with increasing starch content (12, 16, 20, 24%) instead of digestible fibre (hemicelluloses and pectins) were compared. Diets were given ad libitum from weaning (28 and 35 d old, depending on the site) to slaughter (between 68 and 71 d old). The increase (12 points) of dietary starch level led to a double-rise of mortality rate by digestive disturbances: 4.6% and 10.1% respectively for A12 and A24 for the whole period. In parallel, the feed conversion ratio decreased slightly but significantly by 0.15 point between A12 and A24. The feed intake and the digestible energy intake was respectively reduced by only 4.5% and by 1.5% (P < 0.01), between the A12 and A24 diets. During the whole period the growth rate remained similar for the four diets (mean = 42.5 g . d -1 ). To ensure digestive security of the growing rabbit, it is recommended to maintain a dietary starch level below 14% during the post-weaning period, while for the end-fattening period dietary starch could reach 18%. rabbit / feeding / starch / fibre / growth / diarrhoea / mortality

-The effects of the quality of the dietary starch on growth performance and mortality were studied on five experimental sites on 1784 growing rabbits (446 per diet). Four iso-fibre diets varying in starch nature (W-wheat, B-barley, M-maize, EM-Extruded maize) were compared. The diets were given ad libitum from weaning (30 to 35 d. of age, depending on the site) to slaughter (68 to 71 d). From weaning to 49 days of age, the weight gain did not differ significantly according to the starch source (mean = 48.6 g·d -1 on average). The feed intake was higher for the M diet compared to the other three diets (+5%, P < 0.01). During the finishing period (49 d to slaughter), the weight gain was significantly higher for the EM diet compared to the W or B diets (+2%). The feed consumption was 5% higher (P < 0.01) for the M diet, compared to other treatments. Thus, feed conversion was the worst for the M diet, while it was the lowest for the EM diet. During the whole fattening period, the weight gain was only slightly higher with extruded maize feed, compared to the others (meanly +0.8 g·d -1 ). Correlatively, feed intake and conversion index were significantly lower for the EM diet, while they were the highest for the M diet (-2 to -4% compared to B and W diets). On the five experimental sites, mortality was always caused by acute digestive disorders, without specific pathology. The mortality rate due to diarrhoea greatly varied among sites (between 1.7 and 19.4%). The mortality rate between weaning and 49 days of age and during the finishing period was not affected by the dietary starch origin. However, the mortality in the W group was 3 points lower than in the M group (P = 0.07). . Du sevrage à 49 jours d'âge, la vitesse de croissance a été élevée et n'a pas différé significativement entre les 4 traitements (en moyenne = 48.6 g·j -1 ). L'ingestion d'aliment a été plus élevée pour le régime M (+5 %, P < 0,01). En période de fin d'engraissement (49 j à abattage), la vitesse de croissance a été plus rapide pour le régime EM, comparée aux régimes "Blé" ou "Orge" (+2 %). L'aliment à base de maïs a présenté le niveau d'ingestion le plus élevé (+5 %, P < 0,01), et aussi l'indice de consommation le plus haut, tandis que le régime EM a présenté la conversion alimentaire la plus efficace. Durant la totalité de la période de croissance, la vitesse de croissance a été seulement légèrement plus élevée pour le groupe EM (en moyenne +0,8 g·j -1 par rapport aux trois autres groupes), tandis que l'ingestion et l'indice de consommation ont été les plus faibles (-2 à -4 % respectivement comparé aux groupes B et W). Sur les 5 sites expérimentaux la mortalité a toujours été causée par une diarrhée aiguë, sans pathologie spécifique identifiable. Le taux de mortalité par diarrhée a beaucoup varié selon le site (entre 1,7 et 19,4 %). La mortalité post-sevrage ou en fin de croissance ne varie pas significativement en fonction des traitements. Cependant, on peut remarquer un taux de mortalité inférieur de 3 points pour le groupe B par ra...