This study aimed to evaluate how the feeding strategy of rabbit kits at the onset of solid feed intake could affect ecological diversity and co-occurrence patterns of the cecal bacterial community. From birth to 18 days of age kits were exclusively milk-fed, and between 18 and 35 days the young rabbits also had access to solid feed. After weaning at (35 days), young rabbits were exclusively fed solid feed. Three experimental feeds were used: a high concentrate diet [H: 10.16 MJ digestible energy (DE)/kg and 15.3% crude protein (CP)], a low concentrate diet (L: 9.33 MJ DE/kg and 14.7% CP) and a reproductive female diet (R: 10.57 MJ DE/kg and 17.3% CP). The rabbit kits (n = 357) were divided into three groups, differing by the diet received during two periods: from 18 to 28 and from 28 to 49 days of age. In the groups LL and HH, rabbit kits were fed L or H diets, respectively, during both periods. Kits in the group RL received feeds R and L from 18 to 28 and 28 to 49 days of age, respectively. Cecal bacterial communities of 10 rabbits per group were carried out at 18, 28, 35, 43 and 49 days of age by MiSeq Illumina sequencing 16S rRNA encoding genes. Between 18 and 28 days of age, solid feed intake was higher in the group RL compared to the other two groups (+24%; P < 0.01). Overall, 13.4% of the OTUs detected were present in the cecal ecosystem from 18 to 49 days old, whereas 17.4% were acquired with the onset of solid feeding and kept from 28 days on. Exclusive milk consumption constrains the bacterial community toward a similar structure but high phylogenetic beta-diversity. Introduction of solid feed induced a sharp change of microbial community structure and decreased phylogenetic diversity. A strong relationship in bacterial community network occurred only from 43 days on. Our feeding strategy at the onset of solid feed ingestion exhibited only a moderate effect on the microbial community structure (P = 0.072), although the LL group seemed to reach faster maturity compared to the two other groups.

Cette etude avait pour objectif de determiner l'influence de l’âge, de l’etat et du stade physiologiques des animaux sur la digestibilite des nutriments d’un aliment. Nous avons utilise un seul aliment experimental distribue a volonte a 18 lapins en croissance et 26 femelles reproductrices reparties en 3 groupes : gestantes et allaitantes (groupe GA, n = 8), gestantes non-allaitantes (groupe GnA, n = 10), non gestantes et allaitantes (groupe nGA, n = 8). Chez les femelles gestantes la digestibilite a ete mesuree durant la 1ere (1ere periode : P1) et la 3eme (2eme periode : P2) semaine de gestation, qu’elles soient allaitantes ou non. Chez les femelles allaitantes mais non gestantes la digestibilite a ete mesuree pendant la 3eme semaine de lactation (contemporaine a P1). La digestibilite de la matiere organique (+10,0 pts), de l'energie brute (+10,6 pts), de l’NDF (+18,7 pts), de l'ADF (+22,3 pts) a ete plus elevee chez les lapines GA comparees aux lapines nGA, GnA et aux lapins en croissance (P <0,001). La teneur en energie digestible etait la plus faible dans le groupe GnA par rapport aux trois autres groupes (10,4 contre 12,4, 12,9 et 13,4 MJ / kg pour les lapins en croissance, nGA et GA, respectivement, P <0,001). La gestation augmente la digestibilite de tous les elements nutritifs de la ration (+3,7 a +9,5 pts chez les femelles GA comparativement aux femelles nGA, en fonction des elements nutritifs, P <0,05). Nos resultats suggerent que l'extrapolation des mesures de digestibilite obtenues chez les lapins en croissance sous-estime les valeurs nutritionnelles des aliments pour femelles reproductrices, en particulier dans le cas des femelles allaitantes. Le stade de lactation s'est avere avoir un effet plus prononce sur la digestibilite des nutriments que le stade de la gestation.

This study aimed to assess the influence of feed composition at the onset of solid feed intake, at 18 to 28d of age, on growth performance and health in young rabbits until slaughter age (70d). 796 rabbit kits, issued from 64 does followed during two successive reproduction cycles, were divided into 2 experimental groups differing in the diet that the suckling rabbits received from 18 to 28d of age. From 18–28d, young rabbits in the RF group were fed a diet that met the needs of reproductive does (R; 10.57 MJ DE/Kg, 128g DP/kg, 199g DF/kg), while young rabbits in the FF group were fed a diet that met the needs of growing rabbits (F; 9.35 MJ DE/kg, 98g DP/kg, 258g DF/kg). From 28 to 70d rabbits of both groups were fed the F diet. Does received the R diet throughout the experiment thanks to experimental cages that allow separate feeding between mothers and their litters. In both groups, feed was offered ad libitum before weaning (35d) and from 63 to 70d of age but was restricted from weaning to 63d. Feed intake, animal weights and health status were recorded weekly. Mortality was recorded daily. Feed intake was higher in the RF group than in the FF group from 18 to 21d (+ 27%, P<0.001) and 21–28d (+14.7%, P<0.01). Feed intake was similar in both groups from 28 to 35d (34g/d/kit, NS). This resulted in a higher average daily gain from 18 to 28d (+13.9%, P<0.001) and a higher weight at weaning (+7.7%, P<0.001) in the RF group compared to the FF group. This difference in live weight between the two groups was reduced at 70d (+2.4%, P<0.05) due to a lower feed conversion rate in the FF group at 42–49d and 63–70d (P<0.05). Mortality was low before (1.2%) and after weaning (0.4%), and no differences were seen between the groups concerning mortality and morbidity (NS). This did not support the hypothesis that suckling rabbits regulate feed intake based on energy content of the diet at the onset of solid feed intake, but suggests that the moment of distribution of fattening feed before weaning has an impact on weight at weaning and kit health during the fattening period.

This study aimed to determine the influences of feeding strategy and diet for reproductive females on feed intake, BW, reproductive performances, and milk composition and their effects on kit performances from birth (d 0) to 70 d of age (d 70). A total of 133 does followed for 3 reproductive cycles and their offspring, 2,322 kits from 236 litters, were divided into 3 experimental groups that differed only by the diet offered to the doe. Three experimental diets were used: a reproduction (Repro) diet (11.01 MJ DE/kg, 24.0 g lipids/kg, 161 g starch/kg, and 343 g/kg NDF), a lactation (Lact) diet (11.88 MJ DE/kg, 49.0 g lipids/kg, 161 g starch/kg, and 302 g/kg NDF), and a fattening (Fatt) diet (9.73 MJ DE/kg, 23.0 g lipids/kg, 70 g starch/kg, and 415 g/kg NDF). In group RR, does received feed Repro throughout the study (d 0 to 42 of each cycle). In group RF, does received diet Repro from d 0 to 25 and d 35 to 42 and diet Fatt from d 25 to 35. In group LR, does received diet Lact from d 0 to 25 and diet Repro from d 25 to 42. Kits in all groups received diet F from d 18 to 70, where intake was restricted from d 35 to 63. Doe BW was similar throughout the study (4,495 g; > 0.05). Doe feed intake differed only from weaning to the subsequent kindling (+7.8% in group RF; = 0.042). Reproductive performances were similar, except for litter weight at birth (+3.6% in group LR; = 0.029). From d 0 to 25, a negative energy balance was observed in does yet most markedly in group LR (-8.61 MJ vs. -3.15 and -2.39 for groups RF and RR, respectively; < 0.01). Milk intake per kit was greater in group LR than in the other 2 groups at 17 d (+14.5%; < 0.001) and 23 d (+14.9%; < 0.05). Kit BW was highest in group LR at 18 and 25 d (+10.1% and +8.2%, respectively; < 0.01), but no difference was observed at 35 or 70 d ( > 0.05). Feed intake per kit from d 18 to 25 was greater in groups RR and RF than in group LR (+26%; < 0.001) and greater in group RF than in group LR from d 25 to 35 (+8%; < 0.05). Feed intake, when fed ad libitum (63 to 70 d), was similar in all groups ( = 0.292). Kit mortality before weaning was similar in all groups (8.1%; > 0.05) but was lowest in group RF after weaning compared to groups RR and LR (1.7 vs. 4.8 and 5.8%, respectively; < 0.001). Our results suggest that stimulating milk production through the incorporation of fat at the beginning of lactation offers few benefits for females and had a negative effect on early solid feed intake, which could explain animal health after weaning.

Post-weaning feed restriction is a common practice in rabbit farming to reduce mortality, but results in lower growth performance and slaughter weights. This study aimed to assess the influence of 2 diets both rich in fibre and low in starch, with high or low digestible energy (DE) and digestible protein (DP) contents for a constant DP/DE ratio offered from 18 to 70 d of age, on the growth performance and health parameters of rabbits. Eight hundred rabbit kits were divided in 2 experimental groups differing in the feed offered from 18 to 70 d: a high concentrate diet (HC group; 10.37 MJ DE/kg DM and 102 g DP/kg DM) or low concentrate diet (LC group; 9.63 MJ DE/kg DM and 95 g DP/kg DM). Feed was offered ad libitum before weaning (35 d) and from 63 to 70 d, while feed offered from 35 to 63 d was controlled to obtain similar DE intake in both groups. Feed intake, animal weights and health status were recorded weekly. Mortality was recorded daily. Feed intake was similar in both groups before weaning (P=0.204), and consequently the DE intake was higher in the HC group compared to the LC group before weaning (3.91 vs. 3.39 MJ, respectively; P=0.017). Feed intake from 63 to 70 d was lower in the HC than in the LC group (229 vs. 239 g/d/kit, respectively; P<0.001).Total DE ingested after weaning was similar in both groups (45.44 MJ; P=0.143). Kits were heavier in the HC group throughout the study (P<0.05). A higher average daily gain during the periods of 18-28, 35-42 and 56-63 d was seen in the HC group (+8.1%, +16.8% and +4.5%, respectively; P<0.05). Mortality and morbidity rates were similar between groups throughout the study (P=1.0 and P=0.104, respectively). Our results suggest that when the feed intake after weaning is controlled, i) the feeding strategy before weaning determines the weight at weaning and at slaughter age; and ii) rabbits fed a diet more highly concentrated but rich in fibre increase their growth performance without negative consequences on their digestive health.