A bstract Optimizing rabbit does preparation during early life to improve reproductive potential is a major challenge for breeders. Does selected for reproduction have specific nutritional needs, which may not be supplied with the common practice of feed restriction during rearing in commercial rabbit production. Nutrition during early life was already known to influence metabolism, reproduction and mammary gland development later in life, in particular during pregnancy. The aim of this study was to analyze the impact of four different feeding strategies in the early life of rabbit females (combination of high or moderate feed restriction from 5 to 9 weeks of age with restricted or ad libitum feeding regime from 9 to 12 weeks of constituting the pubertal period) on their growth, reproductive capacities and mammary development at mid-pregnancy. Unlike food intake, which remains regular, mean body weight gain was inversely proportional to the dietary restriction applied over the considered periods. The feeding strategies in place for the four groups had no effect on the reproductive parameters of the females at mid-pregnancy, as opposed to certain metabolic parameters such as cholesterolemia, that decreased with dietary intake at puberty (p≤0.05). Furthermore, restriction programs have impacted mammary tissular structures at mid-pregnancy. The expression of lipid metabolism enzymes (Fatty acid synthase N and Stearoyl co-A desaturase) is also increased in mammary epithelial tissue at mid-pregnancy by the dietary strategies implemented (p≤0.05). Moreover, milk gene expression, used as differentiation markers, indicates a better mammary epithelial development regarding further lactation, in the case of the less restrictive strategies during early life period, especially the higher feeding allowance. Our results highlight the importance of investigating feeding conditions of young female rabbits and nutrition in early life rearing, in order to provide specific recommendations for optimizing lactation and thus preventing neonatal mortality of the offspring.

Early feeding in the nest is a promising biomimetic s rategy to improve gut health and prevent digesti v diseases. To formulate adequate starter feed, it is essential to determine the nutritional values of t he preweaning diets. However, the assessment of suckling rabbits’ digestion is challenging since the kits ar e raised together with their mother along with the fa ct that gut morphology and functionalities are deep ly changing during the transition from milk to solid f eed. To study the digestive capacity of the young r abbits, a 15-days digestibility trial was performed from 21 days of age to weaning on rabbits provided with ea rly feeding or not. A mother-litter separate feeding sy stem with controlled suckling was used to monitor i ntake and faecal excretion of 20 litters. All the litters had access to pellet feeds from 15 days. A starter feed in a form of a gel was provided as early as 3 days of ag e to half of the litters. Gut development dynamics and milk intake were taken into account to adjust faeca l digestibility calculations. Digestibility coeffic ients of dry matter, crude protein, gross energy, and fibre fractions (NDF, ADF, Hemicelluloses) were high between 21 and 24 days (64%, 72%, 68%, 44%, 37% and 55%, respectively) and were followed by a decrease between 25 and 27 days (-16%, -10%, -16%, -32 , -37%, -7%). Starter feed supplementation did not modify faecal digestibility. Our original data revealed a short period where digestive capacity of the rabbit seemed to be overwhelmed by the sudden influ x o dry matter in the gut. This could be implement ed in the future for pre-weaning feed formulation.

In young rabbit, digestive disorders are frequently observed around weaning. Stimulating the onset of feed intake in the suckling rabbit might be a way to promote gut health. The aim of this study was to determine the rabbit’s acceptability for different feed presentations and its preferences for flavours at an early stage of life. Two trials were conducted to evaluate the effects of physical form and flavouring on creep feed attractiveness. All the diets tested were provided in the nest from 3 to 17 days, and the daily intake per litter was recorded as of 8 days of age. In the first trial, five feed presentations were tested separately (n = 60 litters). Three dry presentations were chosen: commercial pellet (P), crumb from commercial pellet (cP) and crumb from beet pulp pellet (cBP). Hydrated feeds were also provided with either raw fodder beetroot (B) or a semi-solid feed in agar gel form produced with fodder beetroot juice and pulp (gB). In the second trial, double-choice tests were performed on four feed gels (n = 72 litters), leading to six comparison treatments. These agar gels were made of pellet mash without or with a sensory additive: one non-odorised control gel and three gels with 0.20% banana flavour, 0.06% red berry flavour and 0.10% vanilla flavour, respectively. In the first trial, kits ate more gB in fresh matter than other feed presentations (P < 0.001), with a total intake of 7.0 ± 1.8 g/rabbit from 8 to 17 days. In DM, the total consumption of pellets P (1.6 ± 0.4 g of DM/rabbit) was the highest together with the gB form (1.4 ± 0.4 g of DM/rabbit), whereas cBP was barely consumed (0.3 ± 0.1 g of DM/rabbit). Gel feed supplemented with vanilla was slightly more consumed than other flavoured and non-odorised gels (relative consumption of 57% when compared to control gel; P = 0.001). The gel feed intake was independent of the milk intake but was correlated with the litter weight at 3 days (r = 0.40, P < 0.001). In both trials, rabbit growth before and after weaning was not affected by the type of creep feed provided. Our results confirmed that providing creep feed promotes the solid intake of rabbits at early stages. Gel feed form motivated rabbits to eat and vanilla flavour supplementation increased the feed palatability. Those creep feed characteristics should be explored further for seeking effective stimulation of the onset of the feed intake in suckling rabbit.

Weaning represents a critical period for rabbit, with a high susceptibility to gastrointestinal diseases. Stimulating early solid feed intake could contribute to preserving health in rabbit. Thus, the aims of this study were, first, to quantify early solid intake and, second, to determine young rabbit pellet preferences according to their physical properties. Double-choice tests of pellets processed with different dies were conducted in two trials. An original feeding system was used to specifically measure consumption of suckling rabbits in the nest independent of that of the does. Pellets were provided from 3 to 17 days in the nest box and intake was measured daily. From 15 to 35 days, kits received pellets in feeders and intake was measured every 4 days. In the first trial, four pellet diameters were tested in pairs against each other: (A) 2.0, (B) 3.0, (C) 4.0 and (D) 6.0 mm. In the second trial, pellets of identical diameter (2.5 or 4.0 mm) were manufactured with three die channel lengths: (E) 10, (F) 12, (G) 14 mm or (C) 18, (H) 20 and (I) 24 mm. For a given diameter, pellets were tested in pairs. This resulted in six combinations per trial (n = 10 litters per combination). Solid feed intake began at 8 days for 89 out of 118 litters. Over the first 17 days of life, a rabbit ingested a total of 1.63 +/- 0.76 g of dry matter in the nest in addition to milk. The solid feed intake at 2 weeks of age was correlated with litter weight at the beginning of the experiment (r = 0.50 between 15 and 17 days; P < 0.05). In the feeders, rabbits selected pellet A (61%, 67% and 86% of relative consumption when compared with B, C and D). In the second trial, pellet I was slightly disliked compared to C when provided in the nest (P < 0.05), and compared to H in the feeders (P < 0.05). It was concluded that suckling rabbits were able to ingest solid feed in the nest box and to discriminate pellets according to their presentation when a choice was given. Providing young rabbits with an easy-access feeding system and an optimal pellet presentation may help to stimulate early solid intake and thus pave the way for further studies on nutritional control of microbiota implantation.

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.

Sensory evaluation of meat provides methods for understanding human perceptions products. Across sensory methods, product, environment, and panelist control have to be developed and consistently applied for reliable, repeatable sensory data. The three basic sensory methods of discriminative, descriptive, and consumer sensory evaluation are discussed. Different tools available to meat scientists within each method are discussed, and a description of how to conduct each method is explained. Examples of lexicons, controls, panel training sessions, and ballots are provided to assist meat scientist in selection and conducting the appropriate tool for their sensory objectives.