Effect of parity order and litter weaning age on the performance and body energy balance of rabbit does

This review aims to present the different effects produced by a post-weaning intake limitation strategy on the growing rabbit, now largely used by French professional rabbit breeders. Although a quantitative feed restriction leads to slower growth, feed conversion (FC) is improved, particularly when the rabbits are again fed freely, as compensatory growth occurs. This better FC or the healthy rabbit is because of better digestion resulting from slower passage through the intestine, whereas the digestive physiology is slightly modified (morphometry of the intestinal mucosa, fermentation pattern, microbiota). Meat quality and carcass characteristics are not greatly affected by feed restriction, except for a lower dressing-out percentage. One of the main advantages of limiting post-weaning intake of the rabbit is to reduce the mortality and morbidity rate due to digestive disorders (particularly epizootic rabbit enteropathy syndrome). The consequences for animal welfare are debatable, as feed restriction probably leads to hunger, but it reduces the incidence of digestive troubles after weaning. However, the growing rabbit adapts very well to an intake limitation strategy, without any aggressive behaviour for congener. In conclusion, restriction strategies could improve profitability of rabbit breeding, but they should be adapted to any specific breeding situation, according to the national market, feed prices, etc.

Feed intake limitation strategies for the growing rabbit: effect on feeding behaviour, welfare, performance, digestive physiology and health: a review.

In this invited communication the author proposes a list of nutritional recommendations for rabbits of different categories: growing from 18 to 42 days, from 42 to 80 days, for breeding does according to productivity (40-50 kits weaned per doe/year or more than 50) and for a single diet suitable for all rabbits. Recommendations taking account the last published data, are divided in 2 groups. The first corresponds to nutrients which contribute mainly to feed efficiency: digestible energy, crude and digestible protein, amino acids, minerals, and fat-soluble vitamins. The second group corresponds to nutrients which contribute mainly to nutritive security and digestive health: different fibre components (lignins, cellulose, hemicelluloses) and their equilibrium, starch and water soluble vitamins. In a second part, 387 papers published during the last 30 years on raw material utilisation in rabbit feeding were analysed. In a total of 14 tables, the 542 corresponding experiments were summarised each by the identification of the raw material, by the highest level of incorporation used in the experiment, by the highest acceptable level, by the main ingredient(s) replaced by the raw material studied, and finally by the authors reference. Raw materials studied were those used in temperate as well as in tropical countries. The raw material were grouped according to the following categories : raw material used as single food (24 experiments), cereals and byproducts (43 exp.), other carbohydrates source of energy (62 exp.), fats (27 exp.), full-fat oleaginous grains (10 exp.), oil cakes and meals (43 exp.), proteic seeds such peas or beans (42 exp.), miscellaneous sources of protein such yeast or leaf protein (18 exp.), animal products (21 exp.), non-protein nitrogen source such urea (9 exp.), forages (157 exp.), cereal straws, alkali treated or not (33 exp.), cover or parts of dried grains source of fibre such stalks, hulls or cobs (19 exp.) and industrial byproducts usable as fibre source (51 exp.).

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Reflections on rabbit nutrition with a special emphasis on feed ingredients utilization.

In the European context, the new legislation to avoid mineral contamination and the ban on antibiotics as growth promoters has led to the definition of new objectives in respect of nitrogen supply. The present study summarizes the state of nitrogen nutrition in rabbits and reviews the role of protein and amino acids in rabbit health and the new nitrogen value of protein sources based on true ileal digestibility (TID) for future recommendations. The main sources of nitrogen for microbial growth are ammonia, urea and protein (endogenous and dietary). The surplus of nitrogen flow to the caecum increases mortality rates during fattening by favouring the growth of potential pathogenic bacteria. Accordingly, feeding strategies to reduce ileal nitrogen flow have been reviewed. A large reduction of dietary protein level might have negative consequences on growth performances and mortality. In order to formulate balanced low protein diets, data on ileal and faecal amino acid digestibility of 14 raw materials is summarized. The use of this different unit for amino acid digestibility is also discussed.

https://polipapers.upv.es/index.php/wrs/article/download/664/651

New concepts and objectives for protein-amino acid nutrition in rabbits: a review

Nutrition and feeding strategy: interactions with pathology.

Four diets based on different vegetal protein concentrates: soya bean meal 48 (SB48 diet), soya bean protein concentrate (SB61 diet), sunflower meal 36 (SF36 diet) and a combination of soya bean meal 48 and potato protein concentrate (SB48-P77 diet) were formulated for the starter pe- riod (25-39 days) in early weaned rabbits (25 days of age). These sources of protein accounted for 30% of the total dietary crude protein (CP) content. All diets were formulated to be isonutritive and to meet or exceed all the essential nutrient requirements of growing rabbits. A feeding trial was con- ducted to measure the effect of the treatments on growth performance in 204 rabbits that were fed ad libitum the experimental diets in the starter period and thereafter received a common feed until 60 d of age. Faecal and ileal apparent digestibility of dry matter (DM) and CP (9 and 7 replicates, respec- tively) were determined at 35 d of age. The weights and pH of the stomach and caecal contents, am- monia concentration in the caecum and jejunal morphology were also determined (11 rabbits per diet). The treatments did not affect faecal DM and CP digestibility. However, the source of protein af- fected ileal digestibilities of DM and CP (P < 0.04), which were around 14 and 7% higher for SB61 and SF36 diets, respectively, than for the SB48 diet, whereas the values obtained for the SB48-P77 diet were intermediate. The ileal flux of CP and the N-NH3 caecal concentration were (P = 0.08 and 0.05, respectively) affected by the source of protein. The highest values were observed in animals fed the SB48-P77 diet, increasing by around 25 and 35%, respectively, compared to the other three diets. The treatments had no effect on digestive traits and jejunal morphology. The differences in ileal di- gestion efficacy among treatments led to differences (P = 0.008) in food efficiency the first week after weaning, which was higher (10%, as average) in animals fed the SB61 diet than that observed for ani- mals fed the SB48 and SB48-P77 diets, whereas the value obtained for SF36 was intermediate. In this period, the type of diet tended (P = 0.08) to affect daily gain and food efficiency, with the lowest val- ues obtained for the SB48 diet. The treatments had no effect on mortality in the first two weeks after weaning. However, mortality in the whole fattening period was affected by protein source (P = 0.03), since it was higher in animals fed the SB48-P77 diet after weaning than the animals fed the other three diets (34.6 vs. 16.7%, respectively). In conclusion, SF36 and SB61 are the sources of protein that led 461

/pdf/effect-of-protein-source-on-digestion-and-growth-performance-280vkleaq4.pdf

Effect of protein source on digestion and growth performance of early-weaned rabbits

The role of gut barrier against pathogens and its interaction with dietary factors in weaned rabbits affected with digestive disorders, especially epizootic rabbit enteropathy is reviewed This interaction was studied identifying nutritive factors that influence gut barrier function of mucosa It was examined the morphology, and enzyme activity of mucosa and the gut associated immune system Besides, it was characterized the substrate that reaches the caecum and its capacity to favour pathogen bacteria growth, by reviewing the effect of diet on ileal digestibility of nutrients, transit time and microbiota population The nutritional factors which affect health of early weaned rabbits are level and type of both fibre and protein The optimal dietary level of insoluble fibre to minimise mortality is 30-32% Furthermore, a moderate inclusion of soluble fibre (12%) improves mucosa integrity and decreases mortality and the frequency of detection of Clostridium perfringens and Campylobacter spp in the caecum The reduction of ileal nitrogen flow had a positive effect on pups viability and frequency of detection of C perfringens Furthermore, dietary supplementation with 1% of glutamine reduced fattening mortality, the frequency of detection of C perfringens, and Helicobacter spp, and diminished the counts of Eimeria spp at the jejunum In conclusion, a correct diet formulation may help to limit the epizootic rabbit enteropathy incidence in weaned rabbits Additional key words: fibre, gut barrier function, protein, weaning, young rabbits

http://www.inia.es/gcontrec/pub/015-025-R._New_trends_1204278058515.pdf

New trends in rabbit feeding: influence of nutrition on intestinal health

Effects of starch and protein sources, heat processing, and exogenous enzymes in starter diets for early weaned rabbits

In this study we investigated the influence of the reproductive system on doe reproduc- tive performance. Two experimental treatments were compared using 36 cages per treatment over an 8-month production period. In the intensive system (IS) rabbit does were mate d4da fter parturition and the litters were weaned at 25 d of age, whereas in the control system (CS) the rabbit does were mated 11 d after parturition and the litters were weaned at 35 d of age. In both systems, the does that failed to mate, conceive or lost their pups were immediately given the opportunity to remate. Initially seventy-two New Zealand × Californian does were assigned to the treatments and used to determine the reproductive traits. Early mating of rabbit does associated with 25-d litter weaning (IS) allowed a shorter parturition interval (39.9 vs. 44.4 d, P = 0.0001) and a higher prolificacy (9.07 vs. 8.11 young rabbits born alive per litter, P = 0.06), litter size at 21 d (8.24 vs. 7.51, P = 0.06) and at weaning (8.21 vs. 7.42, P = 0.05) and tended to reduce the number of young rabbits born dead (0.52 vs. 0.94, P = 0.10) as compared to the animals in the CS treatment. Consequently, numerical productivity in- creased from 61.6 to 73.4 young rabbits per cage and year (P = 0.003). The intensively bred does had a lower receptivity to the male at the first mating (54 vs. 86.9%, respectively), but 88% of these does ac- cepted mating within 7da fter parturition. Fertility was high, above 80%, in all the matings. The treat- ments did not affect either the body weight (4301 g as average) or the mortality of the rabbit does (14.6%) and the mortality of the young rabbits during lactation (11.8%). Feed efficiency increased from 0.241 to 0.309 g of young rabbits weaned per g of feed when the remating interval was longer but these results cannot be compared because of the parallel increase in the age and weight of the young rabbits at weaning. This study indicates that, in the conditions of reproductive management used, the numerical productivity can be increased through earlier mating and weaning. However, more infor- mation is needed about the effect of this system on young rabbit performance after weaning, and about the possibility of increasing the receptivity of rabbit does at 4 d by using bio-stimulation methods.

/pdf/the-effect-of-remating-interval-and-weaning-age-on-the-2lmjzzapph.pdf

I. Gutiérrez

Papers

Effect of protein source on digestion and growth performance of early-weaned rabbits

New trends in rabbit feeding: influence of nutrition on intestinal health

Effects of starch and protein sources, heat processing, and exogenous enzymes in starter diets for early weaned rabbits

The effect of remating interval and weaning age on the reproductive performance of rabbit does

Destete precoz en gazapos: situación actual y perspectivas