Feeding silkworm (Bombyx mori L.) oil to growing rabbits improves the fatty acid composition of meat, liver and perirenal fat.

Silkworm oil was used in a rabbit diet to evaluate its benefit on the fatty acid (FA) profile of different carcass portions. Two experimental diets were prepared: a control diet (commercial diet with 13 g/kg sunflower oil) and a silkworm oil diet (SWO) (commercial diet with 13 g/kg silkworm oil). Rabbits received the experimental diets the last three weeks before slaughter, which occurred at 10 weeks of age. At slaughter, hind leg meat, liver, and perirenal fat were sampled for FA profile analysis. The SWO diet significantly increased the n-3 FA of all three sampling sites and halved the n-6/n-3 ratio of hind leg meat and perirenal fat. Furthermore, the liver of SWO rabbits was also richer in C22:6 n-3 compared to that of control rabbits. In conclusion, this study demonstrated that the total dietary replacement of sunflower oil with silkworm oil in fattening rabbits positively changed the FA profile of the considered carcass tissues.

Effect of a dietary inclusion of full-fat or defatted silkworm pupa meal on the nutrient digestibility and faecal microbiome of fattening quails.

Silkworm (Bombyx mori L.) pupae are a by-product derived from silk production, which is often treated as waste and thus discarded: this can cause serious environmental problems and a loss of nutrients. Silkworm pupae are a rich source of protein and lipids, and the resulting protein meal can provide promising outcomes as livestock feed, notably for monogastric species. However, one possible issue that needs to be considered is the possible implication of the 1-Deoxynojirimycin (1-DNJ), a bio-compound of the silkworm that impairs glucose absorption, in poultry nutrition. Therefore, the present study evaluated the effect of the dietary inclusion of full-fat or defatted silkworm pupa meal (SWM) on the apparent digestibility of nutrients, feed choice and faecal microbiome in meat-producing quails. For the digestibility trial, a total of thirty-three 27-day-old Japanese quails (Coturnix coturnix japonica) were individually housed in digestibility cages and received three experimental diets: a control diet (control, commercial feed for fattening quails), and two other diets containing the 12.5% of either a full-fat SWM (SWM-FULL) or a defatted SWM (SWM-DEF). Subsequently, twenty-seven 33-day-old quails were simultaneously provided with Control, SWM-FULL and SWM-DEF diets for a 10-day feed choice trial. The results of the digestibility trial showed that the DM intake and excreta production were higher in both SWM groups than in the Control one (P < 0.001). The apparent digestibility of DM, organic matter, CP, ether extract, starch and energy was lower in both SWM groups than in the control group (P < 0.001), suggesting the possible implication of chitin and 1-DNJ. The feed choice test showed that quails preferred the Control diet (P < 0.001). From the microbiome analysis of the excreta, families such as Streptococcaceae (P < 0.05), Rikenellaceae and Eubacteriaceae (P < 0.01) and taxa at species level such as Lactobacillus delbrueckii (P < 0.05), Aneurinibacillus thermoaerophilus and Bacillus thermoamylovorans (P < 0.01) scored higher in SWM-FULL quails than in SWM-DEF and Control treatments. The present study demonstrated that a successful dietary inclusion of SWM for fattening quails needs to overcome the digestive criticalities caused by the of presence specific bio-compounds, namely chitin and 1-DNJ.

Profile of cabanossi made with exotic meats and olive oil.

The effect of olive oil inclusion on the chemical and sensory characteristics in cabanossi made with ostrich and warthog meat was investigated. Ostrich meat from soybean oilcake (SBOC) and cottonseed oilcake dietary inclusion levels (CSOC), and olive oil were included at three levels (0%, 1% and 2%) resulting in six treatments. The fat content in the cabanossi increased with increasing levels of oil inclusion but were all <10%, which allows it to be classified as a low fat meat product. Total monounsaturated fatty acids in the cabanossi increased whilst total saturated fatty acids and total polyunsaturated fatty acids decreased as olive oil increased. The SBOC cabanossi had a lower fat and higher crude protein content. The inclusion of olive oil at 2% resulted in a cabanossi with increased tenderness, juiciness and cured red meat colour, all factors that appeal to the consumer, while the overall flavour descriptors were not adversely affected by the inclusion of olive oil.

The effects of quercetin supplementation on New Zealand White grower rabbit carcass and meat quality - A short communication.

Control and quercetin dihydrate-supplemented (2 g/kg) feeds were fed to 32 New Zealand White rabbits (both sexes) from 5 to 12 weeks old. Slaughter weight, carcass and organ weights, meat yields and physical and proximate meat quality were determined. Quercetin increased the hindleg meat:bone ratio (P < .001) by reducing hindleg bone weight (P = .01), contrary to the current understanding of the effect of quercetin on the skeletal system. However, this and the increase in skin weight (P = .03) may have been due to the effects of quercetin on connective tissue. Sex affected spleen weight (P = .04; female > male), head weight (P < .001; male > female), reference carcass yield (P = .02, female > male) and loin pHu (P = .02; male > female), without commercial implications. Other physical and chemical meat quality traits were not affected by diet or sex.

Black soldier fly larva fat inclusion in finisher broiler chicken diet as an alternative fat source.

The objective of the present study was to evaluate the effects of partial or total replacement of finisher diet soybean oil with black soldier fly (Hermethia illucens L.; HI) larva fat on the growth performance, carcass traits, blood parameters, intestinal morphology and histological features of broiler chickens. At 21 days of age, a total of 120 male broiler chickens (Ross 308) were randomly allocated to three experimental groups (five replicates and eight birds/pen). To a basal control diet (C; 68.7 g/kg as fed of soybean oil), either 50% or 100% of the soybean oil was replaced with HI larva fat (HI50 and HI100 group, respectively). Growth performance was evaluated throughout the trial. At day 48, 15 birds (three birds/pen) per group were slaughtered at a commercial abattoir. Carcass yield and proportions of carcass elements were recorded. Blood samples were taken from each slaughtered chicken for haematochemical index determination. Morphometric analyses were performed on the duodenum, jejunum and ileum. Samples of liver, spleen, thymus, bursa of fabricius, kidney and heart were submitted to histological investigations. Growth performance, carcass traits, haematochemical parameters and gut morphometric indexes were not influenced by the dietary inclusion of HI larva fat. Histopathological alterations developed in the spleen, thymus, bursa of fabricius and liver and were identified in all of the experimental groups, but HI larva fat inclusion did not significantly affect (P>0.05) the severity of the histopathological findings. The present study suggests that 50% or 100% replacement of soybean oil with HI larva fat in broiler chickens diets has no adverse effects on growth performance or blood parameters and had no beneficial effect on gut health.

Black soldier fly as dietary protein source for broiler quails: meat proximate composition, fatty acid and amino acid profile, oxidative status and sensory traits.

In the perspective of improving the sustainability of meat production, insects have been rapidly emerging as innovative feed ingredient for some livestock species, including poultry. However, at present, there is still limited knowledge regarding the quality and sensory traits of the derived meat. Therefore, the present study tested the effect of a partial substitution of soya bean meal and oil with defatted black soldier fly (Hermetia illucens) larvae meal (H) in the diet for growing broiler quails (Coturnix coturnix japonica) on meat proximate composition, cholesterol, amino acid and mineral contents, fatty acid profile, oxidative status and sensory characteristics. To this purpose, three dietary treatments were designed: a control diet (C) and two diets (H1 and H2) corresponding to 10% and 15% H inclusion levels, respectively, were fed to growing quails from 10 to 28 days of age. At 28 days of age, quails were slaughtered and breast meat was used for meat quality evaluations. Meat proximate composition, cholesterol content and oxidative status remained unaffected by H supplementation as well as its sensory characteristics and off-flavours perception. Differently, with increasing the dietary H inclusion, the total saturated fatty acid and total monounsaturated fatty acid proportions raised to the detriment of the polyunsaturated fatty acid fraction thus lowering the healthiness of the breast meat. The H2 diet increased the contents of aspartic acid, glutamic acid, alanine, serine, tyrosine and threonine thus further enhancing the biological value of the meat protein. As a direct result of the dietary content of Ca and P, the meat of quails fed with the highest H level, displayed the highest Ca and the lowest P values. Therefore, meat quality evaluations confirmed H to be a promising insect protein source for quails. The only potential drawback from feeding H to broiler quails regarded the fatty acid profile of the meat, therefore requiring further research efforts to understand to what extent the fatty acid profile of H can be improved.

Effect of a dietary supplementation with linseed oil and selenium to growing rabbits on their productive performances, carcass traits and fresh and cooked meat quality.

The present experiment tested a dietary supplementation with linseed oil and selenium to growing rabbits. The basal diet (B) contained 3% sunflower oil, while it was substituted with 3% linseed oil in the experimental feed (S). The selenium (Se) content of the two diets was 0.10 vs. 0.46 mg/kg. Rabbits were fed with B diet from the age of 18 days. One group was fed with the B diet until 11 weeks of age (group B), whereas the experimental groups were fed with S diet for 1, 2, 3 or 4 weeks (groups S1, S2, S3 and S4, respectively), before slaughtering (11 weeks of age). Live performance and carcass traits of rabbits, fatty acid (FA) profile and selenium content of their hind leg (HL) and Longissimus thoracis et lumborum (LTL) meat were considered in this study. In addition, the effect of two different cooking methods on the nutritional value of the enriched HL meat was also assessed. The tested dietary supplementation only minimally affected the live performance and carcass traits of rabbits. The S supplementation significantly reduced the Σ n-6 FA and increased the Σ n-3 FA of the HL meat and LTL meat, compared to the B diet (p < 0.001); thus, n-6/n-3 ratio was improved (p < 0.001). In addition, HL meat and LTL meat of S fed rabbits were significantly enriched in Se reaching a twofold increase in both meat cuts (p < 0.01). Therefore, the S supplementation improved the functional value of the rabbit meat. The heat treatment affected cooking loss, Se and vitamin E contents as well as the oxidative status of the HL meat (p < 0.001), with the different cooking methods providing different results. In addition, even if the beneficial C20:5 n-3 and C22:6 n-3 decreased with cooking, the n-6/n-3 ratio remained unaffected.

Technological quality, mineral profile, and sensory attributes of broiler chicken breasts affected by White Striping and Wooden Breast myopathies.

The aim of the research was to study the impact of white striping and wooden breast myopathies on the technological quality, mineral, and sensory profile of poultry meat. With this purpose, a total of 138 breasts were selected for a control group with normal breasts (N), a group of breasts characterised by white striping (WS) myopathy, and a group of breasts having both white striping and wooden breast myopathies (WSWB). Data revealed that the simultaneous presence of the two myopathies, with respect to the WS lesion individually considered, had a further detrimental effect on pH (6.04 vs. 5.96; P < 0.05), yellowness (11.4 vs. 10.3; P < 0.01), cooking losses (30.4 vs. 27.6%; P < 0.05), toughness instrumental values (22.8 vs. 20.0 N; P < 0.01), and perception (6.22 vs. 5.56; P < 0.01). In addition, mineral contents suggest that a defective ions regulation is also present in white striping and wooden breast myopathies.

The effect of dietary Digestarom® herbal supplementation on rabbit meat fatty acid profile, lipid oxidation and antioxidant content.

The experiment tested the effect of Digestarom® herbal supplementation on the antioxidant content, lipid oxidation and fatty acid profile of rabbit meat. At kindling, rabbit does and litters were divided into two dietary groups (N=162 kits/dietary group) and fed either a control diet (C) or the C diet supplemented with Digestarom® (D: 300mg/kg). At weaning (35days) four experimental fattening groups (54 rabbits each) were considered: CC, CD, DC and DD. After slaughtering (12weeks of age), Longissimus thoracis et lumborum muscles were dissected from 20 rabbits/group and analyzed. Rabbit meat of DD group was enriched in essential C18:3 n-3 fatty acid and in other long-chain PUFA of n-3 series. Despite meat of DD group displayed the highest peroxidability index, TBARs value was the lowest. Meat antioxidant content followed the rank order: DD>CD>DC>CC. Digestarom® improved fatty acid composition and oxidative status of rabbit meat, particularly when administered from weaning throughout the growing period.

Black soldier fly as dietary protein source for broiler quails: apparent digestibility, excreta microbial load, feed choice, performance, carcass and meat traits.

In order to expand with validated scientific data the limited knowledge regarding the potential application of insects as innovative feed ingredients for poultry, the present study tested a partial substitution of soya bean meal and soya bean oil with defatted black soldier fly (Hermetia illucens) larvae meal (H) in the diet for growing broiler quails (Coturnix coturnix japonica) on growth performance, mortality, nutrients apparent digestibility, microbiological composition of excreta, feed choice, carcass and meat traits. With this purpose, a total of 450 10-day-old birds were allocated to 15 cages (30 birds/cage) and received three dietary treatments: a Control diet (C) and two diets (H1 and H2) corresponding to 10% and 15% H inclusion levels, respectively (H substituted 28.4% soya bean oil and 16.1% soya bean meal for H1, and 100% soya bean oil and 24.8% soya bean meal for H2, respectively). At 28 days of age, quails were slaughtered, carcasses were weighed, breast muscles were then excised from 50 quails/treatment, weighed, and ultimate pH (pHu) and L*, a*, b* colour values were measured. Breast muscles were then cooked to assess cooking loss and meat toughness. For the digestibility trial, a total of 15 28-day-old quails were assigned to the three feeding groups. The excreta samples were subjected to chemical and microbiological analysis. The same 15 quails were then simultaneously provided with C and H2 diets for a 10-day feed choice trial. Productive performance, mortality and carcass traits were in line with commercial standards and similar in all experimental groups. With the exception of ether extract digestibility, which was lower in H1 group compared with C and H2 (P=0.0001), apparent digestibility of dry matter, CP, starch and energy did not differ among treatments. Microbial composition of excreta was also comparable among the three groups. Feed choice trial showed that quails did not express a preference toward C or H2 diets. Breast meat weight and yield did not differ among C, H1 and H2 quails. Differently, the inclusion of H meal reduced meat pHu compared with C. In conclusion, this study demonstrated that H. illucens larvae meal can partially replace conventional soya bean meal and soya bean oil in the diet for growing broiler quails, thus confirming to be a promising insect protein source for the feed industry. Further research to assess the impact of H meal on intestinal morphology as well as on meat quality and sensory profile would be of utmost importance.

Effect of pre- and post-weaning dietary supplementation with Digestarom® herbal formulation on rabbit carcass traits and meat quality.

This study evaluated effects of Digestarom® (D) dietary inclusion before weaning (0-5weeks old; BW) and/or after weaning (5-12weeks old; AW) on growing rabbit carcass traits and meat quality. During BW, Pannon-Ka rabbits (does, kits) received two diets: a control diet (C) and one supplemented with 300mg Digestarom®/kg (D). At weaning, each group was divided into 3 dietary sub-groups: CC and DD received C and D diets from 5 to 12weeks of age, whereas DC was fed D from 5 to 8weeks and C from 8 to 12weeks of age (54 rabbits/group; AW). Rabbits were slaughtered at 12weeks of age. Digestarom® supplementation improved carcass yield and body mid part proportion only when administered BW. Rabbits fed D BW had higher hind leg meat cooking losses. Loin meat spiciness and rancidity increased with D both BW and AW. In conclusion, Digestarom(®) herbal formulation was ineffective in improving growing rabbit carcass traits or meat quality.

Impact of coccidiosis control program and feeding plan on white striping prevalence and severity degree on broiler breast fillets evaluated at three growing ages.

This study investigated the impact of 2 coccidiosis control systems (vaccine vs anticoccidial) and 2 feeding plans (standard energy vs low energy content, the latter supplemented with threonine and enzymes in the second half of the production cycle) on white striping (WS) prevalence and severity in chicken broiler breasts at commercial slaughter age (51 d). The age of lesion onset was also investigated with the sacrifice of 80 chicks at 12, and 80 chicks at 25 d of age. Seven hundred and twenty ROSS 708 strain male chicks were divided into 4 groups: a non-vaccinated group fed with standard diet (CONTROL); two groups vaccinated against coccidiosis but fed either a standard diet (VACC) or a low-energy diet supplemented with threonine and enzymes (VACC-LE plus); and a fourth group fed a standard diet containing anticoccidial additive except during the finishing period (COX). After live performance, yields, and fillet pH were measured, the breasts were weighed and scored as level 0 (no WS), level 1 (moderate WS), and level 2 (severe WS) at each of the 3 ages; data were covariate for slaughter weight. The results suggest an ameliorative effect of coccidiosis control systems when compared to the control group in terms of live weight, breast yield, and whole breast weight, with heavier fillets characterized by higher pH values. WS appeared at 25 d of age with an average prevalence of 11.5% and with lesions of moderate severity. There were no statistically significant differences due to the experimental treatment at this age. At commercial slaughter age, total average prevalence was 96%, with COX birds showing higher level 2 prevalence (77.6%). This could be related to the higher slaughter weight reached by the COX group (P<0.001) and the treatment effect (P<0.01) that probably adds to the effect of live weight. Diet had no effect on overall live performance of VACC-LE plus chickens, which were similar to those of the VACC group.

Effect of genotype, housing system and hay supplementation on carcass traits and meat quality of growing rabbits.

The aim of the study was to examine the effects of genotype (Pannon Large × Pannon Ka/Large/or Hungarian Giant × Pannon Ka/Hung), housing system (Cage or small Pen) and hay supplementation (Pellet without or with Hay/P+Hay/) on carcass and meat (Longissimus dorsi/LD/ and hind leg/HL/) quality of growing rabbits. Large rabbits showed higher carcass weights, as well as higher fatness and meatiness compared to Hung rabbits. Caged rabbits were heavier, with higher prevalence of the mid part of the carcass, and showed higher fatness and lower meat toughness than Penned rabbits. Caged rabbits meat was richer in MUFA, but poorer in PUFA and Σ n-6 FA. Hay supplementation impaired carcass weight, carcass fatness, L* and a* color, and lipids content. P+Hay increased the HL meat content of C18:3 n-6 and C20:5 n-3 FA. Overall results offer further information on how alternative breeds, housing systems and feeding strategies can affect carcass traits and meat quality.

Effect of housing conditions on production, carcass and meat quality traits of growing rabbits.

Production, carcass traits and meat quality of rabbits housed in cages or in different pens were compared. Rabbits (n=579) were sorted into 5 groups: C=cage (2 rabbits/cage); pen without platform: P11=9 rabbits/pen; P16=14 rabbits/pen; pen with platform: PW=wire net platform, 14 rabbits/pen; PD=platform with straw-litter, 14 rabbits/pen. Feed intake and average daily gain between 5 and 11 weeks, and body weight at 11 weeks were significantly higher in C rabbits than that of the mean of pen-housed groups, while the PD group had the lowest growth performance. C rabbits had the smallest hind part to reference carcass (P<0.001) and the largest percentage of perirenal and scapular fat (P<0.001). The meat/bone ratio was the largest in group C (P<0.05). Differences were recorded in a* value and lipid content of m. Longissimus dorsi. Rabbits housed in cages generally had the best performance whereas those housed in pens with platform exhibited the worst.

Effect of dietary supplementation of Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) on rabbit meat appearance, oxidative stability and fatty acid profile during retail display.

The objective of this study was to evaluate the effect of Spirulina and Thyme supplementation on rabbit meat during retail display. At weaning 294 rabbits were allocated to 7 different treatments (42 rabbits/treatment). Rabbits of the control group (C) received a diet without any supplementation throughout the experiment (5-11 weeks of age). The other groups were fed diets containing 5% Spirulina (S), 3% Thyme (T) or both supplements (ST) for the whole trial (5-11 weeks; treatments S, T and ST), or for a part of the growing period (8-11 weeks; treatments C-S, C-T and C-ST). Colour parameters, pH, water holding capacity and drip loss were determined on fresh and stored Longissimus dorsi muscle of 5 rabbits/treatment. Spirulina- and Thyme-supplemented diets had a significant effect on redness and yellowness of Longissimus dorsi. Drip loss was significantly reduced in C-T and T groups that also showed the highest content of α-tocopherol and n-3 fatty acids content and the lower lipid oxidation.

Application of computed tomography to assess the effect of egg yolk ratio on body composition in chickens of different genotype and gender at hatch and during the rearing period.

1. Computed tomography was used for the in vivo determination of yolk ratio in 7000 domestic hen eggs, originated from two markedly different genotypes, in order to examine the effect of egg yolk ratio, gender and genotype on the development of hatched chicks. 2. Eggs with extremely low, average and extremely high yolk ratio were chosen for further investigation (n = 350 in each group in both genotypes). After incubating the selected eggs, hatched birds were reared and slaughtered at 11 weeks of age. 3. The yolk ratio of eggs significantly affected the body composition of the chickens at hatching and during rearing to 8-9 weeks of age. 4. Chickens of a genotype selected partly for weight gain had significantly higher live weight from hatching to the end of the rearing period and had better slaughter characteristics than those of the dual purpose TETRA-H genotype. 5. At hatching, only the dry matter content of the body was affected by the gender of the birds. The effect of gender on the live weight and body composition of chickens was evident from the 5th week of age to the time of slaughter. 6. It was concluded that eggs with a low yolk ratio were most beneficial for broiler production, because chickens hatched from these eggs had the highest slaughter weight and muscle index and the lowest fat index for their body mass.

First evaluation of unfermented and fermented rooibos (Aspalathus linearis) in preventing lipid oxidation in meat products.

This study consisted of two trials aiming to evaluate, for the first time, the antioxidant potential of rooibos in meat products. With this purpose, the first trial evaluated three unfermented (green) rooibos forms (dried leaves, water extract, freeze-dried extract) added at 2% inclusion level to ostrich meat patties on an 8-day shelf-life trial. A Control group without green rooibos inclusion was also considered. The second trial evaluated the addition of different concentrations (0%, 0.25%, 0.5% and 1%) of a fermented rooibos extract to nitrite-free ostrich salami. The 2% green rooibos inclusion considerably lowered the TBARS content of ostrich patties, in this way extending their shelf-life. The fermented form (0.5% and 1%) was also effective in delaying lipid oxidation in ostrich salami until 15 days of ripening. The antioxidant potential of both green and fermented forms of rooibos in meat products was confirmed, even if its effect on lipid oxidation requires further study and long-term effects are not yet fully understood.

Effect of cottonseed oilcake inclusion on ostrich growth performance and meat chemical composition.

This study investigated the effect of replacing dietary soybean oilcake meal with increasing levels of cottonseed oilcake meal (CSOCM) on the growth performance and meat (Iliofibularis muscle) chemical composition of ostriches in order to decrease total feed costs. A total of 105 ostriches were divided into five feeding groups according to the CSOCM inclusion level in the whole diet: Control (0% CSOCM), 3%, 6%, 9% and 12% CSOCM (of the whole diet), and fed with experimental diets from 6 to 13 months of age. As a result of feeding CSOCM, the final live weight and the average daily gain significantly increased in the 12% CSOCM group. The proximate composition, cholesterol content, mineral and fatty acid profile of the meat remained unaffected. Thus CSOCM may be used as an alternative protein source to the more expensive soybean oilcake meal in ostrich nutrition.

Modeling the relationships between quality and biochemical composition of fatty liver in mule ducks.

The fatty liver of mule ducks (i.e., French "foie gras") is the most valuable product in duck production systems. Its quality is measured by the technological yield, which is the opposite of the fat loss during cooking. The purpose of this study was to determine whether biochemical measures of fatty liver could be used to accurately predict the technological yield (TY). Ninety-one male mule ducks were bred, overfed, and slaughtered under commercial conditions. Fatty liver weight (FLW) and biochemical variables, such as DM, lipid (LIP), and protein content (PROT), were collected. To evaluate evidence for nonlinear fat loss during cooking, we compared regression models describing linear and nonlinear relations between biochemical measures and TY. We detected significantly greater (P = 0.02) linear relation between DM and TY. Our results indicate that LIP and PROT follow a different pattern (linear) than DM and showed that LIP and PROT are nonexclusive contributing factors to TY. Other components, such as carbohydrates, other than those measured in this study, could contribute to DM. Stepwise regression for TY was performed. The traditional model with FLW was tested. The results showed that the weight of the liver is of limited value in the determination of fat loss during cooking (R(2) = 0.14). The most accurate TY prediction equation included DM (in linear and quadratic terms), FLW, and PROT (R(2) = 0.43). Biochemical measures in the fatty liver were more accurate predictors of TY than FLW. The model is useful in commercial conditions because DM, PROT, and FLW are noninvasive measures.

Use of different areas of pen by growing rabbits depending on the elevated platforms' floor-type.

The addition of platforms to rabbit cages increases their accessible area and provides rabbits greater freedom and mobility. Different types of platforms enable rabbits to situate themselves where they are most comfortable. The objective of this experiment was to analyse preference of growing rabbits between different areas of the pen depending on the elevated platforms' floor-type. Pens with a basic area of 0.84 m2 were equipped with platforms of 0.42 m2. Three types of flooring of the elevated platforms were used as treatments: deep-litter floor and an open wire-net floor (Experiment 1), and a deep-litter floor and a wire-net floor with a manure tray beneath it (Experiment 2). Growing rabbits (n = 168; 42 per treatment) between the ages of 5 and 11 weeks were studied, based on 24 h video recordings from infra-red cameras (one recording per week) applying scan sampling method with a frequency of 30 min. When the platform was deep-litter, significantly (P < 0.001) more rabbits used the area under the platform (53.7% and 54.3% in Experiments 1 and 2, respectively) than stayed on the platform (16.7% and 7.6%). In treatments of wire-net platform with and without tray beneath the platform also significantly (P < 0.001) more rabbits stayed under the platform (43.7% and 34.7%, respectively) than on the platform (19.5% and 29.9%, respectively). The differences from the expected 33.3% staying on the platform or under the platform were significant at least at the level of P < 0.05. The results show that the wire-net platform with the manure tray provides the optimal environment as it leads to the rabbits spreading themselves more evenly in the pen (i.e. the platform expands available floor area) without the risk of soiling from above, and without adverse effects on heat dissipation, and with the possibility of seeking cover when desired.