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Abstract: The objective of the experiment was to study the reproductive performance and nursing behaviour of rabbit does under two different lighting schedules: 24h group=16L:8D (n=54 does) and 18h group=12L:6D (n=54 does). There was continuous lighting between 0.00 and 16.00h in the 24h group, however the lighting periods were modified day by day in the 18h group (between 0.00 and 12.00, 18.00 and 6.00, 12.00 and 24.00, 6.00 and 18.00, respectively). Rabbit does were first inseminated at 16.5 weeks of age (mean body weight: 3.69kg). A single batch, 42 day reproductive rhythm was applied. Rabbit does could nurse their kits freely. Nursing behaviour of the does and reproductive performance of the first five consecutive reproductive cycles were evaluated. The body weight of the does, the kindling rate, the litter size (born total, born alive, stillborn, at 21d and at 35d of age), the mortality of the kits and survival of the does were similar in the two groups. The litter and the individual weights at 21 and 35d were higher in the 24h group than in the 18h group (litter weight at 21d:3.21 vs. 3.08kg, P=0.004; at 35d:7.99 vs. 7.66kg, P=0.002; individual weight at 21d:371 vs. 351g, P<0.001; at 35d:931 vs. 883g, P<0.001, in groups 24h and 18h, respectively). Calculations of the numerical and overall productivity per 100 inseminations (kits born alive, number of kits at day 35, weight of weaned rabbits) were comparable. The frequency of nursing events was independent of the lighting schedule but the nursing events were shorter in the 24h than the 18h group (226±38s vs. 247±42s, respectively; P<0.001). In the 24h group, the most nursing events (87.5%) happened during the dark period and in the two hours after the lights were switched on. The same tendency was not observed in 18h group. When the distribution of nursing events of the 18h group was transferred to the 24h lighting schedule (16L:8D) which had been applied until the does' age of 13 weeks, 57.3% of the nursing events happened during the dark period and in the two hours after the lights were switched on. Contrary to our hypothesis, the reproductive performance of the does did not differ between the lighting schedules. The 12L:6D lighting schedule did not increase the nursing frequency of the does. It seems, that 18h rabbit does nursed their kits according to the former 16L:8D lighting schedule, under the control of a circadian clock that operates on a 24h cycle. [Copyright &y& Elsevier]

Demographic history, current status, and efficiency of the mating strategy were analyzed using the pedigree of Pannon White (PW) rabbits born between 1992 and 2007. Potential accumulation of detrimental effects and loss of genetic diversity were also considered. Calculations and estimates were done most often for ral)bits born in 2007, whereas other reference populations (REFPOPXXXX) were specified explicitly. The pedigree contained 4,749 individuals and 580 founders, and its completeness was 82.1% up to 10 and 94.5% up to 5 generations, respectively. Generation intervals through different pathways averaged 1.2 yr. When adjusted to the pedigree completeness, the amount of inbreeding (Fi) of rabbits was comparable (5.54%) with that of other livestock populations, whereas the 10 (30) founders contributing the most to inbreeding explained a large part of the population inbreeding [i.e., 42.24% (73.18%)]. The ancestral inbreeding coefficient of REFPOP2004 (10.67%) was one-half that of REFPOP2007 (20.66%), showing its strong dependence on pedigree length. Family variance, inbreeding, and realized effective population size were 84.18 (REFPOP2006; this variable could not be calculated for the last year examined), 37.19, and 91.08, respectively. The effective numbers of ancestors, founders, and founder genomes were 48, 26, and 7.33, respectively. Although the circular mating scheme applied was generally effective, the large accumulated reduction in genetic variability indicates the need to revise and improve the current breeding strategy. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

There is growing demand by consumers for meat produced in alternative systems. Since its market share is quite small, but is growing, it could be important to deal with this issue. The aim of the experiment was to examine the effects of genotype (terminal line or traditional giant breed), housing system (cage or pen) and feeding method (only pelleted diets or pelleted diets plus hay) on production and ear lesions of growing rabbits. The crossbred rabbits ( n =336) Pannon Large×Pannon Ka (Large) and Hungarian Giant×Pannon Ka (Hung) were weaned at 5 wk of age. Half were randomly housed in cages (3 rabbits/cage) and the other half in pens (14 rabbits/pen). Two other subgroups were formed, rabbits that received only pelleted commercial diets (Pellet) or pelleted commercial diets plus grass hay (P+Hay), ad libitum . Differences were found in body weight at 12 wk of age and in weight gain and pellet intake between 5 and 12 wk in favour of the Large rabbits (3170 vs 2935 g, P <0.001; 42.3 vs 39.5 g/d, P <0.001; 147 vs 132 g/d, P <0.01, respectively). There were no significant differences in feed conversion ratio or mortality. The caged rabbits achieved better results for body weight at 12 wk and daily weight gain than the rabbits housed in pens (3123 vs 2982 g, P <0.001; 42.5 vs 39.4 g/d, P <0.001): while differences in pellet intake, feed conversion ratio and mortality were not significant. The rabbits that consumed only pelleted diets had higher body weights at 12 wk and weight gains than group P+Hay (3093 vs 3017 g, P <0.05; 41.6 vs 40.3 g/d, P <0.05, respectively). Ratios of ear lesions in the Large and Hung rabbits were not significantly different but were affected by housing system (0 and 34%; P <0.001, in cage and pen, respectively) and feeding method (20.6 and 8.3%; P <0.003, in the groups Pellet and P+Hay, respectively). It can be concluded that the alternative systems negatively influenced the production; the genotype had the greatest, while the feeding method had the lowest impact. Housing of rabbits in large groups was contrary to animal welfare (more ear lesions), although the hay supplementation reduced the aggressiveness. [ABSTRACT FROM AUTHOR]

In this study the results of two experiments are presented. The aims of the study were to examine the location preference of growing rabbits depending on the floor types (plastic-mesh, wire-mesh and deep-litter) and temperature (low, medium and high; Trial 1), and to evaluate the productive performance of growing rabbits at medium room temperature (Trial 2). In Trial 1 at the age of 5 weeks, the rabbits were randomly placed in one of the three pens each with a basic area of 3.8m2 (43 rabbits/pen, 11.3rabbits/m2). The floor of each pen was 1/3 wire-mesh, 1/3 plastic-mesh and 1/3 deep-litter. The treatment was repeated in winter, spring and summer with the following room temperatures: 10–11°C (low, n=129), 17–20°C (medium, n=129) and 22–26°C (high, n=129), respectively. With infrared cameras, 24h video recordings were made once a week, between 5 and 11 weeks of age. The number of rabbits in each location in the pens was recorded at every 30min. The rabbits showed the lowest preference for deep-litter (P<0.001) at each age, regardless of the temperature. The preference for wire-mesh or plastic-mesh floor depended on the temperature. At lower temperature most rabbits preferred staying on plastic-mesh, however at medium and higher temperature more rabbits chose the wire-mesh floor during the final period of fattening. In Trial 2 the productive performance was examined. At the age of 35 days, the rabbits (n=126) were randomly sorted to three groups and were housed in pens with a basic area of 1.27m2 (14 rabbits/pen, 11rabbits/m2). The floor type of the pens was plastic-mesh, wire-mesh or deep-litter. The body weights of rabbits between the ages of 7 and 10 weeks were significantly higher in the group on wire-mesh and plastic-mesh compared to the rabbits on deep-litter. Twelve week-old rabbits showed no significant differences among the groups. No significant differences were found for feed intake, feed conversion ratio or mortality between the ages of 5 and 12 weeks, however significant differences were recorded between the plastic-mesh and deep-litter groups for the average daily weight gain. It could be concluded that rabbits do not prefer staying on deep-litter, their preferences between wire-net and plastic-mesh floor depends on the temperature and age. Housing the growing rabbits on wire- or plastic-mesh floors had no substantial differences, while housing rabbits on deep-litter negatively affected certain traits, but the alterations were smaller compared to the results of the relevant literature. [ABSTRACT FROM AUTHOR]

Abstract: 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 11weeks, and body weight at 11weeks 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. [Copyright &y& Elsevier]

Abstract: Genetic parameters were estimated in Pannon White rabbits for average daily gain (ADG, between the ages of 5 and 10weeks), thigh muscle volume (TMV, determined by Computer Tomography-scan) and litter weight at day 21 (recorded separately for each parity within the first four parities, LW21). LW21 of each parity of the first four parities were considered as separate traits, and all traits were analysed jointly using a six-trait animal model. REML procedure was applied using PEST for data coding and VCE software for estimating variance components. The heritability estimates for LW21 were moderately low and ranged between 0.10±0.02 and 0.17±0.02. Higher heritability estimates were recorded for TMV (0.20±0.02) and for ADG (0.21±0.01). The random common litter effects were low for LW21 (ranged between 0.04±0.01 and 0.13±0.04) and TMV (0.14±0.02) but these effects were moderate for ADG (0.18±0.01). An unfavourable genetic correlation was found between LW21 and TMV especially for the 3rd (−0.53±0.09) and 4th (−0.70±0.09) parities. [Copyright &y& Elsevier]

The effect of nutrient supply at foetal, suckling and growing ages on productive, carcass and meat quality traits of rabbits was studied. New-born rabbits were divided into three groups according to their birth weight (low/L/: 35–50g, medium/M/: 58–62g and high/H/: 70–88g). Half of the litters were nursed by one doe (O) and the other half by two does (T). The kits were weaned at 3weeks. From the age of 4weeks, half of the rabbits were fed ad libitum (A), or on a restricted regime (R) (85–90% of the ad libitum feed intake level). Rabbits were slaughtered at 11weeks of age. Difference in average feed intake between groups L and H, groups O and T and between R and A was 11.2%, 7.8% and 11.7%, respectively; in all cases, the latter groups had the highest intakes. Body weight gain between 3 and 11weeks was significantly affected by birth weight and feeding regime. Body weight at slaughter of L rabbits was 124g lower than that of M rabbits and 255g lower than that of H rabbits (P <0.05). Group L had the highest dressing out percentage (58.0%), whereas M rabbits had the lowest dressing out percentage (57.3%) (P <0.05). Ratio of hind part of the reference carcass was higher in group H (39.0%) than in group L (38.1%) (P <0.05). Percentage of perirenal fat was the highest in L rabbits (2.10%) and the lowest in group H (1.64%) (P <0.05). Slaughter weight of T rabbits was 198g higher (P <0.001) than that of group O. Chilled carcass weight and dressing out percentage were 16g (P =0.006) and 0.7% (P =0.002) lower, respectively, in T rabbits. In consequence of feed restriction slaughter weight, chilled carcass weight and dressing out percentage decreased by 141g (P <0.001), 22g (P <0.001) and 0.8% (P =0.001), respectively, while the ratio of liver and kidneys to liveweight increased by 0.57% (P <0.001) and 0.05% (P <0.001). Cooking loss of musculus longissimus dorsi (MLD) was 1.8% lower (P <0.05) in H rabbits compared with L and M animals. Cooking loss was 1.6% lower (P =0.003) in group T than in group O. Due to the restriction, slaughter weight and dressing out percentage decreased by 141g (P <0.001) and 0.8% (P =0.001), respectively. Feeding regime influenced all meat quality parameters except the b* value of meat colour. Rabbits in R group had 0.08 (P <0.001) lower pH, while 1.1 (P <0.001) higher L* and 0.7 (P =0.008) lower a* values resulted lighter colour of MLD. The cooking loss of MLD of R rabbits was 1.2% higher (P =0.028). Results show that the foetal and suckling nutrient supply exert a long-term effect, affecting also carcass traits and meat quality. [Copyright &y& Elsevier]

Abstract: In this experiment the effect of digestible energy (DE) restriction on carcass traits and meat quality of rabbits selected divergently for body fat content was studied. Using a 2×3 factorial arrangement, Pannon White rabbits selected for high (HFAT) or low (LFAT) total body fat content were fed isocaloric diets between 4 and 12 weeks of age. Energy restriction was achieved by reducing the daily feed intake by 10% (M) and 20% (L) compared to the ad libitum fed group (H). Proportional to the reduction of feed intake the nutrient density of diets M and L was increased. Thus, the DE intake was reduced while the nutrient intake remained stable among the 3 dietary groups. Effect of genetic group on carcass traits and on meat quality parameters was less marked than DE restriction. Selection for high body fat content improved the dressing out percentage (58.3 and 57.3% in HFAT and LFAT respectively; P <0.01), and reduced the percentage of the full gastrointestinal tract to slaughter weight (13.7 and 14.3% in HFAT and LFAT respectively; P <0.05). Reduction of DE intake decreased the body weight and the weight of the chilled and reference carcass (P <0.001), while it had no effect on dressing out percentage. In group H the percentage of fore part to reference carcass was higher (29.7 vs 29.0%; P <0.01) while that of the hind part was lower than in group L (37.0 vs 38.2%; P <0.001). The Longissimus lumborum meat from HFAT rabbits exhibited a lower content of moisture (76.1 and 76.5% in HFAT and LFAT respectively; P <0.01) as well as lower L⁎ (53.5 and 54.4 in HFAT and LFAT respectively; P <0.05) and b⁎ (0.42 and 0.81 in HFAT and LFAT respectively; P <0.05) colour values. When compared with ad libitum fed rabbits, those restricted at 20% (L) exhibited a higher content of moisture (76.9 vs 75.8%; P <0.01), as well as higher pHu (5.87 vs 5.73; P <0.01) associated with lower cooking loss (17.8 vs 19.1%; P <0.05). L rabbits also produced lower values of redness (a⁎, 2.21 vs 3.35; P <0.01) and yellowness (b⁎, 0.23 vs 0.91; P <0.01). No effect of the divergent selection for body fat content on the total lipid percentage and on most of the fatty acids in the meat of the hind leg was found. DE restriction resulted in lower SFA (L: 32.1 vs H: 35.8%; P <0.01) and MUFA (L: 21.0 vs H: 28.6; P <0.01) but higher PUFA contents (L: 45.5 vs H: 34.9%; P <0.01) in the hind leg meat. [Copyright &y& Elsevier]

Abstract: This 2×2×2 factorial experiment was conducted to study the effects of housing system (pair caged – cage – : 2 rabbits/0.122 m2 vs open top pen housed – pen – : 13 rabbits/0.86 m2; same stocking density), floor type (wire mesh vs plastic net), and environmental enrichment (with vs without gnawing stick) on the meat quality of Pannon White growing rabbits (n =64). The housing system significantly influenced slaughter weight (2590 vs 2531 g in cage or pen, respectively; P <0.01), reference carcass (RC) weight (1266 vs 1234 g; in cage or pen, respectively; P <0.05), and the hind leg meat to bone ratio (6.11 vs 5.62 in cage or pen, respectively, P <0.001). The animals reared in pens showed paler meat with lower pHu than that of those reared paired in cages. Hind leg meat dry matter and protein content were also influenced by the housing system (26.3 vs 25.9%, 21.9 vs 21.6%; in cage or pen, respectively; P <0.05). Pen housed rabbits had significantly heavier femur and tibia bone weight and higher fracture toughness than pair caged rabbits. Floor type affected the fore part/RC weight ratio (29.2 vs 29.6% of the RC on plastic net or wire mesh, respectively). Gnawing stick presence increased slaughter yield (59.0 vs 58.3%; P <0.05), RC weight (1266 vs 1236 g; P <0.05) and the forepart/RC ratio (29.6 vs 29.2% RC; P <0.05) while significantly reducing the meat colour b⁎ value and increasing m. Longissimus dorsi shear force (0.60 vs 0.50 kg/cm2; P <0.01). The hind leg meat fatty acid profile was only slightly influenced by experimental factors. Although this study showed pair caged rabbits to have increased carcass weight with better meatiness and other meat quality traits, hind leg bone strength was shown to be higher in pen housed rabbits. [Copyright &y& Elsevier]

Abstract: In a 2×2×2 factorial experiment the effects of housing system (pair caged (cage): 2 rabbits/0.122 m2 vs open top pen housed (pen): 13 rabbits/0.86 m2; same stocking density), floor type (wire mesh vs plastic net) and environmental enrichment (with vs without gnawing stick) were studied on live performance, health status and welfare (ear lesions) of growing rabbits (n =176). The housing system significantly influenced the body weight at 11 weeks of age (2630 vs 2557 g; in cage or pen, respectively) and the feed conversion (3.12 vs 3.38 g/g; in cage or pen, respectively). Floor type did not affect the traits tested. Gnawing stick consumption affected the body weight at 11 weeks of age (2553 vs 2622 g; without or with gnawing stick, respectively), the percentage of ear lesions (18.5 vs 1.20%; without or with gnawing stick, respectively). Some of the live performance traits of rabbits reared in pens was slightly lower. The presence of gnawing stick, especially in pens, reduced the aggressive behaviour and improved the welfare. [Copyright &y& Elsevier]

Abstract: The aim of this experiment was to study the effect of genotypes (rabbits selected for high or low body fat content) and level of DE intake (high, medium or low) at constant CP, CF, and EE intake on the performance of growing rabbits, separately and their interactions. Pannon White rabbits selected for high (HFAT) or low (LFAT) total body fat content were weaned at 4 weeks of age and fed one of three isocaloric diets (11.72, 11.60 and 11.66 MJ DE/kg diet, respectively). Diet one was fed ad libitum (treatment H), while diets 2 (treatment M) and 3 (treatment L) were fed at 90% and 80%, respectively of the ad libitum intake. Proportional to the reduction of feed intake the nutrient density of diets was increased (e.g. crude protein: 17.5, 19.8 and 21.9%; crude fibre: 12.9, 13.4 and 14.7%, respectively for the 3 diets). Genotype had a significant effect on feed conversion (3.26 and 3.02 g/g; P <0.001; in groups HFAT and LFAT, respectively). With the reduction of the DE intake the daily weight gain and the body weight at 12 weeks of age decreased significantly (40.7, 38.5 and 33.7g/day, P <0.001 and 2917, 2799 and 2527 g, P <0.001; in groups H, M and L, respectively). On the contrary, the energy reduction had a positive effect on the feed conversion and on the mortality rate (3.29, 3.17 and 3.11 g/g, P <0.05, and 29.5, 28.1 and 4.8%, P <0.05; respectively). It is concluded that the genotype influenced mainly the feed conversion with higher nutrient demand for building fat than for muscle. The performance (weight gain, body weight and feed conversion) was determined by the digestible energy intake, independently of nutrient intake. The effect of reductions of DE intake was independent of the genotype (rabbits with higher or lower body fat content). [Copyright &y& Elsevier]

Abstract: The objective of the study was to determine the effect of birth weight and the influence of nutrient supply during nursing and after weaning on the performance of suckling and growing rabbits (n =182). The experiment was set-up using a 3×2×2 factorial arrangement. Newborn female rabbits were divided on the basis of their birth weight in 3 classes: low /L/=35–45g, medium /M/=53–58g and high /H/=65–70g. Half of the litters were nursed by one (O) doe and the other half by two does (T). Kits were weaned at 3weeks of age. From the age of 4weeks half of the rabbits were fed ad libitum (AL), while the other half were reared on a restricted feeding regime (R) corresponding to 80–85% of the ad libitum feed intake level. Birth weight had a significant effect on the body weight up to the end of the experiment (18weeks of age). H kits attained higher body weight at all ages (3772g at 18weeks of age compared to 3565g and 3373g for L and M rabbits, respectively). Significant differences were found in feed intake between 3 and 15weeks of age, in feed conversion between 9 and 12weeks of age and in weight gain between 3 and 4 and 12 and 15weeks of age, in the majority of cases in favour of the H rabbits. Nursing by one or two does exerted the most pronounced effect on the body weight. T kits had significantly higher body weight than O kits up to 15weeks of age (3306 vs. 3108g). Differences in feed intake, feed conversion and body weight were only periodically demonstrable between the groups O and T. The feeding regime exerted a significant influence on the feed intake, weight gain and body weight of kits. Significant differences in the feed conversion were found, however, only between 15 and 18weeks of age. Although AL rabbits achieved better feed conversion at all ages except the period between 9 and 12weeks of age. It seems that the three factors (birth weight, number of nursing does and feeding regime), especially the feed restriction, could influence the production of does. [Copyright &y& Elsevier]