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[EN] The objective of this study was to estimate the response to selection for total body fat content of rabbits measured by computer tomography (CT). A divergent selection experiment was performed using Pannon Ka rabbits, which were previously selected for number of kits born alive. The so-called zero generation consisted of 351 Pannon Ka rabbits, from which the index, total body fat volume (cm3) divided by the body weight (kg), was measured. Rabbits with low and high fat index values were selected to form the parent groups of the lean and fat lines, respectively. The lines consisted of 55-72 females and 35-47 males, depending on the line and generation. After three generations, the rabbits were evaluated by means of a single trait animal model. The fat index showed a moderate heritability estimate (0.28±0.03). The magnitude of the common litter effect was small (0.10±0.02). The breeding values averaged per generation provided slightly asymmetrical responses. Based on the results, the divergent selection was successful in confirming that CT is a very suitable method for performing selection for body composition traits.

[EN] The aim of the study was to examine the effect of hair shearing in growing rabbits reared at high ambient temperature. The live performance and carcass traits of growing rabbits reared at 20°C (not sheared, C, n=50) or at 28°C (not sheared, H, n=50, or sheared at 5, 7 and 9 wk, HS, n=50) were compared. The ambient temperature and relative humidity were 20.5±1.1°C and 54±11% in the 20°C room and 28.8±0.2°C and 35±8% in 28°C room, respectively. Feed intake of H and HS groups decreased by 29.0 and 20.4%, respectively, compared to C rabbits (P<0.001). The same data for weight gain were 24.6 and 16.9% (P<0.001), and for body weight at 12 wk were 16.8 and 11.5% (P<0.001). At the same time, the feed conversion ratio improved (C: 3.53, HS: 3.34, H: 3.31; P<0.001). Nevertheless, the mortality rate of rabbits was not affected by the studied treatment and was overall low (0-4%). No differences were observed in dressing out percentages either (ratio of chilled carcass (CC) to the slaughter weight: 61.6-61.9%). The ratio of liver to CC differed among the experimental groups, with the highest value recorded in C group and the lowest in H group; HS rabbits showed intermediate results (C: 4.86%, HS: 4.27%, H: 3.91%; P<0.001). Lower ratios of fat deposits to reference carcass were also observed in rabbits kept at high ambient temperature (perirenal fat: C: 2.59%, HS: 1.82%, H: 1.60%; P<0.001; scapular fat: C: 0.89%, HS: 0.66%, H: 0.51%; P<0.001). It can be concluded that the negative effect of higher ambient temperature (28 vs. 20°C) on production in growing rabbits can be reduced significantly by hair shearing.

[EN] The aim of the experiment was to compare the reproductive performance and nursing behaviour of rabbit does reared under 2 different light intensities and observe the preference of does among cages with different light intensities. Female rabbits were randomly housed in 2 identical rooms, under the same housing conditions in wire-net cages. The 2 rooms only differed in the light intensity; group L: 150-200 lux (n=54 does, 230 inseminations), group D: 10-20 lux (n=54 does, 232 inseminations). Reproduction data from the first 5 consecutive reproductive cycles were evaluated. Nursing behaviour of the does (n = 24) was observed at the 2nd or 4th lactation. The preference of does (n=8) among 4 cages with different light intensities (10, 35, 75 or 155 lux) as examined. There were 6-7% difference between the 2 groups in the number of kits born in total and those born alive (born total: 11.25 vs. 10.59 kits, P<0.1; liveborn: 10.75 vs. 10.00 kits, P<0.05; in groups L and D, respectively). Suckling mortality was nearly 2% higher in group D (L: 8.1, D: 10.0%; P<0.1), and in consequence the litter size of this group at 35 d of age was lower than that of the L rabbits (L: 8.75, D: 8.45 kits; P<0.05). The light intensity did not affect litter and individual weights at 35 d of age. The average numbers of daily nursing events (L: 1.23/d, D: 1.32/d), the length (L: 208±49, D: 213±43 s) and the daily distribution of nursing events were not affected by high light intensity. During the light period of the day, the darkest cage (10 lux) was the most preferred by the does (44.0, 18.6, 17.9 and 19.5% in 10, 35, 75 and 155 lux cages, respectively; P<0.001). The lower light intensity had no unambiguously unfavourable effect on the reproductive performance and nursing behaviour of the does. Based on the preference test, a lower light intensity may be advantageous from the point of view of animal welfare.

[EN] The experiment aimed to study the effect of Digestarom® dietary inclusion (herbal formulation containing a mixture of essential oils, herbs, spices and extracts) on apparent digestibility and digestive ecosystem of growing rabbits, as well as the effects of its supplementation before and after weaning on growth performance. At kindling, rabbit does and litters were divided into 2 dietary groups (51 does/group) and fed either a control diet (C) or a diet supplemented with 300 mg Digestarom®/kg diet (D) until weaning, which occurred at 35 d (before weaning supplementation). Each group was further divided into 3 dietary groups: CC received the control diet and DD received the D diet from 5 to 12 wk of age, and DC were fed with D (from 5 to 8 wk of age) and C diets (from 8 to 12 wk of age) (after weaning supplementation; 54 kits/group). An in vivo digestibility trial and a faecal microbial count were carried out on growing rabbits that received only the C or D diets during the trial. The C group showed higher DM intake than D group (215 vs. 196 g/d; P<0.05). The faecal digestibility of ether extract (75.9 vs. 59.8%; P<0.001), cellulose (25.9 vs. 20.6%; P<0.05) and gross energy (51.8 vs. 49.1%; P<0.05) was higher for C than for D group, whereas that of starch (98.9 vs. 98.8%; P<0.001) and the digestible protein to digestible energy ratio (13.9 vs. 13.2 g digestible protein/MJ digestible energy; P<0.01) was the highest for rabbits fed D diet. Stomach and caecal pH, caecal and faecal microbial counts were independent of the dietary treatment. The only exception was the stomach pH in 8 wk-old rabbits, which had the lowest value in C rabbits (P<0.05). The D supplementation before weaning improved feed conversion ratio throughout the growing phase (4.3 vs. 4.4 for D and C, respectively; P<0.05), whereas significant differences in daily weight gain, feed conversion ratio and mortality were observed only in the first period after weaning. Based on the results obtained, die

[EN] The main results and observations on group and individually housed rabbit does were reviewed by Szendrő and McNitt in 2012, but in recent years several new papers in this field have been published. This provides a new opportunity to summarise the current knowledge on alternative housing systems for breeding does. In Switzerland, rabbit does are generally housed in group systems. The recently legislated Belgian and Dutch housing systems will be converted step by step into group housing systems. Recent research demonstrated that with semi-group housing systems much better performance levels are possible than with the Swiss group housing system. However, solutions to eliminate aggression, stress and injuries which are common among rabbit does in group housing systems have yet to be found. Some authors are of the opinion that individual cages are too small and allow limited possibilities for movement and social contact. Positive results were seen when platforms were inserted into the cages and the possibility for movement increased. The does and their kits could jump up and down using the platforms. Using footrests, the incidence of sore hocks declined. Several environmental enrichments which increase the well-being of rabbit does can also be used. These enriched cages (equipped with platforms, footrests, gnawing sticks, etc.) are fully in line with animal welfare requirements. Increasing the size of cages and enriching them increases the production cost and the meat will be more expensive.

[EN] The experiment aimed to study the effect of Digestarom® dietary inclusion (herbal formulation containing a mixture of essential oils, herbs, spices and extracts) on apparent digestibility and digestive ecosystem of growing rabbits, as well as the effects of its supplementation before and after weaning on growth performance. At kindling, rabbit does and litters were divided into 2 dietary groups (51 does/group) and fed either a control diet (C) or a diet supplemented with 300 mg Digestarom®/kg diet (D) until weaning, which occurred at 35 d (before weaning supplementation). Each group was further divided into 3 dietary groups: CC received the control diet and DD received the D diet from 5 to 12 wk of age, and DC were fed with D (from 5 to 8 wk of age) and C diets (from 8 to 12 wk of age) (after weaning supplementation; 54 kits/group). An in vivo digestibility trial and a faecal microbial count were carried out on growing rabbits that received only the C or D diets during the trial. The C group showed higher DM intake than D group (215 vs. 196 g/d; P<0.05). The faecal digestibility of ether extract (75.9 vs. 59.8%; P<0.001), cellulose (25.9 vs. 20.6%; P<0.05) and gross energy (51.8 vs. 49.1%; P<0.05) was higher for C than for D group, whereas that of starch (98.9 vs. 98.8%; P<0.001) and the digestible protein to digestible energy ratio (13.9 vs. 13.2 g digestible protein/MJ digestible energy; P<0.01) was the highest for rabbits fed D diet. Stomach and caecal pH, caecal and faecal microbial counts were independent of the dietary treatment. The only exception was the stomach pH in 8 wk-old rabbits, which had the lowest value in C rabbits (P<0.05). The D supplementation before weaning improved feed conversion ratio throughout the growing phase (4.3 vs. 4.4 for D and C, respectively; P<0.05), whereas significant differences in daily weight gain, feed conversion ratio and mortality were observed only in the first period after weaning. Based on the results obtained, die

[EN] The aim of the experiment was to compare 3 genetic groups, slaughtered at similar weights, to examine their productive and carcass traits and economic value. Three lines of the Pannon Breeding Programme, selected for different criteria, were examined in the experiment. Pannon Ka (PKa, maternal line) does were inseminated with semen of PKa, Pannon White (PWhite) or Pannon Large (PLarge, terminal line) bucks. The kits (PKa×PKa, PWhite×PKa, PLarge×PKa; n=60 in each genetic group) were weaned at 35 d of age and reared until 88, 83 and 79, respectively, when they reached similar body weights for slaughtering (2.8 kg). The weight gain of PLarge×PKa was the largest (51.0 g/d) and that of PKa×PKa was the smallest (47.2 g/d), while PWhite×PKa (41.8 g/d) was intermediate (P<0.001). Difference was found in feed conversion ratio between weaning and the age of slaughter PKa×PKa: 3.03 respect to PWhite×PKa: 2.75 and PLarge×PKa: 2.66; , P<0.05). Dressing out percentage and ratio of hind part to reference carcass of PWhite×PKa, PLarge×PKa and PKa×PKa were 62.4 and 37.7, 61.8 and 37.5, 61.3 and 36.8%, respectively (P<0.01). Results show that PLarge×PKa rabbits were able to exceed the average economic indicators compared to other groups. It may be concluded that the production performance of growing rabbits was affected by the adult weight, but the carcass traits were influenced by the computer tomography (CT)-based selection.

[EN] The aim of the experiment was to compare the reproductive performance and nursing behaviour of rabbit does reared under 2 different light intensities and observe the preference of does among cages with different light intensities. Female rabbits were randomly housed in 2 identical rooms, under the same housing conditions in wire-net cages. The 2 rooms only differed in the light intensity; group L: 150-200 lux (n=54 does, 230 inseminations), group D: 10-20 lux (n=54 does, 232 inseminations). Reproduction data from the first 5 consecutive reproductive cycles were evaluated. Nursing behaviour of the does (n = 24) was observed at the 2nd or 4th lactation. The preference of does (n=8) among 4 cages with different light intensities (10, 35, 75 or 155 lux) as examined. There were 6-7% difference between the 2 groups in the number of kits born in total and those born alive (born total: 11.25 vs. 10.59 kits, P<0.1; liveborn: 10.75 vs. 10.00 kits, P<0.05; in groups L and D, respectively). Suckling mortality was nearly 2% higher in group D (L: 8.1, D: 10.0%; P<0.1), and in consequence the litter size of this group at 35 d of age was lower than that of the L rabbits (L: 8.75, D: 8.45 kits; P<0.05). The light intensity did not affect litter and individual weights at 35 d of age. The average numbers of daily nursing events (L: 1.23/d, D: 1.32/d), the length (L: 208±49, D: 213±43 s) and the daily distribution of nursing events were not affected by high light intensity. During the light period of the day, the darkest cage (10 lux) was the most preferred by the does (44.0, 18.6, 17.9 and 19.5% in 10, 35, 75 and 155 lux cages, respectively; P<0.001). The lower light intensity had no unambiguously unfavourable effect on the reproductive performance and nursing behaviour of the does. Based on the preference test, a lower light intensity may be advantageous from the point of view of animal welfare.

[EN] In this study, the rabbit breeding programme conducted at the Kaposvár University is extensively discussed. Population history and recorded traits, creation of the different synthetic lines, evolution of their selection criteria, stimation of the genetic parameters and genetic trends are the main elements described. The programme (Pannon rabbit breeding programme) is operated with 1 maternal line and 2 paternal lines. At present the maternal line (Pannon Ka) is selected for number of kits born alive, while the 2 paternal lines are pre-selected for litter weight (Pannon White) and average daily gain (Pannon terminal line), respectively, then they are both selected for thigh muscle volume (based on computer tomography (CT) measurements). All these traits are evaluated by BLUP methodology. According to the genetic parameter estimations, the heritability of the reproductive traits (litter size and litter weight) was low (0.05-0.17 and 0.08-0.17). When the litter size component traits were extended with dominance effects, the magnitude of the dominance components varied between 0.05 and 0.08. Average daily gain and thigh muscle volume were moderately heritable (0.21-0.27 and 0.19-0.25), while heritability estimates of the carcass traits (dressing out percentage and hind part ratio) were high (0.47 and 0.59). Computer tomography based traits showed favourable high genetic correlations with the carcass traits (dressing out percentage: 0.45-0.47 and hind part ratio: 0.59). On the contrary, strong negative correlation was estimated between thigh muscle volume and litter weight (–0.37 and –0.70). The selection responses obtained for all analysed traits were within the range published by the relevant literature. The success of the CT-based selection for improving meat production was justified by different methods (crossing experiment, divergent selection, estimated genetic trends). In addition to the slow increase in the inbreeding level of the Pannon White breed, it als

[EN] In this experiment the authors examined the effects of the colour of light and reproductive rhythm on rabbit does' production. The does (n=122) were first inseminated at the age of 16.5 weeks and housed in two rooms. In the first room, white coloured light was applied (W) and blue lighting (B) was used in the second room. In both rooms, the does were randomly divided into two subgroups and inseminated using a reproductive rhythm of 42 (42D) and 56 (56D) days, respectively. The rabbit does' production was examined over 336 days (8 and 6 reproduction cycles in groups 42D and 56D, respectively). During the first gestation, the W rabbits had higher feed consumption (162 vs. 145 g/d, P<0.05) and during the whole period a larger body weight than the B does. The colour of the light did not influence the kindling rate and litter size. In contrast, individual and litter weight measured at 23 days of age was higher in the B group (451g vs. 435g and 3611g vs. 3498g respectively, P<0.05). No significant differences were found for productivity index between the W and B groups. The kindling rate was more favourable in the 56D group (89.3 vs. 82.0%, P<0.05). The 56D does' body weight at kindling was larger than that of the other group (4474 vs. 4188g, P<0.001). No significant differences were found for litter size. Individual weight and litter weight at 23 days of age were slightly higher for the 42D group (447 vs. 439 g, P=0.057 and 3598 vs. 3513 g, P=0.055). Kindling intervals of the 42D and 56D groups were 46.6 and 59.5 days, respectively (P<0.001). The condition of the rabbit does (measured by the TOBEC method at 4-5th parturition) was better in the 56D group. Survival rate at the age of 336 days showed a difference (26 and 13% respectively, P=0.07), higher for 56D group. Based on the results, the blue colour had a favourable effect on the litter weight as well as the individual weight of kits at 23 d (+3.2 and +3.7% respectively). It may be concluded that the effect of t