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The study aimed to evaluate the effect of the dietary inclusion of silkworm (Bombyx mori) oil (SWO) in rabbit diets as a total replacement of sunflower oil on growth performance, carcase traits, total tract apparent digestibility (TTAD) and nutritive value of the diets. A total of n = 64 mixed-sex weaned rabbits (5-week-old) were pair-housed in cages and fed with a commercial diet containing 1.3% sunflower oil (control). From 7 to 10 weeks of age, two experimental groups were formed: half of the rabbits received a control diet, and the other half received a diet where the sunflower oil was replaced by the SWO. During the trial, growth parameters and feed intake were weekly recorded to calculate productive parameters. At 10 weeks of age, rabbits were slaughtered and dissected to determine carcase traits. In parallel to the growth trial, another twenty-four 55-day-old rabbits were individually housed in digestibility cages and randomly assigned to one of the two experimental groups (n = 12 rabbits/group) to study the TTAD and nutritive value of the diets. Overall, the dietary inclusion of SWO did not affect the in vivo performance and carcase traits of rabbits. Additionally, the TTAD of rabbits was unaffected by SWO inclusion, although the SWO diet exhibited lower digestible energy (DE) compared to the control diet (p <.05). These findings emphasise the importance of further investigating the nutritive value of SWO-supplemented diets in future studies. In conclusion, SWO can be considered a promising energy source for growing rabbits, an alternative to conventional vegetable oils. Highlights: Silkworm oil (SWO) is a feasible feedstuff for rabbit diets to substitute conventional energy sources. Total tract apparent digestibility of nutrients was not altered by the inclusion of SWO in growing rabbit diets. Growing rabbits fed with SWO as complete replacement sunflower oil showed satisfactory growth performance and carcase traits. [ABSTRACT FROM AUTHOR]

Simple Summary: The authors investigated what size cage adult chinchillas preferred when given a free choice. Compared to the cages traditionally used in chinchilla farms, the tested cages had a larger floor area, higher height, or both. It was found that the chinchillas chose cages with smaller floor areas and lower heights more often. Especially during the resting period, there was a significant difference between the choice of cages. The explanation for the results is that the wild chinchilla hides from predators in a narrow place, usually seeking shelter between rocks. Chinchillas in farms have retained this behavior and prefer smaller, more protected cages. The study aimed to investigate adult chinchillas' preferences when choosing between cages with different floor areas, heights, or both. The size of the cages with a larger floor area was double that of the standard-sized cages in the farms (0.25 and 0.50 m2), while their height was 2.4 times that of the standard-sized cages (0.4 and 1 m). The chinchillas (10–14 in each cohort) were housed in blocks of cages where they could move freely between the smaller and larger cages. The chinchillas' location preferences were monitored continuously over five days using infrared video recording. The chinchillas were observed in the cages with smaller floor areas 1.9 and 2.7 times more frequently than in the larger ones (p < 0.001) during the dark (active) and light (resting) periods of the day, respectively. When the cage height was 0.4 m, they chose it 3.4 and 6.7 times more frequently, respectively, than the cage that was 1 m high (p < 0.001). When both the floor size and the height were increased, the chinchillas still favored the smaller and lower cages (p < 0.001). The study findings suggest that adult chinchillas show a preference for smaller and shorter cages when the small and large cages are not environment enrichment barren, especially during the rest period of the day, even when the floor area, height, or both are increased. In the future, it would be important to investigate different forms of cage enrichment. [ABSTRACT FROM AUTHOR]

The effect of a dietary butyrate supplementation on the production of fattening rabbits was examined. The control group (n=70 rabbits) was fed with granulated diet whereas the diet of butyrate group (n=70 rabbit) was supplemented with 0.2% of butyrate. The mortality rate was examined on a larger population (n=1050 rabbits/group). Butyrate group had lower weight gain at the ages of 46-52 and 60-66 days (-20 and 17 %, respectively; P>0.001) but higher weight gain at 53-59 days of age (+13%; P

Simple Summary: Maintenance of genetic diversity is important for commercial livestock breeds as well. The Danubia Alba rabbit is a synthetic breed; its breeding goal is meat production. The primary goal of our study was to provide information about the demographic history of Danubia Alba and support the breeder company during its selection work. Besides homozygosity, the deepness of the pedigree, the generation interval, and gene variability were evaluated. We found that the lines of genetic variability decreased, probably due to the selection work. The homozygosity of the lines was estimated using different methods, like Ballou's, Wright's, and Kalinowski's inbreeding coefficients. Though current inbreeding coefficients were different among lines, the present inbreeding level came mostly from previously fixed alleles for each of them. Effective population sizes were estimated, and none of the lines was found to be critical. The diversity of livestock animal breeds is an integral part of global biodiversity and requires careful management for sustainability and future availability. Avoiding inbreeding is a crucial aspect of mating of breeding animals. Our aims were to describe the quality of the pedigree, generation interval, gene origin, inbreeding, and effective population size of Danubia Alba rabbit lines. Line "D" is the maternal, whereas lines "C" and "X" are used as the paternal lines. The pedigree information was followed back from the actual breeding rabbits up to the founder animals. The rabbits having offspring in 2023 were chosen as reference populations for each line. The complete generation equivalent (GenCom) was 17.68 for line "C", 18.32 for line "D", and 17.49 for line "X", respectively. The maximum number of generations (GenMax) was above 30 for each line. The estimated bottleneck effect is mostly the result of selection and not a real genetic loss. The Wright inbreeding coefficient (F_Wright) was the highest for the "X" line rabbits, whereas it was the lowest for the line "D". Kalinowski's decomposition of inbreeding showed that it originated mostly from the past; the current fixation of alleles was quite similar for the line "C" and "D". Based on the predicted effective population sizes, it seems that there is no problem in maintaining of Danubia Alba lines. [ABSTRACT FROM AUTHOR]

The effect of two diets with different fibre contents was examined on rabbit does' performance and parasitological infection. Diet P2 had 1% higher crude fibre, ADF and starch contents than that of diet P1. The performance of 12-12 does and litters per group were examined during two consecutive inseminations. In both dietary groups, according to a 49-day reproduction rhythm, the does were artificially inseminated 18 days after kindling. Most production traits were not affected by the diets (kindling rate, weight of does and their kits, feed intake, mortality; P>0.05). Significant differences were only found in litter sizes as the number of kits was lower in P1 diet fed group at all examined days of lactation. The significant "Diet x Reproduction cycle" interaction showed that the litter sizes of dietary groups did not differ at the first examined insemination, however at the subsequent reproduction cycle 6-8% lower litter sizes were counted in P1 fed does compared to group P2 (litter size at 4 day: 9.00 vs 9.58-9.92, P = 0.004; litter size at 11 day: 8.83 vs 9.58-9.92, P = 0.037 for diet P1 at the 2nd reproductive cycle compared to all the other cases, respectively). The two diets with different compositions did not affect most of the production results of the rabbit does and their kits, but the lower litter size of does consuming P1 diet at the second examined lactation suggests the adverse effect of P1 diet's long-term use. From the collected manure samples not any parasites were detected which presents a very favourable picture of farm from the point of view of hygiene and animal health. [ABSTRACT FROM AUTHOR]

The aim of the experiment was to study the effect of housing growing rabbits in enriched cages with small groups (eight rabbits/cage, C; n = 96; stocking density: 15 rabbits/m2) or in enriched pens with large groups (65 rabbits/pen, P; n = 130; stocking density: 15 rabbits/m2) on their growth performance and on slaughter and meat quality traits. The C rabbits showed higher final body weight (2540 vs. 2443 g, p <.01), better feed conversion ratio (5–11 weeks: 3.39 vs. 3.61, p <.05), lower mortality rate (5.2 vs. 31.5%, p <.001), and lower fecal corticosterone level (26.3 vs. 29.4 nmol/g, p <.05) compared to P rabbits. The increased possibility of physical activity of P compared to C rabbits resulted in more developed hind part of the reference carcase, thicker hind leg bones (34.8 vs. 33.4 g, p <.05), lower perirenal fat (15.1 vs. 20.8 g, p <.001) and hind leg meat lipid content (2.00 vs. 2.42%, p <.05), as well as higher haem iron content of the hind leg meat (5.29 vs. 4.22 mg/kg, p <.01). However, pen housing was detrimental for the dressing out percentage and for the hind leg meat to bones ratio. Physical meat quality traits were not affected by the housing system. Housing of growing rabbits in large cages and large pens was compared. Caged rabbits had better productive performance, lower mortality and stress. Penned rabbits resulted in lower dressing out percentage, carcase adiposity and meat lipids content. Most of the meat quality traits were independent of the housing system. [ABSTRACT FROM AUTHOR]

This experiment compared the productive performance and location of growing rabbits in pens without and with two-level platforms (wire-mesh or plastic-mesh). A total of 174 rabbits of both sexes weaned at 5 weeks of age were randomly divided into three groups (n=58 rabbits/group, 2 pens/treatment, 29 rabbits/pen). The floor area of pens was 1.0-1.83 m, and the floor was made of wire-mesh. Two pens were equipped with wire-mesh (WP) and two pens with plasticmesh elevated platforms (PP) on two levels, and two pens were without platforms (NoP). Treatment had no effect on the productive performance of growing rabbits. Based on video recordings, animal density (rabbits/m2 in each location) was higher (p<.001) on the floor than on the platforms (in WP: 12.0 vs. 5.2, in PP: 10.2 vs. 7.4 rabbits/m², respectively). Animal density on the floor was higher (p<.001) in front of the platforms than under the platforms (in WP 15.7 vs. 9.8 rabbits/m² and in PP 13.3 vs. 8.3 rabbits/m², respectively). The animal density on platforms was 1.4 times higher in group of PP than in WP (p<.001). The animal density was 1.6 and 2.9 times higher on the second floor than on the first one (p<.001), in group of PP and WP, respectively. The concentration of cortisol metabolites in faeces and the ratio of injured rabbits were similar in the three groups. The rabbits showed higher preference staying on the floor compared to the platform. Pens with platforms were not influencing productive performance. [ABSTRACT FROM AUTHOR]

The study investigated the effect of Digestarom® dietary supplementation on the reproductive performances of rabbit does. Pannon Ka (maternal line) multiparous does were randomly divided into two dietary groups since insemination and fed ad libitum. In the first group (n=51), rabbit does were fed with a commercial diet (C), whereas in the other group (n=52) they received the same diet supplemented with 300 mg/kg of Digestarom® (D). The experiment lasted for two reproductive cycles (kindling 1=K1; kindling 2=K2). Body weight of does and litter size (kits born total, alive, stillborn) were recorded at kindling. Litter size and litter weight were registered at 7, 14, 21 days of age after nursing, and the average individual weight of kits was calculated. Kits’ mortality was recorded daily. At K1, rabbit does performances were unaffected by dietary treatments. During K2, D does were significantly lighter than C ones (P<0.05) and displayed a lower kindling rate (P<0.05). Digestarom® did not improve the reproductive performance of rabbit does. They seemed to dislike the D diet in K1 and such behavior could have led to the negative results in K2. Further studies should focus on feed acceptance, dose-dependent effect, physiological adaptation and in vivo oxidative status of does. Finally, several consecutive reproductive cycles are recommended to test the efficacy of new feed supplements. [ABSTRACT FROM AUTHOR]

Simple Summary: Aggressiveness is a well-known trait in different animal species, including the European wild and domesticated rabbit. It is one of the main problems in group housing of rabbit does. The aim of the experiment was to investigate the frequency of aggressiveness and mating behaviour as well as the lifespan of does depending on their rank order. Dominance hierarchy developed during aggressive behaviour, i.e., fighting. In most cases the primary position in the rank order was clear. Mating activity was very high after assembling the groups. In addition to male–female mating, some female-female and female-male mounting was also observed, which could lead to pseudo-pregnancy. A second small peak of sexual activity was observed at the end of the hypothetical pseudo-pregnancy. Based on the results it can be concluded that aggressive behaviour is frequent in group housing systems which is contrary to animal welfare. Natural mating is not effective in group-housing systems. Aggressiveness is one of the main problems in group housing of rabbit does. The aim of the experiment was to investigate the frequency of aggressiveness and mating behaviour as well as the lifespan of does depending on group composition. The female and male rabbits were housed in one of the 7.7 m2 pens (four females and one male per pen). Based on the ages of female rabbits two homogenous groups (HOM) were formed containing four 17-week-old females and two heterogeneous groups (HET) containing three 17-week-old and one 1-year-old female. Twenty-four-hour video recordings were taken during the first month after assembling the groups, and the aggressive actions (fights) and matings were counted. The lifespan was examined over a 200-day experimental period. On the day after assembling the groups the number of fights among does was high in HET group. The same aggressive behaviour only started a week later in HOM group, and some fights between females and the male were also observed. The daily peaks of aggressiveness were in the morning (after the light on) and in the evening (before and after the lights off). The primary position of females in the hierarchy was clear but sometimes no differences were detected among the subordinate females. The mortality of does was connected with their rank order. The number of matings was very high on the day of assembling the groups and a second small peak was observed at the end of the hypothetical pseudo-pregnancy. In addition to mating between male and females, female–female and female–male mounting was also observed. Despite of the small sample size it seems that aggressive behaviour is frequent in group housing systems, which is contrary to animal welfare. Natural mating is not effective in group-housing system. [ABSTRACT FROM AUTHOR]

The present research studied the effect of liquorice extract (in feed and/or directly in burgers) on the shelf-life of rabbit meat. Before weaning, 28 individually caged rabbit does with their litters were divided in two dietary groups: Control, receiving a commercial diet, and Liquorice, receiving the Control diet supplemented with 6 g liquorice extract/kg (L). At 12 weeks of age, 15 fattened rabbits/treatment (one rabbit/cage) were slaughtered and their hindlegs dissected. Hindleg meat was trimmed, individually minced and divided into two parts: one of them was mixed with 0.25% (w/w) L. Storage time significantly reduced the amount of polyunsaturated fatty acids in the burger, to a different magnitude depending on the unsaturation level, experimental group and storage time. The α-tocopherol content showed higher levels during storage in the burgers from the Liquorice group. Also TBARs values showed a significant positive effect of dietary liquorice and a progressive increase at days 3 and 6 of storage. • Effect of in vivo or post-mortem liquorice extract administration on the shelf-life of rabbit burger was tested. • α-tocopherol content showed higher levels during storage in the burgers from the Liquorice group. • Unsaturated fatty acids (C20:5n-3 and C22:6n-3) were higher in the Liquorice groups. • Storage time reduced the amount of PUFA in the burger, depending on the liquorice supply. • Dietary liquorice, improved antioxidant activity and protected rabbit meat against lipid oxidation. [ABSTRACT FROM AUTHOR]