Introduction: Heat stress (HS) represents a major challenge for rabbit production, particularly in regions characterized by high environmental temperatures. The present study investigated the impact of hair shearing on the meat quality traits of growing rabbits exposed to chronic HS conditions. Methods: A total of 150 weaned Pannon Ka rabbits were equally divided into three experimental groups (50 animals/group) and allocated into two rooms. In the first room, a temperature of 20 degrees C was applied and the control group (unsheared, CON) was housed. In the second room, a temperature of 28 degrees C was applied and two groups of rabbits were housed: an unsheared heat-stressed group (HET) and a sheared group (SHR). At slaughter (12 weeks of age), both hind legs (HL) and longissimus thoracis et lumborum (LTL) muscles from 15 carcasses per treatment were collected for physicochemical analyses, sensory evaluation, and heat-shock protein (HSP) expression analysis. Results: Heat stress affected rabbit bone development by decreasing both femur length (P<0.05) and weight (P<0.01). HS also reduced redness and yellowness of the biceps femoris muscle (P<0.01) and increased LTL lightness (P<0.05). Moreover, HS increased LTL meat protein (P<0.05) and ash (P<0.01) contents while reducing lipid content (P<0.05). In contrast, sensory traits of rabbit meat were not affected by HS. Hair shearing partially mitigated most of the observed changes, with sheared rabbits generally showing intermediate values for most traits, except for LTL moisture content, which was the lowest (P<0.05). Gene expression analysis revealed a higher induction of HSP70_1b (P<0.05) and HSP70_8 (P<0.05) in the HET group compared with the CON group, whereas no significant differences were observed in the SHR group compared with either of the other groups. No significant differences were detected in the expression of HSP90 family members. Discussion: Overall, the study confirmed that HS impacts carcass and meat quality of rabbits and that hair shearing can be considered an effective low-cost strategy to alleviate part of the negative effects caused by chronic HS conditions. Hair shearing is particularly applicable in rural production rather than in industrial contexts where this practice would represent a significant labor cost.

The effects of heat stress and feed restriction were evaluated on a total of 180 weaned rabbits divided into three experimental groups (60 animals/group): 2 groups were fed ad libitum and reared under different temperatures (20(degrees)C-20AD and 30 C-degrees-30AD), while a third group was housed under controlled temperature (20 degrees C) but pair-fed to 30AD rabbits, thus feed restricted (20FR). During the trial, both 30AD and 20FR groups exhibited reduced growth performance, including body weight and daily weight gain (both, P < 0.001), although feed conversion ratio improved (P = 0.016). The reference carcasses of 20FR and 30AD rabbits were lighter and leaner (both, P < 0.001) than that of 20AD rabbits, while the slaughter yield decreased only in 20FR rabbits (P = 0.001). Regarding meat physical traits, 20FR rabbits exhibited the highest pHu (P < 0.001) and the lowest total losses (P < 0.001), whereas the meat-to-bone ratio decreased in both 20FR and 30AD groups (P = 0.007). As for meat proximate composition, protein and lipid contents were lower (P = 0.008 and P = 0.0002, respectively) in 20FR and 30AD rabbits, while water content was greater (P < 0.001) compared to 20AD rabbits. At the lipid level, higher TBARS (P = 0.001) were found in both 20FR and 30AD groups. The 20FR and 30AD groups showed some differences in their carcass and meat quality traits, however the majority of changes induced by chronic heat stress were mostly attributed to the reduced feed intake.

Kereskedelmi forgalomban jellemzően 2,5–4,0 mm pelletátmérőjű nyúltakarmányok vásárolhatók. A cél annak vizsgálata volt, hogy a 3 mm és 4 mm átmérőjű pelletált takarmányok etetésekor hogyan alakul a hízónyulak termelése és parazitológiai fertőzöttsége. A hízónyulak egyik csoportja 3 mm, másik csoportja 4 mm átmérőjű pelletált takarmányt ehetett (n = 60 nyúl/csoport). A takarmányok alapanyag és kémiai összetétel tekintetében azonosak voltak. A nyulakat üzemi körülmények között, drótrács ketrecekben hízlaltuk (5 nyúl/ketrec) 45 és 72 napos kor között. Az elhullást azonos elhelyezés mellett, nagyobb létszámú csoportokon vizsgáltuk (n = 1050 nyúl/csoport). A pellet mérete nem befolyásolta a 72 napos kori testsúlyt (3 mm: 2696 g; 4 mm: 2670 g; P > 0,05), a 45–72 napos kor közötti napi átlagos súlygyarapodást (3 mm: 46,3 g/nap; 4 mm: 45,2 g/nap; P > 0,05), a takarmányfogyasztást (3 mm: 176 g/nap; 4 mm: 169 g/nap; P > 0,05) és a takarmányértékesítést sem(3 mm: 4,03; 4 mm: 4,08 g; P > 0,05). Hasmenéses megbetegedést egyik csoportban sem figyeltünk meg a hizlalási időszak alatt. A két csoport teljes hizlalásra vetített elhullása elfogadható szinten maradt és nem különbözött (3 mm: 1,5%; 4 mm: 2,4%; P > 0,05). A parazitológiai vizsgálatok nagyon jó egészségügyi státuszt mutattak, nem találtunk fertőzött bélsár mintát egyetlen vizsgálati időpontban sem. Az azonos összetételű, de eltérő pelletméretű takarmány etetése nem befolyásolta a növendéknyulak termelését és egészségi állapotát.

A házinyulak legnagyobb arányban előforduló egészségügyi problémái a parazitás fertőzések, ezek közül nagyüzemekben a kokcidiózis a leggyakoribb, amelynek előidézésében több Eimeria faj játszik szerepet. Egy több éven át tartó parazitológiai adatgyűjtésére alapozva, vizsgáltuk a magyarországi és szlovákiai nagyüzemi nyúlállományok Eimeria spp. fertőzöttségét, továbbá az évszakoknak, az állatok életkorának, és az alkalmazott kokcidiosztatikumoknak az oocisztákra gyakorolt hatását. Jelen tanulmányban a 2018 március és 2024 május időszakban gyűjtött bélsárminták adatait értékeltük (n = 12020). A bevizsgált minták 35,5%-a tartalmazott oocisztát. A vizsgálati eredmények alapján megállapítható, hogy az Eimeria oociszták minden évszakban és életkorban jelen voltak a nyúlfarmokon. Az Eimeria oocisztákra nézve pozitív minták nagyobb arányban fordultak elő nyáron (40%) és ősszel (39%), mint télen(34%; P < 0,001) és a legkevesebb pozitív mintát tavasszal regisztráltuk (28%; P < 0,001). A kokcidiumok már a laktáció időszakában jelen voltak a nyulak bélsarában, de viszonylagosan kis gyakorisággal. A fertőzöttségi szint a választás utáni időszakban emelkedő tendenciát mutatott, becslő modell alapján a fertőzés szignifikáns emelkedését a 38–40. életnapra tehetjük. A nyulak takarmányában használt két kokcidiosztatikum hatóanyagnak (Diclazuril, Robenidine) a nyulak termelésére és elhullására gyakorolt hatása között nem volt kimutatható különbség.

Given the yearly challenging environmental scenario with more and more frequent and intense heat waves, the livestock sector has to find affordable and sustainable solutions to face the expected increase in meat demand by 2050. Among livestock species, rabbits are particularly sensitive to heat stress (HS) but, paradoxically, the scientific background on the response of different genetics to environmental stressors like HS is rather scarce. This is a significant gap, especially considering that most of the demographic growth, and meat demand, is expected in developing countries where rabbits play a key role in subsistence farming. Therefore, this research investigated the effects of environmental temperature (Control—20 °C; High—28 °C) on growth performance, slaughter traits and meat quality of three Hungarian rabbit genotypes (Pannon Large—PL; Pannon White—PW; Pannon Ka—PK). Animals (n = 360) were housed in wire-mesh cages (3 animals/cage) in two separate controlled-temperature rooms (60 rabbits/genotype/room), from 5 to 11 weeks of age, during which they received ad libitum feed and water. Even if the three genotypes were exposed to the same environmental challenge, they exhibited different responses. The PL line showed superior performance, with the highest carcass weight and yield (p < 0.001), and the greatest water-holding capacity (p < 0.01) in the loin muscle. The PW rabbits showed the largest reduction in overall weight gain (−24.7%; p < 0.001) and the lowest decrease in feed conversion ratio (−3.20%; p < 0.001). PK rabbits experienced the greatest reduction in total dissectible fat (−34.6%; p < 0.001) and hind leg lipid content (−20.3%; p < 0.01), with the highest proportion of polyunsaturated fatty acids (p < 0.01), which fostered meat lipid oxidation (p < 0.05). As expected, these differences in performance and meat quality traits reflected the distinct selection criteria and genetic background of these genotypes: the PL is a paternal line, the PK is a maternal line, and the PW is a productive line. Regarding the temperature effect, PK and PW genotypes were the most impacted by chronic HS: PW rabbits suffered the largest performance depression, while PK rabbits showed the worst carcass and meat quality traits. Instead, PL rabbits demonstrated the best outcomes under chronic HS, showing the greatest productive efficiency and satisfactory meat quality traits.

This study investigated the cage size preferences of juvenile chinchillas using enclosures that allowed free choice between different dimensions. Three comparisons were tested: (1) small floor area (0.15 m2) vs. double floor area (0.30 m2) at constant height; (2) low height (0.4 m) vs. high height (1.0 m) at constant floor area (0.15 m2); and (3) small–low cage (0.15 m2 × 0.4 m) vs. large–high cage (0.30 m2 × 1.0 m). The juveniles consistently preferred the smaller or lower enclosures across all trials. In the floor area tests, chinchillas spent about 66–75% of their time in the small cage compartments (p < 0.001). In the height comparison, the low cage was preferred by 70% (p < 0.001). When both floor area and height were increased, the small–low cage was preferred by 79% (p < 0.001). Differences in preference were most evident during the daytime period. At night, however, cage utilization was more even. These results indicate that young chinchillas strongly prefer smaller, lower spaces. Based on these preference tests alone, simply providing larger cages (without other modifications) did not result in greater use by juvenile chinchillas. These unexpected results suggest that factors such as safety or familiarity drive juveniles to choose smaller enclosures. Further research is needed to clarify the motivation behind these preferences and to determine how best to incorporate them into improved welfare-oriented housing designs.

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.

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<0.05). Butyrate group consumed less feed than the control group between 38-45, 46-52 and 60-66 days (-2.4%, P<0.001; -5.7%, P<0.01; -4.9%, P<0.05, respectively). The feed conversion ratio of the butyrate group was worse between 46-52 days of age (+19%; P<0.01) but favourable at the ages of 53-59 and 67-73 days (-15% and -9%, respectively; P<0.05). Concerning the whole fattening period the weight gain, the feed intake and the feed conversion ratio of the groups did not differ. In the larger examined population, 4.0% and 6.3 % mortality was observed in the control and butyrate groups, respectively. The parasitological tests resulted only negative samples independently of groups. It can be concluded that dietary butyrate supplementation has not improved the performance of the growing rabbits.

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.

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.

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 2 nd 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.

A major problem of large-scale rabbit farming is digestive diseases. Relatively few data on parasitic diseases of industrial rabbit populations are available. The aim of the study was to evaluate the seasonaldependent incidence of Eimeria spp. and Passalurus ambiguus infections at large-scale rabbit farms. The survey was carried out between 2018 and 2022 at 29 Hungarian and 2 Slovakian rabbit farms. Altogether, 7612 faecal samples were examined. Eimeria oocysts and P. ambiguus eggs were detected on all rabbit farms examined, although only a relatively small portion of faecal samples was found positive. Eimeria oocysts and P. ambiguus eggs were found in 32 and 6% of the samples, respectively. Our findings for the seasonal-dependent evaluation of collected data showed that the highest proportion of Eimeria positive samples occurred during the summer (35.3%) and autumn (36.2%) periods. In winter, a significantly lower infection rate was found (29.5 %; P<0.05). The most favourable results were observed in spring (25.1%; P<0.05). As for P. ambiguus, the highest rate of infection was measured in spring (8.4%) and the lowest in summer (4.5%; P<0.01). The autumn and winter periods showed intermediate results (6.7 and 5.5 %, respectively).

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.

Objectives: The aim of our study was to perform parasitological examinations on Hungarian rabbit farms, and to report data on the prevalence and morphology of Eimeria species. Materials and Methods: Fecal samples were collected in 13 Hungarian rabbit farms, and 1235 oocysts were evaluated in this study. Results and Discussion: Eight Eimeria species were identified and more Eimeria species were observed simultaneously in 83% of the samples. The Eimeria species occurred in the samples with the following prevalence: E. media 40.3%, E. coecicola 22.5%, E. magna 18.5%, E. perforans 8.3%, E. irresidua 6.8%, E. flavescens 2.7%, E. intestinalis 0.8%, E. piriformis 0.2%. The proportion of species with different pathogenicity varied considerably from one life stage to another. In case of E. media and E. magna, there was a difference between sporulated and non-sporulated oocysts in terms of both width and length. E. media sporulated oocysts were on average 10% longer and wider (p <0.01), while E. magna sporulated oocysts were 6-11% shorter and less wide compared to non-sporulated oocysts (p < 0.05). For the other identified Eimeria species, there was no difference in the dimensions of sporulated and non-sporulated oocysts. Seventy-one percent of oocysts originated from species with weak pathogenicity, while 25 percent were from moderate and 4 percent from highly pathogenic species. The proportions varied considerably in consecutive production phases. The period of lactation (weeks 1-5 of life) is characterized by weakly pathogenic species, moderately and strongly pathogenic ones appeared in proportions below 10 %. In the post weaning period (weeks 6-9 of life), the proportion of oocysts of species classified as moderately pathogenic increased, but highly pathogenic species were not detected. In the final phase of fattening (weeks 10-13 of life), slightly pathogenic species were again present in higher proportions, the proportion of moderately pathogenic pathogens decreased, and a highly pathogenic species of Eimeria (E. flavescens) was also detected.

The most common disease in growing rabbits is diarrhoea, in the development of which parasites can also play a role in addition to bacteria. Among endoparasites, Eimeria species responsible for coccidiosis are detected in most cases in the digestive system of rabbits. This review collects and discuss the scientific literature on different Eimeria species identified in rabbits, such as their life cycles and pathogeneity or their location in the different parts of the digestive system, and possible alternatives to prevention and treatment.

A szerzők munkájának célja parazitológiai vizsgálataik eredményének összesítése volt, valamint új adatok közlése a különböző Eimeria fajok előfordulásáról és morfológiai jellemzőiről. Nagyüzemi nyúltelepekről származó mintákat vizsgáltak: a parazita fejlődési alakok számlálásán felül az azonosított fajok meghatározása, az oociszták síkbeli mérése, továbbá a termelési ciklus fázisai során megállapítható különbségek vizsgálata is megtörtént. Nyolc Eimeria fajt azonosítottak. A különböző patogenitású fajok aránya életszakaszonként jelentős eltéréseket mutatott. Az Eimeria magna és Eimeria media oocisztái méret- és alakváltozást szenvedtek el a sporuláció alatt.

The study examined the age-dependent feed restriction on growing rabbits' growth and carcass traits. Three groups of weaned rabbits (5 weeks of age, n=243)) were established: AL=control group: ad libitum feeding during the whole fattening period (n=81), RF65 group: 65% of the feed consumption of AL during the first two weeks after weaning, 80% in the third, 100% in the fourth week and ad libitum afterward (n=81), RF70 group: 70% in the first two weeks, 80% in the third, 100% in the fourth week and ad libitum till slaughtering (n=81). Feed consumption was in line with the planned level during the feed restriction period. After finishing the restriction at 100%, the feed consumption increased rapidly, and it was higher between 9 and 11 weeks of age than that of the AL group (P<0.001). Daily weight gain of restricted groups was lower between 5 and 7 weeks of age (47.7 vs. 28.9 and 25.2 g/day in AL, RF70, and RF65, respectively, P<0.001). The differences in body weights were highest at seven weeks of age, and later the differences decreased (body weight at 11 weeks, AL: 2710 g, RF65: 2637 g, RF70: 2655 g, P <0.05). In the first week, the feed conversion rate was better in the AL group, while between 7 and 10 weeks of age, it was better in the restricted groups (P<0.001). Significant differences were found in mortality but independent of treatment. The feed restriction had a slight effect on carcass traits. The weight of the fore part of the carcass was higher in the AL group (P=0.053), while the liver was heavier in the restricted rabbits (84.2 vs. 80.1 g, P=0.388). The perirenal fat content was the lowest in RF65 rabbits (16.9 g) and the highest in the AL group (21.6 g, P<0.05). A stricter and then milder feed restriction after weaning and ad libitum feeding in the final fattening stages could be preferred.

Various applications of farm animal imaging are based on estimating the weight of specific body parts and cuts from CT images of animals. In many cases, the complexity of the problem is increased by the enormous variability in body postures in the CT images due to scanning unsedated live animals. In this work, we propose a general and robust approach to estimate the weights of sections and body parts from CT images of (possibly) live animals. We adapt the segmentation by elastic registration and joint feature and model selection for the regression component to cope with the large number of features and small number of samples. The proposed technique is evaluated and illustrated by real applications in rabbit breeding programs. The r(2) values are 12% higher than those of previous techniques and methods used in the breeding selection programs. The proposed technique is easily transferable to similar problems and is therefore made available in an open source software package for the benefit of the community.

To determine the effect of the replacement of a dietary vegetable oil with the silkworm oil on the rabbit meat quality, two experimental diets were prepared: the control diet (commercial diet with 13 g/kg sunflower oil), and the control diet with total replacement of sunflower oil by silkworm oil (SWO). Rabbits received the control diet from 5 to 7 weeks of age, followed by the two experimental diets until slaughter at 10 weeks of age. Physical traits, proximate composition and sensory evaluation of the hind leg meat were considered. A seven-day shelf-life at retail display of the loin meat evaluated water holding capacity, pH, L*a*b* colour, Warner-Bratzler shear force, and thiobarbituric acid-reactive substances (TBARs) attributed to time and to dietary treatment within time. Experimental diets did not modify any of the considered traits measured on the hind leg meat, with exception of the hind leg weight, heavier in the SWO group (P<0.05). Shelf-life trial showed significant differences for L* and b* colour values of loin meat at day 0 of retail display, with higher values for SWO than control group (P<0.05). However, at day 3 and at day 7 no statistical difference was observed between the dietary groups. These colour differences were not attributable to the meat oxidation as TBARs did not vary neither between treatments, nor among retail display time. In conclusion, this study demonstrated that the total dietary replacement of sunflower oil with silkworm oil in fattening rabbits did not modify the physicochemical and sensory traits of the meat, as well as its shelf-life.