Abstracts of the “26th Hungarian Conference on Rabbit Production”

About 100 participants attended the 26th Hungarian Conference on Rabbit Production at Kaposvár, organised by Kaposvár University, the Hungarian Branch of the WRSA and the Rabbit Production Board. This is the largest and most popular event for rabbit breeders in Hungary. Twenty papers were presented by senior and young scientists. Topics of the papers covered all fields of rabbit production (production, housing and welfare, reproduction, genetics, nutrition, meat quality). Full papers are available from the organiser ([email protected]) on request.World Rabbit Science (2015). Abstracts of the “26th Hungarian Conference on Rabbit Production”. Editorial Universitat Politècnica de València. doi:http://dx.doi.org/10.4995/wrs.2015.3455.SWORD475423

Effect of Digestarom\uae feed additive on rabbit carcass traits and meat sensory attributes

At kindling, rabbit does and litters were divided into two dietary groups (n=162 kits/group) and fed either a control diet (C) or a diet supplemented with Digestarom\uae (D: 300 mg/kg) feed additive. Subsequently, weaned rabbits were allocated to 3 different dietary groups (n=108 rabbits/group): CC and DD received the C and D diet from 5 to 12 weeks of age, respectively. Differently, DC group was fed with D and C diets from 5 to 8 weeks of age and from 8 to 12 weeks of age, respectively. At 12 weeks of age animals were slaughtered and carcass yields were calculated. Fore, mid and hind carcass parts were dissected and ratios to the chilled carcass were calculated. Sensory analysis of the loin meat considered spice, rancid and Digestarom\uae ingredients perception. Before weaning, D positively affected reference carcass weight (P<0.001), carcass yield (P<0.001) as well as the proportion of the mid part on the RC (P<0.05). Differently, the relative amount of the fore part on the RC was significantly higher in C group compared to D (P<0.05). Sensory analysis scores evidenced that D increased meat spiciness both before and after weaning which was associated with rancidity. However, overall acceptability remained unaffected

Experimental results in the field of housing, behaviour and welfare of rabbits at Kaposv\ue0r University between 2008 and 2012

We summarize the results of the experiment carried out at the Kaposv\ue1r University during the last 5 years.. Exp. 1. The objective of this study was to analyse the effects of the sex-composition of group on the production and behaviour of growing rabbits. The rabbits placed to the same pen were full sibs (FS), only females (F), only males (M), or mixed sexes (M). The sex-composition of the groups had no effect on the production. No differences were found on behavioural patterns. Lesions on the body caused by the aggressive animals were initially observed at the age of 7 weeks. It was more frequent for the F group at the ages of 7 and 9 weeks, but on the contrary, at the age of 11 weeks the occurrence of the lesions was 40.5% in the M group, which was higher than that of the other groups (23.8-28.6%). Based on the results it could be concluded that housing the growing rabbits segregated by sex, especially only males, was disadvantageous. Exp. 2. The objective of this study was to test a pen prototype. The basic area of the pen was 4.4m2, the floor and the platform were made of plastic mesh; 65 rabbits per pen were housed. The basic area of cage was 0.54m2, the floor was wire mesh and the platform was made of plastic mesh; 8 littermate rabbits per cage were housed. The rabbits housed in cages had higher body weight at the ages of 11 weeks (2540 vs. 2443 g) and average daily gain, better feed conversion ratio, on the contrary they had lower mortality rate (5.2 vs. 31.5%) compared to rabbits housed in pens. Among the pen-housed rabbits injuries originated to aggression were detected at the age of 9 weeks contrary to the cage-housed rabbits where injured rabbits were detected only at the end of the experiment. The ratio of the mid part and the perirenal fat to the reference carcass were higher for the rabbits housed in cages, while the ratio of the hind part to the reference carcass was significantly larger for the rabbits housed in pens. Based on the results it can be concluded that housing the rabbits in larger groups (pen with plastic mesh floor) is unfavourable from the aspects of production and animal welfare. Exp. 3. Location preference of growing rabbits was evaluated depending on the different floor types (plastic mesh, wire mesh and deep litter), at the temperature of 10\ub0C. The rabbits showed the highest preference for plastic mesh, at every age they spent more time there (70 and 52%, at the ages of 5.5 and 10.5 wk, respectively) than the expected value (33.3%). The preference of the wire mesh floor was lower (between 20 and 33%). Deep litter was the least frequently chosen floor type at all ages (8 and 14%, at the ages of 5.5 and 10.5 wk, respectively). Comparing the productive and carcass traits of rabbits housed on the three different floors, only a slight decline was observed in group of deep litter. Exp. 4. The objective of this experiment was to analyze growing rabbits\u2019 preference between different areas of pen depending on the elevated platforms' floor-type. Two types of flooring of the elevated platforms were used: wire mesh and deep litter floor. When the platform was deep litter, more rabbits used the area under the platform (54 %) than stayed on the platform (12 %). When the platform was wire mesh more rabbits stayed on the platform than under it, because of the rabbits on the platform may urinate on the rabbits underneath the platform. However, when manure-trays were insert under the wire mesh platform, the rabbit preferred the most safety part of the pen, most of them stayed under the platform. The results demonstrate that the wire-net platform with the manure tray provides the optimal environment. At the same time a platform with deep litter could be a good compromise between wire mesh and deep litter floor, because it could be considered positively by consumers. Comparing the productive and carcass traits of growing rabbits housed in cage, pen without and with elevated platform (wire mesh or deep litter), significant differences were found only between cage and pen with deep litter platform, rabbits housed in cages generally had the best performance. Exp. 5. The nursing behaviour of rabbit does in a routine (24h, 16L:8D) and in a proportionally shorter (18h, 12L:6D) lighting schedule was compared. In the 24h group, 78% of the nursing events took place during the dark period and in the two hours after light switch on. This tendency could not be observed in the 18h group. Only a small part of the nursing events was recorded during the dark period. Even if the rabbit does, who were born and grew up in 16L:8D (24h) lighting schedule, were housed in 12L:6D (18h) schedule their nursing events were still based on 24 hours intervals and lighting schedule. Contrary to our hypothesis, applying a \u201creduced day\u201d (12L:6D = 18h) instead of the routine 16L:8D lighting schedule did not increase the number of nursing events per 24 hours. Reproductive performance of the two groups was similar. Exp. 6. The production of single-cged (S) and group-housed does (G) was compared. In group G, four does and one buck were housed in each of four pens with 7.7 m2 with 4 nest boxes in each. In group S half of the does were artifivally inseminated. The average of kindling rate was 77.6, 85.2 and 45.6%, resp. in groups of S-33, S- 42 and G (P<0.001). No significant differences were observed for litter size. The suckling mortality was 14.6 and 38.5% (P<0.001), and the survival of does was 76 and 50%, resp. in groups of S and G (P=0.084). The corticosterone levels (measured in faecal) were 61, 54 and 175 nmol/g. The high mortality of kits was partly connected with stress and aggressive behaviour of does: scratching, biting or killing the kits. Due to high stress, increased mortality and morbidity, and low productivity, group-housing of rabbit does resulted in poorer animal welfare and increased production costs, and therefore, is not recommended. Exp. 7. In this study, the location preferences of rabbit does and their kits were analyzed in two types of pens with elevated platforms (wire-mesh or plastic-mesh). On average the does spent by 25% more time on the platform when they were placed to PP pens compared to the PW pens. After the kits left the nest boxes the does chose the platform more frequently, then after day 21, when the kits started to visit the platform, the does\u2019 platform preference decreased. Usage of the wire-mesh platform by kits was significantly lower than that of the plastic platform. From the aspect of animal welfare cages/pens enriched with platforms can be considered advantageous especially when the platform is made from plastic-mash

PRODUCTION AND BEHAVIOUR OF GROWING RABBITS DEPENDING ON THE SEX-COMPOSITION OF THE GROUPS

The objective of this study was to analyse the effects of the sex-composition of group on the production and behaviour of growing rabbits. Altogether 168 growing rabbits were evaluated between the ages of 5 and 11 weeks. Seven rabbits were placed to each pen (0.9 x 0.5m). The rabbits placed to the same pen were full sibs (FS), only females (F), only males (M), or mixed sexes (FM). The group sex-composition had no effect on the production (weight gain, body weight, feed intake, feed conversion ratio, mortality). No differences were found for the occurrence of the behavioural patterns. Lesions on the body caused by the aggressive animals were initially observed at the age of 7 weeks. It was more frequent for the F group between the ages of 7-9 weeks, but on the contrary, at the age of 11 weeks the occurrence of the lesions was 40.5% in the M group which was higher than that of the other groups (23.8%-28.6%). Based on the results it could be concluded that housing the growing rabbits segregated by sex, primarily only males, was disadvantageous

DIETARY SUPPLEMENTATION OF SPIRULINA (Arthrospira platensis) AND THYME (Thymus vulgaris). PART 4: EFFECT ON RABBIT CARCASS AND MEAT QUALITY

The aim of the study was to evaluate the effect of the dietary supplementation of 5% Spirulina (S) and 3% Thyme (T) leaves and the length of their supplementation on carcass traits and meat quality of fattening rabbits. Maternal line rabbits (n=294) of both sexes were used. S and T were supplemented to isonitrogenous and isoenergy diets formulated to cover the requirements of meat producing rabbits. All diets did not include coccidiostatic. Rabbits received the S and T supplementation separately or combined (TS), during the whole growing-fattening period (5th-11th week of age: S-S; T-T; ST-ST) or only during fattening (8th-11th week of age: C-S; C-T; C-ST). On overall 7 groups of animals of 36 rabbits each were used for carcass evaluation: Control (C-C; not supplemented diet) C-S, S-S, C-T, T-T, C-ST, ST-ST. Rabbits were slaughtered at 77 days of age. Carcasses were dissected and carcass yield, carcass fatness and meatiness were determined and pHu and L*a*b* colour were measured on Longissimus dorsi (LD) muscle. On 15 rabbits per dietary treatment the LD muscle was dissected and frozen for WHC, proximate composition, cholesterol, heme iron and vitamin B12 analyses on raw meat and for proximate composition and cholesterol content on cooked meat. Carcass traits were not affected by the dietary treatments, with exception of the incidence of the scapular fat that showed its lowest value in C-T group (0.39%) and its highest value in S-S (0.56%; P<0.05). Spirulina and Thyme supplementations didn\u2019t affect the rheological traits as well, even though a tendency towards a lower total water loss was found in S-S and C-S groups (33.1 and 33.4%, respectively; n.s.) compared to the other groups (35.2\ub10.86 %). Consequently, cooked LD meat of S-S group contained more water (67%) than the other groups (66.1\ub10.27 %; n.s.). S-S and T-T diets reduced the protein content in the cooked LD meat, compared to the C-C diet (31.3 and 31.5 vs 32.4%; P=0.051), and cholesterol content was found the lowest in S-S group, both in raw and cooked LD meat (49.7 and 76.0 mg/100 g). In this study the effect of Spirulina supplementation as lipid lowering wasn\u2019t confirmed. Based on our results, Spirulina supplement seems promising in enhancing WHC and vitamin B12, and in reducing cholesterol content of rabbit meat, but its inclusion level should be further increased

EFFECT OF SUPPLEMENTATION OF LINSEED OIL, VITAMIN E AND SELENIUM IN DIET FOR GROWING RABBITS ON PRODUCTIVE AND CARCASS TRAITS

The aim of this experiment was to analyse, how additional dietary linseed oil, vitamin E and selenium affects production and slaughter characteristics of growing rabbits. The basal diet (B) contained 3% sunflower oil, while in the experimental feed (S) this was changed to 3% linseed oil. The vitamin E and selenium content of the two diets was 60 vs. 260 mg/kg and 0.10 vs. 0.46 mg/kg, respectively. Rabbits were fed the B diet from the age of 18 days. One group was fed with the B diet until 11 weeks of age, while the experimental groups were fed the S diets for 1, 2, 3 and 4 weeks before the slaughter (S1, S2, S3 and S4 groups). The body weight gain, the body weight, the feed intake and the feed conversion was identical in all groups. The mortality, as compared to the S1 group (0%) was higher in the in the B group by 13.4% and in the S2 and S3 groups (5.6% and 11.1%, resp.). The dressing out percentage was the lowest in the S1 group (61.7%), while it was significantly higher (P<0.05) in the S2 and S3 groups (62.8 and 62.7%). The proportion of the mid part, as compared to the reference carcass was the lowest in the S1 group and the highest in the S3 (31.3 vs. 32.0%, P<0.05). The proportion of the hind part was the highest in the S1 group (P<0.05) and the lowest in the S2, S3 and S4 groups (38.8 vs. 37.3; 37.2 and 37.1%). The weight of the organs, the proportion of the fore part and that of the perirenal fat was identical in all groups. Comparing these results to the literature, it was found that additional dietary linseed oil, vitamin E and selenium has no or only a slight effect on the production and slaughter characteristics

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\u201311 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\u201311 weeks; treatments S, T and ST), or for a part of the growing period (8\u201311 weeks; treatments C\u2013S, C\u2013T and C\u2013ST). 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\u2013T and T groups that also showed the highest content of \u3b1-tocopherol and n 12 3 fatty acids content and the lower lipid oxidation

Experimental results in the field of nutrition and carcass traits of rabbits at Kaposv\ue0r University between 2008 and 2012

In this paper we summarize the results of experiment carried out during the last five years. Exp. 1. The aim of the experiment was to study the influence of feeding medicated or non-medicated diets followed by a feed restriction after weaning on the productive and carcass traits of growing rabbits. Half of the rabbits was fed non-medicated (NOMED), while the other half was fed medicated diet (MED) between 4 and 9 weeks of age then they consumed non-medicated diet afterwards. Within both diet groups, half of the rabbits was fed ad libitum (ADLIB), while the other half restricted (RESTR). In the latter group rabbits were allowed to consume for 9, 10, 12 or 14 hours between 4-5, 5-6, 6-7 or 7-8 weeks of age, respectively, then, they were fed ad libitum afterwards. The feed intake was 26.7, 18.3 (P<0.001) and 5.3% (P=0.059) lower in the RESTR group at the ages of 4-5, 5-6 and 6-7 weeks, respectively. After 7 weeks of age no difference was found between groups. Body weight gain of RESTR rabbits was 20.9 (P<0.001) and 8.5% (P=0.039) lower at the ages of 4-5 and 5-6 weeks, resp., while between 6 and 8 weeks of age it slightly increased. Body weight of RESTR rabbits was 9.2% lower at 5 weeks of age compared to ADLIB group (871 vs. 959 g) but this was partly compensated at the end of the experiment (2737 vs. 2799 g, P=0.056). Feed conversion of RESTR group was better compared to ADLIB rabbits (2.57 vs. 2.64, P=0.01). No significant difference was found in the mortality (1 vs. 3.6%). Dressing out percentage (59.4 vs. 58.6%, P<0.001) and the proportion of hind part (19.2 vs. 18.8%), of hind legs (18.3 vs. 18.0%) and that of the m. Longissimus dorsi (7.1 vs. 6.8%) to the body weight were higher in ADLIB rabbits. No difference was found in the proportion of perirenal fat. Production and mortality of MED and NOMED groups were similar; however, the feed intake and the body weight gain of MED rabbits decreased during the transition from MED to NOMED diet at 9 weeks of age. Exp. 2. The objective of the study was to evaluate the effects of time of changing the breeding diet to fattening pellet on the production of does and growing rabbits. In the first group the does and their kits received breeding pellet till weaning (TT group; n=60). In the second group the breeding pellet was replaced by growing pellet at the 21st day of lactation (TN group; n=59). The rabbits were fed both pellet types ad libitum. The kits were weaned at the age of 35 days. No significant differences were observed for kindling rate, litter size and litter weight. The changing of the pellet affected the body weight of the rabbit does at the 35th day of lactation (-80g, P=0.016, TN<TT), the individual and litter weight of the kits at the 35th day of age (-326g, P=0.001; -42 g, P<0.001, TN<TT) and the condition of the does after parturition. For the growing rabbits the weight differences that were observed at weaning remained until the end of the growing period (11 weeks of age: +91g, P=0.033 in favour of TT group). No significant differences were observed for feed consumption and for feed conversion ratio. Based on the results, feeding the rabbits with breeding pellet until weaning was favourable. Exp. 3. The objective of the experiment was to analyze the production and carcass traits of growing rabbits fed by medicament free or by supplemented (with coccidiostatic, or with 3 different tannin levels) pellet. From the age of 18 days the rabbits were fed by medicament free pellet supplemented by coccidiostaticum (Cc), or by tannin (400g/100kg: T400). At weaning (35 days of age) within both groups 5 sub-groups were formed: medicament free (CO), and supplemented pellet containing coccidiostaticum (Cc), or different levels of tannin (Farmatan) (T200, T400 and T600). At weaning the body weight of the Cc rabbits was significantly higher than that of the T400 rabbits. Except for this finding the fed pellet type did not influence the growing rabbits\u2019 production. The pellet type fed prior to weaning significantly affected the perirenal fat weight (Cc = 28.9 and T400 = 26.3 g; P<0.05). The rabbits fed by tannin supplemented pellet after weaning had a higher mid part ratio (P = 0.1). The mortality rate was low in all groups. It can be concluded that no positive effect can be expected when the rabbits are healthy and the housing conditions and the feed compositions are adequate. Exp. 4. The aim of the experiment was to analyse, how additional dietary linseed oil, vitamin E and selenium affects production and slaughter characteristics and meat quality of growing rabbits. The basal diet (A) contained 3% sunflower oil, while in the experimental feed (K) sunflower oil was changed to 3% linseed oil. The vitamin E and selenium content of the two diets was 60 vs. 260 mg/kg and 0.10 vs. 0.46 mg/kg, resp. Rabbits were fed the A diet from the age of 18 days. One group was fed with the A diet until 11 weeks of age, while the experimental groups were fed the K diets for 1, 2, 3 and 4 weeks before the slaughter (K1, K2, K3 and K4 groups). The production performance was identical in all groups. The dressing out percentage was the lowest in the K1 group (61.7%), while it was significantly higher (P<0.05) in the K2 and K3 groups (62.8 and 62.7%). The proportion of the mid part was the lowest in the K1 group and the highest in the K3 (31.3 vs. 32.0%, P<0.05). The proportion of the hind part was the highest in the K1 group (P<0.05) and the lowest in the K2, K3 and K4 groups (38.8 vs. 37.3; 37.2 and 37.1%). The proportion of the fore part and that of the perirenal fat was identical in all groups. It was concluded that additional dietary linseed oil, vitamin E and selenium has no or only a slight effect on the production and slaughter characteristics. Exp. 5. The objective of the study was to evaluate the effect of supplementation and the length of the supplementation) of the growing rabbits\u2019 diet by Spirulina or/and Thyme on the growing rabbits\u2019 production. At weaning the rabbits were randomly sorted to 7 groups (42 rabbits/group). Rabbits of the control group (C) received a pellet throughout the experiment (5-11 weeks of age) without any supplementation. In the other groups the pellet was completed by 5% Spirulina (S), or 3% Thyme (T) or by both (ST) for the whole (5-11 wk; groups: S-S, T-T, ST-ST), or for end of the growing period (8-11 wk; groups: C-S, C-T, C-ST). Supplementing the diet by Spirulina or/and Thyme had no effect on the rabbits\u2019 weight gain, body weight, feed consumption, morbidity and mortality. Significant differences were only found for feed conversion ratio (8-11, 5-11 weeks) of the C-T and C-C groups to the advantage of the C-T rabbits (P<0.05). The carcass traits of different groups did not differ significantly. Based on the results the feed supplements applied separately or jointly had no substantial effect on the growing rabbits\u2019 production and health status