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 the feeding supplementation with chestnut hydrolysabletannin on the colour and oxidative stability of rabbit meat.

The aim of the study was to evaluate the effect of feeding growing rabbits with pelleted diets medicated-free, or medicated with coccidiostat, or with 3 different chestnut hydrolysable tannin levels, on the oxidative stability of the rabbit meat. From the age of 18 days the rabbits were fed pellets supplemented with coccidiostat (Cc), or with tannin (400g/100 kg: T400). At weaning (35 d of age) within both groups 5 sub-groups were formed: medicated-free (Co), and supplemented pellet containing coccidiost (Cc), or different levels of chestnut tannin (T200, T400 and T600). Rabbits were slaughtered at 11 weeks of age and Biceps femoris muscle was analysed for meat colour, hindleg meat for haem iron concentration, whereas Longissimus dorsi (LD) muscle was dissected and used for fatty acid (FA) profile, TBARS value and conjugated dienes determination. The tannin-supplemented diet T400 fed before weaning seemed to be more effective than the 3 tannin levels administered during fattening period on FA profile change in the LD muscle. T400 diet fed before weaning increased SFA and MUFA (P<0.01) and decreased PUFA (P<0.05), decreasing the n-6/n-3 ratio (P<0.01), however. During fattening, only T600 diet showed significant difference (P<0.05) compared to Cc diet on FA profile, leading to higher SFA and MUFA contents. Meat colour, TBARS value and conjugated dienes were not affected by the tannin supplementation and it can be concluded that dietary chestnut hydrolysable tannins didn\u2019t improve the colour and oxidative stability of the rabhit meat

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

DIETARY SUPPLEMENTATION OF SPIRULINA (Arthrospira platensis) AND THYME (Thymus vulgaris). PART 6: EFFECT ON OXIDATIVE STATUS OF RABBIT MEAT DURING RETAIL DISPLAY

The objective of this study was to evaluate the effect of Spirulina and Thyme supplementation (between the ages of 5-11 or 8-11 weeks) on the oxidative status of rabbit meat during a simulated retail display. The experiment was conducted at the experimental rabbit farm of the Kaposv\ue1r University using maternal line rabbits (n=294). At weaning the rabbits were randomly sorted in 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), 3% Thyme (T) or by both (ST) for the whole (5-11 wk; groups: S-S, T-T, ST-ST), or for part of the growing period (8-11 wk; groups: C-S, C-T, C-ST). After slaughter longissimus dorsi muscles were transported refrigerated to Department of Applied Biology of Perugia to be analyzed. C-T and T-T samples showed the highest value of n-3 fatty acid at the beginning of storage, whereas S-S and ST-ST that of n-6 fatty acids. S-S group showed the highest amount of PUFA at day 1 of trial. In agreement with these results, the C-T and T-T groups showed the highest content of \u3b1-tocopherol, at the beginning and end of the storage period. C-T and T-T groups showed significantly lower lipid peroxidation and at the same time the lower losses of long chain fatty acid of n-3 series