Estimation of dominance effects for reproductive, growth and carcass traits of Pannon White rabbits

Authors analysed the reproductive, growth and slaughter records of Pannon White rabbits based on records collected between 1992 and 2014. The examined traits were: average daily gain (ADG), thigh muscle volume (TMV) and litter weight at day 21 (LW21). Genetic parameters were estimated using basic and extended (with dominance effects) single trait animal models using the REML procedure. Heritability estimates ranged between low and moderate for all traits (ADG: 0.25-0.3±0.01, TMV: 0.21-0.24±0.02-0.03, LW21: 0.07-0.19±0.01). Random litter effects were moderate for ADG (0.24-0.25±0.01) but were low for TMV (0.09-0.1±0.01-0.03). Magnitude of permanent environmental effects exceeded that of the heritability values for LW21 in most models. Applying the extended complete models dominance effects were low for ADG and TMV (0.03±0.01-0.02) and moderate for LW21 (0.23±0.01). Among the estimated genetic correlation coefficients, the observed negative value between ADG and TMV (-0.31±0.03) and between TMV and LW21 (-0.38±0.13) were unfavourable. Based on the different models the estimated breeding values showed high stability as their rank correlation coefficients were close to unity (0.93-0.99)

Effect of adult weight and CT-based selection on the performances of growing rabbits

The aim of the study was to compare the productive performance of different genotypes. Maternal (M; n=32, adult weight /AW/ 4.0-4.5kg, selected for number of kits born alive), Pannon White (P; n=32, AW: 4.3-4.8kg), and Large body line (L; n=32, AW: 4.8- 5.4kg) (P and L were selected for carcass traits based on CT /Computer tomography/data) rabbits were analysed. Average daily gain between 5-11wk of age, body weight at 11wk of age and feed intake were significantly (P<0.001) highest for L rabbits. For M, P and L rabbits, the following values were observed: average daily gain=38.6, 43.1 and 47.4g/d; body weight=2458, 2667 and 2949g; feed intake=115, 121 and 138g/d, respectively. Mortality of growing rabbits was unaffected by genotype. It can be concluded that production traits were mainly affected by the adult weight of the genotypes

Effect of turmeric powder (Curcuma longa L.) and ascorbic acid on physical characteristics and oxidative status of fresh and stored rabbit burgers

The objective of this study was to evaluate the effect of Curcuma longa powder and ascorbic acid on some quality traits of rabbit burgers. The burgers (burgers control with no additives; burgerswith 3.5 g of turmeric powder/100 g meat; burgers with 0.1 g of ascorbic acid/100 g meat) were analyzed at Days 0 and 7 for pH, color, drip loss, cooking loss, fatty acid profile, TBARS, antioxidant capacity (ABTS, DPPH and FRAP) and microbial growth. The addition of turmeric powder modified the meat color, produced an antioxidant capacity similar to ascorbic acid and determined a lower cooking loss than other formulations. Turmeric powder might be considered as a useful natural antioxidant, increasing the quality and extending the shelf life of rabbit burgers

Effect of dietary supplementation of spirulina (Arthrospira platensis) and thyme (Thymus vulgaris) on apparent digestibility and productive performance of growing rabbits

[EN] The aim of this study was to evaluate the effect of dietary supplementation with spirulina (Arthrospira platensis) or/and thyme (Thymus vulgaris) on total tract apparent digestibility of nutrients and the performance of growing rabbits. At weaning (5 wk of age) the rabbits were randomly allotted to 7 groups (42 rabbits/group, 3 rabbits/cage). Rabbits in the control group (C-C) received a control pelleted feed throughout the experiment (5-11 wk of age) without any supplementation (crude protein: 176 g CP/kg, neutral detergent fibre: 325 g NDF/kg). In the other groups, the control diet was supplemented with 5% spirulina (S, mainly in substitution of soybean meal), or 3% thyme (T, mainly in substitution of alfalfa meal) or by both 5% S and 3% T (ST) for the whole (5-11 wk of age; groups: S-S, T-T, ST-ST) or part of the growing period (8-11 wk of age; groups: C-S, C-T, C-ST). Supplementations had no effect on apparent digestibility of dry matter, organic matter, acid detergent fibre, gross energy and digestible energy. The CP TTAD was lowest in rabbits fed the S diet, whereas it was highest in C fed rabbits, the other 2 treatments being intermediate (P<0.001). The starch TTAD was lowest for S fed rabbits (98.3%) and highest for ST fed rabbits (99.4%), the other 2 dietary groups being intermediate (P<0.001). In contrast, the ether extract TTAD was higher in T than ST and C dietary groups (on av. 70.4 vs. 67.7% respectively; P<0.001), with S fed rabbits showing an intermediate value (69.1%). The NDF TTAD of the ST diet was lower than that of the other 3 groups (16.4 vs. 21.0% respectively; P<0.001). The TTAD of Ca reached the lowest value for the S diet (53.5%) compared with the other 3 diets (on av. 59.1%; P<0.001). The S diet also had the lowest digestibility (P<0.001) for K and P,but in this case the C group always showed the highest values (P<0.001), with T and ST rabbits exhibiting intermediate results. Spirulina and/or thyme dietary supplementation had no effect on feed intake (133 g/d), daily weight gain (38.3 g/d), morbidity (9.9 %) or mortality (1.8 %). Significant differences were only found for feed conversion ratio, which was lower for the C-T group (3.39) than for the C-C group (3.54; P<0.05). Based on these results, spirulina and thyme included separately or combined in growing rabbit diets did not exhibit substantial effects on growth performance or health status.Research funded by Padova University research funds (Progetti di Ricerca di Ateneo 2011) code: CPDA117509/11, and the GOP-1.3.1-11/B-2011-0045.Gerencsér, Z.; Szendro, Z.; Matics, Z.; Radnai, I.; Kovács, M.; Nagy, I.; Cullere, M.... (2014). Effect of dietary supplementation of spirulina (Arthrospira platensis) and thyme (Thymus vulgaris) on apparent digestibility and productive performance of growing rabbits. World Rabbit Science. 22(1):1-9. https://doi.org/10.4995/wrs.2014.1351SWORD1922

Effect of feeding programme before weaning on the production of rabbit does and their kits

[EN] The aim of the experiment was to analyse the effect of the feeding programme between 21 day of lactation and weaning on the production of rabbit does and their kits. The does were randomly housed in two rooms. In the first room, a continuous 16-hour light period was applied (16L; n=60). In the second room, an 8-hour light period was used which was extended by an additional 1 hour light period in the middle of the 16-hour long dark period 8 days prior to insemination (8+1L; n=59). In both rooms, two sub-groups were formed: in the first sub-group, does and their kits received breeding pellet from parturition to weaning (DE: 10.4 MJ/kg, crude protein: 17.8%, crude fibre: 13.6%; BB group; n=60 does, 228 parturitions); in the second sub-group, the breeding pellet was replaced by growing pellet from 21 days of lactation to weaning (DE: 9.7 MJ/kg, crude protein: 16.0%, crude fibre: 17.2%; BG group; n=59 does, 234 parturitions). The experiment was completed after 5 reproductive cycles. As no significant interaction was found between the lighting and feeding programmes, the two effects are evaluated separately. In this paper, the effect of feeding programme is discussed. No significant differences were observed between the BB and BG groups for number of inseminations per parturition, body weight of the does measured at parturition and at 21st day of lactation or for litter size. Changing the pellet in BG group significantly affected the body weight of the does measured at 35th day of lactation (4610 vs. 4530g, in BB and BG, respectively; P=0.016), the litter and individual body weight of the kits at day 35 (BB: 8160 vs. BG: 7834g, P=0.001; BB: 1006 vs. BG: 964g, P<0.001, respectively) and the does' condition at kindling, as measured by the TOBEC method (E-value: BB: 1922 vs. BG: 1957, P=0.024). Productivity indexes, expressed as number of kits born alive, number of weaned (at day 35) kits and total weight of the weaned kits per year per doe were similar in the two groups. Body weight of the growing rabbits was significantly higher in the BB group at the ages of 5 and 7 weeks (984 and 937g, P<0.001, 1651 and 1621g, P=0.008; respectively). After this period, the body weight of the two groups was the same. The feeding programme had no effect on the feed conversion ratio and mortality of the two groups. According to the results, it may be concluded that it is preferable to avoid food changes around weaning.The financial help of the TECH_08_A3/2-2008-0384 (OM-00198/2008) project is gratefully acknowledged.Gerencsér, Z.; Matics, Z.; Nagy, I.; Szendro, Z. (2011). Effect of feeding programme before weaning on the production of rabbit does and their kits. World Rabbit Science. 19(4):209-216. https://doi.org/10.4995/wrs.2011.94320921619

Effect of lighting schedule on production of rabbit does

[EN] The aim of the experiment was to analyse the effects of the lighting schedule on the rabbit does' production. The does were randomly housed in two rooms at the age of 11 weeks. In the first room, a continuous 16-hour light period was applied (8:00-24:00) (16L:8D, control group; n=60 does, 239 parturitions). In the second room, an 8-hour light period was used (8:00-16:00) which was extended by an additional 1 hour light period in the middle of the 16-hour long dark period (23:00-24:00) 8 days prior to insemination (8L:7D:1L:8D, treated group; n=59 does, 223 parturitions). The experiment was finished after 5 reproductive cycles. Significant differences were obtained for body weight of the does (higher in treated group, P<0.05), litter size (control and treated groups: total born = 9.23 and 8.69, born alive = 8.83 and 8.24, at day 35 = 8.29 and 7.84, P=0.015, P=0.006, P <0.001, respectively), litter weight, individual weight of kits, suckling mortality and for feed consumption between days 21 and 35 of the lactation period. No significant differences were observed for number of inseminations per parturition, feed intake between days 0-21 of lactation, the does' condition at kindling measured by the TOBEC method and doe survival. The annual performance per doe was superior in the control group for number of kits born alive (65.0 and 58.8, P=0.036), number of weaned (at day 35) kits (58.9 and 53.8, P=0.046) and total weight of the weaned kits (58.2 and 52.7 kg, P=0.049) compared to the treated group. According to the results, the additional one hour lighting period (treated group) had no favourable effect on production compared to the continuous 16-hour light.The financial help of TECH_08_A3/2-2008-0384 (OM-00198/2008) project is gratefully acknowledged.Gerencsér, Z.; Matics, Z.; Nagy, I.; Szendro, Z. (2011). Effect of lighting schedule on production of rabbit does. World Rabbit Science. 19(4):217-223. doi:10.4995/wrs.2011.944SWORD21722319

Rabbit lines divergently selected for total body fat content: Correlated responses on growth performance and carcass traits

The aim of this experiment was to study the effect of divergently selected rabbits for total body fat content (fat index) on growth performance and carcass traits. The fat index was determined at 10 weeks of age by computed tomography and lasted for four consecutive generations. The rabbits with the lowest fat index belonged to the lean line and those of the highest values belonged to the fat line. At generation four, 60 rabbits/line were housed in wire-mesh cages and fed with commercial pellet ad libitum from weaning (5 w of age) to slaughtering (11 w of age). Growth performance, dressing out percentage and carcass adiposity were measured. The lean line showed a better feed conversion ratio (p < 0.001) than the fat line. Furthermore, the carcass of the lean rabbits had the highest proportion of fore (p < 0.020) and hind (p < 0.006) parts. On the contrary, rabbits of the fat line had the highest carcass adiposity (p < 0.001). The divergent selection for total body fat content showed to be effective for both lean and fat lines. Selection for lower total body fat content could be useful for terminal male lines, while the selection for higher total body fat content could be an advantage for rabbit does in providing fat (energy) reserves

Effect of nursing methods and faeces consumption on the development of the bacteroides, lactobacillus and coliform flora in the caecum of the newborn rabbits

The effect of nursing method and ingestion of maternal faeces on the development of the bacteroides, lactobacillus and coliform flora of the caecum in the first 10 days of life were examined in freely nursed pups having access to maternal faeces (Group FF), pups nursed once a day and having access (Group CF), or having no access (Group CN) to maternal faeces. Colonisation of the caecum by Bacteroides commenced already on day 3 after birth. On day 2 the bacteroides counts were below 100, while on day 4 they were already between 100 and 10  000. In Group CN, the Bacteroides counts were lower (by 14 to 40%) throughout the 10-day period studied than in the groups having access to maternal faeces. Differences between groups were significant only on days 4 and 6. The average number of maternal faecal pellets left behind the doe in Group CN was 3–4 (between 0.5 and 6.4 per doe). In Groups FF and CF the pellets became smaller, crumbled and finally disappeared from the nest box, they were consumed by the pups and could be found in their gastric content. The lactobacillus counts decreased in all three groups with age, from 6.0 to 3.5 log10 CFU·g–1 (FF), 4.6 to 2.8 log10 CFU·g–1 (CF) and 5.1 to 3.1 log10 CFU·g–1 (CN), respectively. The coliform counts were higher in the first 4 days in FF (5.6 log10 CFU·g–1) than in CF (< 2 log10 CFU·g–1) and CN (2–3.6 log10 CFU·g–1) animals. Bacteroides could be cultured from the surface of the vulvar labia (max. 1000 colony count) and the vagina (max. 190 colony count), so young rabbits could become “infected” by them already in the doe’s vagina. Thus prevention of ingestion of maternal faeces only slightly influenced the development of the bacteroides flora, the faeces left behind by the doe did not play an exclusive role in their colonisation

Quantitative PCR with 16S rRNA-gene-targeted specific primers for analysis of caecal microbial community in growing rabbits after dietary supplementation of thyme (Thymus vulgaris) and spirulina (Arthrospira platensis)

Objective of this study was to evaluate the effect of supplementation of growing rabbits’ diet with 5% spirulina (Arthrospira platensis) and/or 3% (Thymus vulgaris L.), on composition and amount of rabbits caecal microbiota. After weaning, rabbits were randomly sorted to 4 groups (n = 42/group). The control group received a pellet without any supplementation, in treated groups the dietary supplementation was provided until 77 days of age. On 49, 63 and 77 days of age, six healthy animals/group were randomly selected and slaughtered. From the caecal content the amount of total bacteria, Bacteroides, Clostridium leptum and Clostridium coccoides were determined by quantitative polymerase chain reaction (qPCR), with the aid of bacterial ribosome coding DNA. The copy number of total bacteria, C. leptum, C. coccoides and Bacteroides varied between 2.75 × 1012 to 2.24 × 1013, 5.25 × 1011 to 1.82 × 1012, 2.5 × 1010 to 6.91 × 1011 and 5.89 × 1010 to 1.10 × 1012, respectively. The amount of investigated bacteria represented 0.6%-13.4% of the total bacteria. The use of spirulina and/or thyme supplements influenced the amount of the copy number of each bacteria examined between 49 and 77 days of age. Their effect on the total bacteria number was temporary. Spirulina resulted in more Bacteroides on day 63 but significantly lower amount of Clostridia at 63 and at 77 days of age. The antimicrobial effect of thyme on the absolute Clostridia number was temporary, prevailing on day 63. Thyme resulted in significantly decreasing percentage ratio (within total bacteria) of C. leptum and C. coccoides by 77 days of age