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The effect of nutrient supply at foetal, suckling and growing ages on productive, carcass and meat quality traits of rabbits was studied. New-born rabbits were divided into three groups according to their birth weight (low/L/: 35–50g, medium/M/: 58–62g and high/H/: 70–88g). Half of the litters were nursed by one doe (O) and the other half by two does (T). The kits were weaned at 3weeks. From the age of 4weeks, half of the rabbits were fed ad libitum (A), or on a restricted regime (R) (85–90% of the ad libitum feed intake level). Rabbits were slaughtered at 11weeks of age. Difference in average feed intake between groups L and H, groups O and T and between R and A was 11.2%, 7.8% and 11.7%, respectively; in all cases, the latter groups had the highest intakes. Body weight gain between 3 and 11weeks was significantly affected by birth weight and feeding regime. Body weight at slaughter of L rabbits was 124g lower than that of M rabbits and 255g lower than that of H rabbits (P <0.05). Group L had the highest dressing out percentage (58.0%), whereas M rabbits had the lowest dressing out percentage (57.3%) (P <0.05). Ratio of hind part of the reference carcass was higher in group H (39.0%) than in group L (38.1%) (P <0.05). Percentage of perirenal fat was the highest in L rabbits (2.10%) and the lowest in group H (1.64%) (P <0.05). Slaughter weight of T rabbits was 198g higher (P <0.001) than that of group O. Chilled carcass weight and dressing out percentage were 16g (P =0.006) and 0.7% (P =0.002) lower, respectively, in T rabbits. In consequence of feed restriction slaughter weight, chilled carcass weight and dressing out percentage decreased by 141g (P <0.001), 22g (P <0.001) and 0.8% (P =0.001), respectively, while the ratio of liver and kidneys to liveweight increased by 0.57% (P <0.001) and 0.05% (P <0.001). Cooking loss of musculus longissimus dorsi (MLD) was 1.8% lower (P <0.05) in H rabbits compared with L and M animals. Cooking loss was 1.6% lower (P =0.003) in group T than in group O. Due to the restriction, slaughter weight and dressing out percentage decreased by 141g (P <0.001) and 0.8% (P =0.001), respectively. Feeding regime influenced all meat quality parameters except the b* value of meat colour. Rabbits in R group had 0.08 (P <0.001) lower pH, while 1.1 (P <0.001) higher L* and 0.7 (P =0.008) lower a* values resulted lighter colour of MLD. The cooking loss of MLD of R rabbits was 1.2% higher (P =0.028). Results show that the foetal and suckling nutrient supply exert a long-term effect, affecting also carcass traits and meat quality. [Copyright &y& Elsevier]

Abstract: In this experiment the effect of digestible energy (DE) restriction on carcass traits and meat quality of rabbits selected divergently for body fat content was studied. Using a 2×3 factorial arrangement, Pannon White rabbits selected for high (HFAT) or low (LFAT) total body fat content were fed isocaloric diets between 4 and 12 weeks of age. Energy restriction was achieved by reducing the daily feed intake by 10% (M) and 20% (L) compared to the ad libitum fed group (H). Proportional to the reduction of feed intake the nutrient density of diets M and L was increased. Thus, the DE intake was reduced while the nutrient intake remained stable among the 3 dietary groups. Effect of genetic group on carcass traits and on meat quality parameters was less marked than DE restriction. Selection for high body fat content improved the dressing out percentage (58.3 and 57.3% in HFAT and LFAT respectively; P <0.01), and reduced the percentage of the full gastrointestinal tract to slaughter weight (13.7 and 14.3% in HFAT and LFAT respectively; P <0.05). Reduction of DE intake decreased the body weight and the weight of the chilled and reference carcass (P <0.001), while it had no effect on dressing out percentage. In group H the percentage of fore part to reference carcass was higher (29.7 vs 29.0%; P <0.01) while that of the hind part was lower than in group L (37.0 vs 38.2%; P <0.001). The Longissimus lumborum meat from HFAT rabbits exhibited a lower content of moisture (76.1 and 76.5% in HFAT and LFAT respectively; P <0.01) as well as lower L⁎ (53.5 and 54.4 in HFAT and LFAT respectively; P <0.05) and b⁎ (0.42 and 0.81 in HFAT and LFAT respectively; P <0.05) colour values. When compared with ad libitum fed rabbits, those restricted at 20% (L) exhibited a higher content of moisture (76.9 vs 75.8%; P <0.01), as well as higher pHu (5.87 vs 5.73; P <0.01) associated with lower cooking loss (17.8 vs 19.1%; P <0.05). L rabbits also produced lower values of redness (a⁎, 2.21 vs 3.35; P <0.01) and yellowness (b⁎, 0.23 vs 0.91; P <0.01). No effect of the divergent selection for body fat content on the total lipid percentage and on most of the fatty acids in the meat of the hind leg was found. DE restriction resulted in lower SFA (L: 32.1 vs H: 35.8%; P <0.01) and MUFA (L: 21.0 vs H: 28.6; P <0.01) but higher PUFA contents (L: 45.5 vs H: 34.9%; P <0.01) in the hind leg meat. [Copyright &y& Elsevier]

Abstract: Genetic parameters for average daily gain between the age of 5 and 10 weeks (ADG), the average cross-sectional area of the m. Longissimus dorsi (L) (between the 2nd–3rd and 4th–5th lumbar vertebrae-based on in vivo computerized tomography (CT)) and dressing out percentage (DoP) were estimated in a group of 28,686 Pannon White rabbits reared in 5044 litters and born between 2000 and 2003. Using multivariate animal models with Bayesian procedures, estimated heritabilities were moderate and moderately high for ADG, L and DoP (0.21 to 0.29, 0.25 to 0.42 and 0.19 to 0.71, respectively). Litter effects were moderate for ADG, L and DoP estimates (0.20 to 0.22, 0.10 to 0.18 and 0.09 to 0.30, respectively). Genetic correlation coefficient estimates between ADG and L and ADG and DoP were moderate and negative (−0.41 to −0.01, −0.70 to +0.10). A moderately high positive genetic correlation was found between L and DoP (0.13 to 0.83). [Copyright &y& Elsevier]