The aim of this study was to evaluate 2 alternative breeding systems that differ from the current system in terms of reproduction rhythm, age of females at first insemination and the age of kits at weaning and at slaughter. We measured the performance of 332 females and their offspring over 4 consecutive cycles, as well as the sustainability of the systems. We compared an intensive (group I: reproduction rhythm [RR]=35 d; first insemination [AI 1 ]=20.6 wk of age; weaning age [WA]=32 d; slaughter age [WS]=63 d) an extensive (group E: RR=49 d; AI 1 =16.6 wk; WA=30 d; WS=70 d) and a semi-intensive system (group S: RR=42 d; AI 1 =19.6 wk; WA=35 d; WS=70 d) considered as the control system. Sustainability was evaluated using a multicriteria assessment method that takes 14 economic, environmental and social criteria into account, for which 3 to 5 indicators were expressed as the relative score [–1; –0.5; 0; +0.5; +1] for alternative systems compared to the control system. The productivity measured at 28 d (3.5, 4.2 and 4.6 kg/AI, for groups I, S and E, respectively), at 63 d post-partum (30, 38 and 42 kg/female for 4 cycles, respectively), and the total body energy measured 3 d after the 1st and at the 4th insemination (45.4, 46.8 and 49.5 MJ, respectively), were significantly increased when the reproductive rhythm decreased (P<0.001). Before and after weaning, kit mortality decreased when the reproduction rhythm decreased (11.4, 7.3, and 1.9% and 18.3, 15.3 and 10.6% for groups I, S and E, respectively, P<0.05). Carcass quality (weight and dressing percentage) was lower in I than in the S and E groups (P<0.001). On this basis, the yearly productivity per doe at weaning could be estimated at 79, 83, and 78 kg for groups I, S and E, respectively. Consequently, the productivity per reproductive cycle increases with the extensification of the breeding system. Nevertheless, compared with the current French system (S), simultaneous changes in several breeding practices could lead to new coherent and functional systems capable of improving various aspects of sustainability.

https://polipapers.upv.es/index.php/wrs/article/download/5154/7077

Performance and sustainability of two alternative rabbit breeding systems

The effect of the weaning age of rabbits on slaughter traits and physicochemical properties of meat was The effect of the weaning age of rabbits on slaughter traits and physicochemical properties of meat was investigated. Sixteen New Zealand White rabbits ( investigated. Sixteen New Zealand White rabbits (Oryctolagus cuniculus Oryctolagus cuniculus) were used, divided in two groups: ) were used, divided in two groups: group А (n = 8) - weaned at the age of 21 days (early weaned) and group В (n = 8) - weaned at the age of 35 group А (n = 8) - weaned at the age of 21 days (early weaned) and group В (n = 8) - weaned at the age of 35 days (normally weaned). The animals were fed with two categories of pelleted feed: for weaned rabbits up to days (normally weaned). The animals were fed with two categories of pelleted feed: for weaned rabbits up to 50 days of age and for growing rabbits older than 50 days of age. It was established that the early weaning of 50 days of age and for growing rabbits older than 50 days of age. It was established that the early weaning of rabbits resulted in a statistically signifi cantly lower body mass, dressed carcass weight and dressing percentage rabbits resulted in a statistically signifi cantly lower body mass, dressed carcass weight and dressing percentage as compared to normally weaned animals. Also, the pH of meat by the 24 as compared to normally weaned animals. Also, the pH of meat by the 24 th th hour after slaughtering and the dry hour after slaughtering and the dry matter of m. longissimus lumborum (LL) were signifi cantly lower in group A. Simultaneously, a statistically matter of m. longissimus lumborum (LL) were signifi cantly lower in group A. Simultaneously, a statistically signifi cantly higher water-holding capacity, water content and lightness were established in the meat of early signifi cantly higher water-holding capacity, water content and lightness were established in the meat of early weaned compared to normally weaned rabbits. The protein and fat contents of LL and m. semimembranosus weaned compared to normally weaned rabbits. The protein and fat contents of LL and m. semimembranosus (SМ) in rabbits from group A correlated negatively and signifi cantly with water content, and positively with the (SМ) in rabbits from group A correlated negatively and signifi cantly with water content, and positively with the dry matter. In group B, water content also correlated signifi cantly and negatively with protein content. Fat and dry matter. In group B, water content also correlated signifi cantly and negatively with protein content. Fat and ash in SM meat was in a positive statistically signifi cant relationship for both experimental groups. The results ash in SM meat was in a positive statistically signifi cant relationship for both experimental groups. The results from the present study showed that the weaning age infl uenced both the slaughter traits and physicochemical from the present study showed that the weaning age infl uenced both the slaughter traits and physicochemical properties of rabbit meat. properties of rabbit meat.

Effect of weaning age upon the slaughter and physicochemical traits Effect of weaning age upon the slaughter and physicochemical traits of rabbit meat of rabbit meat

S. S. Ribarski

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Effect of weaning age upon the slaughter and physicochemical traits Effect of weaning age upon the slaughter and physicochemical traits of rabbit meat of rabbit meat