Abstract:

This study aimed to investigate the optimal inclusion level of timothy grass （Phleum pratense） in pelleted feed for Ira meat rabbits and evaluate its effects on growth performance， slaughter characteristics， organ indices， gastrointestinal tract development， and meat quality. The trial was a one-way design， 180 thirty-five-day-old rabbits were allocated to a control group and five experimental groups （I-V）， receiving pelleted diets containing 0%， 10%， 20%， 30%， 40%， and 50% timothy grass， respectively. The trial comprised a 6-day adaptation period followed by a 54-day formal trial period. Results indicated that rabbits fed the 10% timothy grass diet exhibited superior performance： final body weight （2.86 kg） and average daily gain （20.99 g·d^-1） were significantly higher compared to other groups except the control group （P<0.05）. Hepatic development was significantly enhanced in this group， with liver weight reaching 112.69 g and hepatic index 3.55% （P<0.05）. Regarding meat quality parameters， the 10% inclusion group demonstrated significantly elevated redness-greenness coordinate （a* value， 22.33） and yellow-blue coordinate （b* value， 15.95） values at 45 minutes postmortem compared to other test groups except for the 20% addition amount （P<0.05）. Linear increases were observed in jejunal index （1.49%-1.78%）， colonic index （0.75%-0.84%）， cecal length index （7.94%-8.56%）， colonic length index （7.95%-8.58%）， and vermiform appendix length index （2.86%-3.26%） with progressive timothy grass supplementation （P<0.05）. The findings demonstrate that 10% timothy grass inclusion is optimal to enhance growth rate； and promotes hepatic development and improves meat color attributes （redness and yellowness）. However， timothy grass inclusion beyond 20% adversely affected growth parameters， suppressed hepatorenal development， and reduced meat yield， despite improving cecal length index and water-holding capacity.

Key words: timothy grass, growth performance, slaughter performance, meat quality