Heterosis for nutritive value in rice straw quality

摘要

Paddy straw of 14 hybrids and their parents grown under identical field conditions were dried, ground and chemically analysed before and after incubation of sample in nylon bag for 72 hours in the rumen of 3 rumen fistulated adult male cattle. The results indicated hybrids involving low X low quality parents like UPHR-888, UPHR-902, UPHR-913 and PRH-1 to give significantly higher nylon bag dry matter digestibility (NBDMD) and organic matter digestibility (NBOMD) and exhibited heterosis. Similarly hybrid between parents with high quality straw like UPHR-580, UPHR-911, UPHR-914, PSD-1 resulted in hybrid straw with lower NBDMD and NBADFD. The heritability (h~2) estimates were low for NBDMD, NBOMD, nylon bag neutral detergent fibre digestibility (NBNDFD), nylon bag acid detergent fibre digestibility (NBADFD) and were high (0.85) for nylon bag hemicellulose digestibility (NBGHD). The NDF content of straw was negatively correlated with NBDMD (-0.460~(**)) and NBOMD (0.470~(**)). It is suggested to incorporate digestibility as one of the traits in breeding programmes without sacrificing the grain yield and quality of rice straw.