Nutritive value of sun-cured whole plant of Coix ‘Daheishan’ for growing rabbits

In order to develop a roughage source for rabbits, the nutritive value of sun-cured whole plants of Daheishan (Coix lacryma-jobi cv. Daheishan) was determined. The plant was bred by the Maize Research Institute of Sichuan Agricultural University. Twenty-four healthy, 42-day-old French IRA rabbits with the same genetic background and similar weight (1 107.00±98.42) g were randomly assigned to two groups (12 each per group). All rabbits were housed individually in single wire metabolism cages that allowed separation of faeces and urine. The rabbits were fed two diets:basal (100% basal diet) and test (85% basal diet plus 15% whole plant of Daheishan). The experimental duration was for 11 d (7 d of adaptation period, and 4 d of collection period). After the study period, in vivo digestion test was performed. The results showed that the dry matter (DM) content of whole plants of Daheishan was 88.46%. The contents of gross energy (GE), crude protein (CP), crude fibre (CF), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), nitrogen free extract (NFE), ether extract (EE), crude ash (Ash), calcium (Ca), and total phosphorus (TP) of the DM were 16.94 MJ·kg-1, 13.46%, 29.58%, 62.57%, 42.05%, 7.01%, 31.20%, 1.02%, 13.19%, 1.21%, and 0.20%, respectively. The Arg, His, Ile, Leu, Met, Lys, Phe, Thr, and Val contents were 0.47%, 0.15%, 0.37%, 0.74%, 0.14%, 0.41%, 0.46%, 0.45%, and 0.49%, respectively. For growing rabbits, the total tract apparent digestibilities of DM, GE, CP, CF, NDF, ADF, ADL, EE, Ash, Ca, and total P of whole plant of Daheishan were 31.67%, 30.02%, 60.09%, 4.55%, 10.26%, 0.80%, 29.21%, 54.68%, 38.17%, 58.84%, and 6.25%, respectively. DE was 5.69 MJ·kg-1 DM. In addition, the total tract apparent digestibilities of Arg, His, Ile, Leu, Met, Lys, Phe, Thr, and Val were 89.98%, 87.16%, 82.54%, 84.31%, 72.40%, 83.77%, 83.63%, 75.81%, and 83.84%, respectively. These results indicated that sun-cured whole plants of Daheishan had particularly higher crude protein and calcium contents than other contents. Fibre composition was reasonably high, and thus, this plant had a high nutrient digestibility in growing rabbits; Daheishan also had high amino acid content. Therefore, from the perspective of chemical composition and digestibility of nutrients, the whole plant of Daheishan can be used as roughage in rabbit production.