为拓展家兔的粗饲料来源,本研究评定了由四川农业大学玉米研究所选育的大黑山薏苡( Coix lacryma-jobi cv. Daheishan)全株(晒干)对生长肉兔营养价值的影响。在分析化学组成的基础上,将24只42日龄遗传背景相同、体重相近(1 107.00±98.42) g的健康法国伊拉商品兔随机分为两组(每组12只),单笼饲养在粪尿分开的金属网笼(60 cm×60 cm×45 cm)中,分别饲喂基础饲料(100%)和试验饲粮(85%基础饲粮+15%大黑山薏苡全株),进行体内消化试验,试验期11 d(预试期7 d,收集期4 d)。结果显示,大黑山薏苡全株的干物质(dry matter, DM)含量为88.46%。以DM计,总能(gross energy, GE)、粗蛋白质(crude protein, CP)、粗纤维(crude fiber, CF)、中性洗涤纤维(neutral detergent fiber, NDF)、酸性洗涤纤维(acid detergent fiber, ADF)、酸性洗涤木质素(acid detergent lignin, ADL)、无氮浸出物(nitrogen free extract, NFE)、粗脂肪(ether extract, EE)、粗灰分(crude ash, Ash)、钙(calcium, Ca)和总磷(total phosphorus, TP)含量分别为16.94 MJ·kg^-1、13.46%、29.58%、62.57%、42.05%、7.01%、31.20%、1.02%、13.19%、1.21%和0.20%,精氨酸(arginine, Arg)、组氨酸(histidine, His)、异亮氨酸(isoleucine, Ile)、亮氨酸(leucine, Leu)、蛋氨酸(DL-Methionine, Met)、赖氨酸(lysine, Lys)、苯丙氨酸(phenylalanine, Phe)、苏氨酸(L-Threonine, Thr)和缬氨酸(valine, Val)含量分别为0.47%、0.15%、0.37%、0.74%、0.14%、0.41%、0.46%、0.45%和0.49%。对于生长肉兔,大黑山薏苡全株的DM、GE、CP、CF、NDF、ADF、ADL、EE、Ash、Ca 和TP全肠表观消化率分别为31.67%、30.02%、60.09%、4.55%、10.26%、0.80%、29.21%、54.68%、38.17%、58.84%和6.25%,消化能(digestible energy, DE)为5.69 MJ·kg^-1 DM;Arg、His、Ile、Leu、Met、Lys、Phe、Thr和Val全肠表观消化率分别为89.98%、87.16%、82.54%、84.31%、72.40%、83.77%、83.63%、75.81%和83.84%。综上可知,晒干大黑山薏苡全株的营养物质尤其是粗蛋白质和钙含量较高,纤维组分构成较合理,且其营养物质尤其是氨基酸在生长肉兔上的消化率较高。因此,从化学组成和营养物质消化利用角度看,大黑山薏苡全株可作为粗饲料用于家兔生产。

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.