The National Institute of Poultry Husbandry (NIPH), Harper Adams University, Shropshire, UK.
Arch Anim Nutr. 2020 Feb;74(1):57-71. doi: 10.1080/1745039X.2019.1659702. Epub 2019 Sep 23.
The chemical characteristics of rapeseed meal (RSM) produced from two cultivars of UK-grown rapeseed, by both supercritical carbon dioxide extraction (ScCO) and cold-pressed hexane extraction (CpHe) were examined. Their nutritional value, with and without protease, was then assessed in a broiler digestibility trial. Basal feed was substituted with one of four RSM batches (200 g/kg) following adjustments for dry matter (DM) and ether extract (EE) content. Half of each diet was supplemented with a mono-component protease derived from (Axtra®PRO, Danisco Animal Nutrition, Malborough, UK) giving a total of eight test diets. Two control diets, with and without protease were also fed. At 13 d age male Ross 308 broilers were randomly allocated to seven replicate pens (five birds per pen) and assigned to one of 10 diets. Total excreta were collected from 17 to 21 d age and feed intake was recorded. Pre-caecal protein digestibility (pcPd) was determined using TiO as an indigestible marker. Colourimetrically CpHe RSM was substantially darker than ScCO counterparts. The influence of oil recovery method (ORM) was also evident in DM, EE, ash free neutral detergent fibre (aNDFom), neutral detergent insoluble crude protein (NDICP) and glucosinolate content (GLS). The content of DM, EE and GLS was higher in ScCO RSM whereas aNDFom and NDICP levels were greater in CpHe RSM. Protein solubility in KOH was greater in ScCO RSM whilst levels of NDICP were lower. Collectively these results suggest that less heat damage was incurred to the RSM during ScCO extraction. There was no significant main effect of cultivar nor were any significant interactions observed between treatment factors. Rapeseed meal ScCO produced greater metabolisable energy, pcPd, nitrogen retention and energy metabolisability ( < 0.05). Protease supplementation increased pcPd ( < 0.05) irrespective of ORM and cultivar. The key implications of these findings are that by adopting oil recovery methods that minimise the exposure of RSM to thermal treatments and by adding a compatible protease there is scope to increase the nutritional value of RSM for broilers and increase its utilisation in modern poultry production.
采用超临界二氧化碳萃取（ScCO）和冷榨己烷萃取（CpHe）两种方法从英国种植的两种油菜籽中提取菜籽油粕（RSM），研究其化学特性。然后在肉鸡消化试验中评估添加和不添加蛋白酶时的营养价值。根据干物质（DM）和乙醚提取物（EE）含量，用四种 RSM 批次（200g/kg）替代基础饲料。每批饲料的一半用来源于（Axtra®PRO，丹麦诺维信动物营养，马布尔伯勒，英国）的单一组分蛋白酶进行补充，共 8 种试验饲料。还饲喂两种对照饲料，添加和不添加蛋白酶。13 日龄雄性罗斯 308 肉鸡随机分配到 7 个重复栏（每个栏 5 只鸡），并分配到 10 种饲料中的一种。17 至 21 日龄收集总排泄物，记录饲料摄入量。使用 TiO2 作为不消化标记物测定盲肠前蛋白消化率（pcPd）。比色法 CpHe RSM 明显比 ScCO 对应物更深。油回收方法（ORM）的影响也体现在 DM、EE、无灰中性洗涤剂纤维（aNDFom）、中性洗涤剂不溶性粗蛋白（NDICP）和硫代葡萄糖苷（GLS）含量上。ScCO RSM 的 DM、EE 和 GLS 含量较高，而 CpHe RSM 的 aNDFom 和 NDICP 水平较高。KOH 中蛋白质溶解度在 ScCO RSM 中较高，而 NDICP 水平较低。这些结果表明，ScCO 提取过程中 RSM 受到的热损伤较小。品种没有显著的主效应，也没有观察到处理因素之间的任何显著相互作用。油菜籽 ScCO 生产的代谢能、pcPd、氮保留和能量代谢率更高（<0.05）。添加蛋白酶可提高 pcPd（<0.05），无论 ORM 和品种如何。这些发现的主要意义是，通过采用最大限度减少 RSM 暴露于热处理的油回收方法，并添加兼容的蛋白酶，可以提高肉鸡对 RSM 的营养价值，增加其在现代家禽生产中的利用。
