Abstract:
A simple bioassay that quantifies feed intake as an estimation of relative attractability of feeds containing different ingredients in the Pacific white shrimp Litopenaeus vannamei is described. Fish meal (FM), fish protein hydrolysate (FPH), squid meal (SqM) and casein (CN) were assessed at the same dietary level for their relative influence on feed intake rates of Litopenaeus vannamei. A bland diet containing 92% whole wheat grain meal, 6% diatomaceous earth and 2% alginate with a known low attractability was used as the standard control or base diet. Ingredients were added to the bland base control diet at a level of 3% as fed. Shrimp were stocked into 80 L glass tanks (n= 20 per tank) in a recirculating aquaculture system. Tanks were randomly assigned to one of five diet treatments (3tanks/treatment). Experiments measuring the attractability of each feed were conducted twice daily at 0900 hours and 1330 hours over a five day period. For each experiment, 40 feed pellets (ca. 1 g) corresponding to the assigned treatment were provided to each tank. To calculate the rate of feed intake, pellets remaining in each tank were counted at six minute intervals for a seventy-two minute period. Differences in rate of feed intake among diets were evaluated using Cox Regression Analysis. This attractability assay required only small amounts of ingredients and incorporated ingredients into a bland feed, which significantly reduces the influence from other ingredients or compound in the pellets. All of the test protein ingredients, especially SqM, in the feeds significantly increased the feed consumption rate. The diet containing SqM was consumed at a significantly higher rate than those containing casein and FM but not FPH. FPH and CN containing diets were not significantly different but consumed at a higher rate than the diet containing FM. Results of these trials indicate that the presence of certain ingredients can increase feed intake, thereby increasing nutrient availability of the diets. This reported method to determine consumption of diets containing certain ingredients can be considered as a valid method to estimate attractability.
摘要:
描述了一种简单的生物测定法,该生物测定法定量饲料摄入量,以估算太平洋白虾凡纳滨对虾中含有不同成分的饲料的相对吸引力。鱼粉(FM),鱼蛋白水解物(FPH),在相同的日粮水平上评估了鱿鱼粉(SqM)和酪蛋白(CN)对凡纳滨对虾采食率的相对影响。清淡的饮食含有92%的全麦谷物粉,具有已知低吸引力的6%硅藻土和2%藻酸盐用作标准对照或基础饮食。在饲喂时将成分以3%的水平添加到温和的基础对照饮食中。将虾储存在循环水产养殖系统中的80升玻璃罐中(每个罐n=20)。坦克被随机分配到五种饮食治疗中的一种(3个坦克/治疗)。测量每种饲料的吸引力的实验在5天的时间内在0900小时和1330小时每天进行两次。对于每个实验,40个饲料颗粒(约向每个罐提供对应于指定处理的1g)。要计算采食率,每个罐中剩余的颗粒以6分钟的间隔计数72分钟。使用Cox回归分析评估了饮食之间的采食率差异。这种吸引力测定只需要少量的成分和掺入到清淡的饲料中的成分,这显著降低了来自颗粒中的其他成分或化合物的影响。所有的测试蛋白质成分,尤其是SqM,在饲料中显著提高了饲料的消耗率。含有SqM的饮食的消耗率明显高于含有酪蛋白和FM但不含FPH的饮食。含FPH和CN的饮食没有显着差异,但消耗速度高于含FM的饮食。这些试验的结果表明,某些成分的存在可以增加饲料摄入量,从而增加饮食的营养可用性。这种报告的确定含有某些成分的饮食消耗的方法可以被认为是估计吸引力的有效方法。