Omnivores versus carnivores: Can higher levels of pulse starch be tolerated in a wider range of species than corn?

肉食性物种对碳水化合物的耐受性很差，而杂食性动物往往耐受更高的饮食水平。然而，由于蛋白质通常是动物饲料中最昂贵的部分，因此最大限度地增加碳水化合物的量会产生更经济的饲料。为了平衡这些相互矛盾的需求，该提案旨在探索与更标准的碳水化合物来源如玉米淀粉相比，使用可缓慢消化的豆类淀粉（豌豆、扁豆、蚕豆）。与玉米淀粉的快速消化性和较高的血糖指数相比，豆类淀粉的较慢消化性被假设产生较低的血糖指数，较低的胰岛素水平和较少的不良健康影响。我们预测，与杂食性物种相比，使用豆类淀粉的健康益处在肉食性物种中将特别明显。这一预测是基于以下事实：食肉物种往往具有较低的淀粉酶，并且预计从肠道和从血流进入肝脏或肌肉的处置中转运葡萄糖的程度较低。食肉物种也被预测产生更高水平的反应性葡萄糖代谢产物甲基乙二醛，由于较低水平的关键糖酵解酶，这反过来会导致更高水平的氧化应激和炎症相比，杂食动物。为了研究这些假设，我们将比较肉食性物种，猫和虹鳟鱼，杂食性物种，狗和罗非鱼的消化碳水化合物的能力，血糖反应单一喂养和长期喂养试验中的健康影响。此外，由于所有这些物种的饲料，无论是宠物还是水产养殖，通常都以干燥的颗粒形式出售，因此在实现豆类的全部市场潜力之前，需要进一步了解挤压条件如何影响淀粉结构和消化率。有了这些新的、科学支持的豆类营销信息，我们的行业合作伙伴将能够打开新的水产养殖市场，并扩大现有的宠物食品市场，不仅在北美，而且在欧洲和亚洲。

Carbohydrates are poorly tolerated in carnivorous species, while omnivores tend to tolerate higher dietary levels. However, since protein is often the costliest portion of an animal feed, maximizing the amount of carbohydrate produces a more economical feed. In order to balance these contradictory needs, this proposal aims to explore the use of slowly digestible pulse starches (pea, lentil, faba bean) compared to a more standard carbohydrate source such as corn starch. The slower digestibility of pulse starches are hypothesized to produce lower glycemic index, lower insulin levels and fewer adverse health effects compared to the rapid digestibility and higher glycemic index of corn starch. We predict that the health benefits of using pulse starches will be particularly pronounced in carnivorous species compared to omnivorous species. This prediction is based on the fact that carnivorous species tend to have lower amylase and are predicted to transport glucose to a lesser extent, both from the intestine and disposal into liver or muscle from the bloodstream. Carnivorous species are also predicted to produce higher levels of the reactive glucose metabolite, methylglyoxal, due to lower levels of key glycolytic enzymes which will in turn lead to higher levels of oxidative stress and inflammation compared to omnivores. In order to investigate these hypotheses, we will compare the carnivorous species, cat and rainbow trout, to omnivorous species, dog and tilapia in their ability to digest carbohydrate, glycemic responses to single feedings and health effects in longer-term feeding trials. Furthermore, since feeds for all of these species, both pet and aquaculture, are usually sold in a dry pelleted form, further understanding of how extrusion conditions affect starch structure and digestibility is needed before the full marketing potential of pulses can be realized. With this new, scientifically-supported information for the marketing of pulses, our industry partners will be able open new aquaculture markets and expand existing pet food markets, not only in North America, but also in Europe and Asia.