Rendered products from the meat industry provide quality proteins in diets for companion animals. These proteins are exposed to extreme temperatures during processing leading to the potential for decreased diet digestibility and subsequent growth performance. While this would impact production efficiency in livestock species, oxidized ingredients in companion animal diets may impact health and longevity. The objective of this study was to determine the extent to which a feedstuff containing oxidized protein and lipid affect diet digestibility, growth performance, and oxidative stress in nursery pigs. A total of 56 male pigs (21 d of age, initial body weight 5.51 ± 0.65 kg) were randomly assigned to one of the four dietary treatments in a 2 × 2 factorial arrangement with two levels of heat and two levels of antioxidant (AOX). Diets were fed for 35 d and growth performance was measured, while total tract digestibility and nitrogen (N) balance was determined during the trial on day 18–20. Blood plasma was collected on day 34 and jejunum, colon, and liver tissues were collected on day 35 to analyze for markers of oxidative stress. Average daily feed intake (ADFI) was reduced in pigs fed diets without AOXs (P = 0.02). Additionally, pigs consuming diets containing heated chicken byproduct (CBP) meal had decreased gain:feed (GF; P = 0.02). There was an interaction between heat and AOX (P = 0.02) where heating CBP reduced N digestibility in the presence of an AOX but did not have an impact when AOX was not present. The removal of AOX resulted in reduced GE digestibility (P < 0.01). Dry matter (P < 0.01), ash (P < 0.01), and protein (P < 0.01) digestibility were reduced (P < 0.01) as a result of heating. Furthermore, heating (P =0.01) as well as absence of AOX (P =0.01) resulted in reduced digestible energy. No difference was detected in N retention suggesting that oxidation reduces digestibility but has no impact on N utilization. This is supported by the fact that systemic oxidative stress was not consistently affected by heating or AOX inclusion. These results suggest that feeding pigs CBP containing oxidized proteins and lipids did not induce oxidative stress. However, feeding young pigs CBP containing oxidized proteins and lipids did result in reduced energy and nutrient digestibility as well as negatively affected feed efficiency. Because CBP is commonly used in companion animal diets, it is reasonable to revisit their impacts on those species.

中文翻译：

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饲喂氧化鸡副产品粉对保育猪消化率的影响大于生产性能和氧化状态

肉类工业的提炼产品为伴侣动物的饮食提供优质蛋白质。这些蛋白质在加工过程中暴露在极端温度下，可能会降低日粮消化率和随后的生长性能。虽然这会影响牲畜物种的生产效率，但伴侣动物饮食中的氧化成分可能会影响健康和寿命。本研究的目的是确定含有氧化蛋白质和脂质的饲料对保育猪日粮消化率、生长性能和氧化应激的影响程度。总共 56 头公猪（21 日龄，初始体重 5.51 ± 0.65 kg）被随机分配到四种日粮处理中的一种，采用 2×2 因子排列，两个水平的热量和两个水平的抗氧化剂 (AOX) . 饲喂 35 天的日粮并测量生长性能，同时在第 18-20 天的试验期间测定总消化道消化率和氮 (N) 平衡。在第 34 天收集血浆，在第 35 天收集空肠、结肠和肝组织，以分析氧化应激的标志物。饲喂不含 AOX 的日粮的猪平均每日采食量 (ADFI) 降低 (P = 0.02)。此外，食用含有加热鸡副产品 (CBP) 膳食的猪的增重：饲料 (GF; P = 0.02)。加热和 AOX 之间存在相互作用（P = 0.02），其中加热 CBP 在存在 AOX 的情况下会降低 N 消化率，但在不存在 AOX 时不会产生影响。AOX 的去除导致 GE 消化率降低（P < 0.01）。干物质 (P < 0.01)、灰分 (P < 0.01) 和蛋白质 (P < 0. 01) 加热导致消化率降低 (P < 0.01)。此外，加热 (P = 0.01) 以及没有 AOX (P = 0.01) 导致可消化能降低。在氮保留方面没有检测到差异，表明氧化降低了消化率，但对氮的利用没有影响。这得到以下事实的支持：系统性氧化应激并未始终受到加热或 AOX 包含的影响。这些结果表明，饲喂含有氧化蛋白质和脂质的猪 CBP 不会诱导氧化应激。然而，饲喂含有氧化蛋白质和脂质的幼猪 CBP 确实会降低能量和养分的消化率，并对饲料效率产生负面影响。由于 CBP 常用于伴侣动物饮食，因此重新审视其对这些物种的影响是合理的。