將30頭豬（42日齡，初始體重（BW）12.49±1.45 kg）隨機分配到三種氧化蛋白水平的日糧處理組中的一組。以噴霧干燥的牛血漿作為蛋白質來源，分別為不加熱、45℃加熱4 d和100℃加熱3 d。飼喂19 d，測定生長性能。收集血漿（0和18d）、空腸、結腸和肝臟組織（19 d），分析氧化應激標志物（如蛋白氧化、脂質氧化、DNA損傷和谷胱甘肽過氧化物酶活性）。
試驗數據顯示，平均日增重（ADG，P < 0.01）和平均日采食量（ADFI，P < 0.01）與蛋白質氧化水平呈線性正相關，但飼料轉化率（GF）無影響。此外，日糧中蛋白質（P = 0.03）和脂肪（P < 0.01）的消化率隨蛋白質氧化率的增加而降低。隱窩深度與日糧蛋白氧化水平呈線性正相關（P = 0.02）。與未加熱或加熱至100℃的血漿喂養的豬只相比，飼喂加熱到45℃的血漿蛋白組豬只在肝臟樣本中觀察到脂質氧化程度有增加的趨勢（P = 0.09）。空腸DNA損傷與日糧蛋白氧化水平有線性關系的趨勢（P = 0.07）。
Impact of dietary oxidized protein on oxidative status and performance in growing pigs
Rendered products from the meat industry can provide economical quality sources of proteins to the animal and feed industry. Similar to lipids, rendered proteins are susceptible to oxidation, yet the stability of these proteins is unclear. In addition, interest in understanding how oxidative stress can impact efficiency in production animals is increasing. Recent studies show that consumption of oxidized lipids can lead to a change in the oxidative status of the animal as well as decreases in production efficiency. To date, little is known about how consumption of oxidized proteins impacts oxidative status and growth performance. The objectives of this study were to determine if feeding diets high in oxidized protein to growing pigs would: 1) impact growth performance and 2) induce oxidative stress. Thirty pigs (42 d old; initial body weight [BW] 12.49 ± 1.45 kg) were randomly assigned to one of three dietary treatments with increasing levels of oxidized protein. Spray-dried bovine plasma was used as the protein source and was either unheated upon arrival, heated at 45 °C for 4 d, or heated at 100 °C for 3 d. Diets were fed for 19 d and growth performance was measured. Blood plasma (days 0 and 18), jejunum, colon, and liver tissues (day 19) were collected to analyze for markers of oxidative stress (e.g., protein oxidation, lipid oxidation, DNA damage, and glutathione peroxidase activity). Average daily gain (ADG;P < 0.01) and average daily feed intake (ADFI;P < 0.01) had a positive linear relationship to increased protein oxidation, but there was no effect on gain to feed ratio. Furthermore, protein (P = 0.03) and fat (P < 0.01) digestibility were reduced with increased protein oxidation in the diet. Crypt depth showed a positive linear relationship with dietary protein oxidation levels (P = 0.02). A trend was observed in liver samples where pigs fed the plasma heated to 45 °C had increased lipid oxidation compared with pigs fed the plasma either unheated or heated to 100 °C (P = 0.09). DNA damage in the jejunum tended to have a linear relationship with the dietary protein oxidation level (P = 0.07). Even though results suggest dietary oxidized protein did not induce oxidative stress during short-term feeding, differences in performance, gut morphology, and digestibility are likely a result of reduced protein availability.