Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA.
Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907, USA.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skad415.
Poultry meal, a rendered byproduct of poultry slaughter, is a valuable protein source in swine and poultry diets because of its highly digestible protein content and balanced amino acid (AA) profile. Rendering of poultry meal may reduce its AA digestibility because of heat damage to the byproduct. The effect of heat damage on AA digestibility of poultry meal may be different between broiler chickens and growing pigs. For this reason, the objective of this study was to determine the effect of autoclaving time on standardized ileal digestibility (SID) of AA in poultry meal fed to broiler chickens and growing pigs. Poultry meal from the same batch was autoclaved at 134 °C for 0, 30, 60, 90, 120, 150, or 180 min to produce seven heat-treated samples. Eight experimental diets were formulated. Poultry meal served as the sole source of nitrogen in seven diets that each contained one of the heat-treated byproducts and a nitrogen-free diet was formulated to assess basal ileal endogenous losses of AA. In experiment 1, 656 male broiler chickens (initial body weight = 719 ± 97 g) at day 18 post hatching were assigned to the eight diets in a randomized complete block design with body weight as a blocking factor. On day 23, birds were euthanized by CO2 asphyxiation and dissected for the collection of ileal digesta. In experiment 2, 16 barrows (initial body weight = 23.3 ± 0.7 kg) were surgically fitted with T-cannulas at the distal ileum and allotted to a duplicate 8 × 4 incomplete Latin square design with the eight diets and four periods. Each experimental period consisted of 5-day adaptation and 2-day ileal digesta collection periods. Data for experiments 1 and 2 were pooled and analyzed as a 2 × 7 factorial treatment arrangement with the effects of species (i.e., pigs and broiler chickens) and autoclaving time (i.e., 0 to 180 min) as the two factors. Increasing autoclaving time decreased SID of nitrogen and all AA in both species, but the decrease in SID values except for leucine was greater (interaction, P < 0.05) or tended to be greater in pigs compared with broiler chickens. Given the species differences in AA utilization response to the severity of heat damage, target species should be considered when using SID of AA values of poultry meal in diet formulation.
家禽肉粉是家禽屠宰的一种加工副产品，由于其高消化蛋白含量和平衡的氨基酸（AA）谱，是猪和家禽饲料中的一种有价值的蛋白质来源。由于副产物受热损坏，肉粉的氨基酸消化率可能会降低。在肉鸡和生长猪中，热损伤对家禽肉粉 AA 消化率的影响可能不同。出于这个原因，本研究的目的是确定在 134°C 下高压处理不同时间对肉鸡和生长猪家禽肉粉氨基酸标准回肠消化率（SID）的影响。将同一批家禽肉粉在 134°C 下高压处理 0、30、60、90、120、150 或 180 分钟，以生产 7 种热处理样品。设计了 8 种实验饲料。7 种饲料中，家禽肉粉作为唯一氮源，每种饲料都含有一种热处理副产品和一种无氮饲料，以评估 AA 的基础回肠内源性损失。在试验 1 中，656 只 18 日龄肉鸡（初始体重=719±97g）按体重随机分为 8 种饲料的完全随机区组设计，体重为区组因素。在第 23 天，鸡通过 CO2 窒息法安乐死并解剖收集回肠内容物。在试验 2 中，16 头阉公猪（初始体重=23.3±0.7kg）在回肠远端进行 T 型套管手术，并按照 8×4 不完全拉丁方设计分配到 8 种饲料和 4 个周期的双重分配。每个实验周期包括 5 天适应期和 2 天回肠内容物收集期。试验 1 和 2 的数据合并分析，采用 2×7 因子处理设计，设物种（即肉鸡和猪）和高压处理时间（0 至 180 分钟）为两个因素。随着高压处理时间的增加，两种动物的氮和所有 AA 的 SID 都降低，但除亮氨酸外，SID 值的降低幅度更大（互作，P<0.05）或有更大的趋势。考虑到 AA 利用对热损伤严重程度的物种差异，在制定家禽肉粉饲料配方时，应考虑目标物种。
