Regassa A, Kiarie E, Sands J S, Walsh M C, Kim W K, Nyachoti C M
Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada R3T 2N2.
Department of Animal Biosciences, University of Guelph, Guelph, ON, N1G 2W1
Poult Sci. 2017 Feb 1;96(2):388-396. doi: 10.3382/ps/pew235. Epub 2016 Jul 21.
Effects of substituting cornstarch with D-xylose on growth performance, nutrients digestibility, serum metabolites, and expression of select hepatic genes involved in glucose and lipid metabolism were investigated in broiler chickens. A total of 360 one-day-old male Ross chicks were fed 3 diets (n = 24; 5 chicks/cage) for 21 days. A control corn-soybean meal-based diet with 25% cornstarch was formulated to meet specifications. Two additional diets were formulated by substituting cornstarch with 5 or 15% D-xylose w/w. Growth performance and digestibility by index method were determined in 12 replicate cages. Birds in these replicates had free access to feed and water, the BW and feed intake (FI) were monitored weekly and the excreta samples were collected on d 18 to 20. The other 12 replicates were used for blood and liver sampling by serial slaughter. On d 18, baseline (t0) birds were sampled following a 12 h overnight fasting and birds allowed 30 min access to the feed; samples were subsequently taken at 60, 120, 180, 240, and 300 min post feeding. Serum metabolites (glucose, xylose, and insulin) were assayed at all time points, whereas expression of hepatic transcripts was evaluated at zero, 180 and 300 min. Xylose linearly reduced (P < 0.05) FI, BWG, gross energy digestibility, and feed conversion ratio (FCR) but increased (P < 0.05) serum xylose level. Serum glucose and insulin levels were higher (P < 0.05) in the post-fed state compared with baseline, irrespective of treatments. There was an interaction (P < 0.05) between diet and sampling time on the expression of hepatic genes. At t0, xylose linearly increased (P < 0.05) the expression of pyruvate carboxylase, Acetyl Co-A acethyltransferase 2 (ACAT2), and glucose transporter 2. Xylose linearly reduced (P < 0.05) the expression of ACAT2 at 300 min post feeding. In conclusion, 5% or more xylose reduced growth performance and utilization of nutrients linked to hepatic enzymes and transcription factors involved in glucose and lipid metabolism.
研究了用D-木糖替代玉米淀粉对肉鸡生长性能、养分消化率、血清代谢物以及参与葡萄糖和脂质代谢的特定肝脏基因表达的影响。总共360只1日龄雄性罗斯雏鸡被饲喂3种日粮（n = 24；每笼5只鸡），为期21天。配制了一种以玉米-豆粕为基础的对照日粮，其中含有25%的玉米淀粉，以满足规格要求。另外两种日粮是通过用5%或15%（w/w）的D-木糖替代玉米淀粉配制而成。通过指数法测定了12个重复笼中的生长性能和消化率。这些重复笼中的鸡可以自由采食和饮水，每周监测体重（BW）和采食量（FI），并在第18至20天收集排泄物样本。另外12个重复用于通过连续屠宰进行血液和肝脏采样。在第18天，基线（t0）鸡在禁食12小时过夜后进行采样，然后让鸡采食30分钟；随后在采食后60、120、180、240和300分钟采集样本。在所有时间点测定血清代谢物（葡萄糖、木糖和胰岛素），而在0、180和300分钟评估肝脏转录本的表达。木糖线性降低（P < 0.05）采食量、体重增重、总能消化率和饲料转化率（FCR），但提高（P < 0.05）血清木糖水平。无论处理如何，采食后状态下的血清葡萄糖和胰岛素水平均高于基线（P < 0.05）。日粮和采样时间对肝脏基因表达存在交互作用（P < 0.05）。在t0时，木糖线性增加（P < 0.05）丙酮酸羧化酶、乙酰辅酶A乙酰转移酶2（ACAT2）和葡萄糖转运蛋白2的表达。在采食后300分钟，木糖线性降低（P < 0.05）ACAT2的表达。总之，5%或更多的木糖会降低生长性能以及与参与葡萄糖和脂质代谢的肝脏酶和转录因子相关的养分利用率。
