This study examined effects of dietary protein sources and levels on intestinal health of 21 to 35 d-old weaned piglets fed antibiotics-free diets. A total of 150 weaned piglets(21 d of age) were allotted to 5 dietary treatment groups. Diets were formulated, based on corn-soybean meal, with different protein sources(fish meal and soy protein concentrate) to provide different dietary CP levels. Piglets within 5 dietary treatments were fed diets as follows, respectively: 1) control diet of 17% CP(control); 2) 19% CP diets formulated with more soy protein concentrate(SPC19); 3) fish meal(FM19); 4) 23.7% CP diets formulated with more soy protein concentrate(SPC23); 5) fish meal(FM23). The results showed that piglets from control group had higher ADG and lower incidence of diarrhea compared with those of other groups(P < 0.05). The incidence of diarrhea of piglets in FM19 group was lower than those from SPC23 group and FM23 group(P < 0.05). With the higher CP levels, villous height and villous height to crypt depth ratio of piglets in the duodenum and jejunum were decreased(P < 0.05), but crypt depth was increased(P < 0.05). Comparing control group and other groups, we found the expression of inflammatory cytokines interleukin-1β(IL-1β) and interferon-γ(IFN-γ) were increased(P < 0.05) in the jejunum and colon of piglets, as did cystic fibrosis transmembrane conductance regulators(CFTR) in the distal colon. The relative transcript abundance of Zonula occludens-1(ZO-1) in the jejunum, and occludin in the jejunum and ileum of piglets fed 23.7% CP diets were reduced compared with those fed control diet(P < 0.05). In conclusion, the 17% CP diet without in-feed antibiotics helped improve growth performance and relief of diarrhea of 21 to 35 d-old weaned piglets. Dietary CP level, rather than its source(either fish meal or soy protein concentrate), has more significant impacts on the growth performance and intestinal health of 21 to 35 d-old weaned piglets when fed antibiotics-free diets.
Yunpeng WuZongyong JiangChuntian ZhengLi WangCui ZhuXuefen YangXiaolu WenXianyong Ma
本文旨在研究断奶仔猪血清氨基酸含量和生化参数对不同蛋白质水平饲粮的动态响应。选取18头35日龄平均体重为(10.0±1.0)kg三元(杜×长×大)杂交断奶阉公猪,随机分为3组(每组6个重复,每个重复1头猪),并分别饲喂蛋白质水平为14%(LP)、17%(M P)和20%(HP)的饲粮。每头试验猪安装颈动脉血管插管,术后恢复5 d,于第6~8天正式试验。每天采食前,采食后30、60、120、180和300 min连续采集颈动脉血液10 m L,分别检测血清游离氨基酸含量和相关生化指标。结果表明:不同蛋白质水平饲粮对仔猪采食前后各时间点血清中游离赖氨酸(Lys)、蛋氨酸(Met)、苏氨酸(Thr)、色氨酸(Trp)、天冬氨酸(Asp)、丝氨酸(Ser)、甘氨酸(Gly)和谷氨酸(Glu)含量影响均不显著(P>0.05)。但血清中Lys、Met、Thr、Trp含量随饲粮蛋白质水平的降低而升高。HP组仔猪采食前后各时间点血清游离氨基酸[缬氨酸(Val)、异亮氨酸(Ile)、精氨酸(Arg)]和尿素含量显著高于MP和LP组(P<0.05)。采食后120~300 min HP组血清Leu含量显著高于LP组(P<0.05)。采食后各时间点LP组血清总蛋白(TP)、白蛋白(ALB)含量及碱性磷酸酶(ALP)活性显著高于HP和MP组(P<0.05)。各组仔猪采食后血清游离氨基酸含量和相关生化指标随时间变化无显著差异(P>0.05)。综上所述,断奶仔猪饲粮在平衡4种氨基酸(Lys、Met、Thr、Trp)的基础上,常规饲粮蛋白质水平降低3个百分点,血清游离Val、Ile、Arg含量显著降低,但对血清中其他氨基酸和相关生化指标无显著影响;而蛋白质水平降低6个百分点,血清游离Leu和尿素含量显著降低,TP、ALB含量和ALP活性显著升高,但对血清中其他氨基酸和相关生化指标的影响不显著。
