Regulation of muscular glutamate metabolism by high‐protein diet in broiler chicks

The major taste active component, glutamate (Glu), improves the taste of meat. In this study, we investigated the effect of a short‐term high‐protein (HCP) diet on the intramuscular free Glu content to improve the taste of meat. Furthermore, we elucidated how the muscle free Glu content was controlled by the HCP diet. Chicks (14 days old) were fed the control diet or HCP diet for 10 days. Plasma and muscle free amino acid concentrations, and activity and messenger RNA (mRNA) expression of muscle enzymes related to Glu metabolism were determined. Muscle free Glu content was increased (P < 0.01) by 51%. Activity and mRNA expression of glutaminase (GA), which is one of the major Glu‐related enzymes, were significantly decreased (P < 0.05) in the HCP group because of feedback inhibition. The mRNA expression of lysine α‐ketoglutarate reductase (LKR), which is the enzyme involved in lysine (Lys) degradation and Glu production, was significantly increased (P < 0.001) in the HCP group. These results suggest that short‐term dietary HCP feeding is an effective treatment for improving the taste of meat. Furthermore, our results suggest that the free Glu content in muscle is regulated by GA and LKR.     

高粱替代不同水平玉米对育肥猪生长性能、胴体性状及肉品质的影响

本试验旨在研究高粱替代不同水平玉米对育肥猪生长性能、胴体性状及肉品质的影响。选择160头体重[(48.93±3.01)kg]相近的健康杜×长×大三元育肥猪,随机分为4组,即对照组(基础饲粮)、30%替代组(用高粱替代基础饲粮中30%的玉米)、65%替代组(用高粱替代基础饲粮中65%的玉米)和100%替代组(用高粱替代基础饲粮中100%的玉米),每组4个重复,每个重复10头猪(5头去势公猪、5头母猪)。试验期60d。结果显示:1)高粱替代不同水平玉米对育肥猪的料重比、平均日采食量无显著影响(P>0.05);与对照组相比,100%替代组平均日增重降低3.4%(P<0.05)。2)与对照组相比,30%替代组、65%替代组和100%替代组背膘厚度分别提高3.0%、5.2%和4.3%(P<0.05)。3)与对照组相比,30%替代组、65%替代组和100%替代组背最长肌pH45min分别提高0.5%、1.0%和0.4%(P<0.05);65%替代组和100%替代组背最长肌中粗脂肪含量分别提高8.7%和11.3%(P<0.05)。4)与对照组相比,100%替代组背最长肌中谷氨酸和苏氨酸含量分别降低2.5%和11.7%(P<0.05)。5)与对照组相比,100%替代组背最长肌中油酸、反式油酸、花生酸和花生四烯酸含量分别提高15.3%、39.6%、56.8%和52.4%(P<0.05);65%替代组背最长肌中反式油酸、花生酸、二十碳三烯酸和花生四烯酸分别提高37.9%、77.15%、72.2%和53.2%(P<0.05)。综上所述,本试验条件下,用高粱替代饲粮中部分玉米不仅对育肥猪的生长性能无负面影响,还能够通过提高肌肉中部分不饱脂肪酸含量而改善肉品质。     

Effects of amino acids supplementation in low crude protein diets on growth performance,carcass traits and serum parameters in finishing gilts

This study investigated the effects of amino acids (AA) supplementation in low crude protein (CP) diets on growth performance and carcass characteristics in finishing gilts. One hundred and eighty gilts (59.1 ± 5.1 kg) were randomly allotted to one of five diets which consisted of a high CP (15.6%) diet or four low CP (11.6%) diets for 50 days. The low CP diets were supplemented with lysine + threonine + methionine (LCM), LCM + tryptophan (LCT), LCT + valine (LCV) or LCV + isoleucine (LCI), respectively. Gilts were housed at six pigs per pen with six pens per treatment. At the end of the 50‐day experiment, 30 gilts (one pig per pen) with average body weight (BW) of 98 kg were killed to evaluate carcass traits. The pigs fed the diet supplemented with LCV obtained the highest average daily gain (ADG), which was higher than those of pigs fed the diet supplemented with LCM (P < 0.05). Dietary supplementation with tryptophan, valine and isoleucine in low CP diets increased ADG (linear and quadratic effect, P < 0.05), serum levels of valine (quadratic effect, P < 0.05) and isoleucine (linear and quadratic effect, P < 0.05) and immunoglobulin G (IgG) and IgA (linear and quadratic effect, P < 0.05) in finishing gilts. © 2016 Japanese Society of Animal Science     

支链氨基酸对泌乳母猪的营养研究进展

支链氨基酸 (BCAA)是畜禽的必需氨基酸 ,有着重要的营养生理作用 ,对泌乳母猪尤其显著。本文着重阐述BCAA　　对泌乳母猪生产性能方面的影响 ,泌乳母猪对BCAA的需要量及缬氨酸需要量研究模式。     

黄羽肉种鸡对棉籽粕、菜籽粕、禽副粉氨基酸消化率的比较研究

本试验对黄羽和爱拔益加肉种鸡在棉籽粕、菜籽粕、禽副粉3种饲料原料氨基酸消化率进行了比较研究。试验结果表明 ,经内源校正后 ,黄羽肉鸡对棉籽粕、禽副粉的总真氨基酸消化率高于爱拔益加肉鸡 ,对菜籽粕的总真氨基酸消化率和爱拔益加肉鸡十分接近。就单个饲料原料的总真氨基酸消化率而言 ,黄羽肉鸡对禽副粉的消化率最高 ,其次是菜粕和棉粕 ;爱拔益加肉鸡显示相同的规律 ;虽然爱拔益加肉鸡和黄羽肉鸡在谷氨基、酪氨酸、赖氨酸、色氨酸的内源排泄量差异达到显著水平 (P<0.05,P<0.01),两种肉鸡在内源总氨基酸排泄量之间不存在显著差异 (P<0.05)。     

饲粮添加氨基酸锌对育肥羊屠宰性能、肉品质及血液和组织中微量元素含量的影响

本试验旨在研究氨基酸锌对育肥羊屠宰性能、肉品质及血液和组织中微量元素含量的影响.选择4月龄、体重为(29.00±0.61)kg的健康滩湖杂F1代公羊48只,随机分为4组,每组12只.对照组饲粮锌含量为52.80 mg/kg(硫酸锌),其中不含硫酸锌的锌含量为18.02 mg/kg,试验Ⅰ组、试验Ⅱ组、试验Ⅲ组试验饲粮锌...     

合成氨基酸对肉鸡肠道功能的改善作用

鸡球虫病、坏死性肠炎等肠道感染可能对消化道内源性氨基酸损失产生较大影响.虽然对这一课题的了解不多,但相关文献报道了这些疾病对氨基酸表观回肠消化率的影响.在确定肠内氨基酸流动时必须考虑多种因素,包括肉鸡的年龄、是否有病原体、肠内氨基酸代谢等.胃肠道和肝脏共同承担向外周血释放氨基酸的任务,这些氨基酸是支持蛋白质合成所必需的...     

不同饲养水平下蛋白质与氨基酸在阉牛小肠内消化率的研究

选择6头体重500～600kg ,安装有瘤胃、十二指肠前端和回肠末端瘘管的阉牛 ,分3期饲喂以玉米、棉籽饼和氨化稻草为基础原料配合的3种不同饲养水平的日粮 ,测定十二指肠、回肠和粪便中的粗蛋白质和各种必需氨基酸流量 ,计算粗蛋白质、真蛋白、总必需氨基酸、总非必需氨基酸和各种必需氨基酸在小肠内的表观消化率。结果显示 :随着饲养水平的下降 ,粗蛋白质、真蛋白、总必需氨基酸、总非必需氨基酸和亮氨酸、蛋氨酸、色氨酸、缬氨酸、胱氨酸的小肠表观消化率逐渐降低(P<0.05)。在每种饲养水平下 ,真蛋白的小肠表观消化率均大于粗蛋白质 (P<0.05) ;各种必需氨基酸的小肠表观消化率均有差异 ,精氨酸和亮氨酸的小肠消化率通常比真蛋白高 ,色氨酸和苏氨酸的小肠消化率比真蛋白低 ,但各种必需氨基酸的小肠表观消化率并没有一致的大小顺序。与日粮相比 ,十二指肠中的必需氨基酸组成发生了较大的变化 ;与回肠流量相比 ,粪便中的必需氨基酸排泄量也发生了较大的变化。