Graded methionine dietary inclusions influence growth performance and apparent ileal amino acid digestibility coefficients and disappearance rates in broiler chickens

Graded quantities of 1.38,2.76 and 4.14 g/kg L-methionine were included in a control diet formulated to contain 3.07 g/kg digestible methionine.Each of the 4 dietary treatments was offered to 6 replicate cages(initially 8 birds per cage)from 1 to 21 d postehatch.The parameters assessed included growth performance,nutrient utilisation(apparent metabolisable energy[AME],AME:GE ratios,N retention,Ncorrected apparent metabolisable energy[AMEn]),apparent digestibility coefficients and disappearance rates of amino acids in the distal ileum.They also included free amino concentrations in systemic plasma(brachial vein)at 20 d postehatch and in hepatic tissue at 14 and 21 d postehatch.Graded L-methionine inclusions quadratically influenced weight gain(r=0.688;P=0.001)and FCR(r=0.780;P<0.001).It may be deduced from the quadratic regressions that 3.43 g/kg L-methionine supported maximum weight gain of 1,036 g/kg and 3.50 g/kg L-methionine minimum FCR of 1.193,from 1 to 21 d postehatch.The control diet contained specified levels of 3.07 g/kg digestible methionine and 13.0 g/kg digestible lysine.Thus,an inclusion of 3.465 g/kg L-methionine corresponded to a total of 6.535 g/kg methionine or a methionine-to-lysine ratio of 50.3,which is higher than standard recommendations.The implications of this and other outcomes of the present study are reported and discussed.     

液态蛋氨酸对鲤鱼生长性能的影响

[目的]研究液态蛋氨酸对鲤鱼生长性能的影响。[方法]试验采用单因素随机分组试验设计,选取75条体重相近且健康的成年鲤鱼,随机分成5个处理组,每个处理组3个重复,每个重复5条鲤鱼,试验期为31d。基础日粮设计为蛋氨酸缺乏,而其他营养素均满足鲤鱼需要。各处理水平分别为：对照组、DLM（0．10％）、液体MHA．FA（0．12％、0．18％、0．24％）。[结果]添加液体MHA-FA源显著提高了鲤鱼的增重率,降低了饲料系数。提高了蛋白效率（P〈0．05）。[结论]向鲤鱼饲料中添加0．18％的液体MHA-FA之后,鲤鱼的生长性能最好,饲料利用效率最高。     

5～110kg猪可消化氢基酸需要量与平衡

综述了猪饲料氨基酸消化率的测定方法;综合了80年代以来积累的大量猪饲料氨基酸消化率测定数据;对近20多年的70次猪氨基酸需要量试验研究资料进行分析、处理;推荐了5～10、10～20、20～50、50～110kg猪可消化赖氨酸、蛋氡酸+胱氨酸、苏氨酸和色氨酸需要量及其平衡关系。同时,论述了猪“理想蛋白质”的氨基酸平衡模式。     

大豆籽粒不同发育时期基因表达谱分析

以花后15DAF(开花后天数)的大豆籽粒作为对照,通过Solexa高通量测序方法对花后35DAF、55DAF和65DAF的大豆籽粒进行转录水平上的检测,并结合GO功能注释和pathway分析,共有差异表达unigene为9 905个,其中调控脂肪酸合成途径的显著差异表达基因12个,蛋氨酸代谢途径关键基因6个。以55DAF的cDNA为样本,荧光定量PCR检测了12个差异表达基因,其结果可与测序结果互为印证。     

不同水平的蛋氨酸铜对奶牛瘤胃内环境及日粮表观消化率的影响

[目的]为探讨日粮中添加不同水平的蛋氨酸铜对奶牛瘤胃内环境及日粮表观消化率的影响。[方法]在日粮中分别添加0 mg/kg、18 mg/kg、27 mg/kg DM的蛋氨酸铜,采用3×3拉丁方试验设计,试验动物为3头装有永久性瘤胃瘘管的中国荷斯坦奶牛,平均体重500 kg,均处于干奶期,试验基础日粮由混合精料、羊草和玉米全株青贮组成,精粗比为30∶70。[结果]表明,日粮添加蛋氨酸铜有提高瘤胃pH值、NH3-N的趋势;但对各时间点的瘤胃液pH值、NH3-N没有显著影响（P〉0.05）;添加27 mg/kg DM的蛋氨酸铜显著提高了日粮各个营养物质的表观消化率。[结论]添加蛋氨酸铜不影响奶牛瘤胃的内环境,添加27 mg/kgDM的蛋氨酸铜可以提高日粮的表观消化率。     

Effect of ruminally protected Methionine on the productive and reproductive performance of grazing <Emphasis Type="Italic">Bos indicus</Emphasis> heifers raised in the humid tropics of Costa Rica

With the objective of evaluating the effect of methionine supplementation prior to a breeding program, thirty one heifers (Bos taurus x Bos indicus) were used averaging 386  ±  29 days of age and a mean body weight of 402.6  ±  28 kg. Fifteen of the animals received a supplement (SG) during 45 days with molasses-urea mixture (2 kg molasses + 407 g urea/head/day), plus 10 g of ruminally protected methionine. The other sixteen heifers did not receive supplement (CG). Fecal and pastures samples were collected to assess dry herbage intake and digestibility. Serial ultrasound measurements from the ovary were performed in both groups to evaluate follicular dynamics. The heifers were categorized according to their follicular size and presence of a CL. Forage intake and dry matter digestibility were reduced (P  <  0.05) and body condition tended to improve (P  =  0.07) in the supplemented heifers, however, total intake, final weight, daily gain and dorsal back fat were not affected. After the supplementation period, the percentage of females in the categories < 3 mm and 3 to < 6 mm, was greater (P  <  0.05) in CG (25% and 43.7%) that in SG (0% and 26.6%) but in the follicle category of ≥  9 mm, the percentage of animals was 60% in SG and 18.8% in CG (P  <  0.05). The percentage of ovulation for the SG and CG was 86.7% and 62.5%, respectively (P  <  0.05). The combination of supplementation with methionine-urea and molasses at the end of the dry season and the anticipated onset of the rainy season favored the establishment of ovarian activity and follicular dynamics.