饲粮能量蛋白质水平与赖氨酸水平对5～10周龄扬州鹅体重和屠宰性能的影响

本试验旨在研究饲粮能量蛋白质水平与赖氨酸水平对5 ～10周龄扬州鹅体重和屠宰性能的影响.试验采用3×4二因子试验设计,3个能量蛋白质水平,分别为10.83 MJ/kg+15％(低)、11.29 MJ/kg +16％(中)、11.75 MJ/kg+17％(高),其蛋能比均约为14g/MJ;4个赖氨酸水平,分别为0.65％、0.80％、0.95％和1.10％.首先配制低、中、高能量蛋白质水平的3种基础饲粮,通过在3种基础饲粮基础上添加不同水平的赖氨酸,得到12种试验饲粮.选取384只体重相近的5周龄扬州鹅公鹅,随机分为12组(每组4个重复,每个重复8只),分别饲喂不同的试验饲粮,持续至10周龄末.结果表明:1)饲粮能量蛋白质水平对扬州鹅6、8、10周龄的体重无显著影响(P＞0.05);饲粮赖氨酸水平显著(P＜0.05)或极显著(P＜0.01)影响扬州鹅6、8、10周龄的体重,表现为0.65％赖氨酸组6、8周龄的体重显著(P＜0.05)或极显著(P＜0.01)高于0.80％和1.10％赖氨酸组,10周龄的体重显著高于1.10％赖氨酸组(P＜0.05);饲粮能量蛋白质水平与赖氨酸水平对扬州鹅6周龄的体重有显著的交互作用(P＜0.05),对8、10周龄的体重无显著的交互作用(P＞0.05).2)饲粮能量蛋白质水平显著影响扬州鹅的腹脂率(P＜0.05),表现为低能量蛋白质组显著(P＜0.05)或极显著(P＜0.01)低于中、高能量蛋白质组,但对屠宰率、半净膛率、全净膛率、胸肌率和腿肌率无显著影响(P＞0.05);饲粮赖氨酸水平对扬州鹅的各项屠宰性能指标均无显著影响(P＞0.05);饲粮能量蛋白质水平与赖氨酸水平对扬州鹅的各项屠宰性能指标均无显著的交互作用(P＞0.05).结果提示,饲粮较低的能量蛋白质水平与赖氨酸水平即可满足5 ～10周龄扬州鹅获得最佳体重和屠宰性能的需要,本试验认为5 ～10周龄扬州鹅获得最佳体重和屠宰性能时能量、蛋白质和赖氨酸水平分别为10.83 MJ/kg、15％和0.65％.     

影响棉籽饼有效赖氨酸含量因素的试验研究

本试验模拟螺旋压榨榨油工艺，测定不同蒸炒或加热条件对棉籽饼中自由棉酚（ＦＧ）、还原糖（ＲＳ）、有效赖氨酸（Ａ－Ｌｙｓ）含量的影响。对蒸炒前喷洒硫酸亚铁的作用也做了初步探讨。研究发现，加热强度、棉酚结合、还原糖含量与有效赖氨酸含量之间的相关系数分别为－０．９７６５（Ｐ＜０．０１）、－０．９５１５（Ｐ＜０．０１）、０．４３９５（Ｐ＞０．０５）；蒸炒前添加ＦｅＳＯ４，按Ｆｅ∶ＦＧ摩尔比４．５∶１和９∶１时均极显著地（Ｐ＜０．０１）提高Ａ－Ｌｙｓ含量，两剂量组间无差异（Ｐ＞０．０５）；按４．５∶１添加ＦｅＳＯ４可提高Ａ－Ｌｙｓ７．６０％～３７．７７％，同时表明，ＦＧ含量显著降低。     

Effect of Scavenging and Supplementation of Lysine and Methionine on the Feed Intake,Performance and Carcase Quality of Improved Dual-Purpose Growing Chickens

An experiment was conducted with 192 improved dual-purpose chickens from 4 to 12 weeks of age to evaluate the effects of management system (confinement and scavenging) and amino acid supplementation (with and without lysine and methionine) of a low-protein diet on the feed and nutrient intake, performance and carcase quality of improved chickens. Mean daily dry matter (DM), crude protein and metabolizable energy intakes were higher for the confined birds (65 g, 13.3 g and 966 kJ, respectively) than for the scavenging birds (58 g, 12.0 g and 868 kJ, respectively) (p < 0.001) and higher for the unsupplemented (63.3 g, 13.0 g and 945 kJ, respectively) than for the supplemented birds (59.5 g, 12.2 g and 889 kJ, respectively) (p < 0.001). Mean DM intake was 68.0 and 54.9 g/day for the males and females (p < 0.001), respectively. Average daily weight gains (ADG) were higher for scavenging (26.9 g) than for confined birds (23.9 g) (p < 0.001), higher for supplemented (27.6 g) than for unsupplemented birds (23.2 g) (p < 0.001) and higher for males (27.5 g) than for females (23.3 g) (p < 0.001). Carcase, breast and thigh percentages were higher for supplemented than for unsupplemented birds (p < 0.001) and higher for scavenging than for confined birds (p < 0.001). Abdominal fat percentage was significantly lower for the scavenging treatments compared to the corresponding confined treatments (p < 0.001). Feed conversion ratios (kg feed/kg gain) and feed costs/kg gain were lower for the scavenging than for the confinement treatments, and lower for the supplemented than for the unsupplemented birds (p < 0.001). Supplementation of lysine and methionine in diets that were suboptimal in terms of protein and essential amino acids improved performance and carcase quality and reduced feed costs, in particular of the confined growers.     

日粮赖氨酸与粗蛋白质比例对哺乳母猪繁殖性能的影响

选用分娩日期相近的长×大二元母猪 6 0头 ,按胎次 ,体重随机分为 5个处理 ,分别饲喂不同赖氨酸和粗蛋白质比例 (4 .8,5 .3,5 .8,6 .3和 6 .8gLys/ 10 0gCP)的日粮。试验结果表明 :随着哺乳母猪日粮赖氨酸与粗蛋白质比例的增加 ,母猪体重与背膘厚度损失呈二次曲线下降 (P <0 .0 5 ) ;母猪 2 1日龄的产奶量呈二次曲线变化趋势 (P <0 .0 1) ;哺乳期间窝平均日增重呈二次曲线变化趋势 (P <0 .0 5 ) ;哺乳母猪产后 14d和 2 1d血清尿素氮的浓度呈线性或二次曲线下降 (P <0 .0 1) ,而血清游离赖氨酸的浓度则呈二次曲线变化趋势 (P <0 .0 5 )。在本试验条件下 ,粗蛋白质为 17%时 ,长×大二元哺乳母猪最佳的赖氨酸和粗蛋白质比例为 6 .3g/ 10 0g。     

绿豆乳饮料生产工艺的研究

绿豆乳饮料是由绿豆浆和鲜牛奶按适当比例混合,蛋白质含量丰富,必需氨基酸齐全.由于绿豆中赖氨酸含量高,而赖氨酸是许多食物提供蛋白质的限制性氨基酸,能促进铁在肠道内的吸收,增加高铁离子的形成,对防治缺铁性贫血具有特殊食疗作用.因此,在牛奶成分基础上,添加赖氨酸后,可发挥氨基酸的互补作用,使得该产品具有营养高、成本低、价格低廉及生产工艺简单等优点.本文就其最佳工艺条件进行探讨,并就出现的问题提出解决办法.     

Escherichia coli dihydrodipicolinate synthase and dihydrodipicolinate reductase: kinetic and inhibition studies of two putative herbicide targets

Dihydrodipicolinate synthase (DHDPS) (EC 4.2.1.52) and dihydrodipicolinate reductase (DHDPR) (EC 1.3.1.26) have attracted much recent attention as potential herbicide targets. DHDPS was feedback-inhibited by (S)-lysine; inhibition was reversible and uncompetitive with respect to both (S)-ASA and pyruvate. Homoserine lactone was a reversible non-competitive inhibitor of DHDPS with respect to both (S)-ASA and pyruvate. (R)-Cysteine sulfinic acid and (S)-glutamic acid were reversible uncompetitive inhibitors of DHDPS with respect to (S)-ASA. (S)-Aspartic acid was a reversible mixed-type inhibitor. Dipicolinic acid was a reversible competitive inhibitor of DHDPR with respect to the substrate (4S)-4-hydroxy-2,3,4,5-tetrahydro-(2S)-dipicolinic acid, as was isophthalic acid. Δ³-Tetrahydroisophthalic acid was a moderate inhibitor of both DHDPS and DHDPR. These compounds represent possible leads in the development of novel herbicides. © 1999 Society of Chemical Industry     

不同日粮赖氨酸添加水平对生长猪生产性能的影响

28头体重在10kg左右杜长约三元杂交瘦肉型猪随机分成4组,每组7头.预试则为5d,试验期为3Od.对照组饲喂基础日粮,试验Ⅰ组、Ⅱ组和Ⅲ组日粮是在基础日粮的基础上分别添加0.075%、O.15%和O.225%L-赖氨酸盐酸.试验各组平均日增重(分别为542、561和547g/d)比对照组(465g/d)提高了(P<0.O1)16.6%、26.6%和17.6%.试验各组料重比(分别为2.42、2.40和2.45)比对照组(2.73)分别降低(P<0.01)11.4%、12.l%和10.3%.日粮中添加合适的赖氨酸可以提高生长猪的日增重,减少饲料消耗,但过量添加高水平的赖氨酸将减少猪的增重,增加饲料消耗,提高饲料成本.     

“双低”菜粕配合日粮满足生长肥育猪可消化赖氨酸研究

３６头杜洛克×ＤＩＶ杂交猪随机分为３组,在等能等氮的基础上,以玉米－豆粕日粮为对照组（第１组）,“双低”菜粕替代５０％豆粕为试验组,并分别以总赖氨酸和可消化赖氨酸配合日粮,配合成２组试验日粮（第２组和第３组）。试验结果表明：在试验前期,对照组平均日增重最快,为（７７８±２６．２）ｇ,第３组次之,为（７３５．５±３１．１）ｇ,第２组较慢,为（７１７．３±５０．９）ｇ（Ｐ〉０．０５）。在试验后期,各组