Dry heat popping of amaranth seed might damage some of its essential amino acids

Amaranth was a major crop among the Aztecs. In Mexico the seed is popped and eaten with brown sugar. The crude protein content of the seed is 14±2% but its contents of lysine and tryptophan are 6.2 and 1.6 g/16 g N respectively. We developed a popping method based on a fluid bed system (FBS) whereas the traditional method (TM) is just to pop the seeds manually in a hot plate. Assays carried out were evaluation of racemization of the amaranth protein due to heat treatment, amino acid composition of the raw and heat treated seeds and a biological experiment testing whether leucine was the most limiting amino acid of amaranth protein. Male rats were fed both popped amaranths and roasted amaranth. Parboiled amaranth and casein were controls. The results were: (a) Lys, Arg and Cys were damaged in the heat treated seeds; (b) Asp, Met, Glu, Ala and Phe were racemized in that decreasing order in the seeds popped and roasted by the TM; (c) the estimated net protein retention (NPR) and estimated net protein utilization (NPU) of popped amaranths by either method were not different, but were lower than for the parboiled amaranth. The parboiled amaranth was not different from casein; (d) Leu was not the most limiting amino acid in any of the amaranth seeds tested. After Lys, sulfur amino acids appear to be the next most limiting in severely heat treated amaranth. The FBS seems to be a promising method for popping amaranth at industrial level.     

不同粗蛋白和氨基酸组合日粮对实验兔氮代谢和免疫功能的影响

选用100日龄成年日本大耳白兔36只,随机分为6组（Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ和Ⅵ组）,分别喂以6种不同粗蛋白和氨基酸组合的日粮。其中Ⅰ-Ⅲ组日粮粗蛋白水平为12％,赖氨酸含量分别为0．72％,0．9％和1．08％,含硫氨基酸含量分别为0．52％,0．65％和0．78％：Ⅳ—Ⅵ组日粮粗蛋白水平为16％,赖氨酸与含硫氨基酸组成分别与Ⅰ-Ⅲ组相同。通过饲养试验、氮代谢试验和免疫学实验。观察这6种粗蛋白和氨基酸组合日粮对实验兔的氮代谢和免疫功能的影响。试验结果表明,动物的日增重和氮利用率以Ⅲ、Ⅳ组最高,Ⅰ、Ⅵ组最低,Ⅲ、Ⅳ组分别与Ⅰ、Ⅵ差异显著（P〈0．01）,但Ⅲ组的总氮排泄量明显低于Ⅳ组（P〈0．01）。Ⅲ、Ⅳ组动物的脾脏指数和胸腺指数也都高于其他4组动物,Ⅳ组动物的脾脏指数分别与Ⅰ、Ⅱ、Ⅴ和Ⅵ组差异显著（P〈0．01）。抗卵苛白蛋白抗体阳性的动物数以Ⅲ组最多,分别与Ⅱ、Ⅴ和Ⅵ组差异显著（P〈0．05）。血清总蛋白含量随日粮氨基酸水平提高有上升趋势,血清尿素氮含量以Ⅴ和Ⅵ组最高,与其他各组差异显著（P〈0．01,P〈0．05）。综上所述,Ⅲ、Ⅳ组日粮粗蛋白和氨基酸组合比较适宜,考虑到Ⅳ组氮排放量较高,故以Ⅲ组最佳。     

农杆菌介导的转高赖氨酸蛋白基因（sb401）水稻T4代分析

通过农杆菌介导的方法用富赖氨酸蛋白基因（sb401）转化粳稻品种日本晴,获得了独立的10个转化株系,对转化株系进行连续自交,通过筛选得到9个纯合的T4代转化株系。 Southern blotting分析发现,整合位点是随机的,并为低拷贝（1~3个）。TAI-PCR扩增得到8个T-DNA侧翼序列,并定位于日本晴的7条染色体上。蛋白质和氨基酸测定分析发现,sb401基因对各株系的蛋白质、赖氨酸和其他氨基酸组分的提高起到了一定的作用。将杂交结果与T-DNA插入位置结合分析发现,在低拷贝的情况下,表达量的差异不明显。     

Influence of dietary Lys levels and dietary net energy levels on growth performance and nitrogen balance of growing pigs

Two experiments were conducted to determine the effects of L y s ine（Lys） and Net Energy （NE） levels on growth performance （Exp. I） and N balance （Exp. 2） in growing pig. In Exp. 1, 36 castrated pigs [21.35 -4- 0.55 kg of body weight （BW）] were allotted to six treatments with six replicates per treatment. Pigs were fed two levels of Lys （low and high） and three levels of NE （low, med, or high） in a 2×3 factorial arrangement. The experiment lasted for 35 d. There were no effects of dietary Lys and NE on pig performance （P〉0.05, but a Lys×NE interaction in ADG was observed （P〈0.05）. In Exp. 2, 24 pigs were used to determine the effects of diet in Exp. 1 on pig N balance. Neither Lys nor NE level affected N retention （g/d） （P〉0.0）. Lys×NE interaction in N retention （g/d） （P〈0.01） and in N apparent biological value （ABV） （P〈0.05） was observed. Pigs fed the low Lys diet had lower serum urea nitrogen （SUN） concentrations compared with the high Lys treatment （P〈0.01）. Pigs fed the med-NE diet had lower SUN concentrations compared with the pigs fed the low-NE diet （P〈0.1）. These results suggest that pigs from 21 kg to 50 kg BW fed diets containing 0.83% standardized ileal digestible Lysine and 2351 Kcal of NE/kg had maximum ADG and N retention.     

过瘤胃烟酸和胆碱对围产期奶牛泌乳性能和肝脂质代谢的影响

旨在研究日粮中添加过瘤胃保护烟酸(rumen-protected niacin,RPN)和过瘤胃保护胆碱(rumen-protected choline,RPC)对围产期奶牛泌乳性能和肝脂质代谢的影响,为缓解奶牛脂肪肝提供理论依据.本试验选用24头健康、胎次相近的中国荷斯坦围产期奶牛,根据2×2试验设计分为4组,每组6...     

Quantitative dietary lysine requirement of juvenile striped bass Morone saxatilis

Two feeding trials of 8 and 10 weeks each were conducted to quantify the dietary lysine requirement of juvenile striped bass, Morone saxatilis. Diets in both experiments contained approximately 420 g crude protein kg^–1 and 13.4 MJ digestible energy (DE) kg^?1. L ‐Lysine‐HCl was added to the basal diet to yield five and six treatments in the two experiments. Diets in the first experiment were determined to contain 9.2, 14.1, 14.6, 19.9 and 21.0 g available lysine kg^?1 on a dry‐matter basis. Diets in the second experiment were determined to contain 14.8, 18.1, 21.3, 24.5, 27.6 and 30.9 g available lysine kg^?1 on a dry‐matter basis. Weight gain, specific growth rate (SGR), feed conversion ratio (FCR), and apparent nitrogen utilization (ANU) were significantly (P < 0.05) improved by increasing dietary lysine concentrations to approximately 20 g kg^?1 of diet. Least‐squares regression analysis of weight gain and SGR in the first experiment indicated a minimum dietary lysine requirement of 20.1 ± 2 g kg^?1 dry diet. Least‐squares regression analysis of the same criteria measured in the second experiment yielded the following estimates of dietary lysine requirements (g kg^?1 dry diet): 19.8 ± 2.3 for weight gain, 21.7 ± 1.5 for SGR, 23.7 ± 3.5 for FCR and 18.6 ± 1.3 for ANU. From these results the minimum recommended dietary lysine requirement for optimal growth of juvenile striped bass is approximately 21 g kg^?1 dry diet which equates to 49 g kg^?1 dietary protein or 1.57 mg kJ^?1 DE. Although higher than that reported for hybrid striped bass, this requirement level is similar to those reported for many other fish species.     

Reduced dietary lysine enhances proportion of oxidative fibers in porcine skeletal muscle

The present study was conducted to elucidate the effects of dietary lysine levels on the proportion of oxidative muscle fibers in porcine muscle. Two 6-week-old barrows from each of five litters were used. Each littermate was assigned to one of two diets, control (lysine content: 1.16%) or low lysine (LL) diet (lysine content: 0.73%). The diets were iso-energetic and iso-protein, and contained all essential amino acids (apart from lysine) in the recommended amounts. The pigs were fed these diets for 3 weeks. Citrate synthase (EC 4.1.3.4) activity in longissimus dorsi and rhomboideus muscles was higher in the LL group ( P  < 0.05). In both muscles, pigs fed the LL diet had a higher proportion of muscle fiber with activities of reduced nicotinic amide adenine dinucleotide dehydrogenase (EC 1.6.5.3, P  < 0.01). The abundance of mRNA of peroxisome proliferator-activated receptor γ coactivator 1α in rhomboideus muscle was higher in the LL group ( P  < 0.05), and those of peroxisome proliferator-activated receptor γ2 were higher in both longissimus dorsi and rhomboideus muscles in the LL group ( P  < 0.05). We conclude that reduced intake of dietary lysine enhances proportion of oxidative muscle fiber, and hence oxidative capacity of porcine muscle.     

围产期低能饲粮添加过瘤胃赖氨酸对初乳质量、断奶前犊牛生长性能的影响

本试验旨在研究围产期低能饲粮添加过瘤胃赖氨酸(RPL)对初乳质量、断奶前犊牛生长性能和瘤胃发酵的影响。试验采用2×2析因试验设计,即能量(产奶净能)水平设为6.40、5.73 M J/kg DM和RPL添加水平设为0、40 g/(d·头)。选取体况和预产期相近的52头第3胎荷斯坦奶牛,分为4组,分别为基础饲粮(B)组、低能饲粮(L)组、基础饲粮+RPL(BL)组和低能饲粮+RPL(LL)组,每组13头牛。试验从预产期前21天至产后犊牛断奶结束。奶牛产后第1次泌乳时采集初乳,测定初乳中总固形物、蛋白质、脂肪和乳糖、免疫球蛋白(Ig) G、IgM和IgA含量;犊牛出生当天(1日龄)、60日龄测定体重和体尺;犊牛60日龄采集瘤胃液,测定pH、氨态氮(NH3-N)和挥发性脂肪酸(VFA)浓度。结果表明:1)围产期低能饲粮显著降低了初乳总固形物、乳糖和IgM含量(P<0.05);围产母牛饲粮添加RPL对初乳乳糖含量有提高的趋势(P=0.068 2),对其他初乳指标无显著影响(P> 0.05)。2)围产期低能饲粮显著降低了母犊60日龄体重、体高、体斜长和胸围(P<0.05),显著降低了公犊60日龄体斜长和初生胸围(P<0.05)。围产母牛饲粮添加RPL有降低公犊60日龄体重的趋势(P=0.073 0)。3)围产期低能饲粮显著降低了母犊初生体躯指数(P<0.05),对母犊60日龄体躯指数有升高的趋势(P=0.059 6),对公犊初生体躯指数有降低的趋势(P=0.099 1),提高了公犊60日龄体躯指数(P<0.05),降低了公犊60日龄体长指数(P<0.05)。围产母牛饲粮添加RPL对公、母犊体尺指数没有显著影响(P>0.05)。4)围产期低能饲粮显著降低了犊牛瘤胃液中总挥发性脂肪酸、乙酸、丙酸、异丁酸、丁酸、异戊酸和戊酸浓度(P<0.05)。围产母牛饲粮添加RPL对犊牛瘤胃发酵指标无显著影响(P>0.05)。5)围产母牛饲粮能量水平与添加RPL对奶牛初乳质量指标、断奶前犊牛体重、体尺指标、体尺指数和瘤胃发酵指标均不存在交互作用(P>0.05)。综上所述,围产期低能饲粮降低了奶牛初乳质量、断奶前犊牛体重、体尺及体尺指数和瘤胃发酵指标;围产期母牛饲粮添加RPL对奶牛初乳质量和断奶前犊牛体重、体尺及体尺指数和瘤胃发酵无不利影响;围产期低能饲粮中添加RPL并不能替代正常标准能量水平饲粮。     

牛至油和过瘤胃蛋氨酸组合添加对奶牛瘤胃微生物蛋白产量与养分消化率的影响

本试验旨在研究牛至油(Oo)与过瘤胃蛋氨酸(RPMet)的不同添加组合对奶牛瘤胃微生物蛋白(MCP)产量与养分消化率的影响。选取年龄、体重、胎次、产奶量、乳成分及泌乳期(90±15)d的荷斯坦奶牛40头,分为10个组,每组4头。对照(C)组饲喂基础日粮,试验组饲喂不同添加水平的Oo和RPMet,Oo设置3个梯度,添加量分别为11.5(L)、13(M)、14.5(H)g/(d·头);RPMet设置3个梯度,添加量分别为22.5(L)、25(M)、27.5(H)g/(d·头),共组成9个不同的添加量组合,分别为LL、ML、HL、LM、MM、HM、LH、MH、HH(第1个字母为Oo添加水平,第2个字母为RPMet添加水平)。预试期15 d,正试期60 d。结果表明:各试验组奶牛的微生物蛋白(MCP)产量均有提高,其中MH、ML、LH、LM、HM组的MCP产量显著提高;试验组奶牛的养分表观消化率有提高趋势,其中MH、HM组粗蛋白质消化率极显著提高;HH、MH组中性洗涤纤维消化率显著提高,酸性洗涤纤维消化率极显著提高;MH组干物质消化率显著提高。在本试验条件下,综合考虑瘤胃MCP产量以及各主要养分的表观消化率,以Oo 13 g/(d·头)、RPMet 27.5 g/(d·头)组合(MH组)效果最好。