Effects of Dietary Lysine on Growth Performance,Serum Concentrations of Insulin-Like Growth Factor-I （IGF-I） and IGF-I mRNA Expression in Growing Rabbits

The effects of dietary lysine on production performance,serum concentrations of metabolites,growth hormone （GH）,insulin-like growth factor-I （IGF-I） and IGF-I mRNA expression in growing rabbits were examined.One hundred weaned New Zealand rabbits were allocated to individual cages and randomly offered a diet containing 5.5 （L1）,6.5 （L2）,7.5 （L3）,8.5 （L4）,or 9.5 g （L5） lysine per kg diet.The results showed that the average daily gain （ADG） of the rabbits from L3,L4 or L5 was higher than those from L1 or L2 （P 〈 0.05）.The feed gain ratio （F/G） in the rabbits from L4 or L5 was lower than those from L1 or L2 （P 〈 0.05）.Dietary lysine did not affect serum concentrations of total protein （TP）,glucose,insulin （INS）,and growth hormone （GH） （P 〉 0.05）.The quadratic effects of lysine on the serum urea nitrogen （SUN） concentration was detected （P = 0.035）.Serum IGF-I concentrations had a trend to increase quadratically with the increasing dietary lysine （P = 0.07）.A significant correlation was found between serum IGF-I concentrations （x,ng mL-1） and ADG （y,g kg-1）： y = -0.017x2 ＋ 1.984x ＋ 20.87 （R2 = 0.8982,P = 0.003）.The relative abundance of hepatic and muscular IGF-I mRNA tended to increase with increasing dietary lysine levels （P = 0.053 and 0.082,respectively）.Providing the diets mainly consisted of corn,wheat bran and peanut vine,the most appropriate dietary lysine level for growing meat rabbits from weaning to 70 d old was found to be 8.5 g kg-1,and IGF-I may be an important factor controlling growth of weaned rabbits.     

Improving the Field Emergence Performance of Super Sweet Corn by Sand Priming

Abstract

A priming method called sand priming was developed using sand as a priming solid matrix. The effect of sand priming on improving the field emergence performance of five super sweet corn cultivars was investigated. Sand priming significantly improved field emergence performance of all super sweet corn cultivars, and there was marked improvement by priming at 20ºC for 24 hr. After sand priming at 20ºC for 24 hr, field emergence percentage (FEP) of “Green Superman”, “Huatian 1”, “Yangtian 1”, “Mitian 8”, and “Chaotian 43” was increased by 52.1%, 37.5%, 38.0%, 40.9%, and 33.3%, respectively. Their field emergence speed (FES) was 2.3, 1.8, 2.0, 2.0, and 1.8 times of the control, respectively. To further elucidate the effect of sand priming on improving the field emergence performance of super sweet corn, we analyzed the membrane system integrity, α-amylase activity and protein content. Sand priming at 20ºC for 24 hr improved membrane system integrity and α-amylase activity in all super sweet corn cultivars. Furthermore, sand priming at 20ºC for 24 hr accelerated the degradation of embryo protein after 1 d germination in “Green Superman”.     

Content Determination of Ivermectin in the Ivermectin Microemulsion Injection

In order to establish the determination method of ivermectin (IVM) in the ivermectin microemulsion injection by high performance liquid chromatography (HPLC), Hypersil ODS2 colunm (5 μm,4.6 mm×250 mm) was used in this study. The mobile phase composed of methanol, acetonitrile and water (35:60:5,V/V/V) at a flow rate of 1 mL/min. The detection wave length was set at 244 nm and the column temperature was 30 ℃. The results showed that the HPLC system suitability of IVM was good. A good linear correlation of IVM was observed within the concentration range 80 to 320 μg/mL, and the average recovery rate was 101.90%±2.94% with RSD was 2.88%, the regression equation was Y=22 700X+2 510 (R²=0.9998). The RSD of IVM content in ivermectin microemulsion injection was 1.86%. The method was accurate and reliable,reproducible,easy to operate, which could be used in new type of ivermectin microemulsion injection. The method could be used as the basis of quality control and establishing a quality standard, and to provide basis for quality evaluation, also can provide reliable reference for safe veterinary clinical application in the future.     

Survival,growth, wood basic density and wood biomass of seven-year-old Casuarina species/provenances grown at Kongowe,Kibaha, Tanzania

A performance comparison of seven-year-old individuals of 13 Casuarina species/provenances in terms of survival, growth (diameter, height and volume), wood basic density and wood biomass was undertaken at Kongowe, Kibaha, Tanzania. The trial was laid out using a randomised complete block design with four replications. The results showed significant differences (P < 0.0001) in all parameters. Casuarina equisetifolia from Montazah National Park, Egypt, had the lowest untransformed survival (48.8%), whereas C. equisetifolia from Wagait Tower (North Timor), Indonesia, had the highest survival (87.5%). Casuarina equisetifolia from Montazah National Park, Egypt, had the lowest mean diameter (8.6 cm) while the C. junghuhniana provenance from Timor, Indonesia (seedlot no. 19489) had the highest diameter (14.8 cm). Casuarina equisetifolia from Montazah National Park, Egypt, had the lowest mean height (16.2 m), volume (22.1 m³ ha^?1) and biomass production (23.5 t ha^?1), whereas C. equisetifolia from Hadsamira Songkhla, Thailand, had the highest mean height (24.3 m), volume (66.4 m³ ha^?1) and biomass production (72.9 t ha^?1). In terms of wood basic density, the C. junghuhniana provenance from Timor, Indonesia (seedlot no. 19489) had the lowest (617 kg m^?3), whereas C. equisetifolia from Wagait Tower (North Timor), Indonesia, had the highest (731 kg m^?3). Ordinal ranking for the best-performing species/provenances revealed that the best two provenances were C. equisetifolia from Hadsamira Sonkhla, Thailand, and C. junghuhniana from Timor, Indonesia (seedlot no. 19491). The two poorest-performing provenances were C. equisetifolia from Montazah National Park, Egypt, and C. equisetifolia from Cotonou, Benin. The outstanding species/provenances are recommended for pilot planting at Kibaha and similar sites.     

Effects of dietary supplementation with Allium mongolicum Regel extracts on growth performance,serum metabolites,immune responses,antioxidant status,and meat quality of lambs

The present study was to evaluate the effects of dried Allium mongolicum Regel (AMR) powder and its water- and fat-soluble extracts (AWE and AFE) on the growth performance, serum metabolites, immune responses, antioxidant status, and meat quality of lambs. A total of 32 male small-tailed Han lambs (5 months old; initial body weight = 34.8 ± 0.40 kg) were used in a 60-d feeding experiment after a 15-d adaptation period. The lambs were randomly divided into 4 groups (n = 8) and fed a basal diet (control, CON group), the basal diet supplemented with dried AMR powder at 10 g/d per lamb (AMR group), the basal diet supplemented with AWE at 3.4 g/d per lamb (AWE group), or the basal diet supplemented with AFE at 2.8 g/d per lamb (AFE group). Blood samples were collected on d 0, 30, and 60 in the feeding experiment (n = 8). At the end of the experiment, the lambs were sacrificed and the longissimus dorsi muscles collected. Growth performance was not significantly affected by dietary supplementation of AMR, AWE and AFE (P > 0.05). However, significantly lower albumin (P = 0.006), total protein (P = 0.006), globin (P = 0.025), and blood urea nitrogen (P = 0.024) concentrations were observed in AFE group relative to CON and AMR groups. Similarly, a significantly lower lactate dehydrogenase activity (P = 0.018) was observed in AFE group relative to AWE group, but not in other groups (P > 0.05). In addition, significantly increasing trends in glutathione peroxidase (P = 0.06) in AMR, AWE, and AFE groups were observed relative to the control group. Furthermore, significantly lower drip loss (P = 0.011) across the treatment groups and cooking loss (P = 0.048) were observed in the AMR group relative to the control group. Taken together, these results indicate that AMR and its extracts had no significant effect on lamb growth performance, antioxidant status, and immune responses, but could significantly improve meat quality without the occurrence of pathological kidney and liver lesions.     

大排距冲天炉性能分析

为了适应大规模、高效率的生产要求，对普遍冲天炉进行改进，设计出双排、大间距冲天炉。以前延用的是单排、独风口化铁炉，其存在熔化率低、铁水温度低、铁水成分不稳定、工人劳动强度大等缺陷，已不适合现代生产的要求。经改进设计后的冲天炉为双排、多风口，即每排４个风口，一菜８个风口。目的是人为地增加一层氧化一还原带，在炉内形成两个相互分开的燃烧带，使第一还原带的ＣＯ充分燃烧，并与得到充分预热的焦炭迅速发生反应，     

不同Zn源及水平对肉兔生长性能和组织Zn沉积的影响

为了研究不同水平ZnSO4和Met-Zn对家兔生产性能及组织Zn沉积的影响,选用2.5月龄布列塔尼亚肉兔120只,随机分成10组,基础日粮中分别以ZnSO4和Met-Zn形式添加70、105、140、1752、10 mg/kgZn,预试期7 d,正试期30 d。结果表明,在Zn添加量为70~140 mg/kg时,Met-Zn对家兔生产性能的影响优于ZnSO4。日粮Zn含量在70~210 mg/kg时,肉兔肝脏、肾脏、脾脏及背最长肌的Zn含量不呈现明显的变化趋势。     

钙镁型秸秆生物炭肥缓释性能及其对玉米生长的影响

化肥的一次施用量过大造成面源污染,给生态环境带来了诸多负面影响,功能化生物炭是构建化肥缓释的重要材料,是生物炭基缓释肥开发的一条途径。该研究以玉米秸秆为炭原料,鸡蛋壳为钙原料,基于热解转化技术耦合氮磷的同步富集制备钙镁型秸秆生物炭肥(Ca/Mg-BCF)。通过温度和pH值对Ca/Mg-BCF缓释性能的影响试验、缓释动力学和淋溶模拟试验等,研究了Ca/Mg-BCF的缓释性能;结合表征技术,初步揭示其缓释氮磷的机理;利用盆栽试验考察了该炭肥与传统化肥对玉米生长影响。结果表明:Ca/Mg-BCF对N和P的缓释作用明显优于化肥(CF),Ca/Mg-BCF对N和P的释放率(5.90%和8.68%)在缓释48 h后,分别比CF降低了88.10个百分点和74.22个百分点;淋溶试验证明,Ca/Mg-BCF对N和P的累积释放率呈现缓慢增长的趋势;Ca/Mg-BCF对养分的释放受温度(10～40℃)的影响较小,其对N和P的释放分别在pH值为1～7和3～10之间较为平稳。Ca/Mg-BCF对N和P的缓释性能,主要受多种作用协同控制,包括鸟粪石等晶体的溶解速率、磷酸根的再沉淀、静电吸引以及生物炭的限域效应等...