Comparison of the microbial communities of alpacas and sheep fed diets with three different ratios of corn stalk to concentrate

The objective of this study was to investigate the characteristics of ruminal microbial communities of alpacas (Lama pacos) and sheep (Ovis aries) fed three diets with varying ratios of roughage (corn stalk) to concentrate, 3:7 (LS), 5:5 (MS) and 7:3 (HS). Six alpacas (one-year-old and weighing 29.5 ± 7.1 kg) and six sheep (one-year-old and weighing 27.9 ± 2.7 kg) were used in this study, in a replicated 3 × 3 Latin square experiment. Total protozoa concentration was determined under the microscope; total fungi and methanogens were assessed using quantitative polymerase chain reaction and expressed as a percentage of total bacterial 16S rRNA gene copies; bacterial communities were investigated by targeted 16S rRNA gene (V3–V4 region) sequencing. The percentage of fungi was significantly higher in alpacas than in sheep under the LS diet, while the concentration of protozoa was significantly lower in alpacas under HS, MS and LS diets. The alpha diversity including Shannon, Chao l and ACE indices of bacterial communities was higher in alpacas than in sheep, under the LS diet. A total of 299 genera belonging to 22 phyla were observed in the forestomach of alpaca and sheep, with Bacteroidetes and Firmicutes dominating both animal species. Phyla Armatimonadetes and Fusobacteria, as well as 64 genera, were detected only in alpacas, whereas phyla Acidobacteria and Nitrospira, as well as 44 genera, were found only in sheep. The abundance of cellulolytic bacteria, including Butyrivibrio and Pseudobutyrivibrio, was higher in alpacas than in sheep under all three diets. These differences in the forestomach microbial communities partly explained why alpacas displayed a higher poor-quality roughage digestibility, and a lower methane production. Results also revealed that the adverse effects of high-concentrate diets (70%) were lesser in alpacas than in sheep.     

不同粘度矿物油助剂对除草剂活性的影响

室内及温室内测定了10种不同粘度矿物油助剂对除草剂防除苘麻和稗草药效的影响及对玉米苗期的安全性。结果表明,10种矿物油助剂均不同程度地增加了氰草津和烟嘧磺隆防除两种杂草的活性。其中粘度为46 mm2/s (40℃)的矿物油乳剂(MOC46)对供试除草剂药效的增强作用最为明显,其次为粘度32 mm2/s (40℃)的矿物油乳剂。10种助剂对氰草津药效的增强作用大于对烟嘧磺隆。MOC46对除草剂活性的增加由高到低依次为:莠去津、氰草津＞莠去津+氰草津、莠去津+烟嘧磺隆、氰草津+烟嘧磺隆＞烟嘧磺隆;对玉米苗期安全性依次为:莠去津、烟嘧磺隆、莠去津+烟嘧磺隆＞莠去津+氰草津、氰草津+烟嘧磺隆＞氰草津。氰草津与MOC46混用对玉米苗期药害较重。     

Effects of concentrate‐to‐forage ratios and 2‐methylbutyrate supplementation on ruminal fermentation,bacteria abundance and urinary excretion of purine derivatives in Chinese Simmental steers

This study evaluated the effects of dietary concentrate levels and 2‐methylbutyrate (2MB ) supplementation on performance, ruminal fermentation, bacteria abundance, microbial enzyme activity and urinary excretion of purine derivatives (PD ) in steers. Eight ruminally cannulated Simmental steers (12 months of age; 389 ± 3.7 kg of body weight) were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement. Moderate‐concentrate (400 g/kg diet [MC ]) or high‐concentrate (600 g/kg diet [HC ]) diets were fed with or without 2MB (0 g/day [2MB ?] or 15.0 g/day [2MB +]). Dry matter intake and average daily gain increased, but feed conversion ratio decreased with the HC diet or 2MB supplementation. Ruminal pH decreased, but total volatile fatty acid increased with the HC diet or 2MB supplementation. Molar proportion of acetate and acetate‐to‐propionate ratio decreased with the HC diet, but increased with 2MB supplementation. Propionate molar proportion and ruminal NH ₃‐N content increased with the HC diet, but decreased with 2MB supplementation. Neutral detergent fibre degradability decreased with the HC diet, but increased with 2MB supplementation. Crude protein degradability increased with the HC diet or 2MB supplementation. Abundance of Ruminococcus albus , Ruminococcus flavefaciens , Fibrobacter succinogenes and Bufyrivibrio fibrisolvens as well as activities of carboxymethyl cellulase, cellobiase, xylanase and pectinase decreased with the HC diet, but increased with 2MB supplementation. However, abundance of Prevotella ruminicola and Ruminobacter amylophilus as well as activities of α‐amylase and protease increased with the HC diet or 2MB supplementation. Total PD excretion also increased with the HC diet or 2MB supplementation. The results suggested that growth performance, ruminal fermentation, CP degradability and total PD excretion increased with increasing dietary concentrate level from 40% to 60% or 2MB supplementation. The observed diet × 2MB interaction indicated that supplementation of 2MB was more efficacious for improving growth performance, ruminal fermentation and total PD excretion with promoted ruminal bacteria abundance and enzyme activity in the MC diet than in the HC diet.     

调环酸钙25%悬浮剂对直播稻抗倒伏和产量性状的影响

为了研究新型植物生长调节剂调环酸钙在直播稻上的应用效果,本研究设计了调环酸钙25%悬浮剂在直播稻武运粳8号上的田间试验,用来了解其对直播稻的抗倒伏性状和产量性状的影响。试验结果表明:在直播稻武运粳8号的分蘖期使用调环酸钙25%悬浮剂12~15g/667m2均能够显著降低水稻的株高,缩短茎基部节间长度,提高水稻的抗倒伏能力,同时也能显著提高水稻产量。     

Effects of Adding Mannan Oligosaccharides to Diets with Different Concentrate to Forage Ratios on Ruminal Fermentation of Sheep in vitro

The test was aimed at determining the effects of adding MOS to diets with different concentrate to forage ratios on ruminal fermentation of sheep in vitro.The 4×6 two-factor experimental design was chosen.There were 4 diets with different concentrate to forage ratios(20:80, 30:70, 40:60 and 50:50) and added to 6 dosages MOS(0, 0.4%, 0.8%, 1.2%, 1.6% and 2.0%), respectively.The method of gas production in vitro was used to measure the total gas and CH₄ production, IVDMD, IVCPD and IVOMD after cultured for 3, 6, 9, 12 and 24 h.The results showed that the gas(except 12 and 24 h) and CH₄ production(except 9 h) were not impacted by the two factors(P>0.05).The IVDMD, IVCPD and IVOMD were significantly affected by concentrate to forage ratios(P<0.05), while the IVCPD at 24 h was significantly affected by MOS(P<0.05).Meanwhile, all the indexes were not influenced by the interaction of two factors(P>0.05).The IVDMD and IVOMD increased with the rising of concentrate approximately, while the IVCPD decreased with the rising of MOS roughly.The biggest associative effect was gained in 30:70 concentrate to forage diet when adding 1.2% MOS.     

EM菌在水产养殖中的应用概述

为了能改善水质、渔业增殖和修复生态环境,EM菌的应用得到了广泛的关注,成为近几年研究的热点。鉴于此,本研究系统梳理了EM菌的定义及来源,综述了国内外近几十年EM菌在水产养殖中的作用效果及其作用机理,阐述了影响EM菌作用效果的因素等;发现EM菌在调控微生物生态结构、降低水环境中有害物质、提高免疫、增重增产等方面有着显著的效果,但EM菌技术的基础理论研究还比较薄弱,且生产技术及应用过程等还存在着不足。因此今后应提高生产技术,建立和提高筛选系统,并开发EM菌在水产养殖研究和应用的新领域,为水产养殖创造更大的经济价值,并为可持续养殖提供可能。     

Mapping soil salinity and pH across an estuarine and alluvial plain using electromagnetic and digital elevation model data

Increasing pressures from agriculture and urbanization have resulted in drainage of many floodplains along the eastern Australian coastline, which are underlain by sulphidic sediments, to lower water tables and reduce soil salinity. This leads to oxidation of the sediments with a rapid decline in pH and an increase in salinity. Accurately mapping soil salinity and pH in coastal acid sulphate soil (CASS) landscapes is therefore important. One required map is the extent of highly acidic (i.e. pH < 4.5) areas, so that the application of alkaline amendments (e.g. lime) to neutralize the acid produced can be specifically targeted to the variation in pH. One approach is to use digital soil mapping (DSM) using ancillary information, such as an EM38, digital elevation models (DEM – elevation) and trend surface parameters (east and north). We used an EM38 in the horizontal (EM38h) and vertical (EM38v) modes together with elevation data to develop multiple linear regressions (MLR) for predicting EC_1:5 and pH. For pH, best results were achieved when the EM38 EC_a data were log‐transformed. By comparing MLR models using REML analysis, we found that using all ancillary data was optimal for mapping EC_1:5, whereas the best predictors for pH were north, log‐EM38v and elevation. Using residual maximum likelihood (REML), the final EC_1:5 and pH maps produced were consistent with previously defined soil landscape units, particularly CASS. The DSM approach used is amenable for mapping saline soils and identifying areas requiring the application of lime to manage acidic soil conditions in CASS landscape.     

受辐照窄颖赖草花粉DNA进入小麦胚囊的电镜自显影证据及杂种原位杂交鉴定

采用3H 胸腺嘧啶标记窄颖赖草 (Leymusangustus)花粉结合电镜自显影的方法证明受辐照窄颖赖草花粉DNA进入了小麦胚囊 ,运用基因组原位杂交技术证明所得杂种为真杂种 ,经辐照花粉获得的普通小麦J 1 1与窄颖赖草杂种中窄颖赖草染色体发生了数目和结构变异     

Incorporation of sunflower oil or linseed oil in equine compound feedstuff: 1 Effects on haematology and on fatty acids profiles in the red blood cells membranes

Eight trained horses (6 mares – 2 geldings, 6 Selle Français, 2 Trotteur Français, 12 ± 5.8 years old, 538 ± 72.5 kg) were offered three diets to potentially affect haematology and the fatty acids (FA) profiles in red blood cells (RBC) membranes. The control diet was composed of 50% hay and 50% concentrate containing mainly rolled barley (48%) and whole spelt (48%). In the case of sunflower oil diet, sunflower oil (62.0% of α‐linoleic acid, LA) was incorporated at a rate of 8% and substituted by an equal proportion of barley. In the linseed oil diet, first cold‐pressed linseed oil (56.0% of α‐linolenic acid, ALA) was utilised at a similar incorporation rate of 8%. The experimental design consisted of three 3 × 3 latin squares with one being incomplete. Each period lasted 8 weeks. On average, the total feed intake (straw excluded) was 6.2 kg/day and the oil intake 0.278 kg/day. The oils significantly increased the concentrations of RBC, haemoglobin and haematocrit. The oils had no significant impact on the haematology profiles except that platelets tended to decrease in both oil‐based diets. The most abundant FA in the RBC membranes of the control diet samples were in the decreasing order LA, C18:1n9‐7, C18:0, C16:0 and the arachidonic acid (ARA) respectively. The sunflower oil supplementation slightly increased the amount of LA (36.23 vs. 34.72 mg/dl, p = 0.55) and C22:4n‐6 (0.21 vs. 0.09 mg/dl, p = 0.22), while the decrease was observed in case of other FA (C16:1n‐7, 1.08 vs. 1.42 mg/dl, p = 0.03), C20:3n‐6 (0.22 vs. 0.31 mg/dl, p = 0.02), and ARA (1.17 vs. 1.63 mg/dl, p = 0.08). Linseed oil induced similar effects in the n‐6 series FA profiles. In the context of practical applications, our results show that linseed oil incorporation in the diet could improve the haematology and the n‐3 FA profiles potentially leading to an increased performance.