不同植龄啤酒花根际微生物区系的变化及与产量和品质的关系

通过测定22,20,18,8和5年啤酒花农田土壤微生物区系的变化,分析了不同植龄土壤微生物数量及多样性指数与啤酒花产量和品质的关系。结果表明,随着啤酒花植龄的增加,啤酒花根际土壤细菌、放线菌、微生物总数和多样性指数及啤酒花α-酸含量均表现出先增大后减小的趋势,而真菌则一直呈现出增加趋势。与5年植龄的相比,8年植龄的细菌增加了0.37%,而18,20和22年植龄的细菌分别降低了4.25%,10.72%和18.30%,均达到显著差异(除8年外);各植龄的放线菌分别是5年的102.10%,82.23%,74.04%和53.78%,均达到显著差异;真菌分别是5年的136.99%,160.69%,179.77%和194.22%,差异显著;多样性指数分别是5年的106.12%,96.99%,89.85%和89.47%,前三者均达到显著差异;啤酒花α-酸含量分别是5年的100.44%,95.47%,93.14%和90.51%,均达到显著差异(除8年外)。啤酒花α-酸含量与细菌、放线菌数量和多样性指数呈显著正相关,而与真菌数量呈显著负相关关系。随啤酒花植龄的延长,土壤微生物数量的变化,特别是微生物多样性指数的减少,可能是啤酒花品质下降的原因之一。     

不同施肥处理对紫花苜蓿鲜草产量和营养品质的影响研究

研究了在酸性土壤奈件下不同施肥处理对紫花苜蓿鲜草产量和营养品质的影响。结果表明,施肥处理N90-P120-K150＋MgMoB,鲜草产量最高,较对照增产98％;同时,该处理下干物质中粗蛋白质含量也最高,在开花初期和开花期分别达19．04％和18．22％,分别比对照增加了3.42％和0.58％;新复极差测验表明,不同施肥处理各次刈割鲜草产量及鲜草总产量间差异均达到显著水平,且随着氮磷钾施用量的增加,鲜草产量相应增加。     

钾素营养对桑叶产量和品质的影响

浙江嘉兴平原堆叠土上，钾素营养对桑叶产量和品质日趋敏感。本文阐述桑树缺钾症状，钾肥的增产效应及其对叶质的影响，提出桑园中钾肥的一般用量以及多途径增加钾素营养的措施。     

不同施肥处理对扁穗牛鞭草鲜草产量和营养品质的影响研究

研究了在酸性土壤条件下不同施肥处理对扁穗牛鞭草鲜草产量和营养品质的影响。结果表明,施肥处理N375-P120-K150鲜草产量最高,较对照增产5．铴;施肥处理N300-P120-K0营养价值最高,在拔节期和抽穗期分别达12．83％和11．32％;综合比较产量和营养品质,施肥处理N300-P120-K75产量较高,较对照增产2．O％,粗蛋白质含量也较高,在拔节期和抽穗期分别这12．82％和10．29％,分别比对照增加了1．5％和1．4％;新复极差测验表明,不同施肥处理各次刈割鲜草产量及鲜草总产量间差异均达到显著水平,且随着氮磷钾施用量的增加,鲜草产量相应增加。     

硒源对紫花苜蓿产量和营养品质的影响

试验研究不同硒源及其浓度对紫花苜蓿产量和营养品质的影响。试验以紫花苜蓿WL232HQ为研究对象,采用N-Se和Se代表纳米硒和亚硒酸钠2种硒源,在紫花苜蓿的营养生长期分别以0、30、100、250 mg/L多次叶面喷施,共设7个处理,分别为CK、SeT1、SeT2、SeT3、N-SeT1、N-SeT2、N-SeT3。结果显示：SeT2和N-SeT2处理的紫花苜蓿鲜草产量与干草产量均显著高于CK (P<0.05);SeT1、N-SeT1、N-SeT2处理的紫花苜蓿粗蛋白质含量显著高于CK处理(P<0.05)。结合隶属函数值分析发现,低浓度的外源硒可以提高紫花苜蓿的营养品质,不同浓度纳米硒处理的紫花苜蓿营养品质稳定性优于亚硒酸钠。研究表明,施用浓度为100 mg/L的纳米硒时,紫花苜蓿的产量高、营养品质好。     

钾素营养对桑叶产量和品质的影响

浙江嘉兴平原堆叠土上，钾素营养对桑叶产量和品质日趋敏感，本文阐述桑树缺钾症状，钾肥的增产效应及其对叶质的影响，提出桑园中钾肥的一般用量以及多途径增加钾素营养的措施。     

干旱环境下4种高原禾本科牧草产量及营养品质比较

为筛选适宜干旱、半干旱环青海湖地区生长的优良牧草,测定了高原地区生长的4种禾本科本土牧草的生产性能和营养价值指标,并结合灰色关联度分析法进行了综合评价。结果表明,大颖草(Roegneria grandiglumis)和扁穗冰草(Agropyron cristatum)的叶茎比和鲜干比较高,适口性更好;同德短芒披碱草(Elymus breviaristatus cv.Tongde)的干草产量为最高,大颖草、同德短芒披碱草、同德贫花鹅观草(Roegeria pauciflora cv.Tongde)的草产量之间差异不显著;扁穗冰草的营养价值相对最好;4种供试牧草综合评价表现由高到低为：扁穗冰草>大颖草>同德贫花鹅观草>同德短芒披碱草。     

灌溉对饲草谷子产量及营养品质的影响

试验旨在研究灌溉对饲草谷子产量及营养品质的影响。选取赤峰草谷子、118和大白谷等3个谷子品种为试验材料,分析3个品种在不同灌溉条件下各生育期产量和养分含量的动态变化,比较饲草价值的变化规律,确定适合当地种植的品种及最佳收获期的栽培方式。结果显示：在抽穗期,品种118在不同处理下的产量均显著高于其他品种（P<0.05）。在灌浆期,品种118在两种不同处理下的产量均达到了最高水平。在乳熟期,3个品种的灌溉条件下的产量均高于旱作条件下的产量,品种118的产量显著高于赤峰草谷子和大白谷（P<0.05）。品种118的粗蛋白质含量在灌溉和旱作条件下均达到最高,旱作条件下品种118的粗蛋白质含量显著高于赤峰草谷子和大白谷（P<0.05）。品种118在灌溉条件下的中性洗涤纤维含量显著低于旱作条件（P<0.05）。在不同栽培方式下,品种118和大白谷灌溉条件下的可溶性糖含量高于旱作条件,而赤峰草谷子旱作条件下的可溶性糖含量高于灌溉条件（P>0.05）。在灌溉和旱作两种不同条件下,品种118的可溶性糖含量均为最高（P>0.05）。研究表明,在四子王旗种植谷子时,在灌溉条...     

肌内脂肪的营养调控及其与肉质的关系

<正>随着生活水平的提高,消费者越来越注重肉的质量。肌内脂肪的含量影响肉的多汁性、嫩度和风味,2%～3%的肌内脂肪含量是新鲜肉的一个理想标准。Patrici等(1985)对丹麦商品猪的肉质研究发现,提高肌内脂肪含量,肉质嫩度、多汁性也会相应地得到改善。     

Pasture quality and its relation to utilization

The paper evaluates those functions of the grazing‐animal/pasture complex which are influenced by management. The contribution of pasturage to animal production is determined primarily by environment and secondarily by defoliation. In pasture quality evaluation, those approaches which employ both digestibility and intake as basic criteria are generally closely related to animal response. In equating grassland production with animal requirements the determinants of output per animal and output per area must be considered in the perspective of the production system as a whole. The essential influence of grazing method on carrying capacity is stressed and it is suggested that grazing management of natural pasture be based on (i) a knowledge of the contribution of individual species to animal production, (ii) defoliation practice which encourages the most nutritious species and (iii) the introduction of improved pasture species.     

Nutrition in relation to skeletal growth deformities

The pathophysiology of alimentary hyperparathyroidism and its pathological fractures and growth deformities are described. Renal hyperparathyroidism with hyperostotic osteodystrophy in young animals and isostotic osteodystrophy in old animals is briefly mentioned. Hypercalcitoninism caused by excessive prolonged calcium intake in growing dogs will go together with disturbances in skeletal remodelling and disturbed enchrondral ossification, leading to such entities as canine wobbler syndrome, enostosis, osteochrondrosis dissecans, and radius curvus syndrome. Dogs, who are dependent upon dietary vitamin D sources, can develop rickets with skeletal growth deformities when a diet deficient in vitamin D is fed under controlled conditions. Growth plates and mineralisation grade normalised when commercial dog food was given. As a sole therapy normalisation of the diet will not be sufficient in all skeletal growth deformities as described above. Prevention by feeding diets with optimal contents will be of benefit to veterinarians and their patients.     

A comparison of different measures of persistency with special respect to variation of test-day milk yields

Six measures of persistency of milk yield were compared by estimation of heritabilities, genetic correlations and the amount of concentrates required by cows with high and low persistency.Persistency was expressed as ratio between different parts of the lactation (P2:1 and P3:1), as a ratio between maximum test-day milk yield and mean test-day milk yield and as the standard deviation of the test-day milk yields of a lactation. The investigation was based on 39 349 first, 23 910 second and 13 651 third lactation records of Simmental cows from the region of Lower Austria.The heritability estimates ranged from 0.12 to 0.18 for measurements including the first 200 days of lactation and from 0.17 to 0.22 when the whole 305-day lactation was included. The largest values were found for the standard deviation of test-day milk yields (305 days); 0.21, 0.22 and 0.22 for the first, second and third lactation, respectively. Genetic correlations between lactations were high for all measures of persistency, ranging from 0.79 to 0.95. Highly persistent cows required between 69 and 161 kg less concentrate than cows with a poor persistency to produce 5500 kg of milk. The difference was generally larger when the grouping was performed on measures including 305 days of lactation vs. measures including only earlier parts of the lactation; 161 kg was found for P3:1.     

矮嵩草抗氧化物质含量的季节变化及与太阳辐射的关系

对移植西宁地区矮嵩草几种抗氧化物质含量的季节变化测定发现 ,矮嵩草叶片内紫外线吸收色素、抗坏血酸含量以及超氧化物歧化酶的活性在 5到 8月间呈“拱型”变化 ,6、 7月份最高。超氧阴离子自由基的相对含量呈现略微下降趋势。抗氧化物质含量和活性的变化动态与太阳辐射强度呈现一定的正相关关系     

矮嵩草抗氧化物质含量的季节变化及与太阳辐射的关系

对移植西宁地区矮嵩草几种抗氧化物质含量的季节变化测定发现,矮嵩草叶片内紫外线吸收色素、抗坏血酸含量以及超氧化物歧化酶的活性在5到8月间呈"拱型"变化,6、7月份最高.超氧阴离子自由基的相对含量呈现略微下降趋势.抗氧化物质含量和活性的变化动态与太阳辐射强度呈现一定的正相关关系.     

山东省鱼粉生产及质量状况

山东省是我国主要的沿海省份之一，濒临渤海、黄海两大海域，海岸线长达３０００多千米，海产资源十分丰富，１９９８年海洋捕捞量达３３２．５６万ｔ，鱼粉产量逐年稳步提高，现已成为我国重要的鱼粉产地。为评价山东省鱼粉生产和质量状况我们进行了较为系统的调查。１生产概况 鱼粉是全鱼或鱼下脚（鱼头、尾、鳍、内脏等）的干燥粉碎物，原料鱼经蒸煮后滤去汁液，干燥，粉碎成为普通鱼粉。若把滤出或榨出的汁液撤去浮油，浓缩成鱼脂膏，加入普通鱼粉后即成全鱼粉。用鱼下脚为原料生产的鱼粉为粗鱼粉。 鱼粉生产工艺方式较多，主要有以下几…     

Neonatal-piglet weight variation and its relation to pre-weaning mortality and weight gain on commercial farms

To determine the effect of within-litter neonatal-weight variation on pre-weaning mortality and weight gain, we analyzed piglet survival and weight gain within 400 litters from 10 commercial farms. Neonatal-weight variation (independent of mean neonatal weight, litter size and sow parity) was associated with pre-weaning survival and weaning-weight variation-but not with mean weaning weight. Neonatal piglets with weights well below the range of most of the litter (low-birth-weight piglets) had an increased risk of dying and were unable to obtain normal weight gains by weaning if they survived. These piglets experienced lower survival and poorer weight gain in larger litters. These piglets also tended to have lower survival but normal (albeit low) weaning weights if they survived in litters from middle-aged and old sows. High neonatal-weight variation resulted in lower survival and more variable weaning weights. Small piglets had a greater risk for poor survival and weight gain compared to their heavier litter-mates (a disadvantage that was exacerbated in large litters).     

新疆不同植被NDVI的变化及其与气候因子的关系

使用归一化植被指数(Normalized Difference Vegetation Index, NDVI)和气象数据研究了全球气候变化背景下,1982-2003年新疆10种植被类型NDVI时间动态变化及其与气候因子的关系。研究区植被生长季NDVI以0.58%的年平均增长率显著增加,并且春、夏、秋三季的总体及各种植被类型NDVI都显著增加(P<0.01);通过对生长季NDVI和气候因子的相关分析,发现有5种植被类型与降水量呈显著正相关,主要是阔叶林、荒漠、草原、草丛和草甸;与温度显著相关的植被类型为针叶林、灌木、高寒沼泽和高山植被;农田生长季NDVI与降水和温度均不显著相关。通过研究各个季节不同植被类型NDVI与气候因子关系表明,春季植被NDVI与温度关系密切,夏季植被NDVI与降水呈显著正相关关系,秋季NDVI的增加是温度和降水量共同作用的结果。