Biochar effects on soil chemical properties and mobilization of cadmium (Cd) and lead (Pb) in paddy soil

This study focused on the effects of biochar (BC) application on soil chemical properties and mobilization of cadmium (Cd) and lead (Pb) in the paddy soil. BC was applied at the rate of 0, 10, 20 and 40 t ha⁻¹, respectively. BC application caused a significant increase in soil organic carbon contents (SOC), pH, nitrate–nitrogen (-N),and available phosphorus contents (AP) in the top and subsurface soil, while SOC contents in the subsurface soil decreased with increasing rate of BC. BC40 effectively reduced the mobility of Cd and Pb from the top layer to the subsurface soil, while concentrations of Cd and Pb in the topsoil remained unchanged. Path analysis showed that the direct path coefficient AP was highest; SOC, -N and AP had a negative direct effect on the Cd and Pb in subsurface soil. Soil pH and -N had a high negative indirect effect through AP. The decision coefficient decreased in the following order: pH, AP, SOC, -N and -N. Regression analysis showed that soil Cd and Pb had a significant linear correlation with soil AP, whereas soil Pb also had a significant linear correlation with soil pH. In conclusion, BC40 can alter soil chemical properties and reduce the mobility of Cd and Pb from the top layer to the lower subsurface of the paddy soil.     

臭氧组合絮凝工艺处理牛粪沼液的研究

牛粪沼液作为集约化规模化养殖业阶段处理的产物,产量巨大,有限的土地不足以消纳所有沼液从而导致还田利用十分困难。因此急需寻求一种沼液的预处理方法,实现其固液分离,减少固絮物后续处置量,同时上清液经处理后达标排放。臭氧氧化将大分子有机物降解为小分子物质,絮凝处理可以很好地提高沼液内部固体颗粒的沉降性能,以实现后续上清液的深度处理。该研究采用臭氧+絮凝工艺对牛粪沼液进行预处理,结果表明,单独臭氧处理中,当pH值为7.8,臭氧曝气时间为40 min,臭氧投加速率为2.2 g·h-1时,COD去除率可以达到46%;臭氧+絮凝处理中,当pH值为8.3,搅拌时间为2 min,搅拌速率为300 r·min-1,静置时间为15 min,投药量/总固体TS=1.5,最佳沉降比达到14%,极大地提升了沉降性能,总COD去除率最佳达到82%,最终COD降低到4000 mg·L-1左右,同时为后续处理减轻了负荷,对实际处理有较强的借鉴意义。     

An epidemiological and genetic study on registered diseases in Finnish Ayrshire cattle. IV. Clinical mastitis

The epidemiology and genetic variability of clinical mastitis were examined. The data consisted of 70,775 Finnish Ayrshire cows. All cows were from milk recorded herds and calved during 1983. Each cow was under observation from the date of calving for 305 days. Only clinical mastitis diagnosed and treated by a veterinarian during the farm visits were taken into account. The lactation incidence rate of clinical mastitis (LIR) was 5.4 %. The cows calving in April-May had the highest LIR, but the seasonal variation was relatively small. The LIR increased with parity from the first to sixth parity. The cows treated for parturient paresis, infertility or ketosis had a higher risk of clinical mastitis than cows not treated for these diseases. The LIR was higher in herds with a high milk production level. The highest odds ratio estimated from parameters of the logit model was 14.8. The heritability estimates for clinical mastitis on the binomial scale were 3.2 % in parity 1, 1.6 % in parity 2, 0.6 % in parity 3 and 4, and 0.8 % in all parities (corresponding to 19.7 %, 8.3 %, 2.6 % and 3.8 % on the normal scale). These estimates indicate sufficient assurance for progeny testing of bulls and some possibilities of genetic selection against clinical mastitis. Genetic correlations between clinical mastitis and 305-days milk yield were 0.39 in parity 1, 0.51 in parity 2, 0.18 in parity 3–4 and 0.58 in all parities. This means that the best sires for milk yield had daughters with a higher LIR for clinical mastitis than the other sires.     

Ketosis in Norwegian dairy herds--some epidemiological associations

Ketosis data from the Health Card System, and interview data regarding feeding, housing, management and care were the basis for an epidemiological study in 306 Norwegian dairy herds.Management and care were studied by means of an overall care index. The index was based on 20 questions which provided information about the general standard of management and care. Care was the factor having the most pronounced effect on the treatment rate of ketosis. Highest rates were seen in herds with a high standard of management and care, and lowest rates were seen in herds with a low standard.Most ketosis was found in the mountain valley districts Nord-Østerdal/Gudbrandsdal and Valdres, and least in the lowland coastal district Rogaland. The treatment rate decreased with increasing herd size, and with increasing number of different feedstuffs used. Extra provision of feed concentrates between the morning and evening chores was associated with a lower treatment rate. Also associated with a lower treatment rate was the participation by the farmer’s wife in the daily chores.     

实验性奶山羊缺硒病骨骼肌的超微结构研究

实验性缺硒病奶山羊骨骼肌经电子显微镜观察,见有明显的超微病变。肌质膜破裂,肌原纤维溶解断裂;纵管系统(SR)、横管系统(TS)变位,三联体破坏;线粒体肿胀、变形,内部膜溶解,嵴断裂,基质电子密度不均匀,有大块空白区。其中有中等电子密度团块,被单膜包围;肌核膜双层结构不清,局部溶解,染色质外溢。细胞器生物膜损伤。以线粒体损害最为重笃。     

Clinical Response in Anestrous Dairy Cows with High or Low Blood Progesterone Levels to Treatment with the PGF Analog Alfaprostol*

Contents: In a controlled field trial, 211 anestrous dairy cows with palpable corpora lutea were treated once with a luteolytic dose of the PGF analog alfaprostol (1.5 mgl 100 kg bw) or with a placebo solution. In cows not responding with heat within 10 d, the same treatment was repeated. All cows showing heat were bred. Blood progesterone values were determined at the days of treatment, 2 or 3 d thereafter and at breeding. As reported previously, 109 of 199 cases available for final evaluation showed initially high progesterone values (>6.36 nmol/L) and responded to one or two treatments with heat (alfaprostol us placebo: 96.6% us 48.0%). Breeding resulted in an overall pregnancy rate of 71.4% us 3 7.2%. Of the ninety cows showing initially low blood levels of progesterone (<6.36 nmol/L), 93.5% responded to the first or second alfaprostol treatment with heat versus 27.3% of the placebo treated controls. Breeding of these cows resulted in an overall pregnancy rate of 69.6% (alfaprostol) us 27.3% (placebo). Cows with low progesterone levels treated with alfaprostol once or twice responded with a higher level of heat than anticipated from silently cycling animals. This indicates that the well described gonadotropin releasing effects of PGF in cattle may have resulted in the stimulation of follicular growth, followed by overt or covert estrus, ovulations, conceptions and the formation of corpora lutea. Inhalt: Klinische Ergebnisse der Behandlung mit einem Prostaglandin F Analog, Alfaprostol, bei Milchkühen mit hohem oder niedrigem Blutprogesteronspiegel In einem doppelten Blindversuch erhielten 211 anöstrische Milchkühe, die ein palpier-bares Corpus luteum aufwiesen, eine luteolytische Behandlung mit 1.5 mg/100 kg KGW des PGF Analogs Alfaprostol oder eine Plazeboinjektion. Bei Kühen, die innerhalb von 10 Tagen keine Brunst erkennen lieβen, wurde diese Behandlung wiederholt. Alle Kühe, die in Brunst kamen, wurden besamt. Blut für Progesteronbestimmungen wurde am Tag der Behandlung, am 2. oder 3. Tag danach und am Tag der Besamung entnommen. Serumprogesteron wurde rnit einem RIA bestimmt. Wie schon früher berichtet, wiesen 109 von 199 Fällen, die zur Endauswertung zur Verfügung standen, am Tage der Behandlung einen hohen Progesteronwert auf (<6.36 nmol/L) und reagierten auf die 1. oder 2. Behandlung mit Brunst (Alfaprostol : Plazebo=96.6% : 48%). Die Besamung resultierte in einer Trächtigkeitsrate von 71% für Alfaprostol und von 37.2% für Plaze-bobehandlung. Von den 90 anöstrischen Kühen rnit niedrigem Progesteronwert bei Behandlungsbeginn (<6.36 nmol/L) reagierten 93.5% mit Brunst auf die 1. oder die 2. Behandlung mit Alfaprostol, aber nur — wie zu erwarten — 27.3% der mit Plazebo behandelten Tiere; 69.6% (Alfaprostol) und 27.3% (Plazebo) wurden tragend. Kühe mit niedrigem Progesteronspiegel reagierten somit auf die PGF-Behandlung, entgegen den Erwartungen, ebenso mit einem hohen Prozentsatr an Brunst und nachfolgender Konzeption. Es ist bekannt, daβPGF bei Kühen Gonadotropine freirusetzen vermag. Dieser Effekt könnte für die Anregung von Follikelwachstum, Brunst oder Stillbrün-stigkeit, Ovulation, Konzeptionen und die Bildung von Gelbkörpern verantwortlich gemacht werden.     

发情周期中奶山羊下丘脑-垂体-卵巢轴催产素的免疫组化定位

用免疫组化ABC法,对发情周期中奶山羊下丘脑-垂体-卵巢轴催产素(OT)分布进行了观察研究.结果表明,下丘脑中分泌OT的神经元主要分布在室旁核和视上核,在穹窿周核、腹内侧核、腹外侧核、交叉上核、背内侧核、乳头体、下丘脑外侧区、下丘脑前核等核团也有一定数量的阳性神经元;阳性神经纤维仅见于室旁核、下丘脑前核、视上核等少数核团,在正中隆起和第3脑室室周可见到一定数量的阳性神经纤维.在垂体前叶未见到OT免疫反应阳性产物,自垂体柄和正中隆起的一侧可见到平行排列的OT阳性神经纤维断续地延伸至神经部.卵巢的卵泡及间质未见OT免疫阳性反应,,在黄体组织中存在数量较多的免疫反应阳性细胞,阳性细胞主要呈圆形、卵圆形,小梁两侧及黄体中央近腔区域的阳性细胞呈长梭形,有相当数量的阳性细胞具有突起.连续切片HE染色对照观察显示,黄体中OT主要由大黄体细胞产生,但小黄体细胞也存在OT免疫阳性反应.     

奶牛重要营养素--水

本文主要介绍了水在奶牛营养中的重要作用、奶牛饮水量的计算以及影响奶牛饮水量的因素。     

日粮添加酒糟对后备奶牛生长性能和营养物质消化率的影响

文章旨在研究不同比例的酒糟对后备奶牛生长性能和营养物质消化率的影响。试验选择日龄、体重和体况近似的健康荷斯坦育成牛30头,按照日龄和体重进行分组设计,将其随机分为3组,每组10头。对照组饲粮精料成分为玉米和大豆榨油副产物,试验组Ⅰ饲粮精料成分中添加15%的酒糟,试验组Ⅱ饲粮精料成分中添加30%的酒糟。预试期为2周,正试期为24周。试验期间限饲。试验期间每天记录育成牛的采食量。分别于试验开始和结束时测定育成牛的生长性能指标。于正试期第24周进行消化试验,测定营养物质消化率。试验结果表明,日粮中添加不同比例的酒糟替代玉米和大豆榨油副产物对育成牛干物质采食量和生长性能无显著影响(P>0.05)。日粮中添加不同比例的酒糟替代玉米和大豆榨油副产物对育成牛日粮干物质和有机物的表观消化率无显著影响(P>0.05),但显著提高了粗蛋白质和纤维的表观消化率(P<0.05)。30%酒糟添加组育成牛日粮粗蛋白质表观消化率分别比15%酒糟添加组和对照组育成牛高4.55%和6.82%(P<0.05),而15%酒糟添加组和对照组育成牛日粮粗蛋白质表观消化率差异不显著(P>0.05)。30%酒糟添加组育成牛日粮中性洗涤纤维表观消化率分别比15%酒糟添加组和对照组育成牛高6.70%和7.44%(P<0.05),而15%酒糟添加组和对照组育成牛日粮中性洗涤纤维表观消化率差异不显著(P>0.05)。30%酒糟添加组育成牛日粮酸性洗涤纤维表观消化率分别比15%酒糟添加组和对照组育成牛高6.64%和8.04%(P<0.05),而15%酒糟添加组和对照组育成牛日粮酸性洗涤纤维表观消化率差异不显著(P>0.05)。因此,育成牛日粮中可以添加酒糟替代部分玉米和大豆榨油副产物,本试验中最高添加比例为30%。     

不同泌乳量奶牛行为学差异及其与泌乳性能的相关性

本试验旨在研究不同泌乳量奶牛的行为学差异,并分析奶牛行为学与泌乳性能的相关性。选择24头泌乳中期[(114.6±7.5)d]中国荷斯坦奶牛,平均体重为(670±24)kg,胎次为(2.6±0.4)胎,分为高产组[泌乳量(31.90±1.76)kg/d]和低产组[泌乳量(19.30±1.76)kg/d],每组12头。通过24 h视频监控系统、精准饲喂系统及计步器等,观察和统计奶牛48 h内采食(采食量、采食时间、采食次数、反刍时间、反刍次数)、饮水(饮水时间、饮水次数)、运动(躺卧时间、躺卧次数、站立/游走时间、游走步数)等参数,研究奶牛行为学与泌乳量的相关性。结果表明:1)低产组奶牛的乳蛋白率极显著高于高产组奶牛(P<0.01),低产组奶牛的乳脂产量、乳蛋白产量和乳糖率显著或极显著低于高产组奶牛(P<0.01)。2)高产组奶牛的干物质采食量、饮水时间和饮水次数显著或极显著高于低产组奶牛(P<0.05或P<0.01),高产组奶牛的游走步数极显著低于低产组奶牛(P<0.01)。3)总泌乳量与干物质采食量(r=0.829,P<0.01)、饮水时间(r=0.473,P<0.05)、饮水次数(r=0.429,P<0.05)呈正相关,而与游走步数(r=-0.574,P<0.01)呈负相关。综上所述,奶牛行为学与泌乳量之间存在相关性,这些行为的差异,可为寻找通过改变行为学提高奶牛产奶性能的方法提供理论依据。