规模化猪场污水中污染因子的测定研究

通过对规模化猪场四季节所采集的污水样进行分析,测定了四季节污水样的pH值、化学需氧量、氨氮、凯氏氮、总磷、铜、锌等主要指标,对每个指标在各个季节差异性进行了比较分析。结果显示规模化猪场四季节污水中各个指标呈现了一定的变化规律。     

集约化奶牛场四季牛奶磷采集分析的试验

通过对集约化奶牛场四季泌乳牛奶样采集分析,从而计算出四季牛奶的磷含量,并对各季节5组奶样磷含量进行比较分析。结果显示,四季每头奶牛奶样磷含量及5头奶牛磷平均磷含量差异均不显著,集约化奶牛场牛奶中磷全年平均含量0.09%,四季泌乳牛奶样磷含量差异不显著。     

集约化奶牛场奶牛尿中污染因子的测定研究

测定和分析集约化奶牛场4个季节育成牛与泌乳牛两饲养阶段的试验动物尿样中的pH值、化学需氧量、氨氮、总氮、总磷、铜、锌等主要指标.结果显示:集约化奶牛场四季节育成牛尿样中pH值在四季节间差异不显著;产尿量为秋季最大,冬季最小;化学需氧量冬季最大,夏季最小;氨氮为秋季最大,夏季最小;总氮为冬季最大,夏季最小;总磷为冬季最大,春季最小;铜为春季最大,秋季最小;锌为冬季最大,秋季最小,且每个指标季节差异不尽相同.4个季节泌乳牛尿样中各指标值的变化规律:pH值春季最大,夏季最小;产尿量为秋季最大,春季最小;化学需氧量秋季最大,夏季最小;氨氮为秋季最大,冬季最小;总氮秋季最大,夏季最小;总磷为秋季最大,春季最小;铜为春季最大,秋季最小;锌为冬季最大,秋季最小,且每个指标季节差异不尽相同.     

不同季节及厌氧发酵对奶牛场污水及沼液各污染指标的影响

随着奶牛养殖业的迅猛发展,奶牛场排放的废弃物越来越集中,产生的环境问题也日益受到人们的关注。其中奶牛场排出的废水严重污染着水体和土壤,因此对其进行排污分析尤为重要。本试验对规模化奶牛场产生污水的主要污染指标及沼液的特性进行了测定分析,以期为规模化奶牛场污水的处理和利用提供依据。     

规模化奶牛场粪污处理方式探讨

正近年来,随着我国规模化、集约化养殖业的迅猛发展,大量的畜禽粪污给环境造成的污染也日渐严重。结合我国实际情况,综述了几种目前规模化奶牛场粪污常见的处理方式,对奶牛场粪污的综合利用提供了指导,以期实现粪污资源化和无害化利用。我国奶牛产业目前正处在一个由农户散养向规模化、现代化、集约化和标准化的发展趋势过程中,规模化奶牛场的数量越来越多,上千头的规模化奶牛场不断涌现,奶牛场产生的牛粪和污水没有足够的土地和农业     

基于系统化思维的北方规模化奶牛场设计

规模化奶牛场是具有典型代表性的农业建筑,涉及畜牧、建筑、工业生产与管理等多个学科。传统小型农户散养模式正在被大型集约化、工厂化的奶牛场模式所代替。规模化奶牛场需要各个专业的人员协调配合,并且在建设奶牛场时各个阶段和流程相互制约和联系。目前我国奶牛场建设存在各环节不匹配、建造方法落后、不重视奶牛福利、场内流线设置模糊和舍内环境控制差等问题,不仅增加了劳动力和整体投资,还对奶牛的正常生产造成了不利影响。基于此,笔者提出北方规模化奶牛场设计的系统化思维,即以农业建筑学和畜牧学知识为理论基础,从工艺设计、场地设计和建筑设计角度出发,对规模化奶牛场的设计进行较为完整和系统性的研究与分析,旨在提高畜牧工作者对畜牧场设计的重视程度。     

奶牛集约化生产体系中锌产污系数的测定

为了准确测定奶牛粪便中的锌含量,为环境污染治理提供科学依据,试验对集约化奶牛场4个季节育成与泌乳两个阶段奶牛的粪样和尿样进行了分析,从而计算出两个阶段的锌产污系数,并对各季节两个阶段两者间的差异进行了比较分析。结果表明,集约化奶牛场4个季节育成牛锌产污系数平均为0.95 g/(头.d),4个季节泌乳牛锌产污系数平均为1.99 g/(头.d),泌乳牛锌产污系数远大于育成牛锌产污系数。     

奶牛场粪污处理系统及卫生防疫体系(连载十)

随着奶牛热在中国的不断升温，大规模、集约化奶牛场的建成。随之而来的是产生出大量粪尿、污水、有害气体和恶臭。特别是化肥的使用，使大量的粪肥未能还田，加剧了对环境的污染。造成的公害日益严重，在这种情况下，奶牛场本身也受到这种污染的危害，同时也增加了防疫的难度。因此奶牛场粪污处理系统及防疫体系的建设是非常必要的，即能避免奶牛场被污染，又能保护奶牛场周围的环境，更加容易做到奶牛场多级防疫。     

规模化奶牛场废水处理技术研究进展

近年来我国奶牛养殖集约化、规模化水平大幅提高,但随之增多的奶牛场废水量却给环境带来了压力。本文针对奶牛场废水的特征,对国内外废水处理现状进行了分析,简述了还田利用、自然处理和工业化处理方式等处理工艺,为奶牛场废水的处理和资源化利用提供参考。     

规模奶牛场的粪肥如何处理

<正>近年来,随着我国奶牛养殖集约化、专业化、规模化的程度不断提高,建立起了数量多、规模大的奶牛场,奶牛的规模养殖已成为农民增收的主导产业。奶产业飞速发展的同时也产生了大量的养殖废弃物,主要有奶牛粪、尿、牛舍和挤奶厅的冲洗污水及有害气体等恶臭物质。目前,奶牛场对这些废弃物基本不进行处理,除了近几年新建牛场争取到国家沼气能源项目可以处理一小部分粪便外,绝大部分奶牛场积攒牛粪后并没有经过任     

新疆地区荷斯坦干奶牛与泌乳牛四季NH3排放量变化的研究

试验于2011年7月～2012年7月在同一栋牛舍内对20头干奶牛和20头泌乳牛分别进行了四季氨气排放量测定,每个季节根据气象信息所提供的当地气温,分别在季前、季中、季末共选取气温相近的18d,分别对干奶牛（9d）与泌乳牛（9d）进行监测。通过测定不同时间段牛舍内NH3的浓度,把3次实测值进行累加,计算出24h奶牛NH3的排放值。结果表明,四季试验期间干奶牛舍内平均NH3排放量是6．42g／（头·d）,四季泌乳牛舍内平均NH、排放量是10．62g／（头·d）。四季温度的变化对奶牛排放NH3有一定的影响。奶牛NH3的排放量与奶牛的采食量、饲料配方和饲料中CP水平有关,一头体重500kg左右的奶牛一年产生约3．6kg的氨气：     

奶牛场象草地土壤质量现状评价

对养殖场内施用奶牛粪的象草地土壤和未施用粪便的胡枝子园土壤选点采样,测定四个季节土壤样品的相关指标,探讨施用牛粪对象草地土壤质量的影响,并对奶牛场土壤质量现状进行评价。结果表明,象草地的氮、磷负荷量低于土壤氮、磷负荷量警戒值。四个季节（除春季锌的含量和夏季全磷的含量无显著差异外）施用牛粪的土壤中有机质、全氮、全磷、铜、锌等指标含量均显著的高于未施肥的区域（P〈0.05）,四个季节（除冬季全磷和锌含量无显著差异外）距离粪便堆积中心较近的未施肥区域的土壤各指标的含量均显著的高于距离较远的未施肥区域（P〈0.05）。四个季节施用牛粪的象草地土壤铜、锌单项污染指数均小于1,为清洁水平。研究结果为评估奶牛养殖场环境污染风险及与牧草结合的奶牛养殖模式的合理性提供参考。     

季节对成乳母牛产粪量及粪N、P、Cu、Zn等污染物排放量的影响

[目的]为控制与治理奶牛场污染提供科学的理论依据与数据基础。[方法]本文选择健康状况良好、胎次与产奶量相近的中国荷斯坦成乳母牛5只作为试验对象,采用全收粪法研究成乳牛在一年四季中产粪量及粪污染物(N、P、Cu、Zn和有机质)排放量的变化情况及规律。[结果]表明:季节对成乳母牛产粪量与粪样中的含水率、有机质及N、P、Cu、Zn污染物的排放量均存在着极显著(P0.01)或显著(P0.05)的差别。[结论]从而,根据不同季节产粪量及粪中污染物排泄规律来研究配置符合成乳母牛的均衡饲料配方,可达到既满足成乳母牛的生产需要,又能最大限度地降低污染物排放量,减少奶牛场污染的目的。     

产犊季节对北京地区荷斯坦奶牛Wood泌乳曲线参数的影响探究

本研究通过对北京地区1998-2016年28个场区的奶牛生产性能测定（DHI）数据进行分析,旨在比较不同产犊季节对1~3胎奶牛泌乳曲线相关参数的影响。使用Wood模型对1~3胎不同产犊季节群体和个体泌乳曲线进行拟合,并获得相应胎次下不同产犊季节奶牛泌乳曲线参数a、b、c （分别代表泌乳潜力、产奶量上升至顶峰速率、产奶量达到顶峰后下降速率）、泌乳曲线二级参数Per、PY （分别代表泌乳持续力、泌乳峰值）及305 d产奶量（305MY）。群体和个体水平的曲线拟合采用SAS 9.2中NLIN模块进行,采用混合线性模型分析不同产犊季节对各胎次奶牛泌乳曲线参数的影响。结果显示：产犊季节对Wood泌乳曲线的泌乳潜力、达到峰值的上升速率、达到峰值后的下降速率、泌乳峰值及305MY均有显著影响（P<0.05）,对于泌乳持续力没有显著影响（P>0.05）。夏季产犊牛泌乳曲线整体低于其他产犊季节,且胎次越高趋势越明显,1胎牛受到的影响较小;从胎次上分析,头胎牛泌乳持续力极显著高于经产牛（P<0.01）;头胎牛夏季产犊305MY比其他产犊季节的低274.33~490.17 kg,经产牛夏季产犊305MY比其他产犊季节的低440.76~930.68 kg。以上结果提示,北京地区牛场应注重做好经产牛和头胎牛的防暑降温工作,注意调整配种时间,避免夏季产犊牛过多,造成损失。     

Population dynamics of horn fly, Haematobia irritans irritans (L.) (Diptera: Muscidae), on Hereford cattle in Uruguay

Abundance of adult horn flies, Haematobia irritans irritans (L.), was monitored on 25 untreated Hereford cows in Tacuarembó Department, Uruguay, during three consecutive grazing seasons, from October 1999 to May 2002. The population showed a variable pattern of abundance during three years, with peaks in late summer-early fall of each year. Adult flies were continuously present, although in very low numbers in intervening winters. Numbers of flies per cow rarely exceeded a reference level of 200 flies per animal during the grazing season. Degree-day calculations indicated that approximately 12 generations were possible each year. Time series analysis of mean densities among consecutive generations indicated that population growth was governed by simple, direct density-dependence, with additional effects of seasonally varying weather. Response surface regressions confirmed that intergenerational growth was inversely related to mean density, and directly related to temperature. Stochastic simulations with the response surface model suggested that within the range of temperatures observed in our study, horn fly populations on Hereford cattle will tend toward densities of approximately 150 flies per animal in summer, and exceed a nominal level of 200 flies per cow one or more times in about 65 of every 100 grazing seasons.     

Factors affecting milk yield,milk fat,bacterial score,and bulk tank somatic cell count of dairy farms in the central region of Thailand

A study was conducted to determine the effects of season, farm location, and farm size on farm milk yield (FMY), average milk yield per cow (AYC), milk fat, bacterial score, and bulk tank somatic cell count (BTSCC) of dairy farms in the central region of Thailand. Farms were located in the districts of Kaeng Khoi, Muaklek, Pak Chong, and Wang Muang. Collection of data was at the farm level; individual animal records were unavailable. A total of 967,110 daily farm milk yield, 58,575 milk fat and bacterial score, and 24,109 BTSCC records from 1,034 farms were collected from July of 2003 to June of 2006. There were three seasons: rainy, summer and winter. Farms were categorized into small, medium, and large according to the number of cows milked per day. Results showed that FMY and AYC were higher (p <0.05) in winter and lower in the summer and rainy seasons. In addition, the majority of small size farms had higher (p < 0.05) AYC and milk fat values, and lower bacterial score and BTSCC values than medium and large size farms.     

奶牛蹄病的治疗

将患有蹄病的牛按病情严重程度分三级,在每级中各选出12头,并将36头随机分成4组,每组共9头。第1组为对照组,第2组每头牛日粮中加35%石粉18g,第3组每头牛日粮中加硫酸锌1.2g,第4组每头牛日粮中同时加35%石粉18g和硫酸锌1.2g。同样护理,每星期对试验牛群进行修蹄及常规治疗。经过1个月的治疗第1组治愈1头,有效3头,无效5头;第2组治愈2头,有效6头,无效1头;第3组治愈3头,有效4头,无效2头;第4组治愈7头,有效2头,无效0头。卡方检测除第2、3两组差异不显著外,其他各组之间差异显著。说明在日粮中适量提高钙和锌对奶牛蹄病有良好的预防和治疗作用。     

Nitrogen utilisation efficiency in small-scale dairy systems in the highlands of Central Mexico

Nitrogen (N) plays an important role in small-scale dairy systems, both in production costs and as an indicator of environmental impact. The objective of this study was to quantify nitrogen inputs and outputs to identify areas for improvement in nitrogen utilisation efficiency (NUE). Evaluation was in 12 small-scale dairy farms with different feeding strategies. Six followed the traditional cut and carry of irrigated temperate pastures (CUT), and six have implemented grazing of pastures (GRZ), quantifying N inputs and outputs from May 2016 to April 2017. Data were analysed by ANOVA following a split-plot model with season (rainy or dry) as main plots and feeding strategy (CUT or GRZ) as split-plots, with results in kilograms N per hectare and kilograms N per cow. There were differences (P < 0.05) between seasons and strategies in N inputs from purchased N fertilisers and purchased feeds as concentrates and roughages, showing different N inputs and outputs whether in CUT or GRZ strategies. There were also significant interactions between seasons and strategies as in the sale of animals, where GRZ sell throughout the year, while CUT sell at the beginning of the dry season. N balance ranged from 33.9 to 183.0 kg N/ha, and 37.8 to 111.0 as kilograms N per cow with an interaction (P < 0.05) between season and strategies. There was a larger N surplus in GRZ during the rainy season from fertiliser inputs, which reduced N utilisation efficiency (NUE). Mean NUE in kilograms N per hectare and kilograms N per cow was 19%, with the higher efficiency for GRZ in the dry season. Farms with the best NUE had lower use of fertilisers and purchased feeds.

     

A four‐season longitudinal study of enterohaemorrhagic Escherichia coli in beef cow–calf herds in Mississippi and Nebraska

Our objective was to describe the probability of detecting seven serogroups of enterohaemorrhagic Escherichia coli (EHEC‐7) of public health importance in faecal samples from beef cow–calf herds and to test for factors associated with their detection. Fresh faecal samples (n = 85) from two Mississippi and two Nebraska herds were collected in each of four seasons. Samples were tested for each EHEC‐7 serogroup by a molecular screening assay. Separate management groups within herds were sampled, and group‐level factors were recorded. To measure the effects of factors on faecal shedding of EHEC‐7, separate multivariable logistic regression models were used, accounting for the random effect of clustering by group within farm. Statistical significance was set α = 0.05. Fifty‐nine samples (4.3%) were positive for EHEC O26, and Nebraska samples were more likely to be positive than Mississippi samples (OR = 12.4, 95% CI: 1.1, 139.2). Forty‐four samples (3.2%) were positive for EHEC O45. Odds for detection were greater in the summer than all other seasons combined (OR = 4.2, 95% CI: 1.3, 14.0), and odds decreased if a precipitation event occurred (OR = 0.07, 95% CI: 0.006, 0.8). EHEC O103 was detected in 66 samples (4.9%) with increased probability to be detected at increased temperature. EHEC O111 was detected in 71 samples (5.2%), and 43 samples (3.2%) were positive for EHEC O145. Both EHEC O111 and O145 were associated separately with season, with greater probability for detection in the summer. Eighteen (1.3%) and 68 (5.0%) samples were positive for EHEC O121 and EHEC O157, respectively. We failed to detect significant explanatory factors associated with probability to detect EHEC O121 or O157. Factors that vary by time and place, such as precipitation, ambient temperature, region and season, are uniquely associated with the probability to detect EHEC‐7 in fresh faeces collected from cow–calf herds.     

Influence of seasonal forage quality on glucose kinetics of young beef cows

Extensive range livestock production systems in the western United States rely heavily on rangeland forages to meet the nutritional needs of grazing livestock throughout the year. Interannual variation in the quantity and quality of rangeland forage in the Northern Great Plains, as well as throughout much of the western United States, may play a pivotal role in how well grazing ruminants sequester nutrients in their tissues. This variation in forage quality may influence the ability of a beef cow to utilize dietary nutrients via changes in tissue responsiveness to insulin. Identifying specific periods and production states in which this phenomenon is manifested will provide insight into the development and implementation of strategic and targeted supplementation practices that improve nutrient utilization during times of nutritional imbalance and may improve the lifetime productivity of grazing range beef cows. A 2-yr study was conducted to monitor serum metabolites, glucose kinetics during glucose tolerance tests, and forage chemical composition every 90 d in young cows (2 to 4 yr of age; n = 28). In yr 1 and 2, cows were managed on 4 pastures varying in size from 36 to 76 ha in yr 1 and 49 to 78 ha in yr 2. Regardless of year, cow age, or cow physiological status, the main factor influencing glucose half-life was season of the year (P = 0.02). Effects of season on glucose half-life closely followed assessments describing forage quality, with glucose half-lives of 46, 39, 43, and 51 +/- 3.9 min for May, August, December, and March, respectively. Elevated glucose half-life during seasons in which forage quality is of lower nutritive value indicated that tissue responsiveness to the actions of insulin followed seasonal changes in forage quality. Glucose half-life tended (P = 0.09) to decrease between May and August, increased (P = 0.04) between December and March, and showed a tendency (P = 0.10) to decrease in seasons of greater nutrient density (May and August) compared with seasons of lower nutrient density (December and March). Seasonal changes in serum metabolites were also observed and corresponded with changes in forage quality. The results support our hypothesis that as the season progresses and forage quality declines, maternal tissues become less responsive to insulin, indicating that targeted supplementation with glucogenic precursors during these seasons of nutritional stress may improve cow performance.