Systematic evaluation of in-house broiler litter windrowing effects on production benefits and environmental impact

In-house windrowing of broiler litter between flocks has been adopted by producers to reduce pathogens and improve litter quality before chick placement. In this study, 5 consecutive windrow trials were conducted in commercial broiler houses for their effect on litter bacterial populations, organic matter stabilization, cumulative ammonia emissions, and nutrient transformation and compared with litter conditioning (tilling) in adjacent houses. No significant reduction ofClostridium spp. andEscherichia coli populations was found in windrowed litter from d 0 to 7. No significant difference of 7-d mortality was found between windrow and nonwindrow houses. The windrowed house resulted in better foot quality than the nonwindrowed house from 1 of 3 scored flocks. Water-soluble phosphorus increased in both windrowed and nonwindrowed litter; therefore, appreciable biotic and abiotic activity occurred in litter with both treatments after flocks were removed. Overall, no negative effect of windrow treatments on litter quality for agronomic applications was observed. Both the control and windrow treatments resulted in a decrease in litter moisture content (2 to 5%) likely beneficial to bird health conditions. High ammonia emissions persisted after windrow spreading; therefore, a need may exist for an extended period of ventilation or a litter amendment as crucial before chick placement. Litter amendment at a low dose was effective in lowering ammonia concentrations after windrowing and was more economical comparing to operating fans in winter conditions.     

玉米收获机茎秆切割铺放装置的设计与试验

随着畜牧业和工业的发展,农作物秸秆作为重要的饲料与工业原料,其需求越来越多,玉米秸秆的回收利用更是受到人们的广泛关注。为此,设计了一种新型的玉米收获机茎秆切割铺放装置,能够实现玉米茎秆的切割、压整和铺放。经田间试验证明,该装置效果良好,切断的茎秆能够满足打捆要求。     

整秆式甘蔗收获机甘蔗铺放运动学分析

通过对抛出后甘蔗运动过程的高速摄影结果的分析,确立了甘蔗的运动形式,并进行了运动学分析,建立了数学模型,推导出了甘蔗向机车外铺放的条件、以及甘蔗铺放距离、铺放角的理论计算公式,采用Matlab编程,分析了整秆式甘蔗收获机圆弧轨道式柔性夹持输送装置甘蔗铺放过程中运动参数、结构参数以及甘蔗几何参数对甘蔗向外铺放、铺放距离、铺放角的相互影响规律,为甘蔗收获机的设计以及甘蔗铺放质量的提高提供了理论依据。     

4SY-2.2型油菜割晒机设计与试验

针对现有油菜割晒机铺放质量差,导致后熟时间不可控、后续捡拾损失大的问题,设计4SY-2.2型油菜割晒机,可实现油菜的分禾、切割、输送和铺放作业。对油菜茎秆在铺放台上和离开铺放台的运动过程进行分析,给出油菜茎秆能顺利被推送、抛出铺放台的条件。对油菜茎秆离开铺放台后的运动分析可知,油菜的铺放角与油菜本身的生物学特征、割晒机的结构参数和割晒机的运动参数有关。田间试验表明,割晒机作业后形成的油菜铺条整齐性和一致性较好,测得铺放角平均值48.4°,铺放厚度平均值511.6 mm,铺放宽度平均值797.8 mm,割茬高度平均值365.5 mm,铺放质量满足后熟条件和后续捡拾的作业要求。     

Windrowing poultry litter after a broiler house has been sprinkled with water

In-house windrowing of poultry litter between broiler flocks has been promoted as a management practice to improve the litter condition upon chick placement. Before the onset of the current study, low-pressure sprinklers were used during the grow-out period in a broiler house. Different methods of windrowing were then utilized to determine the effect each had on litter composition. Covered, turned, and static 9 d windrow treatments, and one non-windrowed control were applied to a broiler house containing litter used over multiple flock grow-outs. The house was divided into 16 6 × 6 m plots with each treatment being applied to 4 blocks within the house. Litter from each plot was analyzed for particle size, moisture, N, NH₃, P, K, pH, and temperature over a 20-day period, with d 20 representing 7 d after chick placement. All variables except particle size were statistically different. Of all the treatments, the covered treatment showed the greatest reduction in moisture over the 20-day period. Nitrogen content was lowest in the turned treatment. Ammonia decreased from d 9 to 20. Both the covered and static treatments were able to reach recommended temperatures in both the core and the periphery of the windrows. Conclusively, in-house windrowing after utilizing low-pressure sprinklers did not improve N retention, reduce NH₃ volatilization, or decrease P or K in the litter compared to the control. However, the temperatures obtained in the periphery and core of the covered and static treatments show potential for eliminating pathogens present in the litter.     

油菜割晒机拨指输送链式输送装置研制与试验

为了解决油菜割晒作业输送铺放难题,研制了油菜割晒机拨指输送链式输送装置,可以实现油菜割晒输送、铺放作业。该研究对拨指输送链式输送装置进行了结构设计,在排禾口处,在保证拨指运动不干涉的条件下,控制拨指回缩的轨道应尽量前伸,以保证在排禾口处拨指一直对油菜茎秆有拨动输送作用。在分析拨禾轮对油菜植株作用过程以及对已割油菜茎秆推送作用的基础上,给出了油菜割晒作业顺利输送时输送装置、拨禾轮、割刀三者之间水平与垂直安装距离以及输送装置安装倾角。拨禾轮中心与割刀的水平距离调节范围应为0～276 mm,割刀和输送装置前端之间的水平距离应根据油菜茎秆高度而定,一般不超过300 mm。拨禾轮中心的高度应大于1100 mm,高度可调。输送装置前端与割刀的垂直距离应小于125 mm。输送装置安装倾角10°～20°。分析了拨指运动轨迹方程,对输送带上油菜茎秆进行了受力分析。给出了油菜茎秆顺利输送铺放时机器前进速度、输送带速度、拨禾轮转速之间的相互关系。拨禾轮圆周线速度与机器前进速度的比值控制在1.1～1.5,输送带速度与前进速度的比值控制在3.2～5.0。田间试验表明,该输送铺放装置性能稳定,作业顺畅,油菜割晒作业总损失率≤0.85%,油菜茎秆铺放角≤32°,铺放角度差≤25°,铺放质量达到要求。