Feed intake pattern of broiler chickens under intermittent lighting: Do birds eat in the dark?

This paper reflects the results of a short experiment conducted in parallel with a larger trial which aimed to test the assumption that ‘consumption of feed by broiler chickens during periods of darkness is largely negligible’. To that effect, on d 31, feeders of birds raised under intermittent lighting (IL), i.e. 1 h of light [1L]:3 h of dark (3D):1L:3D:1L:3D:1L:3D:2L:6D, were weighed at the onset and at the end of each period of darkness (or scotoperiod). Moreover, in order to compare the feeding behavior of IL birds with that of broilers raised under continuous lighting (CL, i.e. 18L:6D), their feeders were weighed in parallel and at the same time points. On d 31, feed intake of IL birds during scotoperiods represented 45% of their 24 h feed intake. Both CL and IL birds presented anticipatory feed intake prior to the long nocturnal period of darkness (6D), as well as higher feed intake right at the onset of lighting at 06:00. Feed intake of CL birds during the 6D nocturnal scotoperiod was negligible at around 2% of their total feed intake. Intermittent lighting birds exhibited excitement at the start of each hour-length scotoperiod and, within that time, ingested around 2.5 times the amount of feed ingested by CL birds. Although short, this study revealed several interesting observations which might be worth further exploring in a larger, lengthier, behavior-focused experiment. Amongst other factors, it might be interesting to understand whether the high feed intake observed during scotoperiods for IL birds in reflective of the whole flock or rather a coping mechanism developed mainly by hierarchically lower-ranking birds to achieve their daily feed intakes requirements.     

高产奶牛孕检后同期发情程序选择的研究

为了研究适用于高产奶牛的同期发情程序方案,将218头膘情良好、子宫和卵巢发育正常的不同胎次荷斯坦牛随机分成两组,试验1组为106头,试验2组为112头,分别采用两种同期程序(0.5.6.8和0.7.8.9)进行处理,测定情期受胎率,用于评价两种同期程序对高产奶牛的适用性。结果表明,试验2组情期受胎率平均为41.96%,显著高于试验1组的平均情期受胎率30.19%(P<0.01);将参与试验的218头牛根据胎次分成1胎组、2胎组和3胎及以上组,分析不同胎次对输精效果的影响,2胎情期受胎率最高为40.68%,与1胎情期受胎率存在显著差异(P<0.05),3胎及以上的情期受胎率最低为28.79%,与2胎、1胎存在极差异显著(P<0.01)。     

海林市地方国有林区纳入国家天然林保护工程的思考

介绍了海林市地方国有林区的基本情况,分析了国有林场面临的困难和存在的问题,阐述了地方国有林区纳入国家天然林保护工程的重要意义,并提出了相关建议。     

A pre-synchronization program at early postpartum might increase the chances of Bos indicus cows cycling prior to 50 days regardless of the length of calf separation

The aim of this study was to establish if pre-synchronization would enhance the number of animals cycling prior to conventional breeding at 45 days irrespective of the length of calf separation. Multiparous Bos indicus cows were allotted in four groups (n = 10). Control group (C) dams remained with their calves; groups G24, G48 and G72, which were partially weaned for 24, 48 and 72 h, respectively, were estrus synchronized using a controlled internal drug. These procedures were performed at 25 days and again at 45 days postpartum. The number of follicles, presence of a corpus luteum and back fat thickness (BFT) were determined by ultrasound. The proportion of cows with estrus and ovulation at day 25 postpartum was statistically different between the control and treated groups, with the values being 20, 60, 50 and 70 for the control, G24, G48 and G72 groups respectively (P < 0.05). At days 45 postpartum, the proportion of cows with estrus and ovulation was different in group G48 compared with the other groups (P <0.05). The average BFT and body condition score for the four experimental groups in the two periods were similar (P >0.05). Animals with a higher proportion of follicles from 17 to 21 mm, BFT values above 3.5 mm and a regular body condition were significantly different regardless of whether the dams remained with their calves or were separated, regardless of the length of this event. It can be concluded that (1) a pre-synchronization program at day 25 could trigger the onset of ovarian activity and facilitate a breeding program at day 50 and (2) temporary weaning enhances the effect of a pre-synchronization program.     

土壤养分与树木生长相关分析的程序处理

在进行树木的生长与土壤养分的相关分析过程中，采用QBASIC语言编写程序来进行处理，减轻了繁重的计算，操作方便灵活，提高了工作效率。     

退耕还林还草地区土壤有效水含量及蓄水性能研究--以陕西省吴旗县柴沟流域为例

对陕两省吴旗县黄土丘陵沟壑区退耕还林工程区的乔术（山杏和刺槐）、灌木（荆条、沙棘）及对照农田的土壤水分有效性和蓄水能力进行了比较研究。结果表明，不同植被类型的土壤有效水含量为1．92％～15．73％，林地比农田增加约75．3l％；0～40cm土层土壤蓄水量为228．30～251．07t／hm^2，林地比农田增加约8％；刺槐林地的蓄水性能好于山杏林地。结果对于科学地评价退耕还林工程的土壤改良效益、水源涵养效益具有重要的意义。     

数字林业在天然林保护工程中的应用研究

本文阐述了数字林业的概念及涵义,指出其最初的切入点是国家林业局提出的六大林业生态工程。针对天然林保护工程的现状,提出用数字林业技术解决其存在的问题,构建了基于3S技术的天然林保护工程管理地理信息系统,使天然林保护工程的管理步入规范化、科学化、现代化的轨道。     

区域景观生态规划中的绿化程序设计

区域景观生态规划中绿化程序是:(1)确立区域绿化目标;(2)地点调查;(3)地点分析;(4)地表准备;(5)绿化实施;(6)长期监控和管理.对程序各个环节的技术细节作了较详尽的论述.     

石羊河流域主要作物的需水量及需水规律的研究

试验于2008年在甘肃武威进行,采用水量平衡法在充分灌溉的条件下研究了石羊河流域春小麦、春玉米、制种油葵、色素辣椒、小麦/玉米带田等5种作物的需水量及需水规律,并根据作物生育期需水规律提出了适宜的灌溉制度.试验结果表明,春小麦全生育期需水量为480.5 mm,需水关键期为拔节期和抽穗开花期;春玉米需水量为569.0 m...     

茶饮料中7种农药残留检测能力验证分析

为保证农药登记残留试验水平,农业部农药检定所2010年组织了78个实验室参加了茶饮料中莠去津、吡虫啉、哒螨灵、腐霉利、乐果、高效氯氰菊酯和咪鲜胺7种农药残留检测能力验证试验。统计分析结果表明,7种农药全部合格的单位有41个（52.6%）,6种农药合格的有14个（17.9%）,5种农药合格的有11个（14.1%）,4种农药合格的有3个（3.8%）,3种农药合格的有4个（5.1%）,2种农药合格的有2个（2.6%）,只有1种农药合格的有1个（1.3%）,7种农药均不合格的有3个（3.8%）。