饮水添加沼液对肉鸡生产性能的影响

沼气池的建设是农村新能源综合开发利用推广项目之一,极大地提高了农民生活质量。沼液、沼渣的再开发利用是进一步推进该项目所面临的问题。饮水中添加50%的沼液饲喂4周龄AA肉仔鸡进行35d生长试验,效果明显。平均每只鸡增重0.0666±0.0166Kg,比对照组提高7.5%,总耗料量降低2.7%,料重比降低0.34,均差异显著(P<0.05)说明饲料转化率明显提高。成活率试验组比对照组提高2个百分点。屠宰率提高0.85个百分点,差异不显著(P>0.05),但胸肌率比对照组提高4个百分点,差异显著(P<0.05)。     

氟喹诺酮类药物多组分残留检测抗体的筛选

通过N-羟基琥珀酰亚胺活性酯法将诺氟沙星、环丙沙星、达氟沙星和沙拉沙星分别与牛血清白蛋白偶联制备免疫抗原,与卵清白蛋白偶联制备检测抗原,筛选一种可用于多种氟喹诺酮残留的检测抗体。将免疫抗原分别免疫獭兔制备多克隆抗体,采用间接竞争ELISA法测定抗体特异性。诺氟沙星抗体特异性较强,与同类药物的交叉反应较少,沙拉沙星抗体与同类药物发生交叉反应最多,且与诺氟沙星、环丙沙星和恩诺沙星的交叉反应率较高。结果表明,确定沙拉沙星抗体作为进一步研究的抗体。     

The effects of continuous and rotational grazing of sourveld on the quality of herbage selected by Simmentaler heifers

A grazing trial was conducted at the Kokstad Agricultural Station to compare the dry matter digestibility (DMD) and crude protein content (CP) of diets selected by four fistulated cattle which were continuously and rotationally grazing sourveld. Two stocking rates of 1,0 and 2,3 animals/ha (0,5 and 1,2 LSU/ha) were applied under each grazing method. The mean DMD and CP values of diets selected in the continuous and rotational grazing treatments, respectively, were: DMD=64,3%, 62,3%; CP=6,63%, 6,88%. The effect of stocking rate on the quality of the diet selected varied between the two grazing methods. DMD and CP of diets selected under rotational grazing decreased with time during the week‐long period of stay in each paddock. On average, DMD and CP values on the first and sixth day respectively, were: DMD=66,6%, 60,5%; CP=8,37%, 6,01%. These differences were more pronounced at the higher than at the lower stocking rate. It was concluded that, although some of the treatment differences were small, grazing method differences in the DMD of diets might at least partially account for observed differences in livemass gains under the two grazing systems.     

Towards the development of a bioeconomic stocking model for the semi‐arid savanna of KwaZulu‐Natal

Abstract

Rainfall variability is a major determinant of system dynamics and profitability of livestock enterprises in arid and semi‐arid environments. Range managers consequently require detailed information on the financial and ecological implications of various stocking strategies in order to formulate viable management systems. Data collected over seven seasons (1986–1993), from a series of extensive grazing trials in the semi‐arid savanna of KwaZulu‐Natal with cattle stocked at three rates (0.17, 0.23 and 0.30 LSU ha^?1) were used to develop a bioeconomic stocking model (LOWBEEF). The model comprised two biological sub‐models (BEEF and GRASS), and an integrated economic component. The BEEF sub‐model related seasonal live mass gain to stocking rate and rainfall. The GRASS sub‐model related residual herbage at the end of summer to summer stocking intensity, range condition (indexed as the sum of proportions of three key forage species, Themeda triandra, Panicum maximum and P. coloratum) and rainfall. The period over which supplementary feeding would be required to maintain cattle mass was related to residual summer herbage mass. The biological sub‐models were linked to an economic component model (ECON) to reflect the influence of various environmental and economic parameters on profitability.     

绵羊冷冻精液研究进展

随着肉羊产业化、工厂化的发展,冷冻精液人工授精技术亟待应用于生产中.绵羊精液冷冻保存技术虽然得到了快速发展,但目前仍处在试验研究或小范围的应用阶段.因此,绵羊精液冷冻技术还需要深入、系统的研究.文章从绵羊精液冷冻保存稀释液中的添加剂、冷冻速率、冷冻-解冻对绵羊冷冻精液品质的影响,精液输精对受胎率的影响等方面进行了综述,为精液冷冻保存研究提供一定参考.     

海狸色獭兔与皱襞型獭兔不同交配组合生产性能比较研究

试验为探究海狸色獭兔与皱襞型獭兔不同交配组合生产性能比较,随机选取6~7月龄健康皱襞型獭兔和海狸色獭兔各40只（30只母兔和10只公兔）,进行不同交配组合试验,分别为海狸纯繁组（海狸色獭兔（♂）×海狸色獭兔（♀））、皱襞纯繁组（白色皱襞型獭兔（♂）×白色皱襞型獭兔（♀））、正交组（海狸色獭兔（♂）×白色皱襞型獭兔（♀））和反交组（白色皱襞型獭兔（♂）×海狸色獭兔（♀））,测定母兔繁殖性能和后代生长性能、屠宰性能及被毛品质。结果显示：正交组初生窝重320.71 g、产仔数6.71只、泌乳力1 727.43 g、仔兔断奶成活率83.91%、仔兔断奶窝重5 304.14 g、幼兔料重比4.06、屠宰率62.43%、皮张面积1 160.20 cm²、被毛密度15 951.70根/cm²、被毛细度16.32 μm、粗毛率6.83%;反交组初生窝重315.14 g、产仔数6.52只、泌乳力1 710.00 g、仔兔断奶成活率80.19%、仔兔断奶窝重4 814.82 g、幼兔料重比4.30、屠宰率62.93%、皮张面积1 172.20 cm²、被毛密度16 092.01根/cm²、被毛细度16.43 μm、粗毛率6.78%,经比对两组间差异均不显著（P>0.05）;而海狸色纯繁组的初生窝重、产仔数、泌乳力、仔兔断奶成活率、仔兔断奶窝重、皮张面积、被毛密度、被毛细度均较皱襞型纯繁组低、而幼兔料重比、屠宰率及粗毛率均较皱襞型纯繁组高,经比对两个纯繁组间除料重比、屠宰率、被毛细度和粗毛率差异不显著外（P>0.05）,其他各指标差异均显著（P<0.05）。综上所述,正交组合亲代的繁殖性能及F1代的生长性能和屠宰性能均略好于反交组合;而反交组合F1代的被毛品质略好于正交组合。     

分离Y精子在茸鹿性别控制中的应用研究

为研究一种新的茸鹿繁殖方法,2007～2008年对469头马鹿,79头梅花鹿进行性别控制技术研究。结果表明：性别控制冻精情期受胎率马鹿为87．21％,梅花鹿为60．76％,两者之间差异极显著（P〈0．01）,性比率（指产公仔率）马鹿为90．95％,梅花鹿为93．75％,两者之间无显著差异（P〉0．05）;性别控制冻精与普通冻精输精比较,马鹿情期受胎率之间、性比率之间和梅花鹿性比率之间都存在极显著差异（P〈0．01）,梅花鹿情期受胎率之间则无显著差异（P〉0．05）。普通冻精受胎率马鹿为94．89％、梅花鹿为61．63％,性比率马鹿为50．22％、梅花鹿为49．06％,性别控制冻精受胎率整体接近普通冻精,性比率则提高40％以上,比较分析认为对茸鹿X、Y精子分离进行性别控制试验是成功的。     

苗期紫花苜蓿品种抗旱性初步研究

运用多元统计分析方法,以来自、美国、澳大利亚、加拿大及中国的22个紫花苜蓿Medicago sativa品种（种群）为试验材料,对紫花苜蓿在苗期进行短期干旱胁迫,依据试验测定的15个形态指标和生理指标,应用主成分分析、聚类分析法,对22个紫花苜蓿品种试验材料的抗旱能力进行综合评价。通过运用主成分分析法将15项相关的抗旱性指标简化为5个独立且功能明确的主成分,并以5个主成分的得分系数运用聚类分析法把22份材料聚为三大类,从而将22份材料分为强抗旱性品种、中抗旱性品种、弱抗旱性品种,为下一步抗旱机制的研究提供参考。     

Factors responsible for levels of male sterility in photoperiod-sensitive cytoplasmic male sterile (PCMS) wheat lines

A `two-line system' using photoperiod-sensitivecytoplasmic male sterility (PCMS) caused by Aegilops crassa cytoplasm has been proposed as a newmeans of producing hybrid wheat. The PCMS line ismaintained by self-pollination under short-dayconditions (14.5 h light period), and F<sub>1</sub> seedscan be produced by outcrossing of the PCMS line witha pollinator under long-day conditions (15 h lightperiod). As the levels of male sterility in PCMSlines under the long-day conditions is a crucialfactor in determining hybrid purity of the F<sub>1</sub>seeds, a study was conducted into the effect ofseeding rate on male sterility in PCMS lines. Threedifferent density levels were tested using analloplasmic line of Japanese wheat cultivar `Norin 26'which exhibits PCMS. Levels of male sterility of thePCMS line increased at sparse planting, because tiller(ear) number per plant increased at low seedingdensity and late-appearing ears tended to exhibithigher levels of male sterility than early-appearingears. On the other hand, male sterility levels of thePCMS lines depended on genotype, e.g., the PCMS`Fujimikomugi' was completely male sterile, whereasthe PCMS `Norin 26' showed partial male sterility. APCMS line showing complete male sterility, such as thePCMS `Fujimikomugi', should produce F<sub>1</sub> seeds withhigh purity. However, the PCMS `Fujimikomugi' showeda lower female fertility. For practical use, it isnecessary to produce PCMS lines having high malesterility with high female fertility under long-dayconditions.     

内蒙古典型草原地区常见植物光合、蒸腾速率和水分利用效率的比较研究

在所测78种植物中，光合(Ph)、蒸腾速率(Tr)和水分利用效率(WUE)的平均值，分别以反枝苋、藜和西伯利亚滨藜最高。在不同分类系统中，Ph、Tr和WUE个指标，C4植物大于C3植物；双子叶植物通常大于单子叶植物；藜科植物高于其他科植物；1—2年生草本高于其他生活型植物；撂荒地植物一般高于其他植被类型的植物。方差分析表明，光合速率的差异显著性水平在各分类系统中均高于蒸腾速率和水分利用效率。