漳河水库入库洪水抗误差预报方案

漳河水库由观音寺水库和鸡公尖水库通过半天然明槽相互连通组成，因受库水位观测、明槽输水计算、动库容计算误差等的复杂影响，以往多次建立的洪水预报方案均未达到可供应用的水平。在分析漳河水库入库洪水误差产生特点的基础上，通过建立抗误差产汇流预报模型和自适应实时校正技术，使漳河水库洪水预报方案平均确定性系数达91.09%，洪峰合格率达100%，峰现时间合格率达90.91%；观音寺水库洪水预报方案的平均确定性系数达90.63%，洪峰合格率达100%，峰现时间合格率达100%，终于建立了达到甲等水平的漳河水库洪水预报应用方案。     

The effect of footrot on body weight and wool growth of sheep

Body weight and traits associated with production of wool were measured over a 2-year period between 1985 and 1987 in south-western New South Wales in a flock of Merino wethers experimentally infected with footrot. The disease was allowed to spread freely amongst 150 of the flock but kept at very low prevalence in the remaining 50 by preventive footbathing during transmission periods. Severe, underrunning footrot had a significant adverse effect on body weight, for each year of the trial. Body weight was most severely reduced at times of the year when footrot was spreading among animals and lesions were severe. The mean body weight of the infected group at the end of the 2 years of observation was 7.3 kg (11.6%) below that of the control group. Footrot also depressed wool growth, with the mean clean fleece weight of the infected group being 0.4 kg (8%) lighter than that of the controls at each of the 2 annual shearings. There were no consistent differences between the groups for the other wool characteristics measured.     

Studies on Immunological Effect and Immunological Mechanism Avian Encephalomyelitis Oil Emulsion Inactivated Vaccine

Oil emulsion inactivated vaccine was prepared by susceptible embryos, with different strains of AEV. Four groups of normal chickens of 2 - 7 days of age were given injections for immunization, respectively. Another group was used as control. This study was expected to evaluate the immunological effect and discuss the immunological mechanism by means of five different experiments, i.e. the agar-gel precipitin test,the isolation of lymphokine, the isolation, purification and analysis of blood serum IgG, embryo-susceptibility test, and clinical and pathological examination. The results of these experiments indicated that oil emulsion inactivated vaccine is safe and effective. The chickens were normal when inoculated with AE strong virus after immunity at 4 and 37 weeks. Immunological mechanism is that the humoral immunity played an important role and celluar immunity exists, but it is not important in the process of the resistance to AEV.     

Estimate of the variability of the lysine requirement of growing pigs using the indicator amino acid oxidation technique

Although AA requirements for the mean in a population of growing pigs are well established, there are no direct estimates of their variability within the population. The indicator AA oxidation method allows repeated measurements in a short period of time so that the AA requirement can be determined for individual pigs. The objective was to determine the Lys requirement in individual pigs to derive a first estimate of the population mean requirement and its variability. Nine individually housed barrows (15 to 18 kg) were surgically implanted with venous catheters for isotope infusion. Pigs were offered, in random order, isonitrogenous and isoenergetic diets with one of seven Lys concentrations (4.8 to 15.5 g of Lys/kg diet, as-fed basis). The pigs were fed twice daily, except for study days when they received one-half of the daily allowance in eight equal hourly meals. After a validated minimum adaptation period, indicator (Phe) oxidation was determined for each dietary Lys level during a 4-h primed, constant infusion of L-[1-(14C)]Phe at a rate of 464 kBq/h. The Lys requirement was calculated using a two-phase linear regression crossover analysis within individual pigs. For each pig, Phe oxidation decreased linearly (P < 0.02) as the dietary Lys concentration increased until the requirement was reached; thereafter, Phe oxidation was not different. The true ileal digestible Lys requirement ranged from 7.5 to 10.6 g/kg of diet (as-fed basis) for the nine animals. The mean requirement for all pigs was 9.1 g/d (CV, 11.6%) or 93.9% (CV, 9.8%) of the predicted (NRC, 1998) requirement based on each pig's mean BW and energy intake. The measured and predicted requirements did not differ. The indicator AA oxidation method gave values for Lys requirement similar to conventional methods. The short (< 3 wk) experimental period allows, for the first time, the estimate of population variability, which provides for more accurate calculation of the effect of altering Lys intake on herd performance and production economics. This method is suitable to use with all dietary indispensable AA.     

策勒黑羊选育现状及其对策

策勒黑羊是以生产羔皮为主的多胎优良地方品种,深受当地群众的喜爱。作者从育种的角度阐述了策勒黑羊选育现状及存在的问题,提出了今后的选育方向和对策。     

The threonine requirement of sows increases in late gestation

Current AA recommendations for sows are to provide a fixed amount of AA intake throughout gestation based on the assumption that there is a constant demand for AA; however, the demand for nutrients changes from maternal lean tissue in early gestation to fetal and mammary growth in late gestation. The objective of this study was to determine the Thr requirement in early (d 35 to 53 and 25 to 55 for Exp. 1 and 2, respectively) and late (d 92 to 110 and 81 to 111 for Exp. 1 and 2, respectively) gestation using the indicator AA oxidation (IAAO) method with l-[1-(13)C]Phe as the tracer AA. A total of 14 multiparous sows were used: 6 in Exp. 1 and 8 in Exp. 2. Each sow received each of 6 diets in random order in both early and late gestation. A basal diet was formulated to contain Thr at 60% of the 1998 NRC recommendation in Exp. 1 and 20 and 60% of the 1998 NRC in Exp. 2 for early and late gestation, respectively. Crystalline l-Thr was added to create additional diets with approximately 10% incremental increases in Thr. Sows were placed in respiration chambers, and expired air and blood were collected every 30 min for 5.5 h. Tracer Phe [mg/(kg of BW·h)] was given orally over the last 4 h divided into eight 0.5-h meals. Expired air and plasma were measured for (13)CO(2) enrichment and free Thr concentration, respectively. Background (13)CO(2) was subtracted from plateau (13)CO(2) enrichment. Data were analyzed using a 2-phase nonlinear Mixed model. The overall litter size and litter weight were 13.5 ± 3.1 and 20.5 ± 3.9 kg, respectively. Based on IAAO, the Thr requirement in early gestation was 6.1 g/d (R(2) = 0.59, Exp. 1) and 5.0 g/d (R(2) = 0.71, Exp. 2). In late gestation, the Thr requirement based on IAAO was 13.6 g/d (R(2) = 0.60, Exp. 1) and 12.3 g/d (R(2) = 0.58, Exp. 2). Based on plasma Thr, the Thr requirement in early gestation was 7.0 g/d (R(2) = 0.90, Exp. 1) and 3.9 g/d (R(2) = 0.90, Exp. 2). In late gestation, the Thr requirement based on plasma Thr was 10.5 g/d (R(2) = 0.67, Exp. 2). There was a linear response to increasing Thr intake in late gestation in Exp. 1. Feeding a single amount of AA throughout gestation results in overfeeding AA in early gestation and underfeeding AA in late gestation. The 2-fold increase in Thr requirement in the last third of gestation suggests that phase feeding sows in gestation will more closely meet the demands for nutrients and that the requirement for essential AA in gestating sows should be re-evaluated in early and late gestation separately.     

粗饲料品质对体外发酵部分指标的影响

本试验以安装有永久性瘤胃瘘管的3头荷斯坦奶牛为动物模型,利用体外批次培养法,比较研究了玉米青贮、苜蓿干草、羊草和玉米秸秆等四种单一粗饲料体外发酵效果。本试验以GI为指标对粗饲料品质进行测定,GI指数分别为9.05MJ、48.71MJ、9.41MJ和1.81MJ。结果表明:粗饲料品质对培养液pH值有显著影响(P<0.05),平均值分别为(6.436、.476、.506、.41),随着培养时间的延长,各组pH值均呈下降趋势,其中秸秆组下降幅度最大,24h培养液pH值为6.27,羊草组pH值下降幅度最小;粗饲料品质对培养液NH3-N、产气量、VFAs和BCP产量有显著影响(P<0.05),其中苜蓿最高,秸秆最低,青贮NH3-N和VFA产量高于羊草,羊草产气量和BCP产量高于青贮;各组培养液乙/丙比例平均值大小顺序为羊草>秸秆>苜蓿>青贮,平均值分别为(2.132、.042、.001、.73)。