基于响应面法和NSGA-II算法的麦弗逊悬架优化

应用响应面法和经过改进的非支配排序遗传算法(NSGA-II)进行悬架结构参数优化.在ADAMS/Insight软件中进行设计参数的灵敏度分析，针对灵敏度较大的设计参数，建立车轮定位参数在车轮跳动过程中最大变化量的2阶响应面近似数学模型对该模型进行稳定性分析，并且应用加入精英保持策略和去除重复个体算法的NSGA-II优化算法对多目标响应面模型进行优化求解.优化结果表明该方法具有较高的精确性与有效性.     

Molecular characterisation of Theileria equi and risk factors associated with the occurrence of theileriosis in horses of Punjab (Pakistan)

Theileria equi (T. equi) is an obligate intra- and extra-erythrocytic parasite that causes equine theileriosis (ET) in equids. Equine theileriosis is considered a notifiable disease of global significance, a major constraint to the international movement of horses, and endemic in many countries. This disease may be difficult to diagnose, as it can produce variable and nonspecific clinical signs. A cross-sectional study was designed for the molecular characterisation of T. equi and to investigate the associated risk factors of ET accompanied by its consequences on haematological and sero-biochemical parameters. A convenience sampling of 500 blood samples were collected from ET suspect horses from January to December 2017. PCR was performed on all blood samples targeting the 18S rRNA gene of T. equi followed by sequencing; 9% animals tested positive with confirmed sequences. The isolates of this study showed high homology with Cuban, Russian and Brazilian isolates of T. equi (accession numbers KY111762.2 , MG551915.1 and KY952237.1 , respectively). Based on multivariate analysis, the principal risk factors consisted of absence of dogs on the premises and presence of tick infestation. The haemato-biochemical parameters showed a decrease in granulocytes and erythrocytes, and an increase in lymphocytes, monocytes, mean corpuscular volume, mean corpuscular haemoglobin, mean platelet volume, glucose, phosphorus and aspartate aminotransferase in positive horses. This is the first study which identified ET in Punjab (Pakistan) using molecular techniques and risk factors together with the haemato-biochemical variations in horses.     

三种荒漠植物叶绿素荧光参数日变化特征

利用Photosynq MultiseQ多功能植物测量仪测定塔克拉玛干沙漠腹地3种主要防护林植物头状沙拐枣、多枝柽柳和梭梭的叶绿素荧光参数日变化,探讨其与环境因子的关系,以揭示3种植物对极端环境的适应策略,为沙漠公路防护林的管护提供理论依据。结果表明：1）3种土壤都呈碱性;0~30 cm土层中的电导率（EC）远高于30 cm以下的土层。1 m内梭梭土层中的含水量高于多枝柽柳高于头状沙拐枣。2）3种植物的光合有效辐射（PAR）、叶片温度和线性电子传递（LEF）及植物周围的大气温度日变化均先升后降,且都在14：00达到最高;而大气湿度、实际光化学效率Y_（II）日变化均呈‘V’型。3）PAR基本上与3种植物的LEF、非光化学淬灭系数（NPQ）、调节性能量耗散量子产量Y_（NPQ）、非调节性能量耗散量子产量Y_（NO）呈显著正相关,与实际光化学效率Y_（II）呈显著负相关;3种植物的Y_（II）与Y_（NPQ）、Y_（NO） 均呈极显著负相关。3种植物的LEF、Y_（II）、Y_（NPQ）的日均值差异不显著,但梭梭与多枝柽柳的NPQ和Y_（NO）日均值差异显著。4）在3种植物的叶绿素荧光参数中,梭梭和头状沙拐枣的LEF、NPQ和Y_（II）要高于多枝柽柳;而多枝柽柳的Y_（NO）要显著高于头状沙拐枣和梭梭。因此,高温和高光均对3种植物造成了不同程度的影响,通过主成分分析表明,3种植物的抗逆性强弱顺序分别为梭梭>头状沙拐枣>多枝柽柳。     

返青期休牧对退化高寒草地植被特征及优势种光合生理的影响

为探讨返青期休牧对退化高寒草地植被特征及优势种光合生理的影响,本研究在祁连山区选择已实施返青期休牧6年的高寒草甸开展了植被特征及优势种光合生理相关指标的调查研究。结果表明：返青期休牧6年后,高寒草甸的植被盖度、地上生物量、地下生物量和土壤含水量较未休牧区分别增加了38.44%,985.00%,209.56%和62.62%,其优势禾草垂穗披碱草（Elymus nutans）株高、叶片净光合速率、光化学量子效率、呼吸速率、叶面积、相对叶绿素含量和叶片氮含量分别提高了965.77%,139.86%,4.92%,269.37%,254.13%,197.02%和96.24%（P<0.05）,其地上地下生物量与除叶温和光化学猝灭系数外的指标显著相关,叶片净光合速率与除叶温外的指标显著相关。因此,返青期休牧可显著增强高寒草地优势禾草的光合作用和呼吸作用,促进植物生长及退化草地的恢复。本研究为推广实施返青期休牧这一措施来恢复退化高寒草地植被提供了理论基础。     

Relationship between serum cortisol levels and some physiological parameters following reining training session in horse

The changes of cortisol, red blood cells (RBC), hemoglobin (Hb), hematocrit (Hct), heart rate (HR), respiratory rate (RR) and rectal temperature (RT) were evaluated after a reining training session in eight Quarter Horses. All parameters were measured before exercise (T0), immediately after exercise (T1), 1 h after exercise (T2), 2 h after exercise (T3) and 24 h after exercise (T4). One‐way analysis of variance (ANOVA) for repeated measures, followed Bonferroni's post hoc test, showed a significant effect of the reining training session (P < 0.0001) on cortisol, RBC, Hb, Hct, HR, RR and RT. Simple linear regression analysis showed the positive correlation (P < 0.05) between cortisol changes and variations of studied parameters in T1, T3 and T4. Exercise‐induced cortisol concentrations reflect the physiological response of reining training, suggesting that the changes observed are useful to assess the performance in reining horses and their reining training adaptability.     

Effect of micronized pea seeds (Pisum sativum L.) as a substitute of soybean meal on tissue fatty acid composition and quality of broiler chicken meat

This study aimed to evaluate the effect of micronized pea seeds introduced into feed mixes for broilers on the slaughter yield, blood lipid parameters, content of fatty acids in selected tissues, and meat quality. The studies involved 150 1‐day‐old Ross 308 chicks split into three groups (for 42 days). The feed rations differed in terms of the source of proteins: in the control group (C), it was post‐extraction soybean meal (SBM) 100%; in group I, SBM 50% and micronized peas 50%; and in group II, micronized peas only, 100%. Irradiated pea seeds added to the feed ration for chicks reduced the fattening grade of carcasses (P < 0.05). Additionally, significant improvement of blood lipid indices was recorded. The share of the irradiated pea seeds in feed mixes decreased the share of saturated fatty acids in the muscles and abdominal fat and had a positive effect on the n‐6/n‐3 ratio, hypocholesterolemic / hypercholesterolemic ratio, as well as the atherogenic and thrombogenic indices (P < 0.05).     

Incorporation of sunflower oil or linseed oil in equine compound feedstuff: 1 Effects on haematology and on fatty acids profiles in the red blood cells membranes

Eight trained horses (6 mares – 2 geldings, 6 Selle Français, 2 Trotteur Français, 12 ± 5.8 years old, 538 ± 72.5 kg) were offered three diets to potentially affect haematology and the fatty acids (FA) profiles in red blood cells (RBC) membranes. The control diet was composed of 50% hay and 50% concentrate containing mainly rolled barley (48%) and whole spelt (48%). In the case of sunflower oil diet, sunflower oil (62.0% of α‐linoleic acid, LA) was incorporated at a rate of 8% and substituted by an equal proportion of barley. In the linseed oil diet, first cold‐pressed linseed oil (56.0% of α‐linolenic acid, ALA) was utilised at a similar incorporation rate of 8%. The experimental design consisted of three 3 × 3 latin squares with one being incomplete. Each period lasted 8 weeks. On average, the total feed intake (straw excluded) was 6.2 kg/day and the oil intake 0.278 kg/day. The oils significantly increased the concentrations of RBC, haemoglobin and haematocrit. The oils had no significant impact on the haematology profiles except that platelets tended to decrease in both oil‐based diets. The most abundant FA in the RBC membranes of the control diet samples were in the decreasing order LA, C18:1n9‐7, C18:0, C16:0 and the arachidonic acid (ARA) respectively. The sunflower oil supplementation slightly increased the amount of LA (36.23 vs. 34.72 mg/dl, p = 0.55) and C22:4n‐6 (0.21 vs. 0.09 mg/dl, p = 0.22), while the decrease was observed in case of other FA (C16:1n‐7, 1.08 vs. 1.42 mg/dl, p = 0.03), C20:3n‐6 (0.22 vs. 0.31 mg/dl, p = 0.02), and ARA (1.17 vs. 1.63 mg/dl, p = 0.08). Linseed oil induced similar effects in the n‐6 series FA profiles. In the context of practical applications, our results show that linseed oil incorporation in the diet could improve the haematology and the n‐3 FA profiles potentially leading to an increased performance.     

The suitability of some blood gas and biochemical parameters as diagnostic tools or early indicators of ascites syndrome in broiler sire lines

In recent few years, there have been some attempts to find a reliable indicator trait as a selection criterion against susceptibility to ascites syndrome (AS). Blood parameters were of great interest as they could be measured in live animals without implementing an ascites‐inducing challenge (AIC). In this work, the suitability of some blood parameters was evaluated for diagnosing AS‐susceptible chicks in later steps of the disease in trial 1 as well as their early predictive ability in trial 2. In the first trial, one hundred 1‐day‐old chicks from two pure broiler lines namely S₁ and S₂ and, in the second trial, 226 1‐day‐old chicks from line S₂ were subjected to AIC. Saline drinking water (1200 mg/l) and lower‐than‐standard ambient temperatures were the implemented AICs in trials 1 and 2 respectively. The blood parameters including pH, partial pressure of O₂ (pO₂), partial pressure of CO₂ (pCO₂), bicarbonate ion concentration (BIC), percentage of haematocrit (HCT) and saturated haemoglobin (SaO₂) were measured twice per each bird at days 28 and 35 in trial 1 and once in trial 2 at day 21. The results of the first trial revealed that in line S₂ some of the blood parameters differed significantly between the ascitic and non‐ascitic groups following exposure to AIC. In this line, the incidence of AS was accompanied by a lower pO₂, SaO₂ and BIC, while with higher pCO₂ and HCT values. In the second trial, however, although almost all of the parameters showed meaningful differences between the ascitic and non‐ascitic broilers, only mean difference of BIC parameter was statistically significant. The general conclusion of this study is that the blood parameters can somewhat have diagnostic ability in the condition in which the AIC is already present, whereas the results did not approve their usefulness as early predictors of AS.     

The influences of ambient temperature and crude protein levels on performance and serum biochemical parameters in broilers

This study was undertaken to investigate the effects of ambient temperature, crude protein levels and their interaction on performance and serum biochemical parameters of broiler chickens. A total of 216 Arbor Acre broiler chickens (108 males and 108 females) were used in a 2 × 3 factorial arrangement and randomly reared at two temperatures (normal temperature: 23 °C; daily cyclic high temperature: 28–32 °C) and fed on three diets with different crude protein levels (153.3, 183.3 or 213.3 g/kg, with constant essential amino acids) from 28 to 42 days of age. Daily cyclic high ambient temperature decreased final body weight, average daily weight gain, average daily feed intake and serum total protein contents (p < 0.001, p < 0.001, p < 0.001, p = 0.008 respectively), but increased feed/gain, mortality, respiratory rate, rectal temperature, serum uric acid contents and serum creatine kinase activity (p = 0.008, p = 0.003, p < 0.0001, p < 0.0001, p < 0.0001, p = 0.003 respectively), irrespective of crude protein levels. At the ambient temperature, reducing crude protein levels resulted in an increase in feed/gain (p < 0.001), but a decrease in serum total protein and uric acid contents. Only serum creatine kinase activity in broiler chickens was interacted by daily cyclic high ambient temperature and dietary crude protein levels (p = 0.003). These results indicated that daily cyclic high ambient temperature had a great effect on performance and serum biochemical parameters in broiler chickens, whereas dietary crude protein levels affected them partially.     

微生物菌剂在蔬菜基质研发与应用上的研究进展

综述了在固体有机废弃物基质发酵过程中,添加微生物菌剂对堆体温度、p H值、养分含量和C/N等关键腐熟指标的影响,分析了微生物菌剂在蔬菜基质育苗和栽培上的应用效果及其作用机制,并展望了微生物菌剂在未来基质研发上的应用前景,以期为含有微生物菌剂的功能型蔬菜基质开发提供新的思路。