计算机视觉技术在智慧羊场中的研究进展

智慧羊场具有科学化、标准化管理的优点,是羊场转型发展的趋势.计算机视觉技术是人工智能的核心,可以实现非接触性、自动化、实时监测羊的个体信息.本文总结并分析了计算机视觉在羊场的个体识别方法、行为识别方法、体尺与体重估测、疾病监测的研究现状,并指出计算机视觉在智慧羊场的进一步发展趋势.     

Length–mass allometries in amphibians

Body mass is rarely recorded in amphibians, and other body measurements (e.g. snout to vent length, SVL) are generally collected instead. However, length measurements, when used as proxies of body mass in comparative analyses, are problematic if different taxa and morphotypes are included. We developed allometric relationships to derive body mass from SVL measurements. We fitted phylogenetic generalized least square models for frogs (Anura) and salamanders (Caudata) and for several families separately. We tested whether allometric relationships differed between species with different habitat preferences and between morphs in salamanders. Models were fitted with SVL–mass measurements for 88 frog and 42 salamander species. We assessed the predictive performance of the models by cross‐validation. Overall, the models showed high explained variance and low forecasting errors. Models differed among semi‐aquatic, terrestrial and arboreal frogs, and between paedomorphic and non‐paedomorphic salamanders. Body mass estimates derived from our models allow for comparability of studies on multiple taxa and can be used for testing theories built upon evolutionary and ecological processes which are directly related to body mass.     

The effects of chronic intermittent noise exposure on broiler chicken performance

Effects of different noise levels (70 or 80 dB) that broilers were exposed to during the entire fattening period and also the effect of the timing of the first exposure to intermittent noise in the course of fattening (day 1 vs. day 7) were monitored. After 7 days of exposure to intermittent noise, experimental chickens already showed a significant decrease in live body weight in comparison with the control group. The difference between the group exposed to intermittent noise at 70 dB and the group exposed to 80 dB levels was not statistically significant, although the mean live body weight of broilers in the latter was lower during the entire fattening period. The chickens exposed to intermittent noise from day 1 of age showed lower mean live weight throughout the fattening period compared to chickens exposed to the same level of intermittent noise only from day 7 of age, although at the end of fattening the difference was statistically significant only in chickens exposed to the higher level of intermittent noise (80 dB).     

The influence of body mass and thoracic dimensions on arterial oxygenation in anaesthetized horses and ponies

ObjectiveTo examine the relationship between body mass and thoracic dimensions on arterial oxygen tensions (PaO₂) in anaesthetized horses and ponies positioned in dorsal recumbency.Study designProspective clinical study.AnimalsThirty six client-owned horses and ponies, mean [±SD (range)] age 8.1 ± 4.8 (1.5–20) years and mean body mass 467 ± 115 (203–656) kg.MethodsBefore general anaesthesia, food and water were withheld for 12 and 1 hours respectively. Body mass (kg), height at the withers (H), thoracic circumference (C), thoracic depth (length between dorsal spinous process and sternum; D), thoracic width (between point of shoulders; W), and thoracic diagonal length (point of shoulder to last rib; L) were measured. Pre-anaesthetic medication was with intravenous (IV) romifidine (0.1 mg kg⁻¹). Anaesthesia was induced with an IV ketamine (2.2 mg kg⁻¹) and diazepam (0.05 mg kg⁻¹) combination and maintained with halothane in 1:1 oxygen:nitrous oxide (N₂O) mixture. Animals were positioned in dorsal recumbency and allowed to breathe spontaneously. Nitrous oxide was discontinued after 10 minutes, and arterial blood samples obtained and analysed for gas tensions at 15, 30 and 60 minutes after connection to the anaesthetic breathing circuit. Data were analysed using anova and Pearson's correlation co-efficient.ResultsThe height per unit body mass (H kg⁻¹) and thoracic circumference per unit body mass (C kg⁻¹) correlated strongly (r = 0.85, p < 0.001 and r = 0.82, p < 0.001 respectively) with arterial oxygen tensions (PaO₂) at 15 minutes.ConclusionsThere is a strong positive correlation between H kg⁻¹ and C kg⁻¹ and PaO₂ after 15 minutes of anaesthesia in halothane-anaesthetized horses positioned in dorsal recumbency.Clinical relevanceReadily obtained linear measurements (height and thoracic circumference) and body mass may be used to predict the ability of horses to oxygenate during anaesthesia.     

散养模式下白羽肉鸭屠宰性能与体尺指标相关性研究

本研究对30只94日龄中畜小型白羽肉鸭(CMD)在大群地面散养方式下的屠宰性能和体尺指标进行了测定,并对测定结果进行了相关分析,结果发现活重与体斜长、龙骨长、胸宽、胫围、半潜水长等体尺指标的相关系数分别达到0.588、0.660、0.618、0.654、0.582,均达到极显著水平(P<0.01);全净膛重与体斜长、龙骨长、胫围、半潜水长等体尺指标的相关系数分别达到0.476、0.566、0.552、0.455,均达到显著(P<0.05)或极显著水平(P<0.01)。此外,研究分别建立了活重与体斜长、龙骨长、胸宽、胫围、半潜水长以及全净膛重与体斜长、龙骨长、胫围、半潜水长的回归模型,两个回归模型经F检验均达到显著水平(P<0.05)。     

蒙古羊羊水源干细胞分离培养及其成骨分化研究

试验旨在建立羊水源干细胞系并对其诱导形成成骨细胞的潜能进行研究。在胎牛血清浓度为15%的条件下对羊水源干细胞进行建系,并检测其类胚体形成能力;检测不同代数细胞的干细胞标志基因Oct-4、SH2、SSEA-1、Nanog、HLA-ABC、CD117的表达情况;利用地塞米松、β-甘油磷酸钠、抗坏血酸等因子进行诱导。结果表明,羊水源干细胞在体外可以持续增殖,悬浮培养形成的类胚体表达三胚层相关标记基因,经诱导可形成成骨细胞。试验成功分离了蒙古羊的羊水源干细胞并建系,且其具有向成骨细胞分化的潜能。     

植酸酶对金鳟体成分及金鳟椎骨中钙、磷含量的影响

采用喷涂法和预处理两种方法,在豆粕型金鳟饲料中添加不同浓度的植酸酶,通过90 d的饲喂试验,研究植酸酶对金鳟(Oncorhynchus mykiss Walbaum)体成分及其椎骨中钙、磷含量的影响。结果显示:喷涂法和预处理法添加植酸酶的处理组与对照组相比,粗蛋白、粗脂肪的含量均有所下降;喷涂法添加植酸酶的处理组的鱼体粗灰分、磷和钙含量均高于对照组,其中,喷涂法添加1500 U/Kg植酸酶组鱼体磷含量、灰分含量和钙含量显著高于对照组(P(0.05),且此组鱼体磷高于其它试验组;喷涂法各组椎骨中粗灰分、磷含量较对照组提高显著(P(0.05),2500 U/kg植酸酶组椎骨磷含量最高,椎骨中钙含量除D1和D8组外,添加植酸酶的处理组均较对照组提高显著(P(0.05)。预处理法添加植酸酶的处理组与对照组相比,鱼体和椎骨中粗灰分、磷和钙含量均有显著提高(P(0.05),但植酸酶试验组间椎骨中粗灰分、磷含量和钙含量差异均不显著(P(0.05)。结果表明,金鳟饲料喷涂法添加植酸酶1500~2500 U/kg浓度最适,预处理法添加植酸酶500 U/kg浓度较为宜。     

基于全基因组填充重测序关联分析鉴别影响苏山猪初生体尺与乳头数性状的遗传位点

旨在鉴别影响苏山猪初生体尺和乳头数性状的遗传位点,开发可用于辅助育种的分子标记,为苏山猪生长和繁殖性能的持续选育提供理论基础。本试验对269头苏山猪初生仔猪(出生后24 h内)的体尺和乳头数表型进行测定,并采集耳组织样品。基于全基因组重测序及基因型填充策略,利用全基因组关联分析(genome-wide association study, GWAS)和群体分化指数(fixation index,Fst)的方法挖掘与目的性状强关联位点,并对位置功能候选基因开展GO和KEGG分析,确定最有可能的主效基因。本研究共鉴别到4个候选位点,分布在13、14和X染色体上,其中与初生体尺性状显著关联的位点有2个,与乳头数性状显著关联的位点有2个。本研究筛选出1个与体长性状相关的候选基因ACTA2;1个与胸围性状相关的候选基因COL4A6;3个与乳头数性状相关的候选基因ACTA2、CRTAP和SEPTIN6,为苏山猪初生体尺性状和乳头数性状的遗传改良提供了重要的分子标记。     

生长抑素(SS)与硫氧还原蛋白(Thioredoxin)相融合生成的2种基因工程化融合蛋白SS-N/X和SS-N/S的表达特性

对基因工程化生长抑素（somatostatin,SS)-硫氧还原蛋白（Thioredoxin)融合蛋白SS－N／X和SS－N／S的表达产量、水溶性、Triton X-100对SS融合蛋白水溶性的影响、包涵体的溶解和复性特点以及SS的抗原性与免疫原性等特性进行了研究。结果显示，在30℃的低温下用IPTG诱导表达，SS－N／X融合蛋白主要以可溶性形式存在，占75．8％，色涵体仅占24．2％；而SS－N／S融合蛋白则主要以包涵体的形式存在，占81．1％，可溶性蛋白仅占18．9％；32C载体（pEG-32C)蛋白则居二者之间，可溶性蛋白与包涵体大约等比例出现。SS－N／S在低温下诱导可超量表达SS融合蛋白，其表达量约占菌体总蛋白的40．94％。0．5％ Triton X-100对融合蛋白的不溶性有非常显著的影响，几乎可使所有的SS－N／X融合蛋白和大部分SS－N／S融合蛋白及32C硫氧还原蛋白变成水溶性的。32C硫氧还原蛋白包涵体在尿素中的溶解度明显高于SS－N／S包涵体，2mol/L尿素可使近一半的32C硫氧还原蛋白包涵体溶解，而SS－N／S包涵体只有27．5％溶解；但在5mol/L尿素时，两者均可基本全部变为可溶性的。在SS融合蛋白包涵体溶解时加入还原剂二硫苏糖醇，可明显降低SS的抗原性。SS融合蛋白（水溶性融合蛋白和复性后的包涵体）具有良好的SS抗原性和免疫原性。由SS融合蛋白与弗氏不完全佐剂制成试验用疫苗，免疫BALB／c小鼠、仔猪和羔羊等动物，可显著提高免疫动物的增重。