影视剧和综艺节目中的工作犬

正近来,热播电视剧《长安十二时辰》中的细犬"阿细",电影《小Q》中的拉布拉多犬"小Q",以及萌宠综艺节目《哈喽伙计》中的"治疗犬"等,它们活泼可爱的形象给观众们留下了深刻的印象。随着对工作犬的进一步宣传展示,更多人知晓了工作犬背后的那些或精彩或平凡的故事。《长安十二时辰》细犬是中国古老的狩猎犬种     

波尔级进杂交二代山羊体重及体尺生长曲线分析

用Compertz模型和Logisitic模型拟合了波尔山羊与唐山奶山羊级进杂交二代 (波唐杂交一代母羊与波尔山羊公羊回交 ) 1～ 7月龄的体重、体长、体高和胸围四个指标的生长曲线 ,并根据Compertz方程计算了各指标的指数生长率。结果表明 ,两个模型均能很好地拟合体重及体尺指标的生长曲线 ,所有曲线的拟合优度都在 0 .985以上 ,Compertz模型拟合效果好于Logisitic模型 ;体重在生后时期的生长强度明显高于体尺指标的生长强度 ;体长和胸围的生长强度大于体高的生长强度 ;不同性别的山羊也存在较明显的差异 ,公羊各指标的生长优于母羊 ,尤其是在 2月龄以前     

固原地区秦川牛利杂群体生长曲线拟合分析

[目的]研究固原地区秦川牛的生长发育规律。[方法]本实验采用随机抽样法测定了309头固原地区秦川牛利杂群体不同生长阶段的体尺和体重指标,利用Logistic、Brody、Gompertz、Bertallanffy四种生长曲线模型拟合其生长曲线,分别估算出四种曲线方程中的相关参数值。[结果]陕西秦川牛和固原本地秦川牛利杂...     

新杨黑羽蛋鸡商品代生长曲线拟合及产蛋早期蛋品质变化规律研究

为了解新杨黑羽蛋鸡商品代蛋鸡的生长发育规律及早期蛋品质变化规律,采用Bertalanffy、Gompertz和Logistic三种非线性生长曲线模型拟合0~20周龄生长曲线,测定24~32周龄蛋品质指标。结果表明:三种模型均能很好地拟合其生长曲线,其中Bertalanffy模型拟合效果最佳(R2=0.9998),拟合结果新杨黑羽蛋鸡商品代成熟体重为2 005.33 g,拐点体重为594.17 g,拐点周龄为7.73周龄;蛋品质指标与产蛋周龄有密切关系,蛋重随产蛋周龄增加而增大,蛋壳颜色、蛋黄颜色随产蛋周龄增加而降低。     

浅谈兽医临床择时服药

祖国兽医学认为,家畜的生命活动都是按照自身固有的时间规律有周期性有节律地进行着。疾病的发生多与时辰有关,患病之后,也有周期性的轻重变化,一般规律是旦慧、昼安、夕加、夜甚,在治疗上,中兽医     

双列杂交后代冠高生长曲线拟合

鸡冠发育情况是衡量优质肉鸡经济价值的重要指标。本研究采用完全双列杂交设计,选用岭南黄鸡中生长早期鸡冠发育明显差异的品系S和品系B进行正(S♂×B♀)反(B♂×S♀)杂交,S和B分别自交,共4组进行试验。利用3种生长曲线模型(Logistic、Gompertz、Bertalanffy)拟合冠高的生长曲线。结果表明:正反交对冠高影响不大,两者之间差异不显著(P>0.05);3种生长曲线模型均能较好地拟合各组合冠高的生长曲线(R2>0.983),其中以Bertalanffy模型的拟合度最高(平均♂R2=0.998,♀R2=0.991),且与实际情况较为相符。所以利用3种生长曲线模型研究优质鸡的冠高的生长发育趋势是可行的,同时,冠高的发育程度与繁殖、营养水平等因素呈高度相关,通过生长曲线拟合和估计,可以为繁殖、营养等其他调控手段提供评价指标。     

解析"犬四联"弱毒疫苗质量与最佳冷冻干燥曲线的关系

依据4种病毒生化指标设计了3种不同冻干曲线，配制10批“犬四联”弱毒疫苗分别进行冷冻干燥比较试验。结果表明：采用16h和22h冻干曲线冻干后的疫苗效价比冻干前下降1～2个滴度，抗原损失较大；采用20h冻干曲线冻干后的疫苗效价仅降低0．5个滴度，而且CPV和CPIV的血清抗体滴度(SN)也略高于用前两种冻干曲线冻干的制品，其冻干产品外观优于应用前两种冻干曲线的产品。因此选择总冻干时间20h的冻干曲线为“犬四联疫苗”较理想的冻干曲线。     

西农萨能奶山羊泌乳期产奶量、乳成分及血液生理生化指标变化规律研究

旨在探索西农萨能奶山羊泌乳期生产性能、乳成分、血液生理生化指标和营养物质摄入量等变化规律及其相互关系。本研究选取15只体重、胎次、产奶量、分娩日期相近,体况健康的西农萨能奶山羊。单圈饲喂54周,试验期内准确测定个体生产性能、乳成分、血液生理生化指标和营养物质摄入量等,建立各项指标随泌乳期变化规律模型及泌乳期内指标间的相关关系模型。结果表明:1)不同泌乳阶段显著影响奶山羊生产性能(干物质采食量(DMI)、产奶量、料奶比)、乳成分(乳蛋白率、乳脂率、总固形物率(TS))及营养物质摄入量(粗脂肪(EE)、粗蛋白(CP)、有机物(OM)、酸性洗涤纤维(ADF)和中性洗涤纤维(NDF))等性状指标(P0.05)。2) Wood模型成功拟合了产奶量、乳脂率和乳蛋白率随泌乳期变化的规律;CP可拟合二次曲线;DMI、料奶比、非脂乳固形物率(SNF)、TS和NDF可拟合三次曲线。产奶量、乳脂率和料奶比等拟合效果最佳,拟合度均高于0.94。3)生产性能—DMI、产奶量与料奶比间极显著相关(P0.01);乳成分—乳蛋白率、乳脂率、SNF与TS间极显著相关(P0.01);营养物质摄入量—DMI、OM、CP、NDF与ADF间极显著相关(P0.01)。显著相关指标可通过二次曲线、三次曲线、线性模型、指数模型和"S"型曲线模型等高度拟合。西农萨能奶山羊个体年平均产奶量为504.91 kg。奶山羊生产性能、乳成分、血液生理生化指标和营养物质摄入量等指标之间以及与泌乳期均显著相关,Wood模型拟合泌乳曲线为Y=1.233t~(0.414)×e~(-0.041t)。根据拟合曲线可通过产奶量预测料奶比;乳脂率、乳蛋白率和总固形物率之间可相互预测。研究结果对了解奶山羊的基本生理状况及生产规律具有重要意义,为奶山羊不同泌乳阶段合理安排生产,进而实现精准饲喂具有指导作用。     

一年鱼事歌

1 月冰天大小寒,修塘消毒莫等闲,小塘改大浅改深,死水改活水质新 2 月立春雨水到,投放鱼苗时辰好,青草鲢鳙鲤鲫鳊,合理混养效益添 3 月惊蛰与春分,鱼儿食量日渐增,投饵施肥要适当,量少次多鱼健长     

五指山猪(WZSP)近交系生长曲线分析与拟合的研究

畜禽生长曲线的分析和拟合是研究畜禽生长发育规律的主要方法之一。生长曲线可描述动物体重随年龄增加而发生的规律性及连续性变化过程。生长曲线模型（growth curve model，GC）是在研究生物的某指标随时间的增长而变化建立的一种模型，在生物中有广泛的应用。Brody（1954）提出了生长曲线的二阶段性，即生长前期自加速阶段和生长后期自抑制阶段，并分别用不同的数学模型加以描述。以后又建立了Logistic模型、Gompertz模型和Richards模型。     

Circadian variation in biochemical markers of bone cell activity and insulin-like growth factor-I in two-year-old horses

Studies in humans have found circadian changes to be one of the most important sources of controllable preanalytical variability when evaluating bone cell activity using biochemical markers. It remains unclear whether similar circadian changes influence bone marker concentrations in the horse. The aim of this study was to characterize changes in serum concentrations of three biochemical markers of bone cell activity over a 24-h period in six 2-yr-old Thoroughbred mares, and to determine circadian variability in IGF-I, which regulates bone turnover. Three bone markers were measured in serum: osteocalcin, a marker of bone formation, the carboxy-terminal propeptide of type-I collagen (a marker of bone formation), and the carboxy-terminal telopeptide of type-I collagen (a marker of bone resorption). Data were analyzed using the cosinor technique, which fits a 24-h cycle to each dataset. A significant circadian rhythm was observed for osteocalcin (P = 0.028), with an estimated amplitude of 7.6% of the mean (95% confidence interval 1.3% to 16.3%), and an estimated peak time of 0900. However, the observed rhythm for the carboxy-terminal telopeptide of type-I collagen (amplitude = 7.4%) was not significant (P = 0.067), and there were no significant changes in concentrations of the carboxy-terminal propeptide of type-I collagen over the 24-h study period (P = 0.44). There was a small but significant circadian rhythm for IGF-I (P = 0.04), with an estimated amplitude of 3.4% (95% confidence interval 0.2 to 7.1%) and peak at 1730. Further studies are now required to determine the potential association between circadian changes in IGF-I and osteocalcin in the horse. Although no significant circadian variation was found in concentrations of the car-boxy-terminal propeptide of type-I collagen and the carboxy-terminal telopeptide of type-I collagen, this may in part be a result of the age of the animals that were still skeletally immature. Future studies should aim to determine whether these markers develop a circadian rhythm at a later age when growth is complete. In the meantime, consistency in time of sampling should continue to be considered best practice when measuring biochemical markers of bone turnover in the horse.     

热激蛋白研究进展

热激蛋白(Heat Shock Protein)是生物体在多种刺激下产生的一种蛋白质。其特点是分布广泛、表达具有多样性。其生理功能主要起分子伴侣作用，维持生物体正常生理功能。热激蛋白基因的表达调控主要在转录水平上进行，但也有部分表现为翻译水平调控。其基因一般含有保守序列，根据序列的保守性和多样性可推断相应生物体在生物进化过程中的位置。同时本介绍了热激蛋白在体外表达的研究状况。     

Daily rhythmicity of body temperature in the dog

Research over the past 50 years has demonstrated the existence of circadian or daily rhythmicity in the body core temperature of a large number of mammalian species. However, previous studies have failed to identify daily rhythmicity of body temperature in dogs. We report here the successful recording of daily rhythms of rectal temperature in female Beagle dogs. The low robustness of the rhythms (41% of maximal robustness) and the small range of excursion (0.5 degrees C) are probably responsible for previous failures in detecting rhythmicity in dogs.     

Lactation Biology Symposium: circadian clocks as mediators of the homeorhetic response to lactation

The transition from pregnancy to lactation is the most stressful period in the life of a cow. During this transition, homeorhetic adaptations are coordinated across almost every organ and are marked by changes in hormones and metabolism to accommodate the increased energetic demands of lactation. Recent data from our laboratory showed that changes in circadian clocks occur in multiple tissues during the transition period in rats and indicate that the circadian system coordinates changes in the physiology of the dam needed to support lactation. Circadian rhythms coordinate the timing of physiological processes and synchronize these processes with the environment of the animal. Circadian rhythms are generated by molecular circadian clocks located in the hypothalamus (the master clock) and peripherally in every organ of the body. The master clock receives environmental and physiological cues and, in turn, synchronizes internal physiology by coordinating endocrine rhythms and metabolism through peripheral clocks. The effect of the circadian clock on lactation may be inferred by the photoperiod effect on milk production, which is accompanied by coordinated changes in the endocrine system and metabolic capacity of the dam to respond to changes in day length. We have shown that bovine mammary epithelial cells possess a functional clock that can be synchronized by external stimuli, and the expression of the aryl hydrocarbon receptor nuclear translocator-like gene, a positive limb of the core clock, is responsive to prolactin in bovine mammary explants. Others showed that 7% of genes expressed in breasts of lactating women had circadian patterns of expression, and we report that the diurnal variation of composition of bovine milk is associated with changes in expression of mammary core clock genes. Together these studies indicate that the circadian system coordinates the metabolic and hormonal changes needed to initiate and sustain lactation, and we believe that the capacity of the dam to produce milk and cope with metabolic stresses in early lactation is related to her ability to set circadian rhythms during the transition period.     

Monitoring the circadian rhythm of serum and salivary cortisol concentrations in the horse

Daily fluctuations of cortisol concentration in the blood or saliva have been repeatedly reported. However, several contradictions in the existing literature appear on this subject. The present study was performed to definitively establish options for testing adrenocortical function. To the best of our knowledge, this is the first study to evaluate parallel circadian rhythms in salivary and serum cortisol concentrations during a 24-h period. Twenty horses were examined under the same conditions. Blood and saliva samples were taken every 2 h for 24 h to determine the daily changes in cortisol concentrations of saliva and serum at rest and to determine the relationship between salivary and serum cortisol levels. Cosinor analysis of group mean data confirmed a significant circadian component for both serum and salivary cortisol concentrations (P < 0.001 in both cases). The serum cortisol circadian rhythm had an acrophase at 10:50 AM (95% CI, 10:00 AM–11:40 AM), a MESOR of 22.67 ng/mL, and an amplitude of 11.93 ng/mL. The salivary cortisol circadian rhythm had an acrophase at 10:00 AM (95% CI, 9:00 AM–11:00 AM), a MESOR of 0.52 ng/mL, and an amplitude of 0.12 ng/mL. We found a significant but weak association between salivary and serum cortisol concentrations; the Pearson correlation coefficient was 0.32 (P < 0.001). The use of salivary cortisol level as an indicator of hypothalamic-pituitary-adrenal axis activity may be warranted. However, the salivary cortisol levels are more likely to be correlated with free plasma cortisol than with the total plasma cortisol concentration.     

Daily rhythm of total activity pattern in domestic cats (Felis silvestris catus) maintained in two different housing conditions

Housing conditions and human presence have been shown to have an influence on daily amount of activity in herbivores. Only few studies on the behavior of cats and interactions between cat and human were conducted, and these few works are referred to cats housed in laboratories. At the same way, only few and conflicting reports about the presence of circadian rhythms in cats are present. In view of this incomplete literature, the main aim of our study was to investigate the influence of different housing conditions on daily rhythm of total locomotor activity (TLA) in cats.For this purpose, 10 clinically healthy adult domestic cats were used. They were divided into 2 equal groups living with their owner in their home. Group A lived in 80-100 m² house and had free daily access to 20-40 m² garden from 08:00 to 9:00. Group B lived in 200-250 m² house, had free access to 2000-2500 m² garden all day, and from 21:00 to 08:00 they were kept outside. Our results showed that in group A, that live in strong symbiosis with owners respect to group B, the amount of activity was higher during the photophase. This supporting the view that domestic cats adapt their lifestyle with their owners. Group B exhibited the highest level of locomotor activity during the scotophase. Moreover, a robust daily rhythmicity of TLA was observed in group B; on the contrary, in group A, TLA showed no daily rhythmicity. Our findings underline the high influence of human presence and care on the amount of activity and daily rhythm in cats.     

浅析光照信息对肉鸡免疫功能的作用

光照信息是自然界中最重要的环境因素之一,它通过对动物的视觉系统和昼夜节律生物钟系统的调控,进而影响着生物体的多种生理功能。肉鸡属于光敏感动物,其视网膜和松果体上存在着不同的光感受器以及昼夜节律生物钟,通过位于其上的光受体接受外界环境的光信息（光照波长、光照周期和光照强度）,再把不同光信息处理后转化为特定的生物信号,从而影响机体的生长发育、生产性能和免疫功能。作者综述了不同的光照信息：光照周期、光照强度及光照波长对肉鸡免疫功能的增强或抑制作用并重点讲述了褪黑激素通过其受体途径和非受体途径（抗氧化作用）介导着不同光照波长（光色）对肉鸡免疫功能的调控,以期为现代化肉鸡养殖过程中合理运用光照信息提供理论依据。     

Influence of time of food administration on daily rhythm of total locomotor activity in ponies

The activity rhythm can be entrained by nonphotic cues, especially food availability. Daily feeding schedules can act as “Zeitgeber” to synchronize the circadian system. In this study, the authors evaluated the influence of different feeding schedules on the daily rhythm of total locomotor activity in ponies. Six clinically healthy Shetland ponies were kept under natural 12/12-h light/dark cycle and monitored during 4 different feeding schedules: fed twice (at 8 am and 8 pm), fasted, fed at 8 pm, fed at 8 am, and fed twice a day again. Water was available ad libitum. To record total activity, we equipped the animals with actigraphy-based data loggers (Actiwatch-Mini). Two-way analysis of variance revealed a significant main effect of the time of day and no effect of feeding schedules on the amount of total locomotor activity. Locomotor activity showed daily rhythmicity in all experimental conditions, with diurnal acrophase. The amplitude of the rhythms and their robustness statistically changed across all experimental conditions. Our findings support the theory that when given essentially free choice hay, the time of feeding did not entrain activity, and suggest that feeding behavior can influence the distribution of locomotor activity during a 24-hour period in ponies, with changes in the amplitude and robustness of the rhythm.     

乳汁中褪黑素的节律与功能

牛奶被誉为“白色血液”,除营养素外,还含有一系列其他非营养成分。作为一种多功能的小分子物质,褪黑素最突出的特性是其对昼夜节律的调节以及抗炎、抗氧化作用。哺乳动物乳汁中的褪黑素影响乳汁的功能与免疫活性。本文通过综述哺乳动物乳汁中褪黑素的节律变化以及其来源与功能,旨在为进一步研究和挖掘乳汁中褪黑素的功能提供参考。     

Daytime profile of the intraocular pressure and tear production in normal dog

Objective  To evaluate the circadian rhythms of intraocular pressure (IOP) and tear production in dog exposed to a natural photoperiod.
Animals studied  We used 12 clinically healthy Beagles dog housed under natural photoperiod at indoor temperature and humidity.
Procedure  Intraocular pressure and Schirmer tear test (STT) I were measured every 4 h over a 48-h period in both eyes in each animal. Statistical analysis of the data was performed by one-way repeated-measures anova , Student's t -test, and single cosinor method.
Results  On each day, there was a highly significant effect of time on both parameters. A statistically significant difference of STT I values was observed comparing left and right eyes ( P  < 0.0001). Robust daily rhythms were observed for both parameters, IOP values showed diurnal acrophase (left eye: 09:33 ± 00:50 h; right eye: 09:25 ± 00:22 h), while STT I values showed nocturnal acrophase (left eye: 20:27 ± 00:46 h; right eye: 20:00 ± 00:05 h).
Conclusion  This study has demonstrated circadian rhythms in both IOP and STT I.