Drug therapy in cats: mechanisms and avoidance of adverse drug reactions

This is the first of a 4-part series concerning drug therapy in cats. In this article, factors that may increase the incidence of type-A adverse drug reactions in cats are discussed. Factors related to species and age differences, drug interactions, and the effects of disease are emphasized. Those that tend to be unique to cats, such as species-induced differences in drug disposition, are described in detail when sufficient information was available from the literature. General recommendations regarding drug administration are made, which will facilitate the implementation of rational drug therapy in cats, thus reducing the incidence of adverse reactions.     

猪巴氏杆菌病的发生与气候因素相关性研究

对猪巴氏杆菌病的发生与气候因素(温度、相对湿度、降雨量、日照时数)的相关性进行了分析研究.结果表明,该病的发生与气候因素有一定的相关性.与温度、相对湿度、日照时数呈正相关,相关系数分别为0.249 4,0.361 9和0.039 6;与降雨量呈负相关,相关系数为-0.2 366,但差异均不显著,说明在防治疾病时,应考虑这些气候因素,但不是主要因素.     

Morphofunctional diversity of equine of varied genetic compositions raised in the Pantanal biome of Brazil

Evaluating phenotypic diversity makes it possible to identify discrepancies in aptitudes among animals of different genetic bases, which is an indicator of adaptive or selective differences between populations. The objective of this work was to evaluate the morphofunctional diversity of 452 male and female adult equines (Arabian, Quarter Mile, Pantaneiro, and Criollo breeds, and undefined crossbreeds of horses and mules) raised in the Pantanal biome (Brazil). Linear measurements were performed to estimate conformation indexes. Initially, a discriminant analysis was performed, regardless of the animal’s size, followed by factor analysis. The factors were characterized and used as new variables. The diversity among equines and their relationship with the factors were evaluated using multivariate analysis. The factors were classified according to their decreasing importance: balance, rusticity, and robustness for the measurement factors; and load, ability, conformation, and equilibrium for the index factors. The genetic groups of equines have well-defined morphofunctional characteristics. The main differences are based on the rusticity and ability typologies in relation to those based on performance. Equines introduced to the Pantanal biome presented a more robust and compact body with good conformation. As a result, these horses may have superior athletic performance during equestrian activities when compared to the Pantaneiro local breed. However, this biotype may represent less rusticity (less adaptive capacity). Therefore, the regional breed can be equal or better in equestrian activities than breeds introduced to the Pantanal biome. Thus, breeders may cross horses from local breeds as an alternative to those introduced. Undefined crossbred male equines presented a different profile from the Pantaneiro breed, which may indicate little use of crossbreeds in breeding.     

Insulin-like growth factors and binding proteins in ruminants and their nutritional regulation.

Insulin-like growth factors (IGF) are important mediators of growth, lactation, reproduction, and health. Considerable information on their role in ruminant animals has been learned in the past several years, but the precise mechanisms of their action are not known. The exact biological response of target cells is undoubtedly determined by the developmental state of the cell and synergism with other growth factors. Overall, somatomedins and their binding proteins seem to be major links between cellular developmental processes and nutrient supply. The mechanism by which nutrients control biological actions of somatomedins is not known but clearly involves the synthesis of IGF, as well as their binding proteins and receptors. In ruminants, severe feed restriction decreases circulating concentrations of IGF-I, whereas subtle alterations typical of those that occur in production systems have minimal effect. However, the responses of IGF to somatotropin are affected by modest alterations in nutritional status, including differences in nutritional status that are typically encountered in animal production systems.     

Factors to adjust litter weight of pigs to a standard 21 days of age

Factors to standardize litter weights of nursing pigs to 21 d of age were calculated from daily weights measured on 64 crossbred litters from 10 to 32 d of age. The results were compared to published factors derived from a data set of Duroc pigs weighed every 3 to 4 d. Dams in the present study were white crossbred sows and gilts, and sires were maternal or terminal breed types. Multiplicative factors were calculated by dividing the mean 21-d litter weight (LW21) by mean daily litter weight. Linear and quadratic regression coefficients of LW21 on age at weighing were fitted to the factors (R2 = .997). The final equation for adjusting litter weights to a 21-d basis was 2.5246 - .1041 x (d of age) + .0015 x (d of age)2. There were good agreement with published factors for d 19 to 25, but divergence for younger and older litters resulted in significant differences between the linear coefficients. These differences may be due to departure from a linear growth curve, which daily measurements would incorporate, or differences in sow populations. Thus, use of the new factors should be considered for white crossbred sow populations. A least squares analysis indicated that LW21 was significantly altered by parity, not by the number of pigs allowed to nurse or by breed of sire. After adjustment to 21 d, litter weights also should be adjusted for differences in parity before evaluating sow productivity, by using additive factors such as those recommended by the National Swine Improvement Federation.     

山西铁杆蒿草地群落碳、氮密度区域差异及其驱动因素

为明确山西铁杆蒿（Artemisia sacrorum）群落碳、氮密度的区域差异,以及导致这种空间变化的驱动因素,本试验以山西省铁杆蒿草地群落为研究对象,通过测定晋北半干旱地区和晋南半湿润地区铁杆蒿群落的碳（C）、氮（N）密度,分析了其与年均气温、年降水量、土壤理化性质和地上、地下生物量等生态因子的相关性。结果表明：山西南北铁杆蒿群落碳、氮密度空间分布存在差异,晋南地区铁杆蒿群落的群落碳、氮密度分别为651.83 g C·m^-2和20.63 g N·m^-2,晋北地区铁杆蒿群落的群落碳、氮密度分别为418.89 g C·m^-2和13.90 g N·m^-2。以群落各组分碳、氮密度代表样点进行RDA（Redundancy analysis）冗余分析排序得出造成两地区群落碳、氮密度分异的主要生态因子均为地上生物量、地下生物量、年均气温、年降水量、土壤有机碳含量以及土壤砾石比。可见,山西晋南和晋北地区铁杆蒿群落碳、氮密度空间分布存在差异,不同气候区铁杆蒿群落碳、氮密度空间差异与生物量的积累密切相关,驱动晋南和晋北地区铁杆蒿群落碳氮密度分异的环境因素为年均气温、年降水量、土壤有机碳含量以及土壤砾石比。     

Second-intention repair in the horse and pony and management of exuberant granulation tissue.

Second-intention repair is faster in ponies than in horses and faster in body wounds than in limb wounds. To a large extent, the differences between horses and ponies can be explained by differences in the local inflammatory response, which are a result of the functional capacity of leukocytes. In ponies, leukocytes produce more inflammatory mediators,resulting in better local defense, faster cellular debridement, and a faster transition to the repair phases, with more wound contraction. In horses,leukocytes produce fewer mediators, initiating a weak inflammatory response, which becomes chronic. This inhibits wound contraction and gives rise to the formation of exuberant granulation tissue. The anatomic environment that influences the inflammatory response and wound contraction most probably determines the differences between body and limb wounds. In body wounds, better perfusion results in faster initiation of the inflammatory phase. The weaker local resistance results in a greater degree of contraction. In limb wounds, particularly of horses, the initial inflammatory response is weak and wound contraction is restricted. Both factors give rise to chronic inflammation, which further inhibits wound contraction and promotes exuberant granulation tissue. The high incidence of exuberant granulation tissue in limb wounds of horses can thus be explained by the chronicity of the inflammatory response as well as by the common use of bandages during treatment. Chronic inflammation is often not recognized as a cause of exuberant granulation tissue. It must be prevented and treated to promote the healing process. Bandages and casts stimulate the formation of exuberant granulation tissue; however, they are advantageous in many respects and play an important role in support of the overall healing process.     

Differences in wound contraction between horses and ponies: the in vitro contraction capacity of fibroblasts

The contribution of wound contraction to wound closure determines the speed of second intention wound healing and it has been shown that significant differences exist with regard to both contraction and inflammatory response between horses and ponies and between various areas of the body. In this study, the contraction capacity of fibroblasts from limbs and buttocks of 4 Dutch Warmblood horses and 4 Shetland ponies was studied in vitro, in order to determine whether differences in wound contraction are due to differences in the inherent contraction capacity of the fibroblasts or to differences in tissue environmental factors, such as the inflammatory response. Fibroblasts were harvested from subcutaneous tissue, cultured and then suspended in both floating and anchored collagen gels. Contraction capacity was assessed by measuring the decrease in area of the floating gels and by measuring the microforces generated in the anchored gels using a custom-built measuring device. In the floating gels, no difference existed in the contraction capacity of fibroblasts from horses and ponies, or from limbs and buttocks. In the anchored gels, no differences existed between horse and pony fibroblasts, but the fibroblasts from the limbs started to contract significantly sooner and produced significantly higher forces than those from the buttocks. It is concluded that the in vivo differences in wound contraction between horses and ponies and between different sites of the body are not caused by differences in the inherent contraction capacity of fibroblasts. The in vitro differences between fibroblasts from limbs and buttocks are thought to be due to the lower proliferation rate and the longer culture time of the fibroblasts originating from the limbs, because mature fibroblasts can develop higher contraction forces than immature fibroblasts. This means that tissue environmental factors, such as cytokine profiles during the inflammatory response, determine the extent of contraction during wound healing. Further research should be directed towards the role of the inflammatory response in wound healing.     

Across-breed adjustment factors for expected progeny differences for carcass traits

Adjustment factors to allow comparison of EPD from several breed associations for birth, weaning, and yearling weights have been available for more than 10 yr. This paper describes steps to calculate adjustment factors for EPD for 4 carcass traits: marbling score, fat thickness, ribeye area, and retail product percentage. The required information is the same as for the weight traits: 1) breed of sire solutions based on measurements on progeny at the US Meat Animal Research Center (USMARC) that have sires with breed association EPD, 2) mean EPD of sires weighted by number of progeny at USMARC (USMARC progeny not included in breed association EPD), and 3) mean EPD of nonparents from breed associations (defined as animals born 2 yr prior to calculation of EPD). Records at USM-ARC are adjusted to 100% heterozygosity because the purpose of the adjustment factors is to allow prediction of performance of progeny of sires mated to other breeds of dam. A critical step is to adjust breed of sire solutions, which are based on an earlier sample of sires, to the equivalent of a sample from a more recent nonparent group using the difference between mean EPD from information sources 2) and 3). The difference is multiplied by the coefficient of regression of USMARC progeny on EPD of their sires. With weight traits, these coefficients are not greatly different from unity. With the carcass traits, 2 sets of coefficients can be used depending on whether the EPD are based on carcass or ultrasound measurements. The regression coefficients also reflect differences in conditions for USMARC progeny (all steers) and factors associated with breed association EPD. Only for marbling score and ribeye area were any estimates of the regression coefficients near unity. For other traits, the coefficients ranged from 1.65 to 2.82. The solutions for breed of sire, differences in mean EPD, and regression coefficients are then used to calculate adjustment factors for EPD of 11 breeds including the arbitrary base breed, Angus.     

Heredity of navicular disease

Bone structure, nutrient canals, form and definition, and a total evaluation of both fore navicular bones were radiologically evaluated in 169 three- and four-year-old Dutch warmblood mares divided into eleven daughter (half sister) groups. On the basis of the 'total evaluation', differences between the three- and four-year-old horses were detectable. Using the 'total evaluation', significant differences were found between daughter groups consisting of three-year-old mares. These differences support the theory that podotrochleosis may be (partly) due to the presence of genetic factors. The possibilities concerning selection are presented. The results of the radiological evaluation of the stallion do not have predictive value as far as his progeny is concerned.     

Circadian and seasonal variability and influence of sex and race on eight clinical chemistry parameters in budgerigars (Melopsittacus undulatus, Shaw 1805)

The aim of the study was to investigate if there is a clinically relevant influence of daytime or season and if there are sex-dependant differences in some frequently determined clinical chemistry parameters. The study was performed with 99 1.5- to 2-year old healthy budgerigars of three races. A harmonic regression analysis was performed taking into account linear and cyclic trends over the year. Correlations were investigated by the calculation of Spearman correlation coefficients. Summarizing, it can be said that some circadian, seasonal, as well as sex- and race-dependant influences have been shown. However, although the differences are statistically significant, they were too small to have an impact on clinical decision making. As clinical chemistry results are in practice independent from the influence factors investigated, their meaning and use as a diagnostic tool is further substantiated.     

Patterns and causes of geographic variation in bat echolocation pulses

Evolutionary biologists have a long‐standing interest in how acoustic signals in animals vary geographically, because divergent ecology and sensory perception play an important role in speciation. Geographic comparisons are valuable in determining the factors that influence divergence of acoustic signals. Bats are social mammals and they depend mainly on echolocation pulses to locate prey, to navigate and to communicate. Mounting evidence shows that geographic variation of bat echolocation pulses is common, with a mean 5–10 kHz differences in peak frequency, and a high level of individual variation may be nested in this geographical variation. However, understanding the geographic variation of echolocation pulses in bats is very difficult, because of differences in sample and statistical analysis techniques as well as the variety of factors shaping the vocal geographic evolution. Geographic differences in echolocation pulses of bats generally lack latitudinal, longitudinal and elevational patterns, and little is known about vocal dialects. Evidence is accumulating to support the fact that geographic variation in echolocation pulses of bats may be caused by genetic drift, cultural drift, ecological selection, sexual selection and social selection. Future studies could relate geographic differences in echolocation pulses to social adaptation, vocal learning strategies and patterns of dispersal. In addition, new statistical techniques and acoustic playback experiments may help to illustrate the causes and consequences of the geographic evolution of echolocation pulse in bats.     

影响牛奶trans11C18∶1和CLA合成的因素

乳脂肪受日粮因素的调控的可塑性大，CLA是乳脂肪中的一种微量不饱和脂肪酸，影响乳脂肪的物理和生物学特性。CLA最初发现于奶牛瘤胃，但牛奶中CLA主要通过乳腺组织Δ9去饱和酶作用于trans11C18∶1而内源合成。研究结果表明，日粮因素、动物个体间的差异和动物组织间SCD酶活性的差异是影响乳脂CLA合成的关键因素。作者针对影响trans11C18∶1和Δ9去饱和酶的因素对CLA合成调控因素作了简要论述。     

工蜂寿命研究进展

蜜蜂是完全社会化的昆虫,有2种不同的雌性级型,它们在寿命方面表现了显著的级型差异。蜂王的平均寿命是1～2 a,而工蜂在繁殖季节平均寿命是30～40 d,越冬季节平均寿命是90～200 d。显然工蜂寿命有可塑性,受各种因素控制。综述了近年来对工蜂寿命的研究,阐述了影响工蜂寿命的几种因素。     

Comparative anatomic and morphometric examination of the interosseous muscle,sesamoid ligaments and flexor tendons of the fetlock in South American camelids

This study presents a comparative morphological and morphometrical examination of the interosseous muscle (IOM), digital flexor tendons and associated structures of all four species of South American Camelids (SACs): Lama (Lama glama), alpaca (Vicugna pacos), guanaco (Lama guanicoe) and vicuna (Vicugna vicugna). Our findings show that the lamoid interosseous muscle and digital flexor tendons are very similar between species and differences, which have been reported previously, are possibly due to diverging examiner interpretation. Lumbricalis muscles were mostly found as single muscles in this study. The definition of the terminal and dorsal branches of the interosseous muscle is critically revised. The analysis of morphometric data indicates that the size of the individual has a substantial influence on the cross-sectional area (CSA) of the examined structures. Metacarpal/metatarsal bone width is a main predictor of CSA, while the factor species only shows significance in specific sample points. For lama and alpaca, no differences in CSA in relation to species as factor were found. The IOM shows the largest CSAs of the three examined structures in all species, which implies an important load-bearing function. Considerable individual variation remains unexplained by the mentioned factors. This lowers the prospect of CSA reaching diagnostic importance in SAC fetlock pathology.     

Productivity and socio-economic profile of dairy cattle farmers amongst rural smallholder communities in northern Vietnam

The objective of this field questionnaire survey was to describe the productivity and socio-economic profile of dairy cattle farmers in northern Vietnam considering regional differences in rural smallholder farming communities which have been targeted by a governmental dairy development policy. Using two-stage cluster sampling, a total of 99 dairy farming households (11 per commune) were recruited from 9 of 32 communes in Ba Vi District, Ha Tay Province, northern Vietnam. The results from this study indicate that there were regional differences in relation to basic management practices such as effective utilisation of agricultural by-products for feeding and hygiene practices. These can be explained by variation amongst the regions with respect to environmental factors affecting agricultural activities such as constraints on land use and access to water resources. There were also regional differences in the use of governmental support such as agricultural extension services and financial institutions. These can be attributed to proximity of the communities to each of the extension institutions as well as the phased and community-specific approach to the provision of governmental financial support for dairy development.     

畜禽规模养殖废水污染因子监测评价分析

对奶牛、猪、禽规模养殖30个废水样品,分二次应用标准方法监测15个不同参数,并进行单项与综合指数评价分析.结果表明:不同畜禽养殖废水污染超标因子按污染指数大小排序存在差异性,猪氨氮＞总磷＞总氮＞砷＞铜＞CODcr＞铁＞锰;牛氨氮＞总氮＞铁＞CODcr＞总磷＞锰＞砷＞汞;禽总磷＞ 氨氮＞砷＞总氮＞CODcr＞铁＞锰.从中可见总磷、氨氮、砷、总氮、CODcr、铁和锰为污染共性因子,另有猪铜与牛汞个性因子,而且猪的污染超标因子污染指数最大.     

Factors affecting pharmacokinetics of benzimidazole anthelmintics in food-producing animals: The consequences and potential risks

Benzimidazoles are frequently and widely used veterinary anthelmintics. Unfortunately, an administration of these anthelmintics does not always result in the expected therapeutic success. Many host-related factors modify pharmacokinetic behavior and efficacy of a chosen anthelmintic. Pharmacokinetics of anthelmintics varies among animals of different species, sex and age. Also diseases, medication, feed and environmental conditions can significantly affect behavior of anthelmintics and resultant drug efficacy in animals. The presented review gathers information, gained in last 20 years, on factors which bring about the variability in performance of benzimidazole anthelmintics in food-producing animals. It is focused particularly on differences in absorption and metabolism of these anthelmintics as these stages of the pharmacokinetic process seem to be the most important for the overall anthelmintic efficacy. The consequences of abnormalities and alterations in pharmacokinetics of benzimidazole anthelmintics are summarized and discussed.     

牛卵巢活动对超数排卵影响研究进展

超数排卵在实际生产中提高了胚胎移植技术对单胎动物的繁殖率,但是,超数排卵的结果存在很大的差异性。影响超数排卵结果的因素有很多,如牛的自身因素,超数排卵方法的选择,所使用促性腺激素的种类,激素的质量,环境因素等。文章以牛自身卵巢活动对超数排卵的影响为出发点,综述了牛正常卵巢活动及卵泡活动对超数排卵影响的研究进展,包括卵泡波动力学,卵泡波发育过程中促性腺激素的作用;分析了卵巢对促卵泡素(FSH)及促黄体素(LH)的特异应答性机制,对各个卵泡波进行了比较,根据卵泡波动力学理论列举了几种切实可行的同步卵泡波的超排方法,对超数排卵结果差异性的原因做了补充说明。