Assessment of sodium status in large ruminants by measuring the sodium-to-potassium ratio in muzzle secretions.

OBJECTIVE: To develop a simple diagnostic test to assess sodium status in large ruminants on the basis of the sodium-to-potassium ratio (Na:K) and to determine its relevance. ANIMALS: 7 buffalo heifers and 21 lactating, pregnant, and nonpregnant dairy cows and heifers. PROCEDURE: Buffalo heifers were subjected in 2 experiments to variable dietary sodium intake or sodium depletion and changes in sodium and potassium concentrations; Na:K was simultaneously monitored in various body fluids to study its value for indicating sodium status. Validity of the muzzle secretion test was assessed. RESULTS: Muzzle secretion and urinary Na:K and sodium concentration, but not serum electrolyte concentrations, reflected the sodium status of buffalo heifers in response to the widely variable intake of sodium (0.03 to 0.16% of dry matter [DM]). Progressive sodium depletion during an 11-day period, using saliva deprivation caused reciprocal changes in sodium and potassium concentrations in saliva and muzzle secretion, but not in urine. Decreasing urine sodium concentration was associated with decreasing urine potassium concentration. Saliva, urine, and muzzle secretion Na:K closely reflected the degree of sodium deficit. CONCLUSIONS AND CLINICAL RELEVANCE: Buffaloes or dairy cows maintained on optimal sodium intake had muzzle secretion and urine Na:K > 0.30. Muzzle secretion or urine Na:K < 0.20 or < 0.10, respectively, was indicative of sodium deficiency. Analysis of muzzle secretion Na:K, and to a large extent urine Na:K, may be used as a convenient diagnostic tool to assess sodium status in large ruminants. It has accuracy similar to that of saliva Na:K.     

反刍动物蛋白质评定体系研究进展

长期以来 ,人们一直沿用粗蛋白质体系或可消化蛋白质体系来研究反刍动物蛋白质的营养价值 ,但是随着研究的不断深入 ,人们逐渐认识到了这种理论的局限性 ,主要原因是这种理论忽视了反刍动物与单胃动物在消化生理上的差别。反刍动物由于特殊的消化生理结构 ,在瘤胃中存在大量的细菌、原虫和厌氧真菌等微生物 ,使反刍动物利用蛋白质的方式明显不同于单胃动物。饲料中的蛋白质经过瘤胃微生物的作用后 ,到达小肠中的蛋白质主要由三部分组成 :瘤胃微生物合成的蛋白质 (MCP)、瘤胃非降解饲料蛋白质 (UDP)以及很少量的内源性蛋白质 (ECP) ,这三…     

Assessment of the mammary system.

Assessing the health status of the mammary gland is a complex and often perplexing endeavor. One must use all of the faculties available to come up with an accurate diagnosis. A detailed history of the individual and the herd or flock plus a thorough physical examination that includes specific attention paid to the mammary gland are essential. One cannot overlook these basic tenets in favor of more sophisticated means of evaluation such as somatic cell counts and milk microbiology. A holistic approach to mastitis diagnosis, treatment, and, most importantly, control is necessary.     

Assessment of the urinary system.

History and physical examination alone will most often provide conclusive evidence of urinary tract disorders in ruminants. Detailed examination of the urinary system is described, and examples of disease are presented. Ancillary testing may be indicated to confirm the diagnosis, direct treatment, or clarify the prognosis. Serum chemistry interpretation, urinalysis, urinary tract endoscopy and radiography, ultrasonography, abdominocentesis, and renal biopsy are discussed.     

Assessment of the nervous system.

This article describes the examination of the neurologic and ophthalmic systems in ruminants. Neuroanatomy with respect to lesion localization is reviewed. Pertinent age and species differences are addressed. The practical aspects of assessing the neurologic system are stressed, and the reader is directed to other sources of information for assistance in determining the differential diagnosis and therapy of neurologic disease.     

Assessment of the musculoskeletal system.

Assessment of food animal lameness provides a great challenge but also can be extremely rewarding for the practitioner. An accurate diagnosis is essential if treatment, control, and prevention are to be successful. All facets of veterinary medicine and animal science must be applied in order to make an accurate diagnosis. The complaint, history, and signs are the basic considerations in arriving at an accurate assessment and determining the cause so that lameness problems can be solved.     

Lungworms of ruminants.

Several species of nematodes parasitize the respiratory tract of ruminants. Disease due to infection with these parasites occurs less frequently in North America than in other parts of the world but can be locally and regionally important. The life cycles, epidemiology, pathology, diagnosis and treatment of Dictyocaulus viviparus, Dictyocaulus filaria, and Muellerius capillaris are summarized in this article.     

Chemical restraint in ruminants.

Physical restraint is generally required when working with food animal patients. Adding a degree of chemical restraint can make many procedures more pleasant for both practitioner and patient. The enhanced level of patient cooperation improves efficiency, offsetting the modest additional cost of the drugs used. Chemical restraint techniques used in ruminants range from mild sedation of standing patients to semianesthetized recumbency.     

Pain management in ruminants.

Based on the available literature, the most important tool available in modern veterinary medicine is preemptive analgesia. Veterinarians must capture "opportunities" to prevent the onset of pain, prevent noxious stimuli or their perception, and limit the pain-stress-distress cascade that results in altered behavior and deviation from physiologic norms. Rational treatment of pain requires an appreciation of its consequences, a fundamental understanding of the mechanisms that are responsible for its production,and a practical appreciation of the analgesic drugs that are available. The goal of pain treatment should be to restore normal (physiologic) pain responses and to eliminate pathologic pain processes. In this context, pain therapy should be directed at the multiple mechanisms (multimodal therapy)responsible for its production, and analgesic therapies should be instituted before (preemptive therapy) pain is initiated (eg, surgery) whenever possible.     

Diagnostic ultrasonography in ruminants.

The use of diagnostic ultrasound equipment is becoming widespread within various sectors of veterinary practice. Ultrasonographic examination has several advantages over other imaging modalities and it can be applied in hospital and ambulatory settings. It has the potential for widespread use in the diagnosis of disorders of several body systems in food animal species. This article describes its application to gastrointestinal, hepatobiliary, cardiothoracic, urogenital, and umbilical disorders. Normal and abnormal findings are portrayed and discussed. Accurate and timely use of this diagnostic modality requires a modest amount of training and practice, but it allows for relatively rapid, inexpensive, and noninvasive acquisition of clinically relevant data.     

Assessment of the ruminant respiratory system.

With practice, complete use of the methods of this assessment: history, detailed examination of the head and neck, cough induction, chest auscultation and percussion, and chest auscultation following forced rebreathing can be completed within 10 minutes. The examination can provide a great deal of new information regarding the respiratory system that would go undetected on a more general physical examination. In cases in which the diagnosis is still in question or requires confirmation, this will also enable the optimal use of appropriate ancillary tests, as described in the article on ancillary testing for the respiratory tract elsewhere in this issue.     

Assessment of the ruminant digestive system.

Evaluation of the gastrointestinal system of ruminants is a logical progression of investigation and elimination. Important aspects of the animal's history pertinent to the gastrointestinal system are described. A systematic, comprehensive technique for physical examination is presented with emphasis on the digestive and lymphatic systems. Examples of potential signs of disease are provided for each body section.     

Classification of hematopoietic system neoplasia in the dog

This article contains an overview of the classification of neoplasia of the hematopoietic system in the dog. The objective of this article is to convey an understanding of currently used classification schemes and to correlate this classification with modern concepts of hematopoietic system biology. This article will be concerned with those neoplastic disease processes that are derived from the mesodermally derived pluripotent hematopoietic stem cells and their progeny.     

Assessment of PCR for routine identification of species of the Mycoplasma mycoides cluster in ruminants

DNA amplification techniques offer considerable promise for the identification of Mycoplasma mycoides cluster members. They avoid antigenic cross-reactivity and variability that hamper serological methods. Many sets of primers, specific of these different members and of Mycoplasma putrefaciens, have been proposed. To assess the reliability of some of these PCR tests in routine laboratory diagnostic use, 230 field strains supposed to belong to this group were simultaneously identified by PCR and an antigenic method. The results were well correlated to antigenic identification for M. putrefaciens, but PCR failed to identify respectively 74% and 52% of M. mycoides subsp. mycoides Large Colony type and M. capricolum subsp. capricolum strains. Any identification of M. mycoides subsp. mycoides Small Colony type must be confirmed by two different tests. Difficulties in defining the M. species bovine serogroup 7 were also encountered with both the PCR and immunological methods. The occurrence of putative variable antigen(s) on the mycoplasma surface may explain part of the identification difficulties encountered with the immunological methods.     

Caseous lymphadenitis in small ruminants.

Caseous lymphadenitis is a contagious bacterial disease that affects sheep and goats. It is characterized by abscess formation in the skin, internal and external lymph nodes, and internal organs. The causative agent is Corynebacterium pseudotuberculosis. The disease can become endemic in a herd or flock and is difficult to eradicate by virtue of its poor response to therapeutics, its ability to persist in the environment, and the limitations in detecting subclinically affected animals. The disease causes significant economic impact on the small ruminant industry through decreased meat yield, damaged wool and leather, decreased reproductive efficiency, culling of affected animals, and mortality from the internal environment.     

A new system for the protein feeding of ruminants: The PDI system

To replace the digestible crude protein system (DCP) a new system is proposed which is named the PDI system (Protéines Digestibles dans l'Intestin grêle). It estimates the quantity of amino nitrogen N × 6.25 absorbed in the small intestine from the dietary protein which has escaped fermentation in the rumen, and the microbial protein arising from that fermentation.The extent of N degradation in the rumen and the microbial protein yield (135 g/kg of digestible organic matter intake) were obtained using an equation describing the flow of non-ammonia N entering the duodenum. The true digestibility of microbial true protein (80% of microbial crude protein) was considered equal to 0.70 and that of dietary protein was calculated from nitrogen and organic matter digestibilities of each feed.Two PDI values are ascribed to each feed: one (PDIN) calculated from both its non-degradable N and degradable N contents and the other (PDIE) from both its non-degradable N contents and its content of rumen available energy (in fact its digestible organic matter content). When calculating the PDI value of a diet, the PDIN and PDIE values of the different ingredients are summed separately: the PDI value of the diet is the lower of the two values.The PDI requirements of animals have not been measured previously. They were calculated from nitrogen balance trials on non-producing animals and from feeding trials on producing animals. The mean efficiency of PDI utilization was found to be 0.67 for milk production in cows, 0.60 for body gain in cattle and 0.60 for pregnancy in sheep. These values have also been used with animals of other species.The advantages of the PDI system over the DCP system, as well as its shortcomings, are discussed. It is compared with alternative systems which have been proposed recently in other countries.     

Transmissible spongiform encephalopathies in ruminants.

Transmissible spongiform encephalopathies (TSEs) have been observed in North American sheep, cervidae, and cattle. The causative agent of TSEs seems to be proteins that induce a conformational change in normal host proteins. Common clinical signs ofTSEs include chronic weight loss and deteriorating neurologic function. Mechanisms of TSE transmission vary among host species.The diagnostic approach for TSEs of ruminants is presented,and the history and justification of regulatory programs to control and eradicate TSEs are outlined.     

Cryptosporidium spp. in ruminants at the Lisbon Zoo.

Feces from 34 species of ruminants housed at the Lisbon Zoo was examined for Cryptosporidium spp. oocysts. Three hundred and eighty-eight samples were analyzed. Three hundred and eighty species-specific group fecal samples were collected monthly, from September 1998 until August 1999, along with eight individual specimens from eight neonates. All samples were examined by four different techniques: microscopic observation of direct and concentrated fecal smears, staining with modified Ziehl-Nielsen, immunofluorescent assay, and immunoenzymatic assay. The prevalence of infection was 3.6%. Five neonates with diarrhea were infected. Cryptosporidial oocysts were shed more frequently during winter months. Some facilities may have permitted oocysts to remain viable, possibly contributing to cryptosporidial transmission between animals.     

Ectoparasite control in small ruminants.

Ectoparasites are a common problem in small ruminants of North America. Management of ectoparasites in small ruminants can be challenging for producers and veterinarians. It is important for the veterinarian to make an accurate diagnosis of the type of ectoparasite that is infesting the animal, then to develop a plan that most effectively and economically controls the ectoparasite. Effective and economic control of an ectoparasite infestation begins with an understanding of the ectoparasite's life cycle and how that life cycle affects the animal. It should be noted that climate and geographical area can affect the life cycle of specific ectoparasites, so it is important for veterinarians to educate themselves about their specific environment. Once the life cycle has been addressed, then the veterinarian should decide which intervention will provide the best control. Intervention possibilities may range from insecticides to environmental management or a combination of several methods. The veterinarian should provide the producer with realistic goals that define specific limitations of ectoparasite control.