Médecine vétérinaire

Introduction Examination and assessment of the genital system is an important part of the veterinary management of dairy cows.  The target on many dairy farms is for cows to achieve a calving to calving interval of 365 days.  To achieve this target the reproductive performance of the cow has to be closely managed. Some consider this calving interval to be an unattainable and possibly undesirable goal in high yielding cows. On many farms it is only achieved by close monitoring of the cows’ reproductive performance and intervention with strategic hormone therapy. An assessment of herd fertility should involve examination of animals, including any problem animals, as they are presented for routine fertility checks. It should also involve consideration of the farm husbandry and management.  Information required should include the overall disease profile of the farm, milk yields and both past and present fertility records. The cow has an average gestation length of 283 days. To achieve

Introduction The skin has been described as the largest organ in the body. It defends the body it covers and is involved in the maintenance of homeostasis including water conservation. The skin is involved in body temperature conservation through insulation and in heat loss through perspiration. The sensory nerves of the skin recognise pain and temperature extremes. The skin provides protection against minor physical injuries, supports hair growth and offers some defence against microbial invasion. The condition of the skin is a reflection of the general health of the animal, deteriorating in cases of ill health, ill thrift and debility. In some conditions, such as jaundice, the skin may provide through discolouration direct diagnostic evidence of a specific disease process. In other conditions, such as parasitism or severe mineral deficiency, a nonspecific general deterioration of skin health may occur causing a greater number of hairs than normal to enter the tel

 Lymphatic system The lymphatic system consists of the carcase lymph nodes, the network of lymph vessels which connect them and the lymphatic parts of the spleen. Many of the nodes are readily palpable in the healthy animal. Others can be palpated only when enlarged. Details of the location of the individual nodes and their ease of palpation are given below. The lymph vessels are normally palpable only if they are enlarged. Some vessels may be seen and palpated as they run subcutaneously towards the regional lymph nodes. Clinical examination of the lymphatic system Grossly enlarged lymph nodes may have been seen during observation of the patient before it is handled. Further observation and palpation is possible when the animal is restrained. The lymph nodes can be examined as a separate system or checked during the examination of the skin when the clinician’s hands run over the whole body surface. Each paired node should be compared for size and consistency with

La consommation volontaire de la vache laitière subit une double régulation, d'abord volumétrique puis biochimique permettant un bon ajustement aux besoins énergétiques comme chez tous les animaux. • La régulation volumétrique met en cause l'encombrement des préestomacs qui est directement lié à la faible densité énergétique des aliments fibreux (UFL par kg MS ou par 1) et à leur lente dissolution ruminale, et qui est quelque peu en relation inverse avec leur digestibilité. Elle restreint le niveau d'ingestion des rations à base de fourrages, d'autant plus que ceux-ci sont plus médiocres. Réciproquement, l'amélioration de la qualité des fourrages et au besoin l'association d'un minimum de concentrés équilibrés pour augmenter la concentration nutritive a le triple mérite d'accroître conjointement l'ingestibilité, la digestibilité et le rendement métabolique. A ce titre, un optimum de concentration nutritive, autorisant une ingestion maximale,

Une dangereuse accumulation rumi-nale d'ammoniac résulte d'une dysharmonie entre une ammoniogenèse à tendance explosive et une protéo-synthèse microbienne toujours relativement lente et limitée. • L'ammoniogenèse trop rapide est encore renforcée par des apports trop abondants, trop brutaux ou trop peu fractionnés d'azote trop rapide-ment dégradable ; • La protéosynthèse microbienne trop faible est davantage ralenlie par une inadaptation de la microflore ou un approvisionnement de glucides fermentcscibles insuffisant, désynchronisé ou discontinu par rapport à la libération en ammoniac (voir figure 36). Les manifestations suraiguës en sont bien connues en raison de leur caractère spectaculaire : tétanie de nutritionet tétanie d'herbage (compliquée d'hypomagnésémie), ainsi que enté-rotoxémies vraies (par prolifération ruminale de Clostridiales). Les formes cbroniques, beaucoup plus insidieuses et polymorphes sont largement sous-estimées alors qu'elles son