奶牛真胃变位研究概况

近年来奶牛真胃变位病的发生呈上升趋势,探讨其病因及预防和治疗方法非常必要.文章在总结大量的临床实践和试验研究的基础上,对奶牛真胃变位病的病因、发病机理、诊断要点及治疗方法进行了总结,认为本病的主要病因是奶牛采食过量高精料日粮和缺乏运动;手术整复与固定是该病的主要治疗方法;预防该病的发生主要是增加优质粗饲料的喂量和加强奶牛怀孕后期管理.     

不同日粮条件下绵羊皱胃食糜氨基酸的研究

利用四头装有瘤胃和皱胃瘘管的阉公羊以及四头未装瘘管的阉公羊进行两系列实验,测定通过瘤胃蛋白、皱胃氨基酸通过量以及瘤胃消化代谢和氮的利用。分别给试验绵羊(湖羊)饲喂未处理大豆粉日粮(Ⅰ),甲醛处理大豆粉日粮(Ⅱ),稻草 精料日粮(Ⅲ)和稻草 精料 异丁叉二脲日粮(Ⅳ),皱胃食糜中各种氨基酸含量未见有明显改变。饲喂甲醛大豆粉日粮时,流经皱胃的各种氨基酸增加,饲喂含异丁叉二脲日粮时则明显减少。皱胃总氨基酸(TAA)通过量与通过瘤胃蛋白氮量,呈强正相关。日粮对流经皱胃总必需氨基酸(TEAA)中各种氨基酸比例以及总非必需氨基酸(TNEAA)中各种氨基酸比例没有明显影响。饲喂日粮Ⅰ时流经皱胃的TEAA/TAA和TNEAA/TAA分别为48.62％,51.38％;日粮Ⅱ时为48.42％,51.58％;日粮Ⅲ时为48.18％,51.82％;日粮Ⅳ时为48.26％和51.74％。各日粮间差异不显著。     

黄牛皱胃积食前后瘤胃内容物pH值与纤毛虫数量变化的探讨

从患有皱胃积食的5例黄牛瘤胃中采用胃管吸引法获得手术前、胃腔冲洗后及术后采食3 d后的瘤胃内容物,分别测定瘤胃内容物的pH值和纤毛虫数量。结果表明,患有皱胃积食的黄牛经5～8 d病程,其瘤胃内容物pH值为8.12±0.225,呈弱碱性,纤毛虫含量为(4.9±2.4)×10~4个/mL;手术掏空瘤胃并进行冲洗后,经过3 d采食,瘤胃内容物由刚冲洗完毕时的pH值为6.06±0.31、纤毛虫数量为阴性逐渐变化到pH值为7.5±0.179、纤毛虫数量为(25.8±9.7)×10~4个/mL。     

Abomasal parasite syndrome in North American elk (Cervus elaphus canadensis)

CASE HISTORY An 18-month clinical course of chronic ill-thrift, weight loss and emaciation, and eventual death occurred in a group of 520 translocated elk of mixed age and sex. Trans-location was carried out without regard to animal welfare or health risks associated with the translocation. Mortality was approximately 84% (436/520) despite supportive nutritional and medical treatment.

PATHOLOGICAL FINDINGS: General clinical and post-mortem examinations indicated only Se and Cu imbalances and nutritional inadequacy. Additional purposeful post-mortem examination and histological evaluation of tissue sections from four of the affected adult elk demonstrated elevated abomasal pH and proliferative abomasal lesions as the most significant findings, consistent with Type-II ostertagiosis; intra-lesional nematodes were seen in the abomasum of two animals.

DIAGNOSIS: Fading elk syndrome, or abomasal parasite syndrome in elk.

CLINICAL RELEVANCE: Abomasal parasite syndrome initiated by Type-II ostertagiosis should be considered as a differential diagnosis in cases of ill-thrift and wasting in elk or elk-red deer hybrids. Changes to the architecture and secretory function of the abomasal wall lead to apparently irreversible digestive pathophysiology and nutritional disease.     

Effects of the two production programs ‘Naturafarm’ and ‘conventional’ on the prevalence of non-perforating abomasal lesions in Swiss veal calves at slaughter

Non-perforating abomasal lesions are a considerable problem affecting more than half the population of veal calves. The objective of the present study was to assess the prevalence of pyloric and fundic abomasal lesions in Swiss veal calves at slaughter and to compare the occurrence of non-perforating abomasal lesions between two different production programs (‘Naturafarm’ and ‘conventional’). ‘Conventional’-production settings met the minimal standards as defined by the Swiss animal welfare legislation, whereas ‘Naturafarm’ production complied with increased animal welfare requirements. In order to identify risk factors for the development of abomasal lesions, information on management, housing, and feeding was obtained by a questionnaire. A total of 125 abomasa were randomly selected in one large abattoir. They were examined macroscopically, and the occurence of lesions in either the fundic or pyloric region of the abomasum was recorded separately. Animals raised in the ‘conventional’-production setting revealed a significantly higher prevalence of lesions in the fundic part. Factors significantly affecting the prevalence of non-perforating lesions in the fundic part were the ‘conventional’-production environment, including missing access to an outside pen, missing access to water and straw as the only roughage, feeding by bucket and the liquid milk by-product Protofit in combination with the powder Sprayfit.     

Pathophysiology of abomasal parasitism: is the host or parasite responsible?

Nematode larvae developing within the glands cause local loss of parietal cells and mucous cell hyperplasia whereas reduced acid secretion, increased serum gastrin and pepsinogen concentrations and generalized histological changes are associated with parasites in the abomasal lumen. Parietal cells with dilated canaliculi and/or degenerative changes typical of necrosis are present soon after the transplantation of adult worms, and abomasal secretion is also affected. Anaerobic bacteria survive in greater numbers as the pH rises, with bacterial densities becoming similar to ruminal populations at an abomasal pH of 4 and above. Failure to lyse bacteria may affect adversely the nutrition of the host. The parasites may initiate the pathophysiology through the release of excretory/secretory (ES) products which either act directly on parietal cells or indirectly through enterochromaffin-like (ECL) cells by provoking inflammation or by disrupting the protective mucosal defence system.Parietal cell dysfunction is proposed as a key event which leads to loss of mature chief cells and mucous cell hyperplasia, as well as hypergastrinaemia. Inflammation increases circulating pepsinogen concentrations and may also contribute to increased gastrin secretion. Stimulation of mucosal proliferation and differentiation of parietal cells in the isthmus by the raised serum gastrin levels will be beneficial by generating a new population of active parietal cells and adequate acid secretion.     

Gastrointestinal parasites in an isolated Norwegian population of wild red deer (Cervus elaphus)

Background

Thirteen red deer (Cervus elaphus), culled from the isolated population at the Mongstad Oil Refinery, Norway, were investigated for gastrointestinal helminths. These animals, enclosed by the refinery fence, do not have contact with other ruminants and have a high population density considering the available browsing area (1 km²) within the refinery site (3 km²). The population was estimated to be 110-130 at the time of culling.

Results

The helminth fauna among these sampled red deer was enumerated and species were identified based on morphology. Ostertagia leptospicularis/O. kolchida was detected in 83% [CI 55 - 95%], Spiculopteragia spiculoptera/S. mathevossiani in 92% [CI 65 - 99%] and Trichostrongylus axei in 42%, [CI 19 - 68%] of the abomasa examined. Characterisation of the intestinal parasite fauna revealed Capillaria bovis, Cooperia oncophora, Oesophagostomum venulosum, Trichuris globulosa and tapeworm fragments (presumed anoplocephalids) in seven individuals. Only one calf had an infection with more than one intestinal helminth (tapeworm fragment and Trichuris globulosa). The remaining six deer had single species intestinal infections.No significant age related trends were seen, with the exception of higher intensity of infection of T. axei in yearlings relative to other age classes. Assessment of abomasal parasite burden and body condition revealed no significant trends. In calves, statistically non-significant correlation was seen between increased parasite burden and decreased slaughter weight, whilst the opposite was seen in adults with the heaviest adults exhibiting the higher burdens. Given the small sample size the trends that were seen need further investigation. The parasite burden was aggregated with three adult red deer harbouring 75% of the total abomasal parasite count.

Conclusion

This isolated population was parasitised by a reduced subset of gastrointestinal nematodes typical of this cervid across an extensive geographic range in Eurasia. The intensity and abundance of abomasal nematodes was higher in this isolated population than reported in similar studies of red deer populations across Europe.     

Prognostic value of plasma L-lactate concentration measured cow-side with a portable clinical analyzer in Holstein dairy cattle with abomasal disorders

BACKGROUND: L-Lactate has been used as a prognostic indicator for ill humans and animals. A portable analyzer that measures L-lactate could help veterinarians decide to proceed with correction of a displaced abomasum. HYPOTHESES: The likelihood of a dairy cow with a displaced abomasum remaining in the herd can be predicted by lactate concentration and other variables. ANIMALS: Thirty-four healthy early-lactation dairy cows, and 131 cows with abomasal displacements (DA) presented to Cornell University, Ithaca, NY. METHODS: Plasma L-lactate was measured using a commercial analyzer (i-STAT). A cow had a positive outcome (PO) if she remained in the herd 30 days after surgical correction of the displaced abomasum and a negative outcome (NO) if she was culled or died in that time. A multivariable model with physical examination and clinicopathologic variables for predicting NO for cows with right-sided abomasal displacements was constructed. RESULTS: The median plasma L-lactate was 0.54 mM/L (interquartile range, 0.42-0.74) in healthy lactating Holstein cows. In cows with right-sided displaced abomasa, median plasma L-lactate concentrations were higher in cows with NO (5.88 mM/L) versus PO (3.23 mM/L) (P = .002). In a multivariable model, which identified chloride, heart rate, and L-lactate as the best fitting variables for cows with right-sided displacements, the probability of NO increased as L-lactate increased. CONCLUSIONS AND CLINICAL IMPORTANCE: Plasma L-lactate concentration might be a useful predictor of productive outcomes in cows with right-sided abomasal disorders.