Bleeding abomasal ulcers in dairy cows

The clinical signs and changes in blood and rumen fluid, and the results of therapy are described in 35 cows suffering from bleeding abomasal ulcer. The most important pathological findings were moderate to severe anaemia with pale mucous membranes and tachycardia, dark coloured to black faeces, a disturbed general condition and anorexia. Two of the cows were slaughtered immediately. The others were treated by the transfusion of several litres of blood and the intravenous administration of a solution containing sodium chloride and glucose and other drugs such as calcium solution, vitamin K, vitamin C and metoclopramide. Two animals died in spite of the treatment and three had to be slaughtered because of the deterioration in their condition. The other 28 cows recovered within a few days and their general condition, appetite and defecation returned to normal.     

Perforated abomasal ulcers in adult dairy cows

Case records of adult dairy cattle with abomasal ulcers admitted to the University of Pennsylvania from 1968 through 1980 were evaluated. Of 6,385 adult dairy cattle admitted during that period, 69 had abomasal ulcers of clinical importance. Of 43 ulcers that had perforated, 17 were associated with local peritonitis and 22 were associated with diffuse peritonitis; 4 had perforated so recently that peritonitis had not had time to develop. Perforated ulcers were found in 40 cows that had recently calved (32 cows with ulcers that had perforated within 4 weeks after calving) and often had concurrent disease(s) (39 cows with at least one other disease). Ten cows with local peritonitis survived, whereas only 2 of the cows with diffuse peritonitis survived.     

Phosphorus homeostasis in dairy cows with abomasal displacement or abomasal volvulus

Abnormal phosphorus homeostasis occurs in dairy cows with an abomasal displacement or volvulus. The goal of this study was to identify potential mechanisms for hypophosphatemia and hyperphosphatemia in cows with a left displaced abomasum (LDA), right displaced abomasum (RDA), or abomasal volvulus (AV). Accordingly, the results of preoperative clinicopathologic analyses for 1,368 dairy cows with an LDA (n = 1,189), RDA, or AV (n = 179) (data set 1) and for 44 cows with an AV (data set 2) were retrieved. Laboratory values were compared by Student's t-tests, and correlation and regression analyses were performed. Thirty-four percent of the animals from data set 1 (463/1,368) were hypophosphatemic (serum phosphorus concentration ([Pi]) < 1.4 mmol/L), and 9% (122/1,368) were hyperphosphatemic ([Pi] >2.3 mmol/L). Serum [Pi] was significantly lower (P < .05) in cows with an LDA (1.60 +/- 0.53 mmol/L; mean +/- SD) than in cows with an RDA or AV (1.85 +/- 0.68 mmol/L). For cows with an LDA, [Pi] was correlated with serum urea nitrogen concentration ([SUN]) (r = 0.34) and serum concentration of magnesium ([Mg]) (r = 0.20). For cows with an RDA or AV, linear correlations existed between [Pi] and [SUN] (r = 0.45), [Mg] (r = 0.43), and serum chloride concentration ([Cl]) (r = -0.27). Stepwise logistic regression analysis indicated that low [SUN] and the diagnosis of an LDA had the strongest associations with hypophosphatemia. In cows with hyperphosphatemia, [Pi] was most strongly associated with azotemia. In cows with an AV, the strongest correlations with [Pi] were found for [SUN] and serum creatinine. We conclude that hypophosphatemia in cows with an LDA is primarily due to decreased feed intake. In contrast, hyperphosphatemia in cattle with an RDA or AV appears to result from dehydration and decreased renal blood flow.     

Risk factors for abomasal displacement in dairy cows.

OBJECTIVE: To determine whether various periparturient events or 305-day milk production during the previous lactation period were associated with abomasal displacement in dairy cows. DESIGN: Retrospective, case-control study. ANIMALS: 75 pairs of case and control cows from 3 university-owned and 3 commercial dairy herds. PROCEDURE: Cows with abomasal displacement were matched with control cows on the basis of herd of origin, breed, age, and calving date. Frequency of specific periparturient events during the period from 2 weeks prior to parturition to diagnosis of abomasal displacement, as well as milk production during the preceding lactation period, were compared between case and control cows. RESULTS: Multivariate analyses indicated that case cows were significantly more likely to have had retained placenta, ketosis, a stillborn calf, metritis, twins, or parturient paresis than were control cows. Dystocia, mastitis, and milk production during the previous lactation period were not associated with abomasal displacement. CLINICAL IMPLICATIONS: Results indicated that a variety of periparturient events were associated with development of abomasal displacement among dairy cows.     

Determination of the effect of single abomasal or jejunal inoculation of Clostridium perfringens type A in dairy cows

A randomized study was conducted to determine if inoculation of the abomasum or jejunum with Clostridium perfringens Type A would induce jejunal hemorrhage syndrome in healthy cows. Twelve adult nonlactating dairy cows were inoculated with 10 mL of pure culture broth of C. perfringens type A (beta2 toxin positive) into the abomasum (n = 6) or jejunum (n = 6). On day 6, the cows were euthanized and samples for culture were taken from the abomasum, jejunum, and feces. No cows developed clinical signs of jejunal hemorrhage syndrome during the course of the study. Five of 6 abomasal samples and 1 of 6 jejunal samples were positive for C. perfringens Type A (beta2 negative) prior to inoculation. Eight of 12 abomasal samples, 11 of 12 fecal samples, and 10 of 12 jejunal samples were positive for C. perfringens Type A (beta2 negative) after inoculation. Intraluminal inoculation of C. perfringens Type A alone at this dose and under these conditions did not induce clinical signs of jejunal hemorrhage syndrome in adult dairy cows. The multifactorial nature of the disease likely contributed to our inability to reproduce the disease in this study.     

胆碱的生理功能及RPC对围产期奶牛的调控作用

胆碱(choline,CHO)在构成细胞结构、维持神经系统正常功能和调节脂肪代谢等方面发挥重要作用。过瘤胃胆碱(rumen-protected choline,RPC)是对CHO进行保护的一种添加剂产品,为了提高CHO的有效利用率。研究发现RPC对围产期奶牛具有调控作用,可以提高奶牛的生产性能,调节脂肪代谢进而影响奶牛血浆生化指标。文章主要从CHO的生理功能、奶牛围产期生理特点以及RPC对奶牛生产性能、血浆生化指标的影响等方面来进行综述,旨在为奶牛养殖行业提供一些理论参考。     

Prevalence of endotoxemia in healthy postparturient dairy cows and cows with abomasal volvulus or left displaced abomasum

Left displaced abomasum (LDA) and abomasal volvulus (AV) occur most commonly in postparturient dairy cows. Our main hypothesis was that endotoxemia occurred more frequently in the peripheral blood of cows with LDA or AV than in healthy cows because increased luminal pressure in AV or LDA, or the presence of a hemorrhagic strangulating obstruction in AV, may have injured the abomasal mucosa, thereby facilitating translocation of luminal endotoxin into the circulation. Therefore, our main objective was to compare the prevalence and magnitude of endotoxemia in healthy postparturient cows with the prevalence and magnitude of endotoxemia in cows with AV and LDA. We examined 60 adult dairy cows in early lactation that were diagnosed with AV (n = 15) or LDA (n = 15) or were healthy on physical examination (control group, n = 30). Jugular venous blood was obtained from cows in all 3 groups, and right gastroepiploic venous blood was obtained during surgical correction of AV and LDA immediately after repositioning of the abomasum. Platelet-rich plasma endotoxin concentrations were measured with a chromogenic limulus amoebocyte lysate assay. Endotoxin was detected in jugular vein plasma in 50% (15/30) of control cows; however, the prevalence of endotoxemia was significantly lower (P < .05) in cows with AV (7%, 1/15) or LDA (20%, 3/15). Endotoxin was detected simultaneously in right gastroepiploic and jugular vein plasma in only 1 cow with LDA and 0 cows with AV. Contrary to our hypothesis, we conclude that endotoxemia is infrequently present in postparturient dairy cows with AV or LDA.     

Effects of stage of lactation on the response of dairy cows to abomasal infusions of casein

Two Friesian cows in their third week, and two other cows in their seventh month of lactation were given abomasal infusion of 0, 350, 700 and 1000 g per day of casein. The casein infusion increased yields of milk, protein and total solids, the increases being much greater in early than in late lactation. Casein infusion did not change the plasma concentration of insulin in early lactation while a linear increase from 9.9 to 24.5 mU 1⁻¹ was observed in late lactation. This increase was not related to changes in plasma glucose.     

输精部位对奶牛超排效果的影响

对奶牛超排时输精部位进行了研究。结果发现,在其它实验条件相同的情况下,在子宫角部位输精的供体牛的超排效果好于在子宫体部位输精的供体牛,其可用胚数(7±6.353)极显著高于子宫体部位输精的(4.182±1.870)(P<0.01),且无精卵数和停滞卵数(0.222±0.183和0.222±0.183)都分别极显著低于子宫体部位输精的(1.091±0.848和0.909±0.468)(P<0.01)。这说明超排时在子宫角部位进行输精能够提高超排效果。     

Peritoneal fluid analysis in dairy cows with left displaced abomasum and abomasal volvulus

Peritoneal fluid (PF) was evaluated in 40 cows with left displaced abomasum (LDA) and 15 cows with abomasal volvulus (AV). PF was obtained by abdominocentesis at the right ventral abdomen at admission. Simultaneously, a blood sample was taken from the jugular vein. Biochemical and cytological variables in blood and PF specific for ischaemia, inflammation and cell damage were compared. Total protein, albumin, glucose and cholesterol were normal in PF of cows with LDA and AV. Although L-lactate increased in both groups, cows with AV had significantly higher values (LDA: 1.47/0.69/2.68 mmol/l; AV: 6.45/4.55/12.89 mmol/l (median/1. quartile/3. quartile)). D-dimer (LDA: 0.50/0.22/0.88 mg/l; AV: 1.11/0.40/1.85 mg/l) and LDH (LDA: 663/437/943 U/l; AV: 1099/750/1439 U/l) were only increased in PF of cows with AV. The number of leucocytes was normal; however, significantly more peritoneal neutrophils appeared necrotic or apoptotic after AV. PF of cows with abomasal displacement showed distinctive features of ischaemia and inflammation. Characteristics of haemostatic dysfunction and cell damage were mainly evident in PF of cows with AV. The results suggest that anti-inflammatory therapy is indicated in each cow with abomasal displacement. Additionally, medical treatment should be directed to prevent complications of ischaemia and reperfusion in cows with AV.     

Studies on the pH value of abomasal contents in dairy cows during the first 3 weeks after calving

The pH value of the abomasal contents in adult cattle is normally constant and has a value of 2. Abomasal contents with pH values of 5.5 and higher could give rise to bacterial fermentation with subsequent gas production. The accumulation of gas is thought to form a key event in the pathogenesis of abomasal displacement. The aim of the present study was to determine the pH values of abomasal contents of dairy cows in the first 3 weeks after calving. The pH of the abomasal contents was, over several days. higher than the pH value of the abomasal juice in mid-lactation cows. The highest pH values were measured on day 14 after calving, thereafter the pH declined. Possible explanations for the rise in the pH value of the abomasal contents are discussed.     

Adrenocortical function testing in dairy cows and its effect on milk yield.

Administration of 6IU synthetic ACTH1-24 intravenously to six Holstein-Friesian cows resulted in a cortisol peak concentration after 1 hour of 148 +/- 34.2 ng/ml. Basal plasma cortisol concentration (4.84 +/- 0.83 ng/ml) was reached 5 hours after ACTH injection. Until 7 days after ACTH administration no effect on milk yield was recorded. So it is concluded that a dose of 6 IU ACTH1-24 is sufficient for a conspicuous release of cortisol without any alteration in milk production. This dose can be used as a standard test for the evaluation of adrenocortical function in lactating cows when administered intravenously at 9 a.m. and when plasma samples for cortisol assay are collected just prior to administration and at 10 a.m.     

Macromineral status of dairy cows with concurrent left abomasal displacement and fatty liver

Abstract

AIM: To evaluate the macromineral status of field cases of dairy cows surgically treated for left abomasal displacement (LDA), with concurrent fatty liver of different severity, and compare this for animals that died or recovered.

METHODS: Sixty-eight Holstein dairy cows with LDA and 110 control cows, from 28 farms, were used in the study. Blood samples and liver biopsies were obtained during standing surgery for correction of LDA, and from control cows. The concentration of macrominerals in serum, and of total lipids (tLPD) and triglycerides (TG) in liver were determined. Liver was examined histologically, and classified for its severity of fatty liver. Cows with LDA were grouped according to severity of fatty liver. Cows in Groups 1 to 3 recovered, whereas those in Group 4 died within 4 weeks of surgery. Group 1=mild (n=4) or moderate (n=6 cows, n=4 heifers) fatty liver, Group 2 = moderate to severe fatty liver (n=13), Group 3=severe fatty liver (n=15 cows, n=5 heifers), Group 4 = severe fatty liver (n=17 cows, n=4 heifers).

RESULTS: The concentration of macrominerals in serum was affected by the concurrence of fatty liver and LDA; Ca, K and Mg were significantly (p<0.05) lower in animals that died than those that survived. For cows with severe fatty liver, concentrations of tLD and TG were higher in the animals that died compared with those that recovered (p<0.01). Cows with LDA and severe fatty liver that died were earlier in lactation (median days in milk (DIM) 13 days) compared with the other cows with LDA (median DIM 21–26 days) (p<0.05); they were also significantly older (median 6 years old) than cows in the other groups (median 4 or 5 years old) (p–0.05).

CONCLUSIONS AND CLINICAL RELEVANCE: Concentrations of macrominerals in serum were influenced by the concurrence of LDA and fatty liver. Animals with low concentrations of Ca, K and Mg had a guarded prognosis. The concentration of K should always be evaluated in cows with LDA and concurrent fatty liver when providing a prognosis. Most cows with severe fatty liver were detected in the first 4 weeks of lactation, but older animals and those that had more recently calved had a worse prognosis.     

Short communication: ultrasonographic examination of the abomasal position in dairy cows during the peripartal period

The objective of this study was to document the abomasal position during the peripartal period by ultrasonographic measurement to get more data about the topographic dynamic. In 12 dairy cows the abomasal position was measured daily from the 5th day before calving up to the 5th day after calving by a transabdominal ultrasonographic examination (5 MHz convex transducer). The abomasal position was described by means of 3 measured distances: (a) the distance between the cranial margin of the abomasum and the xiphoid cartilage, (b) the distance between the right margin of the abomasum and the median line and (c) the distance between the left margin of the abomasum and the median line. Prepartal the abomasal position was different from the position during the postpartal period. Its position was more cranially (p < 0.05) and more right laterally (p < 0.05). The left margin was not detectable at the left side of the mid-line ante partum. Directly after calving the left margin of the abomasum was found left of the linea alba (p < 0.05). These results show that there is a great influence of the gravid uterus on the abomasal position. The abomasum is positioned more cranially and more right lateral during the end of pregnancy. This position changes immediately after calving.     

Interdependence of the level of total proteins, magnesium and beta-carotene in the plasma of dairy cows

The degree of dependence of the concentration of total protein, magnesium and beta-carotene in the blood plasma of over 3,400 dairy cows in the first and second phases of lactation and in months 8 and 9-9.5 of pregnancy was attested statistically. It was shown that in late pregnancy the concentration of all three indices drops both with winter and summer feed rations and that the connection between all three pairs of indices is positive. The highest values of the linear correlation coefficient were ascertained between the total protein and magnesium of blood plasma (+0.87 in the winter period, +0.63 in the summer period and +0.75 in both periods), the correlation was somewhat lower between magnesium and beta-carotene (+0.56, +0.75 and +0.36) and it was lowest between total protein and beta-carotene (+0.45, +0.41 and +0.42). The discussion deals with the causes of the stochastic correlation of these components of blood plasma.     

The effect of stress on udder health of dairy cows

The appropriate literature has been reviewed for the purpose of defining the phenomenon of stress in lactating dairy cattle, establishing a baseline concept of lactation stress and emphasizing the most significant aspects of the natural mammary defence mechanisms. Data on the general adaptation syndrome (GAS) make it clear that stress is essentially the rate of wear and tear of the biological system affected by a stressor either eliciting stress of the organism as a whole or partly so. Owing to the variety of stressors which may affect the dairy cow at physiological and pathological levels, a definition of stress in the broad sense is indicated. This is essential from the point of view of the anti-homeostatic effects (metabolic and immunological) of lactation stress, aggravated by anti-homeostatic effects elicited by superimposed other types of stress (e.g. heat stress). The lactating cow, as a ruminant in a state of sustained stress, requires a special profile of hormonal mediators. In high yielding cows, for example, acute and sustained heat stress promotes increased activities of prolactin, progesterone and catecholamines. Compared with the mainly glycogenic/glycogenolytic metabolism of non-ruminant mammals, the lipogenic/lipolytic and glycogenic/glycogenolytic metabolism of the dairy cow depends on hormonal mediators which differ from those of the former not so much in their nature but in their magnitude and ratios. Stressors induce the development of GAS reactions in the dairy cow. These enable the cow to create and maintain homeostasis of its integrated 3 main physio-pathological systems and thus to endure the stressor(s). The cow's compensating adjustments to a stressor are therefore the effects of stress. This means that natural lactation is the effect of the lactation stress induced by the cow's progeny (i.e. the natural lactation stressor). Artificial lactation stressors (e.g. removal of milk by hand and machine) may affect the lactation stress in magnitude but not necessarily in nature. Likewise, a range of behavioural, physiological, lactational and lacteal changes related to other stressors are the effects of different types of stress. Lactation stress, like other types of stress, shows 3 stages of development, i.e., an overcompensating alarm phase (= lactogenesis), resistance phase (= galactopoiesis) and exhaustion phase (= regression). They facilitate adjustments of the cow's homeostasis from the level of involutional homeostasis (= no lactational activity) to that of lactational homeostasis. Like other tissues in a state of stress, the lactating mammary epithelium requires a greatly increased supply of glucose.(ABSTRACT TRUNCATED AT 400 WORDS)