The significance of ketonuria in lactating cows

In two large sized farms in Hungary and in several small and medium farms in Bavaria the authors studied the development of ketonuria in cows after calving. In two flocks without problems 30 percent of the cows developed ketonuria, whereas the rate was 56 percent in one problematic flock. Milk yield of the cows observed was above 5000 kg per year, their age differing only slightly. Cows with ketonuria revealed an increased enzyme activity of AST and a decreased plasma-glucose concentration in comparison to the ketone-free animals. Also, the ketonuria cows showed higher amounts of free fatty acids in plasma and lower amounts of total cholesterol. Additionally, these animals more often revealed reproductive disorders. The rate of culling and emergency slaughter was also increased, whereas their pregnancy rate was decreased.     

Hormonal treatments for fertility disorders in cattle

In dairy cows, hormonal treatments are commonly implemented for acyclicity, silent heat and endometritis. Before treatment, causes of infertility need to be detected and severe failures in housing, feeding or other diseases must be eliminated. Without sustainable improvement of herd management, the use of intensive hormonal treatments will not improve reproductive performance. The most common cause of anoestrous is silent heat. In cows with a palpable corpus luteum, injection of prostaglandin F2α (PGF) reliably induces oestrous. A satisfactory treatment for acyclicity (ovarian dystrophy, ovarian cysts) does not exist. Combinations of different hormones have greater treatment success than a single use of gonadotrophin releasing hormone (GnRH) or human chorionic gonadotrophin (hCG). Strategic use of PGF during the early postpartum period cannot be recommended because positive effects on uterus involution and resumption of the oestrous cycle after calving have not been verified. In contrast, application of GnRH combined with PGF in the puerperal phase appeared to have positive effects on fertility of cows with endometritis. The same applies to PGF for cows with chronic endometritis. Cases of endometritis with fetid odour of vaginal mucus or isolation of Trueperella pyogenes should be treated with antibiotics. Treatment before the 27th day post partum is not advisable. In conclusion, hormonal treatments can be used to treat fertility disorders. Nevertheless, in order to enhance the reproductive performance at the herd level, a sustainable improvement of the general conditions (housing, feeding, animal health, management) is a prerequisite.     

The prevalence and economic significance of liver disorders and contamination in grain-fed and grass-fed cattle

SUMMARY Livers were examined from 5,647 grain-fed and 621 grass-fed cattle of similar breed, age and weight, killed at a Queensland abattoir in 1980–81. The prevalences of disorders found in grain-fed cattle were liver abscesses 5.6% and 11.1% (after 80 and 120 days in the feedlot), telangiectasis 8.4%, Echinococcus granulosis 3.3%, Fasciola hepatica 0.4%, unclassified lesions 7.4%, and contamination 3.2%. In grass-fed cattle liver abscesses were 0.2%, telangiectasis 1.0%, E. granulosis 18.9%, F. hepatica 5.4%, unclassified lesions 6.5%, and contamination 1.0%. Liver abscess disease was the main cause of loss in grain-fed cattle and the mean carcase weight of affected steers was 298kg±42kg, compared wiith 308kg±40kg in non-affected (p 0.01). Liver weights of grain-fed and grass-fed cattle were highly significantly correlated with carcase weights (r - 0.78 and 0.49 respectively). Total losses were $2.25 per head in grain-fed steers and $0.90 in grass-fed steers.     

The relationship between feeding and fertility in dairy cattle]

The possible relationship between nutrition and fertility in dairy cows are reviewed. Study of the literature shows that opinions on the effect of the various nutrients differ markedly. The conclusion which can be made is that in countries where standards of dairy farming are high, nutrition only plays a minor role in the problem of herd subfertility. In the course of time deficiencies in a large number of minerals, trace elements and vitamins have been stressed as a cause of inadequate fertility. However cows are at present generally fed with a lot of well balanced concentrates and therefore deficiencies are very unlikely to occur. During early lactation every high producing dairy cow has a negative energy balance. In a number of cows this results in anoestrus and in a long interval from parturition to first insemination. Overfeeding during late lactation and the dry period does not adversely affect subsequent reproduction but may cause puerperal disorders. The relation between protein nutrition and fertility is complex. Protein effects on fertility are minor. Problems can arise if there is a combination of a high percentage of crude protein (greater than 18%), a high rumen degradability of the protein and a low energy content of the diet. The value of metabolic profile tests is minimal because they do not differentiate between normal herds and herds with fertility problems.     

Dynamics of clinico-biochemical indicators in cattle with ketonuria during the dry period and after parturition

The study was performed in eight high-pregnant cows in which medium to high ketonuria was repeatedly detected. The control group consisted of six cows free from ketonuria before parturition. Blood and urine were sampled from the cows two to eight weeks before parturition, on the day of parturition, 24 hours, three to five days and two to six weeks after parturition. The concentrations of oxidated ketone bodies and beta-hydroxybutyrate were determined by the distilling method. Further, the values of clinico-biochemical parameters in the urine and blood were determined within the range of the preventive diagnosis system. No marked changes in the health condition were found by the current clinical examination. The average concentration of total ketone bodies in the blood of the cows two to eight weeks before parturition was 29.2 mg per litre; the respective values recorded in the control cows were lower by about a half. The concentration of ketone bodies in the blood of the cows in the experimental group decreased on the day of parturition. The decrease was followed by a gradual rise of the total ketone bodies content in the blood up to 50.6 mg per litre two to six weeks after parturition. Alterations testifying to a disorder in the function of liver were observed in the cows of both groups throughout the period under study. The disorder was due to excessive administration of crude protein to the high-pregnant cows combined with the use of low-quality silage. After parturition the feed ration was not differentiated according to performance and was deficient in the basic nutrients and vitamins. Ketonuria was obviously due to the simultaneous intensification of hepatal and alimentary ketogenesis, caused by hepatopathy in combination with the intake of large amounts of poor-quality silage containing butyric acid.     

Ultrasonography as a diagnostic and prognostic approach in cattle and buffaloes with fatty infiltration of the liver

The aim of the present study was to determine whether ultrasonographic evaluation of the hepatic parenchyma could be used as a diagnostic and prognostic approach in cows and buffaloes with hepatic lipidosis. For this purpose, cows (n=16) and buffaloes (n=10) with fatty infiltration of the liver were examined by ultrasonography. Treated cows and buffaloes were monitored for hepatic changes ultrasonographically, biochemically and histologically. Clinical findings were non-specific and included anorexia, recumbency, muzzle necrosis, and icteric mucosal membranes. Laboratory data revealed neutrophilia, hyper gamma-globulinemia, elevated activities of aspartate aminotransferase, gamma-glutamyl transpeptidase, creatine kinase and lactate dehydrogenase, and high concentrations of insulin, total bilirubin, non-esterified fatty acids and beta-hydroxyl butyric acid. Laboratory results 7, and 21 days after treatment showed progressive improvement in the chemistry profile. On admission, ultrasonographic examination of the hepatic parenchyma in cows and buffaloes revealed either increased or decreased hepatic echogenicity; histologic examination revealed marked fatty infiltration of the hepatocytes. One week after treatment, the hepatic parenchyma was visualized easily, liver boundaries were clearly imaged, and histologic examination of hepatic specimen showed a moderate degree of fatty infiltration. Three weeks after treatment, the hepatic parenchyma was almost similar to normal, the hepatic and portal blood vessels could be easily imaged, and the histologic picture had greatly improved where the liver resembled the normal organ. Six cows and seven buffaloes made a full recovery while the remaining ten cows and three buffaloes were slaughtered and thoroughly examined postmortem. Ultrasonography showed a good correlation with histologic and laboratory findings.     

Mastitis and fertility disorders in cows

Udder inflammations, independently of significant losses in milk yield and alteration of its quality, can negatively affect cows' reproduction efficiency. Mastitis causes changes in many active constituents, both in milk and blood. Pathogenic changes in existing constituents and new active chemical compounds, generated during disease, can affect other organs, particularly the reproductive system and its mechanisms. Fertility disorders in mastitic cows are mostly connected with the activity of cytokines (especially TNF-alpha), cortisol, prostaglandin F2-alpha, reactive oxygen species (ROS), and classic inflammatory mediators. The successful treatment of mastitis as well as protection against udder infections should be considered important methods for prophylaxis of fertility disorders in cows. The first Polish trials indicated that injection of supportive drugs (antioxidants or lysozyme dimer or flunixin meglumine) to intramammarily treated cows can increase fertility in cows with mastitis.