Maria A. Karatzia

The role of lactate dehydrogenase, alkaline phosphatase and aspartate aminotransferase in the diagnosis of subclinical intramammary infections in dairy sheep and goats

The objective was to investigate the changes occurring in the activities of the enzymes lactate dehydrogenase (LDH), alkaline phosphatase (ALP) and aspartate aminotransferase (AST) in sheep and goat milk as a result of subclinical intramammary infections (IMI) and to evaluate the use of these enzymes for the diagnosis of subclinical IMI in dairy sheep and goats. A total of 206 samples of sheep milk and 162 samples of goat milk, obtained from equal udder halves, were used in the study. For each species they were divided into two groups: a no-infection group and a subclinical infection group. Activities of LDH, ALP and AST were significantly higher in the subclinical infection group than in the no-infection group (P<0.05) in both sheep (LDH: 350.42+/-11.25 v. 120.91+/-4.41; ALP: 2773.43+/-105.18 v. 2189+/-94.24; AST: 29.57+/-0.74 v. 17.32+/-0.46) and goats (LDH: 354.07+/-13.33 v. 103.79+/-3.75; ALP: 311.13+/-25.74 v. 137.24+/-19.62; AST: 27.59+/-6.42 v. 15.87+/-0.45). The activity of LDH was identified as indicator for subclinical IMI in both sheep and goats. The optimum cut-off values for LDH activity, offering the highest diagnostic sensitivity (DSn) and diagnostic specificity (DSp), determined by receiver operating characteristic (ROC) analysis, were at 197 U/l, 185 U/l and 197 U/l for sheep, goats and both species, respectively. DSn for sheep, goats and both species at these cut-off values was 92.8%, 98.2% and 94.0%, whereas DSp was 95.4%, 96.3% and 96.3%, respectively. It was concluded that the determination of LDH activity in milk serum is a sensitive and reliable method for the detection of subclinical IMI in dairy sheep and goats.

Alternatives to antibiotics for farm animals

Nowadays, there is an increasing concern for the public health about the consequences from the long and increased use of antibiotics in livestock production. The use of antibiotics in animal feed as growth promoters has been completely banned by the European Union since 2006, based on their possible negative effects on human and animal health. The removal of growth promoters has led to animal performance problems and a rise in the incidence of certain animal diseases. Thus, there is an urgent need to find alternatives to antibiotics, especially in EU. Due to the modern consumers’ concern about the potential development of antibiotic-resistant bacteria as well as at the same time the need to prevent economic losses of the farmers, alternatives to antibiotics has been developed to prevent the health problems and to improve the growth performance in farm animals. Owing to the full ban of antibiotic use in EU there is an urgent need to find alternatives to in-feed antibiotics. New strategies and commercial products must be developed to improve animal health and performance, based on their safety, efficacy and cost-effectiveness. The aim of this study is to summarize the beneficial effects of currently used alternatives to in-feed antibiotics, i.e. probiotics, prebiotics, organic acids, phytogenic compounds and zeolites on health and growth performance in farm animals (swine, poultry and ruminants).

Evaluation of a portable glucose meter for use in cattle and sheep.

BACKGROUND In farm animal practice, determination of blood glucose concentration under field conditions is often necessary. OBJECTIVE As there is no portable glucose meter device developed for use in farm animals, the analytical accuracy of a portable glucometer designed for people was evaluated for its use in cattle and sheep. METHODS Blood samples from 90 cattle and 101 sheep were used in the study. Glucose concentration was determined in whole blood immediately after blood collection from the jugular vein with the One Touch Vita portable glucometer and in serum with an enzymatic colorimetric method. The agreement between methods was assessed by Passing and Bablok regression analysis. The precision and the accuracy of the measurements were determined using the concordance correlation coefficient. RESULTS There was a strong linear relationship between the glucose values obtained using the portable glucometer and those obtained by the bench method in both cattle and sheep. Precision was 95% for cattle and 88% for sheep, whereas accuracy was 92% and 99%, respectively. The mean glucose values obtained using the portable glucometer were significantly lower by 8.3% in cattle and 3.2% in sheep than those determined by the bench method. CONCLUSION The One Touch Vita portable glucometer can be used in clinical practice to determine blood glucose concentrations in cattle and sheep, but reference intervals (RI) must be corrected to allow for negative bias. Based on these equations the RI for blood glucose in cattle and sheep using the portable glucometer were corrected to 1.84-4.17 and 2.41-4.35 mmol/L, respectively.

Liver flukes promote cholelithiasis in sheep.

The main objective of this study was to investigate whether cholelithiasis in sheep is related to parasitism or other commonly observed disorders such as liver abscesses. Additionally, the features of the observed biliary calculi are described. The livers of 254 randomly selected clinically healthy adult dairy sheep were used. All visible concretions in the bile were considered as stones. Based on the macroscopical examination, 60 livers were normal, 40 were parasitized with Fasciola hepatica, 42 were parasitized with Dicrocoelium dendriticum, 28 were parasitized with both D. dendriticum and F. hepatica, 40 livers had abscesses and 44 had hydatid cysts. Biliary calculi were detected in 40 livers. Twenty livers had pigment stones and 20 livers had cholesterol stones. The percentage of cholelithiasis was significantly higher in livers parasitized with flukes compared with the others (P<0.05) and the parasitoses with F. hepatica and D. dendriticum were proven to be significant risk factors (P<0.05) for the presence of cholelithiasis in sheep.

The influence of dietary Ascophyllum nodosum on haematologic parameters of dairy cows

The aim of the study was to investigate the effect of Ascophyllum nodosum, an edible brown macroalga, on some haematologic parameters of dairy cows. Nineteen clinically healthy Holstein cows, an average 4.3 years old, were divided into two groups for 49 days. Ten cows received control diet (roughages and concentrate) while the concentrate of 9 cows was additionally supplemented with 80 g A. nodosum/cow/day. Average daily milk production (controls 39.6 kg/cow; A. nodosum 40.2 kg/cow), milk protein and fat were not affected by the alga supplementation. Glucose, sorbitol dehydrogenase, haemoglobin, haematocrit and white/red blood cells were evaluated in weekly blood samples. It was seen that A. nodosum increased blood glucose and decreased sorbitol dehydrogenase compared to controls, without any adverse effects on the other examined parameters. Consequently, A. nodosum may be suggested as a functional ingredient in dairy cow nutrition, improving energy utilization and expressing hepatoprotective effect.

Diet supplementation with clinoptilolite improves energy status, reproductive efficiency and increases milk yield in dairy heifers

The objective of this study was to investigate the effect of long-term dietary inclusion of clinoptilolite on the energy status, reproductive parameters and milk yield of dairy heifers. Eighty Holstein pregnant heifers were equally divided to two groups: treatment group heifers were fed the ration supplemented with 200 g clinoptilolite per day; control group heifers were fed the basal ration and served as controls. The experiment started on Day 210 of gestation and lasted until the end of the first lactation period. Blood samples were collected from each animal at the start of the experiment, 30 days later on the day of calving and then on a monthly basis and were analysed for serum glucose and ketone bodies. On the same days, all animals were monitored for body condition score. Cows were observed for heat every day and were inseminated at first heat after the 60th day postpartum. Calving to first heat interval, calving to first service interval, number of services per conception and calving interval were calculated for both groups. Milk yield for each cow was recorded monthly and 305-day milk yield was calculated. Clinoptilolite supplementation significantly increased body condition score and blood serum concentration of glucose and significantly decreased blood serum concentration of ketone bodies. Clinoptilolite also improved significantly the reproductive parameters evaluated and significantly increased milk production. These results indicate that daily dietary administration of 200 g of clinoptilolite can be used for the improvement of animal performance in dairy herds.

Evaluation of the in-field efficacy of oregano essential oil administration on the control of neonatal diarrhea syndrome in calves

Abstract The objective of this study was to evaluate under field conditions, whether daily administration of oregano essential oil is effective in preventing and/or diminishing the severity of neonatal diarrhea syndrome in calves aged less than 15days. Ninety-one newborn calves from three dairy farms were assigned into two groups; “Eco” group (n=46) calves were drenched with Greek oregano (Origanum vulgare ssp. Hirtum) essential oil (ECODIAR® liquid 5%) at the dose of 12.5mg/kg body weight once per day until the age of 10days. “Conts” group (n=45) calves were left untreated and served as controls. All animals were monitored daily for the incidence of diarrhea until the age of 15days and their fecal score was recorded. Fecal samples were collected on days 3, 6 and 10 for microbiological and parasitological evaluation. Average fecal score throughout the experiment, incidence of diarrhea, duration and severity of diarrhea episodes were significantly lower in Eco group compared to the controls. Daily administration of oregano essential oil in calves for the first 10days of their life effectively diminishes the severity of naturally acquired diarrhea under field conditions and, under certain hygiene practices, possess a preventive effect against neonatal diarrhea syndrome.