Natalija Fratrić

Blood serum free amino acids pattern in newborn calves on colostral diet and orally treated with zeolite.

Oral zeolite treatement effects on the blood serum free amino acid pattern in newborn calves was investigated. The total number of 30 newborn Holstein calves of both sexes, weighting 35±3 kg (mean±SD), were immediately after parturition separated from their dams and placed in individual pens. Calves were divided in two experimental groups, 15 calves each. All calves were bottle-fed twice/ day (1.5 L/meal) during the first 48 hours after delivery, in 12 hour intervals, with their mothers first (during 24 hours postpartum) or second colostrum (at 24-48 hours postpartum), starting two hours after delivery. Zeolite suspension (20 mL, 25% suspension in distilled water) was added to every meal for treated calves. Colostrum samples were collected from six cows at 0-12h and 24h after delivery. Total and colostral whey protein concentrations were determined using the colorimetric method. Blood samples were taken from the jugular vein of calves at 6, 16, 30 and 40 hours after birth. After spontaneous coagulation at room temperature blood serum was separated and stored at -20°C until analyzed. Total protein concentration was determined by the colorimetric method. Blood serum immunoglobulin G (IgG) concentrations were determined using single radial immunodiffusion (sRID) plates. Pooled blood serum free amino acids (aspartic acid - Asp, glutamic acid - Glu, serine - Ser, histidine - His, glycine - Gly, threonine - Thr, alanine - Ala, proline - Pro, tyrosine - Tyr, arginine - Arg, valine - Val, methionine - Met, Leucine - Leu, Isoleucine - Ile, phenylalanine - Phe) were identified and quantified using high-performance liquid chromatography (HPLC, GBC Australia). Total and colostral whey protein concentrations were significantly higher in the first colostrum and decreased between 50-75% at 24-48 hours later on. Mean blood serum IgG concentration was significantly increased at 6 and 16 hours in the treated calves (26±7:20±5 and 55±15:42±13 g/L, p<0.05). Blood serum free amino acids (AA) first were separated at nonessential and essential AA (NEAA and EAA, respectively), both being increased at all time intervals after birth in treated calves. However, when the pooled blood serum free AA were clustered according to polarity and electrical charge and presented as relative values (% of the control group values) at the 6h there was a massive increase of polar positive (Arg, His), polar neutral (Ser, Thr, Tyr) and nonpolar neutral free AA (except Met). The minimal effect of oral zeolite treatment was on the negative polar blood serum free AA concentration (Asp and Glu).

Brix Refractometry of Colostrum from Primiparous Dairy Cows and New-Born Calf Blood Serum in the Evaluation of Failure of Passive Transfer

Abstract Failure of passive transfer (FPT) of immunoglobulins (IgG) is associated with increased morbidity and mortality of calves. In this study we evaluated the digital Brix refractometer usefulness for the assessment of FPT. A number of 16 colostrum samples from the first milking (2-3h post-partum) of Holstein-Friesian dairy heifers and 29 blood sera of 3-6 days old calves were analyzed with a digital Brix refractometer. Total proteins were determined by the biuret reaction. Colostral IgG were determined by radial immunodiffusion (RID), and colostral whey and blood serum γ globulin (composed almost entirely of IgG) were determined by agarose protein gel electrophoresis (APE) and densitometry. Colostral % Brix score was 25.5±3.4%. Concentrations of colostrum IgG and colostral whey γ globulin were 130±33 g/L and 100±24 g/L respectively. The concentration of total proteins in colostral whey was 134±30 g/L. The correlations between Brix values and the concentrations of IgG determined with RID and the concentrations of γ globulin determined with APE were positive and highly significant (P<0.001 and P<0.01). The concentration of serum proteins of new-born calves was 57.75±11.8 g/L, the concentration of γ globulin was 14.4±7.8 g/L, and the Brix score was 8.6±1.0%. FPT (serum γ globulin<10 g/L) was detected in 34.5% (10/29) calves. Brix score correlated with the concentration of blood serum γ globulins in all examined calves. The results have confirmed that digital Brix refractometry allows the producers to use this technique in order to estimate colostral and calf serum IgG, thereby monitoring both colostrum quality and success of passive transfer.

Serum proteins and lipids in mild form of calf bronchopneumonia: candidates for reliable biomarkers

Abstract Calf bronchopneumonia is complex multifactorial disease and for its accurate diagnosis and therapy, besides clinical examination, microbiologic, hematologic and biochemical analyses could be necessary. In general, additional analyses are not implemented, mainly because the disease biomarkers are not defined. To establish which analysis might be useful for determining the severity of the disease, we analyzed 23 three-month old calves with mild clinical signs of bronchopneumonia and 15 age-matched healthy calves. Pasteurella multocida was isolated from deep nasal swabs of diseased calves. Peripheral blood erythrocyte and leukocyte count of bronchopneumonic and healthy calves showed no difference. Serum proteins, lipoproteins and lipids were analyzed with spectrophotometry, agarose gel electrophoresis, non-reducing SDS-PAGE, gel zymography, and thin-layer chromatography. The bronchopneumonic calves had an increased level of circulating immune complexes and α globulins, which contain some of the positive acute phase proteins. In diseased calves the increased concentration of total γ globulins (IgG), due to an increased concentration of anionic γ globulins (predominately IgG1), was detected. The increased concentration of anionic γ globulins followed by increased concentration of transferrin (negative acute phase protein) and HDL cholesterol, decreased concentration of LDL-cholesterol, unchanged activity of matrix metalloproteases and leukocyte counts might reflect the obvious absence of generalized inflammation. A positive correlation was found between the acquired results and the appearance of mild clinical signs. Therefore, we believe that the parameters analyzed in the peripheral blood could be applied as reliable disease markers to distinguish between severe (inflammatory) and mild forms of calf bronchopneumonia and to predict a better outcome for these calves.

Progesterone concentration, pregnancy and calving rate in Simmental dairy cows after oestrus synchronisation and hCG treatment during the early luteal phase

Early embryonic development may be negatively affected by insufficient progesterone (P4) production. Therefore, the aim of our study was to increase P4 by gonadotropin-releasing hormone (GnRH) and/or human chorionic gonadotropin (hCG) treatments after inducing oestrus by prostaglandin (PG) treatment. Lactating Simmental dairy cows (n = 110), between 1 to 5 lactations, with an average milk production of 6,500 1/305 days, at 40-80 days postpartum were used and grouped as follows: (1) PG + GnRH treatment at AI (GnRH group), (2) PG + hCG treatment at day 7 after AI (hCG group), (3) PG + GnRH at AI + hCG treatment at day 7 after AI (GnRH/hCG group), and (4) spontaneous oestrus (C: control group). All animals were double inseminated (at the time of oestrus detection and 12 ± 2 h thereafter). Blood serum and milk samples were collected at the day of observed oestrus (day 0), and 14, 21 and 28 days after AI. Serum P4 was determined using a commercial radioimmunoassay (RIA) test (INEP, Zemun), and milk P4 was determined using enzyme-linked immunoassay (ELISA) test (NIV Novi Sad). Pregnancy status was confirmed by ultrasonography between days 28 and 35 after AI. Differences of serum or milk P4 medians, pregnancy (and calving) rate were determined using Dunns Multiple Comparison Tests and Z test, respectively. Serum P4 medians were significantly higher at days 14, 21 and 28 after AI in the hCG-treated animals, indicating increased luteal activity, with a similar tendency in whole milk P4 values. Treatment with hCG during the early luteal phase significantly contributed to the maintenance of gestation at days 28-35 after AI, and also increased the calving rate in Simmental dairy cows.

Biologically active compounds in colostrum: Significance and possibilities for increasing their resorption

Colostrum in domestic animals contains numerous bioactive substances like insulin and insulin-like growth factors (IGF-I and IGF-II), epidermal growth factor (EGF), immunoglobulins (Ig), lactoferin (Lf), transferin (Tf) and others. Many of them have distinct functions and stimulate growth and glucose utilization, or have some other, still unknown regulatory function. Bioactive substances influence growth and development of the gastrointestinal tract (GT), and cause many metabolic and endocrine changes in the neonate. Resorption of the bioactive substances from the GT of the neonate could be a specific, receptor dependant, or nonspecific process, and in many cases the exact mechanism has not been completely elucidated. On the other hand, there are technological procedures and substances that could effectively increase concentration of some bioactive compounds in the systemic circulation of the neonate. We are still unaware of the full importance of these technological procedures and products, partly because of the very complex additive and/or synergic effects of the different bioactive substances from the colostrum on the newborn animals.