Effects of oral supplementation with organically modified clinoptilolite during prepartum period on colostrum quality in primiparous dairy cows.

This research paper addresses the hypothesis that an oral supplementation with organically modified clinoptilolite will improve colostrum quality in primiparous dairy cows whilst having no adverse effects on the cows' health. A total of 36 pregnant Holstein primiparous dairy cattle were randomly assigned to receive daily oral drenching, two hours following morning feeding, with 1 l of water containing either 0 g/l (n = 16) or 150 g/l (n = 20) of clinoptilolite. Treatment lasted from 24 ± 4 d prior to expected parturition until two days postpartum (pp). Colostrum was collected at 2 to 3 h, 12, 24 and 36 h pp and blood samples were collected at 24 ± 4 and 4 ± 2 d prior to parturition and 1, 2 and 7 d pp. Overall mean dry matter, fat and total protein percentage as well as IgG concentration and mass were significantly greater in colostrum collected from cattle drenched with clinoptilolite (total protein increased by 15% and IgG concentration and mass by 21 and 38% respectively at first sampling and further at second sampling). Total γ globulin and most other blood serum biochemistry parameters did not differ between cattle treated and not treated with clinoptilolite, the only exception being the fast anionic γ globulin fraction that was 17% greater at 4 ± 2 d prior to parturition and 10% lower on the 1st day pp in treated cattle. These results showed that organically modified oral clinoptilolite supplementation at 150 g/d significantly increases the IgG concentration in colostrum and has no adverse effects on the energy status, protein, lipid, and mineral metabolism in primiparous dairy cattle during prepartum period.

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 Dunn's 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.

Circulating immune complexes of calves with bronchopneumonia modulate the function of peripheral blood leukocytes: In vitro evaluation.

In this work we studied if circulating immune complexes (CIC) of calves with bronchopneumonia have the capacity to modulate function of peripheral blood leukocytes of healthy cattle. CIC of three month old calves (6 healthy and 6 diseased) were isolated by PEG precipitation. Peripheral blood mononuclear cells (MNCs) and granulocytes from healthy calves and cows were the CIC responder cells in in vitro tests. The most remarkable increase of adhesiveness to polystyrene and ROS synthesis (assessed by NBT test) was detected in cows' granulocytes stimulated with CIC of diseased calves. Results of MTT test showed that CIC of both healthy and diseased calves reduced granulocytes' viability. The strongest effect of inhibition of cows' granulocytes resulted from CIC of diseased calves. CIC only moderately reduced spontaneous viability of calves' MNCs. Again, the strongest effect of CIC isolated from diseased calves was observed. In contrast to the low impact of CIC on non-stimulated cells, their inhibitory effect on viability of mitogen stimulated MNCs was very strong. With CFSE assay we showed that both types of CIC stimulated spontaneous, but inhibited mitogen induced proliferation of calves' MNCs. Propidium iodide staining reviled that CIC increased apoptosis/necrosis of both non-stimulated and mitogen stimulated MNCs. CIC of both healthy and diseased calves modulated the function of peripheral blood MNCs and granulocytes, but a stronger effect of CIC of diseased calves was shown. The age of the donors (calves or cows) of the responder cells, and the activation state of these cells, were also of influence.

Effects of Different Amounts of Supplemental Selenium and Vitamin E on the Incidence of Retained Placenta, Selenium, Malondialdehyde, and Thyronines Status in Cows Treated with Prostaglandin F2α for the Induction of Parturition.

The incidence of retained placenta (RP) in cows increases in cases of parturition induced by prostaglandin F2α . We analyzed the effects of different doses of supplemental selenium and vitamin E on the incidence of RP, blood selenium, plasma thyronines, and malondialdehyde concentration. Thirty-three clinically healthy, multiparous Holstein-Frisian cows were assigned to 3 groups and supplemented with a single intramuscular injection of sodium selenite (SS) and tocopherol acetate (TAc) between days 250 to 255 of gestation: control-unsupplemented; group A-10 mg SS + 400 mg TAc; group B-20 mg SS + 800 mg TAc. Parturition was induced using PGF2α not before day 275 of gestation. The RP incidence was reduced from 66.7% in the control to 38.2 and 30.8% in groups A and B, respectively. Blood selenium and glutathione peroxidase activity in treated groups were significantly higher compared to control, with no significant difference between groups A and B. Plasma malondialdehyde in group B was significantly lower than that in control and group A, while thyronines levels were not affected. Comparison of RP and non-RP cows, independently of supplement treatment, revealed higher blood selenium and glutathione peroxidase activity and lower MDA and thyroxine in non-RP animals, while triiodothyronine level did not differ.

Evidence that calf bronchopneumonia may be accompanied by increased sialylation of circulating immune complexes' IgG.

Immune complexes (IC) could have an important role in the pathogenesis of pre-ruminant calves' bronchopneumonia. IC are potent activators of complement and neutrophils and they might be responsible for immune protection, as well as for pulmonary damage. Immunoglobulin G (IgG), as constituents of IC, initiates the effector phase of immune response through binding of Fcγ and complement receptors. The oligosaccharide moieties expressed on IgG can modulate their antigen affinity and effector function. Structural characteristics of IgG molecules from IC in the pre-ruminant calves have not been studied in detail. The aim of our study was to determine if the glycosylation profile of IgG from circulating IC (CIC) in calves with bronchopneumonia differed from those of healthy control calves. A total number of 13 Holstein-Friesian calves, at the age of three months were included in the study. All calves were clinically examined by a veterinarian. Calves were classified by signs of respiratory disease in two groups: healthy (n=6) and diseased (n=7) calves. The CIC from calves' sera were isolated by the polyethylene glycol precipitation (PEG) method. IgG molecules were isolated from PEG precipitates by Protein G affinity method. The level of expression and localization N-acetylglucosamine, galactose, sialic acid, and fucose within the isolated IgG was determined by lectin blot assay. Calves with bronchopneumonia had a statistically significantly increased level of CIC. IgG molecules were isolated from CIC of both healthy and diseased calves. Several other proteins in complex with IgG were detected in both groups of animals. The isolated IgG heavy chains of healthy calves expressed N-acetylglucosamine, galactose, sialic acid, and fucose. The light chains of IgG expressed N-acetylglucosamine, sialic acid, and fucose whereas galactose was not detected in healthy calves. In diseased animals, galactose was detected on light chains, and both heavy and light IgG chains were more sialylated. Proteins in complex with IgG were also lectin reactive, and their glycosylation in diseased animals was different compared to healthy controls. Increased sialylation is a characteristic of anti-inflammatory IgG. The increased sialylation of IgG from CIC in bronchopneumonia might be an attempt of immune system of calves to protect lung tissues against damages provoked by activated cells and secreted pro-inflammatory cytokines. At the same time, increased IgG sialylation could explain the inability of calves' immune system to initiate the process of antigen elimination by activation of Fcγ receptors.

Ovarian activity and uterus organometry in delayed puberty gilts.

About 30% of the total number of gilts selected for reproduction at the large breeding farm units in Vojvodina (Republic of Serbia) are culled due to prolonged pre-insemination anoestrus (estrus not detected until 8 mo of age). The aim of this study was to provide the answer to the following question: do the culling gilts reach cyclic ovarian activity at all? One hundred seventy five culled gilts in which external estrus manifestations were not detected by 8 mo of age were sacrificed and their reproductive organs were examined for determination of sexual maturity (ovaries exhibiting pre-ovulatory follicles 8 to 11 mm in diameter, corpora hemorrhagica, corpora lutea and corpora albicantia). Uterine weights and horn length were also determined. Functional ovaries were observed in 107 (61.1%) examined gilts, with 62 animals having one and 45 having two puberty ovarian cycles (57.9% and 42.1%, respectively). Pathomorphological changes which could result in prolonged pre-insemination anoestrus were not observed on the reproductive organs of sexually mature gilts. Our results indicate that most of the culling gilts have reached cyclic ovarian activity. The main reason for culling due to the absence of external estrus manifestations in sexually mature gilts could be inadequate estrus detection technology.