Serum Of Dairy Cows Research Articles

CERULOPLASMIN ACTIVITY AND ITS RELATION TO COPPER LEVEL IN BLOOD SERUM OF FRIESIAN DAIRY COWS.

The relationship between ceruloplasmin, a metalloenzyme with oxidase activity, and copper was investigated in Frisian dairy cows.The oxidase activity of ceruloplasmin correlated closely with the serum copper concentrations in Frisian dairy cows. Variations of copper (Cu) concentration and ceruloplasmin (Cp) activity in serum of dairy cows at different stages of lactation were assessed in 60 Frisian dairy cows. Furthermore, ceruloplasmin to copper ratios were also investigated. The cows were classified according to their lactation stages into three different groups as early lactation stage (4–6 weeks postpartum), mid-lactation stage (17–22 weeks postpartum) and late-lactation stage (25-30 weeks post-partum). Each group consisted of 20 multiparous cows. Serum samples were obtained from each cow for estimation of cereloplasmin activity and copper levels. Concentrations of serum copper (sCu) were higher in the group of early lactation stage than the other groups (P < 0.05). Serum cereloplasmin (sCp) activity also showed significant difference between early lactation, mid and late lactation groups (P < 0.05). The ratios of cereloplasmin activity to copper concentration (Cp/Cu) were significantly changed in the different lactation stages of dairy cows (P< 0.05). For evaluation of copper status, use of sCp/sCu identified more animals as ‘low’ and ‘marginal’. It can be concluded that ceruloplasmin and copper undergo a physiological increase justafter calving; thus, their values should be interpreted with caution during assessment of copper status. Further research is required to refine diagnosis criteria for use of such ratio in determining copper status in Frisian dairy cows.

Preliminary trial in treatment of postpartum endometritis with intrauterine application of hyperimmune serum in dairy cows

ObjectiveTo evaluate the efficacy of hyperimmune serum (HS) in treatment of postpartum endometritis. MethodsIn a field trial, cows with vaginal discharge, 25–35 d in milk were randomly assigned to three treatment groups. In group 1 (n=42), cows received an intrauterine treatment with 50 mL HS. HS was produced against Arcanobacterium pyogenes and Escherichia coli that had already been isolated from the Iranian dairy farms. In group 2 (n=39), cows were treated with one intrauterine infusion of 5 g oxytetracycline (OTC). In group 3 (n=65), cows affected with endometritis were treated with 0.5 mg cloprostenol (PG). Group 4 (n=89) included clinically healthy cows as control (HC) group without any treatment in groups HS, OTC and PG; all cows were re-examined 39–49 d in milk. ReultsCure rate after treatment defined as the absence of vaginal discharge at the re-examination, was 64.3%, 61.5% and 72.3% in HS, OTC and PG groups, respectively (P>0.05). Cows categorized as E1 and E2 showed higher cure rate and reproductive performance measures than E3 cows in both treatment groups but their differences were not significant. Conception rate to all services for cows with endometritis (category E1, E2 and E3) was 52.9% in HS group, 57.1% in OTC and in PG 62.1% compared to 66.7% in HC (P>0.05). The difference in the conception rate between the HS and HC group was not significant. ConclusionsWe suggest that HS could be the no antibiotic alternative treatment choice for postpartum endometritis in dairy cattle.

Intraday variation of metabolic key indicators in serum of dairy cows between week 2 antepartum and week 12 postpartum

Metabolic diseases during early lactation in dairy cows can be routinely diagnosed assessing key indicators in blood. The objectives of the present study were to characterize the impact of interindividual along with intraday variation on specific metabolites and to investigate the effect of the sampling time point relative to calving. Serum samples of four high-yielding, clinically healthy, multiparous dairy cows (body weight 589 &amp;plusmn; 27 kg) were obtained in 3-h intervals during 24-h intervals throughout the transition period and early lactation (week &amp;ndash;2 antepartum (ap), weeks 1, 2, 3, 5, 7, and 12 postpartum (pp)). The lowest intraday variation (less than 15%) as indicated by relative coefficients of variation (CV) was found for glucose, cholesterol, and aspartate aminotransferase (AST). Intraday variation characterized by a CV between 15 and 30% was typical of urea, &amp;beta;-hydroxybutyrate (BHB), total bilirubin, and non-esterified fatty acids (NEFA). The highest intraday variation (CV &amp;gt; 30%) was assessed for insulin. Week relative to calving had significant influence on interindividual means of BHB, NEFA, insulin, and cholesterol in blood, but did not affect the interindividual variation of all parameters investigated. No significant intraday variation patterns were found. It is concluded that the considerable intraday variation of especially BHB and NEFA has to be taken into account in herd health monitoring for estimating the proportional outcome in respect to animals exceeding thresholds for specific metabolic key parameters. &amp;nbsp;

The influence of the corpus luteum on metabolites composition of follicular fluid from different sized follicles and their relationship to serum concentrations in dairy cows

The presence of corpus luteum may have a local effect on metabolite composition of follicular fluid (FF) and could indirectly influence follicular development and oocyte quality. The purpose of this study was to examine the influence of the corpus luteum on metabolite composition of follicular fluid (FF), harvested from different-sized follicles and the relationship between metabolite composition of FF to blood serum in dairy cows. Ovaries and blood samples were collected from 30 female adult Holstein Friesian cows, 4–7 years old, with clinically normal reproductive tracts. The animals were in the diestrus stage and selected post mortem. The ovaries collected were classified based on the presence and absence of corpus luteum (CL+/−). Visible follicles on the surface of the ovaries were classified into (i) small (3–5mm), (ii) medium (6–9mm) and (iii) large (10–20mm) based on their diameter. Follicular fluid was aspirated from follicles with different sizes in CL+ and CL− ovaries. Blood and FF samples were analyzed for various biochemical constituents including glucose, cholesterol, triglyceride, total protein, albumin and globulin. The results showed that serum concentration of glucose, cholesterol and triglyceride was significantly different (p≤0.05) in FF from follicles of different size categories. Differences between various follicle size categories in CL− ovaries were only significant for concentrations of glucose, cholesterol and triglyceride. FF concentration of glucose and cholesterol in the same follicle size categories in CL+ ovaries was significantly lower than that of CL− ovaries. These results indicate that levels of the biochemical metabolites in serum and FF differ significantly. In addition, FF concentrations of biochemical metabolites were related to follicular size and to the presence or absence of corpus luteum.

Effects of high dietary zinc concentration and zinc sources on hematology and biochemistry of blood serum in Holstein dairy cows

The purpose of this study was to investigate high concentration of dietary zinc (Zn) and to compare the effects of organic and inorganic zinc sources on hematological and biochemical parameters of blood serum in dairy cows. Eighteen dairy cows were randomly allocated to one of three dietary treatments in a randomized and blocked design. Animals in group 1 were treated as control (no zinc supplementation); whereas, animals in groups 2 and 3 supplemented with 500mg of zinc/kg dry matter from either zinc sulfate monohydrate (ZnS) and zinc methionine (ZnM), respectively. The numbers of red blood cells, hemoglobin concentration, packed cell volume, and mean corpuscular hemoglobin concentration in the ZnM group was higher than the control group. Activities of lactate dehydrogenase and superoxide dismutase in ZnM and ZnS groups were higher (P<0.05) than the control group. There was no difference in the other metabolites between groups, but the serum zinc concentration was higher (P<0.05) in cows fed ZnM or ZnS. There was no difference among groups for biochemical parameters and some hormones in serum may due to the competition levels of zinc supplementation reducing availability of other minerals. Therefore, the results obtained may be beneficial in demonstrating the effects of zinc with no negative effects of high Zn concentration on hematological and biochemical parameters.

Survey of Vitamin A, β-Carotene, Calcium and Phosphorus Concentrations in Serum of Dairy Cows with Retained Placenta

Survey of Vitamin A, β-Carotene, Calcium and Phosphorus Concentrations in Serum of Dairy Cows with Retained Placenta

Development of a flow cytometric immunoassay for recombinant bovine somatotropin‐induced antibodies in serum of dairy cows

Administration of recombinant bovine somatotropin (rbST) to enhance milk production in dairy cows is banned within the European Union. Therefore, methods for pinpointing rbST abuse are required. Due to the problematic detection of rbST itself in serum, methods are also focused on detecting changes in rbST-related biomarkers. In this study, a fast and easy-to-perform microsphere-based flow cytometric immunoassay (FCIA) for detection of rbST-induced antibodies in serum was developed. Until now, detection of rbST-induced antibodies was also problematic due to non-specific binding of serum proteins resulting in a high rate of false positive results. Therefore, five different sample preparation methods, i.e. dilution, octanoic acid precipitation, filtration, protein G purification, and a previously described generic FCIA sample preparation were critically compared to overcome non-specific binding to the microspheres. Only the generic FCIA sample pretreatment was effective in reducing non-specific binding. As a result, an absolute decision level for detecting rbST antibodies in serum of dairy cows was determined and its applicability was demonstrated. In accordance with biological expectations from literature, rbST antibodies were induced in three out of four rbST-treated dairy cows. These rbST-induced antibodies were successfully detected for up to 4 weeks after the last rbST treatment, whereas no false positive results were obtained for 27 untreated dairy cows. This is the first method, able to overcome the interference of serum proteins and therefore, can be applied with high confidence for screening unknown herds of cattle for rbST antibodies, an important biomarker for pinpointing at rbST abuse in cattle.

Concentrations of Sodium, Potassium, Magnesium, and Iron in the Serum of Dairy Cows with Subclinical Ketosis

Serum concentrations of sodium, potassium, magnesium, and iron were measured in dairy cows with subclinical ketosis. Compared with healthy cows, the subclinically ketotic cows had significantly higher levels of non-esterified fatty acids and β-hydroxybutirate in serum and significantly lower levels of blood glucose (p < 0.01). No significant differences were observed, suggesting that the mineral elements measured are not involved in the pathogenesis of subclinical ketosis.

Determination of Clostridium botulinum Toxins in Dairy Cows with Abomasal Displacement

Summary A new form of bovine Clostridium botulinum toxicity was described as visceral botulism. Long-lasting absorption of very low quantities of botulinum toxin may interfere with neurological control of intestinal physiology instead of acute or subacute lethal effects. The objective of this study was to investigate the presence of C. botulinum toxins and their types in abomasal content and serum of dairy cows diagnosed with abomasal displacement. Abomasum displacement was confirmed in 17 cows by laparoscopic examination and abomasal content and serum samples were collected during surgical correction. The mouse toxicity and neutralization bioassay was used to detect and identify the C. botulinum toxins in samples. Clostridium botulinum toxin type C was detected in 2 of abomasums contents and in 1 of sera. The toxin detected animals were fed with silage. Although the identification ratio (17.6%) of C. botulinum type C toxin in this study seems so farther to correlate AD with C. botulinum toxins; we are of the opinion that C. botulinum toxins, especially type C, may be associated with AD because AD is considered to be a multifactorial disease.

Relationships Between the Concentration of Insulin-Like Growth Factor-1 in Serum in Dairy Cows in Early Lactation and Reproductive Performance and Milk Yield

The objective of this study was to evaluate the relationships of different insulin-like growth factor-1 (IGF1) measures [5 distinct IGF1 concentrations on particular days, area under the curve (AUC), and linear regression coefficient] in the postpartum period in lactating dairy cows and reproductive performance. A total of 417 healthy multiparous Holstein-Friesian cows were enrolled in the study. Serum samples for the determination of the concentration of IGF1 were collected on d 0, 4, 10, 20, and 40 postpartum (pp). The concentration of total IGF1 in serum was determined by immunometric chemiluminescence immunoassay. All cows were examined for vaginal discharge as a sign of clinical endometritis at 20 d pp by external inspection and rectal palpation. The mean concentration of IGF1 ranged from 57±18.9 ng/mL within the first 12h pp to 74±19.9 ng/mL at 40 d pp. On d 10 pp, first and all artificial insemination conception rates were greater in cows with IGF1 concentrations above the median compared with cows with IGF1 concentrations below the median. Cows with greater AUC (second to fourth quartile) conceived earlier (11.4, 16.0, and 18.8 d) than cows in the first IGF1 quartile (117.0±43.6). Proportion of cows pregnant within 200 d pp increased significantly from the first to the third IGF1 quartile of AUC (58.7, 66.7, and 74.0%). The proportion of cows culled decreased from the first to the fourth IGF1 quartile. Correlations between IGF1 measures and days to pregnancy were significant (except for the linear regression coefficients) but low (R2=0.0009 to 0.025). Differences between single or composite measurements of IGF1 were not significant. We could also demonstrate a statistically significant correlation between the concentration of IGF1 in serum and the average 10-d milk production (31.6 to 44.0kg). In conclusion, our study indicates that single or multiple measurements of IGF1 concentration in the postpartum period have very limited value to predict individual fertility in dairy cows.

Relationships between the Concentration of Igf-1 in Serum in Dairy Cows in Early Lactation on Reproductive Performance and Milk Yield

The quality of the transition period determines the lactation of dairy cows and its profitability. In early lactation over 90% of the dairy cows are in a negative energy balance (NEB). NEB has its peak in the first four weeks postpartum and is associated with major alterations in the growth hormone, insulin-like growth factor (GH-IGF) axis. The catabolic situation leads to GH resistance of the hepatic tissue because the liver GH receptors are down regulated in dairy cows. The early lactation period in dairy cattle is characterized by elevated blood GH concentrations while insulin is down regulated. A low IGF-1 concentration in serum is the consequence of this metabolic situation. Another result of this metabolic situation is the induction of gluconeogenesis and ketogenesis in the liver. The cause of low fertility in dairy cows is multifactorial. The objective of our study was to describe concentrations of IGF-1 in serum in the postpartum period of multiparous, high yielding, dairy cattle. We evaluated the effect of the concentration of IGF-1 in serum on reproductive performance.

Relationships between the Concentration Of IGF-1 in Serum of Dairy Cows in the Puerperal Period and Back Fat Thickness and Metabolic Parameters

Major endocrine and metabolic changes occur around parturition and the onset of lactation in dairy cows. These changes influence milk production and reproductive performance in the next lactation. Results of this study describe inter-relationships between concentration of IGF-1 in serum in the postpartum period and milk yield, metabolic parameters (i.e. BHBA, NEFA, urea, bilirubin) and body condition as measured by back fat thickness (BFT).

Bovine platelet-activating factor acetylhydrolase (PAF-AH) activity related to fertility

Plasma platelet-activating factor acetylhydrolase (PAF-AH), the enzyme characterized by the association with plasma lipoproteins, degrades platelet-activating factor (PAF) as well as PAF-like oxidatively fragmented phospholipids produced during oxidative stress. Apart from pro-inflammatory properties, PAF is also related to reproductive processes and successful fertility. In order to get a better insight into the involvement of PAF-AH in the fertility of cows, the aim of the study was to determine the PAF-AH activity as well as the C-reactive protein, cholesterol and high density lipoprotein-cholesterol (HDL-C) in the serum of dairy cows throughout the pregnancy and lactation, as well as in infertile cows. The results showed that serum PAF-AH activity changes throughout pregnancy and lactation with a lower level during periparturient period. It is also found higher PAF-AH activity in lactating cows with reproductive disorders compared to high lactating cows without reproductive disorders. Strong correlation between PAF-AH activity and HDL-C concentration indicates that HDL could have considerable influence on PAF-AH activity in bovine plasma. CRP concentration was also lower during transition period suggesting that lactation might stimulate CRP synthesis in bovine. A higher CRP concentration in cows with reproductive disorders compared to fertile cows at the peak of lactation, demonstrates that milk production is not the only factor influencing CRP in cows. A significant correlation between PAF-AH activity and CRP level shows that both parameters could be influenced by reproductive status of dairy cows.

Postparturient change in endotoxin levels of ruminal fluid and serum in dairy cows.

The changes in the endotoxin levels of ruminal fluid and serum in postparturient cows were evaluated. Five cows were fed hay and concentrates on an individual basis (farm A) and the other 5 cows were given complete feed ad libitum (farm B) after parturition. Ruminal pH levels decreased in both groups after parturition. Subsequently, the ruminal endotoxin levels increased with the declining pH on both of the farms. The ruminal endotoxin levels were slightly higher in cows of farm B than those of farm A. Serum endotoxin levels also showed episodic fluctuations, however, there were no parallel changes between the endotoxin levels of the ruminal fluid and sera.

The effect of feeding rapeseed on the fatty‐acid composition of milk lipids and on the concentration of metabolites and hormones in the serum of dairy cows

ZusammenfassungDer Einfluß von Rapssaatfütterung auf die Fettsäurenzusammensetzung der Milchlipide sowie die Konzentration einiger Stoffwechselprodukte und Hormone bei MilchkühenDas Ziel der Untersuchungen bestand darin, Informationen über die Input/Output‐Relationen der Fettsäuren vom Rapsöl zum Milchfett zu erhalten, um das Fettsäurenspektrum der Butter im ernährungsphysiologisch günstigen Sinn sowie hinsichtlich Streichfähigkeit zu verbessern.Zwei Gruppen von je 10 Milchkühen erhielten eine Maissilageration mit bzw. ohne 1 kg gemahlenem Vollfettraps über 3 Monate. Während einer darauf folgenden 3 wöchigen Versuchsperiode wurde der Rapssaatanteil isonitrogen auf 1,5 kg/Tier/Tag erhöht.Ungeachtet der höheren Milchleistung der Kühe, die Rapssaat erhielten, bestanden keine signifikanten Differenzen in der Fett‐ und Eiweißleistung zwischen Kontroll‐ und Versuchsgruppen. Die mit der Milch ausgeschiedene Menge an kurz‐ und mittelkettigen Fettsäuren (C4:0‐C17:0) verminderte sich pro Tag um 148 bzw. 174 g, während sich die Produktion an langkettigen Fettsäuren um 138 bzw. 183 g/Tier/Tag erhöhte (bei 1 bzw. 1,5 kg täglichem Rapssaatverzehr).Das Butterfett der Kühe, die Rapssaat aufnahmen, enthielt ein Drittel weniger Palmitinsäure und zwei Drittel mehr Ölsäure. Dieser für die Humanernährung günstige Effekt trägt gleichzeitig zu einer wesentlichen Verbesserung der Streichfähigkeit bei, die vom Verhältnis C18:1/C16:0 als Maß für die Fetthärte bestimmt wird.Offensichtlich hat der höhere Fettsäurentransfer aus dem Rapsöl in das Milchfett eine glucosesparende Wirkung. Sowohl Glucose als auch Fettsäuren gelten als potente Stimulatoren der IGF‐I‐Synthese, die ihrerseits die Milchsynthese beeinflußt. Mit ansteigendem Fettgehalt der Ration vermindert sich der Vorteil, da bei höherem Fettanteil sowohl die Verdaulichkeit als auch der Lipid‐Transfer zum Euter eingeschränkt werden.Für eine optimale Input/Output‐Relation kann 1 kg gemahlene Rapssaat pro Milchkuh und Tag bzw. 5% Gesamtfett in der Ration als obere Grenze angesehen werden.

Antipenicillinase in the Serum of Dairy Cows

Serum from dairy cows was tested for inhibitory effect on penicillinase from a penicillin-resistant Staphylococcus aureus strain of mastitic origin. Among cows with subclinical mastitis caused by penicillin-resistant S. aureus there was a significantly higher frequency of individuals with penicillinajse-inhibiting serum than among healthy cows. Among the subclinical cases, a foregoing penicillin treatment of clinical mastitis appeared to increase the serum antipenicillinase activity.

An Effect of the Stage of Lactation on the Concentration of Albumin in the Serum of Dairy Cows

The mean concentration of albumin in the serum of dairy cows from 5 large dairy herds was shown to be lowest in those cows which had recently calved. There was a significant, positive, linear relationship between the concentration of albumin and the stage of lactation duringthe first 120 days of lactation, the average rate of increase in albumin concentration being between 3.7 and 6.9 mg/100 ml/day. A similar relationship between the concentration of serum albuminand stage of lactation was found when blood samples were taken repeatedly from a group of 8 other cows. The fall in albumin concentration at calving, however, was shown to occur in only 3 of the 8 cows. By using 125I-labelled albumin this fall was shown to be caused partly by decreased synthesis by the liver and partly by increased loss from, or dilution in, the blood.

Effects of season and stage of lactation on protein bound iodine and total cholesterol in serum of dairy cows

Protein bound iodine (PBI) and total cholesterol levels in serum were determined from 589 arterial samples of healthy dairy cows in different stages of lactation during a period of 18 months. PBI values varied from 2.10 to 6.29 ɣ %, with approximately 79 % of the cases occurring between 3 and 5 ɣ % and the average PBI level being 3.935 ɣ %. Cholesterol values varied from 37.6 to 494.4 mg %, with approximately 66 % of the cases between 100 and 300 mg % and the average colesterol level being 197.43 mg %. The stage of lactation had a greater influence on total cholesterol level than on PBI level. PBI level was lowest one month post partum (3.65 ± 0.08 ɣ %), but remained rather constant from the 5th to 13th month post partum, varying between 3.96 ± 0.08 and 4.11 ± 0.08 ɣ %. It was assumed that during the early stages of lactation the disappearance of thyroid hormones from the serum may be somewhat faster than their synthesis within the thyroid gland, and after an adaptation period in the later stages of lactation, the thyroid gland is able to maintain an optimal PBI level in the serum. The average cholesterol level of 177 mg % one month post partum was relatively low in regard to milk production compared with cholesterol levels obtained at later stages of lactation. The relatively low cholesterol values in the early part of lactation may have reflected a state of physiological undernutrition or an adaptation of the liver and rumen to increasing milk production. The total cholesterol was parallel with milk production from the 3rd to 13th month post partum. The lowest cholesterol values occurred in the serum of dry cows. Significant seasonal variations were noticed in PBI and cholesterol levels. The highest average PBI levels were obtained in April, May, and June and the lowest at the end of July and at the beginning of August. The cholesterol levels were highest during the indoor feeding period from December to May and lowest during the pasture feeding period. Since seasonal variations of total cholesterol level resembled greatly those of PBI, it was assumed that there are common factors influencing simultaneously both the PBI and cholesterol levels.