Efficacy of oral calcium and/or sodium phosphate in the prevention of parturient paresis in cows

The goal of this study was to investigate the efficacy of calcium chloride, sodium phosphate or a combination of these two substances administered orally immediately postpartum for the prevention of parturient paresis in cows. Thirty-two cows that had had parturient paresis at the previous calving, and in which serum biochemistry had shown hypocalcaemia and hypophosphataemia, were used in the study. The cows were transferred to the Department of Farm Animals, University of Zurich, five days before their expected due dates. On a randomized trial, the cows were given calcium chloride, sodium phosphate, both substances or no treatment (controls) via a stomach tube immediately postpartum and 12 hours later. The cows were monitored for 96 hours during which time blood was collected on a regular basis for the determination of total calcium, ionized calcium, inorganic phosphorus and magnesium concentrations. Of the 32 cows treated, 19 (59%) had parturient paresis and 13 (41%) did not. The incidence of parturient paresis did not differ significantly among the groups although there was a tendency for a lower incidence in cows treated with both calcium chloride and sodium phosphate. The various treatments had no apparent effect on serum calcium concentration. The concentration of inorganic phosphorus increased significantly in cows treated with sodium phosphate compared with the controls. The results of this study showed that cows treated with both calcium chloride and sodium phosphate orally tended to have a lower incidence of parturient paresis. Further investigation into multiple administrations of oral calcium chloride and sodium phosphate, started before parturition, for the prevention of parturient paresis is required.     

The effect of oral calcium lactate in postpartum cows

The oral administration of calcium lactate for prophylaxis of bovine parturient paresis has been promoted for a number of years. The goal of the present study was to investigate the effect of this treatment on the serum concentrations of calcium, inorganic phosphorus and magnesium in parturient cows. Five fresh calved cows were given a drench containing calcium lactate and 5 control cows received the same drench but without calcium lactate. There were no significant differences in the serum concentrations of total and ionised calcium and magnesium between treated and control cows within 24 hours of treatment. Because the calcium lactate drench did not significantly affect calcium concentrations in the blood of fresh cows, it appears highly questionable whether the administration of calcium lactate decreases the risk of bovine parturient paresis. Based on our results, the oral administration of calcium lactate can not be recommended for prophylaxis of bovine parturient paresis.     

The prophylactic use of vitamin D3 in parturient paresis in the cow in a practice district in eastern Norway. A retrospective investigation.

The prophylactic effect in parturient paresis of an intramuscular injection of 10 million i.u. vitamin D3 one week prior to the expected calving date, was investigated in 84 cows which had previously suffered from parturient paresis. Clinical observations in connection with the development of parturient paresis after injection of vitamin D3 were compared with corresponding observations made on cows within the same population at the previous calving when no vitamin D3 was administered. The incidence of clinical parturient paresis in cows given vitamin D3 was 44.3 per cent. There were no significant differences in the incidence of parturient paresis in cows injected with vitamin D3 during the periods less than 2, 2--4, 5--8 and greater than 8 days before parturition. Average plasma calcium levels (mg/100 ml) before first calcium treatment, results of treatment, and the incidence of retained placenta in vitamin D3 injected cows did not differ significantly from corresponding data for cows with clinical parturient paresis which had not been given vitamin D3 before calving. It is concluded that vitamin D3 does not have any prophylactic effect in parturient paresis in cows in Eastern Norway.     

Prolactin, estradiol, and progesterone changes in paretic and nonparetic cows during the periparturient period

We studied the relationship of serum prolactin, estradiol-17 beta, and progesterone concentrations to plasma calcium, phosphorus, and free hydroxyproline concentrations, as well as to dry matter intake, in 14 aged dairy cows (mean of 4.5 parities), 7 of which became paretic, from 28 days before to 4 days after calving. Plasma calcium and phosphorus concentrations and dry matter intake decreased more at parturition in paretic cows than in nonparetic cows. Prolactin concentrations were not different between paretic and nonparetic cows, but were variable. Concentrations of estradiol were higher in paretic cows from 15 to 5 days before parturition, whereas hydroxyproline concentration was lower in paretic cows on days 10 through 3 before parturition. Progesterone concentration was lower in paretic cows and decreased earlier at parturition, compared with that in nonparetic cows. The findings suggested that high estradiol concentrations in late pregnancy inhibit bone resorption and predispose aged cows to parturient paresis. The earlier decrease in progesterone concentration at parturition and lower concentrations throughout late pregnancy might have contributed to the greater inappetence in paretic cows at parturition. The importance of prolactin in the pathogenesis of parturient paresis is not clear.     

Use of 1alpha-hydroxycholecalciferol in the prevention of bovine parturient paresis.

A synthetic biologically active derivative of vitamin D (350 microgram of 1alpha-hydroxycholecalciferol [1alpha(OH)CC]) was injected into 2 nonlactating 7-year-old Israeli-Friesian cows. Plasma calcium values increased after 24 hours, peaked at 48 hours, and returned to base-line values 120 hours after injection. An injection of 350 microgram of 1alpha(OH)CC was given to 23 parturient-paresis-prone Israeli-Friesian cows from 7 days to 6 hours prepartum; 13 cows were injected once, 6 were injected twice, and 4 were injected 3 times, all at 48-hour intervals. Parturient-paresis-prone cows (n = 23) of the same breed were used as controls. Within 0 to 36 hours postpartum, plasma calcium concentrations were found to be higher in cows injected with 1alpha(OH)CC than in the control cows. The increase was highly significant (P less than 0.01) in cows injected at least twice. None of the cows injected with 1alpha(OH)CC, within 72 to 24 hours prior to calving developed parturient paresis; but 9 of 23 control cows developed parturient paresis. Prior to calving, none of the injected cows developed hypercalcemia and there was no local or systemic clinically detectable signs of toxiosis. When given at the right time prepartum, 1alpha(OH)CC is considered to be an improvement over previous methods of preventing bovine parturient paresis.     

Lipid mobilization in parturient cows.

The blood levels of calcium, inorganic phosphorus, magnesium, glucose and NEFA were studied in cows at the time around partus. Eight of 16 cows developed hypocalcaemic paresis. Besides hypocalcaemia the paretic cows showed lower levels of inorganic phosphorus and higher levels of glucose and NEFA than non-paretic cows 24 hrs. post partum. It is known that lipolysis is associated with uptake of calcium in adipose tissue. The calcium content in perirenal adipose tissue was however lower in paretic cows than in non-paretic parturient cows and lactating cows slaughtered 3–5 months after calving. The calcium content in omental adipose tissue was about the same in all 3 groups. Despite increased lipolysis the calcium content in adipose tissue is thus not increased in cows suffering from parturient paresis.     

Effects of long-term dietary supplementation with clinoptilolite on incidence of parturient paresis and serum concentrations of total calcium, phosphate, magnesium, potassium, and sodium in dairy cows

OBJECTIVE: To determine whether dietary supplementation with clinoptilolite affects the incidence of parturient paresis and serum concentrations of total calcium (tCa), inorganic phosphorus (PO(4) (2)), magnesium (Mg2+), potassium (K+), and sodium (Na+) in dairy cattle. ANIMALS: 52 dairy cows. Procedure-Cows were placed into 3 groups. The first 2 groups (group A [n = 17] and group B [17]) were offered a concentrate supplemented with 1.25% and 2.5% clinoptilolite, respectively. The third (group C [n = 18]) served as a control and was offered the concentrate alone. The experiment started 1 month before parturition and lasted until the beginning of the next nonlactating period. Around the time of calving, all cows were monitored for the development of parturient paresis. Blood samples were taken at the commencement of the experiment, on the day of calving, and thereafter at monthly intervals to measure serum tCa, PO(4) (2), Mg2+, K+, and Na+ concentrations. Results-The incidence of parturient paresis in group B cows was significantly lower, compared with group C cows. However, serum concentrations of tCa, P(O4) (2), Mg2+, K+, and Na+ were not significantly affected by long-term supplementation with clinoptilolite. CONCLUSIONS AND CLINICAL RELEVANCE: In the context of this experiment, clinoptilolite supplementation at 2.5% appeared to have reduced the incidence of parturient paresis in dairy cows, suggesting that its effectiveness depends on the amount incorporated in the ration of cows. Addition of clinoptilolite in the concentrate of dairy cows during the nonlactating period could be used as a cost-effective preventive treatment for parturient paresis.     

Effects of dietary acidity on calcium balance and mobilisation, bone morphology and 1,25 dihydroxyvitamin D in prepartal dairy cows

The effect of an acid or alkali diet was investigated in 14 mature dairy cows during the last 28 days of pregnancy. The acid diet reduced the incidence of parturient hypocalcaemia compared with the alkali diet and was associated with higher blood ionised calcium and plasma chloride concentrations and lower blood pH and acid-base excess before parturition. Plasma 1,25-dihydroxyvitamin D concentrations before parturition were increased by the acid diet but the concentrations of parathyroid hormone and intact 1–86 parathyroid-hormone-related peptide were unaffected. The estimated fractional calcium absorption and calcium mobilisation rate during an ethylenediamine tetraacetic acid infusion were increased by the acid diet 14 days before parturition. Cortical bone remodelling occurred in all the animals during late pregnancy but was particularly evident in the cows given the acid diet. The data suggest that an acid diet ameliorates parturient hypocalcaemia by enhancing calcium mobilisation before parturition by increasing calcium absorption and bone resorption, these increases possibly being mediated by increases in the plasma concentration of 1,25-dihydroxyvitamin D.     

Effect of intravenous calcium and oral sodium phosphate in cows with parturient paresis

The goal of this study was to determine whether oral administration of sodium phosphate in conjunction with intravenous calcium is more efficaceous than intravenous calcium alone for the treatment of parturient paresis. Thirty cows with parturient paresis were examined and treated by the same veterinarian. The cows were divided randomly into two groups of 15 cows each. Cows in group A received 500 ml of a 40 per cent calcium borogluconate solution containing 15.65 g calcium gluconate and borogluconate, with a supplement of 6 per cent magnesium hypophosphite (9.85 g magnesium hypophosphite) intravenously over a period of approximately 15 min. Cows in group B received the same treatment as well as 350 g of monobasic sodium phosphate (70 g inorganic phosphate, NaH2PO4 2 H2O, Streuli) dissolved in 0.5 litres of distilled water orally via a stomach tube. After treatment, the heart rate, respiratory rate, rectal temperature, superficial body temperature, rumen motility, appetite and defecation of the cows were monitored every hour for eight h. The cows' attempts to rise and their ability to stand were also noted. Initially, the results of clinical examination and serum electrolyte analyses did not differ between the two groups of cows.Within one hour of treatment, stupor was not observed in any of the cows. The general demeanour after treatment did not differ significantly between the two groups. In both groups, the average rectal temperature increased within two hours of the initiation of treatment, from 38.0 +/- 0.95 degrees C to 38.5 +/- 0.40 degrees C. There was no significant difference in the recovery rate between the groups. Of the 30 cows, 22 (73.3 per cent) stood within eight hours of treatment (10 cows from group A and 12 cows from group B). The type of treatment did not affect the time required to stand: cows in group A stood within 47.3 +/- 44 minutes and cows in group B stood within 24.2 +/- 32 minutes after the start of treatment. Our findings do not support the hypothesis that oral treatment with 350 g of sodium phosphate together with intravenous infusion of calcium in cows with parturient paresis results in an improved outcome, even though all the cows had hypophosphataemia as well as hypocalcaemia.     

The course of selected bone resorption marker concentrations in response to short-term hypocalcemia experimentally induced with disodium EDTA infusions in dairy cows

The collagen metabolites hydroxyproline (HYP), deoxypyridinoline (DPD), and the carboxyterminal telopeptide of type I collagen (ICTP) are suitable markers for bone resorption in humans and several animal species. The purpose of this study was to describe the course of bone resorption markers during short-term hypocalcemia induced with disodium ethylenediaminetetraacetic acid (Na2EDTA) and to investigate whether bone resorption is increased in dairy cows under these conditions. EDTA infusions have been used as a model for periparturient paresis in dairy cows and to estimate the calcium mobilization rate from body reserves in ruminants. In this study, hypocalcemia was induced by means of a 5% Na2EDTA infusion (0.55 mg/kg/min Na2EDTA for 5 h = total dose of 100.6 g). Two experiments were conducted: (1) Six 4-11 years-old Brown Swiss cows were infused intravenously with EDTA for 5 h. Blood and urine samples were taken repeatedly from 1 day before until 10 days after infusion. (2) Towards the end of the lactation, the experiment was repeated with the same animals after a 14-day-period of feeding a low calcium diet (26 g/animal per day). The EDTA-infusion induced hypocalcemia and hypophosphatemia. The HYP-, DPD- and ICTP-concentration remained mainly unaffected during both infusions. Only DPD showed an increase during infusion and HYP an increase 2 days after the infusion. In conclusion, the EDTA infusion had little effect on the concentrations of the measured bone markers, which may be due to the fact that the serum calcium pool was refilled by increased absorption of Ca via the gastrointestinal tract. From these results, it can be concluded that bone resorption was not influenced by EDTA infusion.     

Parturient paresis and hypocalcemia in ruminant livestock

Parturient paresis (hypocalcemia) is most likely to affect dairy cattle around the time of parturition. It causes progressive neuromuscular dysfunction and flaccid paralysis. Older dairy cows, cows with a history of parturient paresis during a previous lactation, high-producing cows, and cows from the Jersey and Guernsey breeds are at highest risk for developing parturient paresis. Nonparturient hypocalcemia may also occur and is related to events other than parturition, such as severe stress, that temporarily overwhelm the mechanisms of calcium homeostasis. Beef cattle, sheep, and goats are affected less frequently by hypocalcemia than are dairy cows. Because these species are not as stressed for milk production as dairy cattle, nonparturient hypocalcemia makes up a higher proportion of cases in nondairy ruminants. Clinical signs of hypocalcemia in beef cattle, sheep, and goats tend toward hyperesthesia and tetany rather than the classic flaccid paralysis that occurs in dairy cattle with parturient hypocalcemia. Prompt and effective treatment of hypocalcemia helps to reduce the incidence of secondary complications, such as muscle damage or mastitis. The standard treatment regimen of 500 ml of 23 per cent calcium gluconate, administered intravenously, will elicit a favorable response in approximately 75 per cent of recumbent cows within 2 hours of treatment. Relapses following successful initial therapy are common and may be prevented in part by supplementation of intravenous treatment with an additional 500 ml of 23 per cent calcium gluconate administered subcutaneously. Proper nursing care following treatment speeds recovery and reduces the incidence of secondary complications owing to hypocalcemia.     

Interaction between the levels of hormones and minerals in sera of healthy and sick cows

An interaction between blood levels of parathyroid hormone, calcitonin, 1.25-dihydroxycholecalciferol and levels of calcium, phosphorus and magnesium was examined in 85 cows, which included healthy cows and cows with ostemalacia, mastitis and paresis. Levels of parathyroid hormone (PTH) and calcitonin were determined in vitro using IMMULITE analyser (Diagnostic Products Corporation, USA), by means of immunometric assay. Levels of vitamin D were measured using the enzyme linked immunosorbent assay (ELISA). Levels of calcium, phosphorus and magnesium were determined using the automated Eos-Bravo analyser (Hospitex Diagnostics, Italy) with HOSPITEX reagents. The lowest blood levels of calcium (1.38 +/- 0.18 mmol/L) and phosphorus (0.65 +/- 0.12 mmol/L) were found in cows with parturient paresis. Decreased blood levels of phosphorus and magnesium were also determined in cows with osteomalacia. For cows with parturient paresis, which received a mineral supplement, the average serum level of calcium was by 20.7% higher than the level found in those which did not receive a supplement, and the level of phosphorus was by 23.6% higher, however, these levels remained low. The blood level of parathyroid hormone ranged from 3.47 to 5.20 pmol/L in healthy cows and from 3.95 to 15.21 pmol/L in sick cows. The highest and statistically significant increase in blood PTH level (up to 18.31 +/- 1.88 pmol/L) was found in cows with parturient paresis. The blood level of PTH correlated inversely with the level of calcium in cows with osteomaliacia (r = -0.89) and in cows with parturient paresis (r = -0.49 and r = -0.61, respectively). The serum level of calcitonin ranged from 1.46 pmol/L to 2.40 pmol/L in healthy and sick cows and the difference was not statistically significant. Lower serum levels of vitamin D were found in heifers-in-calf and in cows with mastitis. A clear correlation between levels of calcitonin, vitamin D and macronutrients was not found.     

Treatment of parturient paresis with high-dose calcium

The goal of the present study was to evaluate a calcium dose that was higher than the conventional dose for treatment of parturient paresis in cows. Thirty cows with parturient paresis received 1000 ml of 40 per cent calcium borogluconate solution supplemented with 6 per cent magnesium hypophosphite. Cows in group A received 200 ml of the solution intravenously over a 10-minute period, and the remaining 800 ml via a slow intravenous drip over a six-hour period. Cows in group B received 500 ml of the solution intravenously over a 20-minute period, and the remaining 500 ml via a slow intravenous drip over a six-hour period. Afterwards, the cows were monitored continuously and examined every hour for eight hours. Samples of blood were collected from all the cows before treatment and at 10, 20, 40, 60, 90, 120, 180, 240, 300, 360, 420 and 480 minutes and 24, 48 and 72 hours after treatment. The concentrations of total calcium, ionised calcium, inorganic phosphorus and magnesium were determined. Cows that did not stand within 12 hours of treatment received one or more additional treatments. There was no significant difference in the recovery rate between the two groups. Of the 30 cows, 14 (47 per cent) rised after one treatment and 15 others (50 per cent) were cured after two or more treatments. One cow did not respond to repeated treatments and was euthanased four days after the start of treatment. The results of electrolyte analyses before treatment did not differ significantly between the two groups. In 27 (90 per cent) cows, the concentrations of calcium and inorganic phosphorus were lower than normal and in 3 (10 per cent) cows, only the concentration of inorganic phosphorus was lower than normal.The concentration of total calcium increased markedly ten minutes after the start of treatment in both groups, and at eight hours, the mean concentration of calcium was within the normal range. At 24 and 48 hours, the mean concentration of calcium was below normal, but at 72 hours it was again within the normal range. The concentration of inorganic phosphorus increased slowly in both groups, although it was not within the normal range at eight hours. In both groups, it achieved normal values at 24, 48 and 72 hours.The mean electrolyte concentrations did not differ significantly at any measuring point between cows that stood within eight hours of treatment and those that did not. Our results indicate that increasing the dose of calcium administered does not improve the recovery rate of cows with parturient paresis.     

Effects of mithramycin on calcium metabolism and bone in dogs.

Mithramycin (0.1 mg/kg) was administered intravenously to eight Beagle dogs on days 0 and 7 to determine its effects on calcium and phosphorus metabolism, serum parathyroid hormone concentration, osteoclastic bone resorption, and serum biochemical and hematologic parameters. Ionized calcium concentration was paradoxically increased on day 1 and decreased on day 8 in association with an increased serum parathyroid hormone concentration. Serum phosphorus concentration was decreased on days 1 and 2. Osteoclastic bone resorption in iliac cancellous bone was significantly decreased on day 8. There were mild increases in serum alkaline phosphatase (days 1, 2, 4, 8, 9), aspartate aminotransferase (day 9), and gammaglutamyl transpeptidase (days 7, 9) activities. Platelet numbers were increased on days 7 through 13, and packed red blood cell volumes were mildly decreased. This investigation demonstrates that two doses of mithramycin can be administered safely to dogs and may inhibit bone resorption in diseases associated with increased osteoclastic bone resorption, such as humoral hypercalcemia of malignancy.     

Vitamin D Status and Hypocalcemic Response to Protamine in Exercised and Non-exercised Dairy Cows

Bone resorption was studied in post parturient cows using intravenous injection of protamine. Protamine inhibits bone resorption and the protamine-induced hypocalcemia can be taken as a measure of this process. The studies were performed in a herd where half of the cows had been tied indoors for 21/2 years, the other half had been given daily exercise during the same period. All animals were fed in the same way.The hypocalcémie response to protamine was the same in both groups, which indicates that exercise did not change bone resorption.The serum levels of calcium, inorganic phosphorus and magnesium around parturition did not differ. The daily exposure to daylight increased the serum level of 25-(OH)-chole-calciferol in late summer in the exercised group.     

Disease frequencies in dairy cows in Sweden. II. Retained placenta

An epidemiologic study of retained placenta in dairy cows in Sweden covering 140 000 calvings is presented and various risk factors identified.

Swedish Friesian Breed (SLB) had a higher incidence than Swedish Red and White Breed (SRB). The incidence showed a linear increase with age, both when analysing the entire data set and when analysing the frequencies in cows negative for risk factors shown to increase the incidence of retained placenta, e.g., twinning, parturient paresis and dystocia. Male calves increased the risk. Loose-housed cows of both breeds had a lower incidence than tied zero-grazing cows, suggesting exercise to be a sparing factor. An increased recurrence risk ratio was found in second, third and fourth calvings for SRB and in second and third calvings for SLB.

SRB cows with a positive report of retained placenta had an increased risk of removal during the lactation. In dystocia and parturient paresis negative SLB cows, retained placenta increased the risk of removal, whereas a positive report of this disease in dystocia and/or parturient paresis positive cows did not further increase the risk removal.     

Equal calcitonin response in paretic and non-paretic cows after intravenous calcium infusion

Seventeen cows divided into 3 groups were studied: Group 1 consisting of newly delivered cows (1–3 days post partum) suffering from parturient paresis; Group 2 comprising newly delivered (1–4 days post parturn) healthy cows and Group 3 consisting of non-pregnant, non-lactating cattle. All animals were given an intravenous standard Ca infusion, and blood samples were obtained before treatment and at intervals during a 3-hour period thereafter. Plasma levels of calcitonin (CT), calcium (Ca) and inorg. phosphate (P) were determined. No significant difference for the mean CT response existed between animals in Groups 1 and 2. Blood levels of inorg. P increased significantly with time in animals of Groups 1 and 2 but not in animals of Group 3.The finding here of a similar CT response after Ca stimulation in both paretic and non-paretic cows demonstrates that the C-cells in both groups of animals have the same capacity to secrete CT.     

The role of dietary calcium concentration in the use of anionic salts to prevent parturient paresis in dairy cows

The role of dietary calcium concentration during the feeding of anionic salts (AS) was reviewed. Hypocalcaemia is still the major cause of parturient paresis in dairy cows. Feeding AS is an established method for preventing severe hypocalcaemia by activating the calcium metabolism in the last two to three weeks before parturition by inducing a metabolic acidosis. In compensation for this acidosis, the organism increases the concentrations of ionised Ca [Ca2+] in the blood. This increase leads to an increasing excretion of calcium via the urine, which is ensued by an increased calcium absorption in the intestine. The ongoing metabolic acidosis changed the flux of Ca. The size of the Ca pool, however, remained unchanged. As the calcium metabolism is activated by AS, it seems necessary to increase the amount of calcium that is fed to the cows. Several studies examined the impact of different dietary calcium concentrations on the acid-base balance and the calcium metabolism in cows fed anionic salts. The study designs vary concerning the amounts of calcium fed and the use of pregnant or non-pregnant cows. Only one study combined the feeding of AS with a very low amount of calcium, which fell below the daily requirements of pregnant cows in the last three weeks before parturition. In this study, the calcium balance post partum was better in the cows that were administered AS and a high calcium diet. In the other studies, the amount of calcium in the different experimental groups and the difference between the amounts of calcium fed varied greatly. As far as it was monitored in the studies, the calcium concentration of the diet did not have a significant impact on the degree of acidosis induced by AS. In pregnant cows, no significant differences in the calcium concentration in serum or urine occurred before parturition. Some of the researchers found a lower incidence of parturient paresis when cows were fed a combination of AS and a higher amount of calcium, but some other researches did not. Interestingly, the parameters of bone metabolism did not change between experimental groups. According to what is currently known, the feeding of AS to transition cows should not be combined with a dietary calcium concentration that falls below the requirement of cows in this stage of lactation. On the other hand, there is no need to increase the Ca concentration. When AS are used the dietary calcium concentration should be between 9 g and 12 g/kg dry matter. Further research is needed to investigate the role of dietary calcium regarding the use of AS for improving Ca metabolism in dairy cows around parturition.     

An epidemiological and genetic study on registered diseases in Finnish Ayrshire cattle. III. Metabolic diseases

The epidemiology of clinical ketosis, hypocalcaemia and hypomagnesaemia was examined. In addition, the genetic variability of ketosis and parturient paresis was investigated. The data set consisted of the lactation records of 70,775 Finnish Ayrshire dairy cows. Each cow was under observation for 2 days before and for 305 days after calving. Lactation incidence rates (%) were: ketosis 6.0, parturient paresis 3.8, non-parturient paresis 0.6, hypomagnesaemic tetany, outdoor 0.6, and indoor 0.2. These diseases formed 22 % of all first treatments by veterinarians during farm visits. 92 % of the cases of ketosis occurred with 8 weeks of parturition, with the highest occurrence 3–5 weeks after calving. Four % of cases of parturient paresis occurred before, and 45 % within 24 h after calving. When cases were categorized by month of calving the risk of ketosis was higher during indoor feeding (October-April) than during outdoor feeding (May-September). The risk of parturient paresis did not significantly vary with month of calving. The occurrence of ketosis increased with parity up to the 4th and decreased thereafter. The occurrence of parturient paresis increased with parity. Both the increase in herd milk yield and the increase in individual milk yields were positively associated with the occurrence of ketosis and parturient paresis. The cows with a history of the reproductive tract infection had a higher risk of contracting ketosis. Heritability estimates for ketosis in various parity groups were from 1.6 % to 4.1 % on the binomial scale (corresponding to 7.3 %–14.4 % on the normal scale), and for parturient paresis from 3.5 to 10.5% (corresponding from 18.3 % to 27.4 %). The genetic correlation between ketosis and parturient paresis, and these and current milk production for all material were insignificant.     

Impact of a simultaneous application of anionic salts and rumen buffer on acid-base-balance and mineral metabolism in dairy cows

In this study, the influence of simultaneous application of anionic salts (AS) and rumen buffer (RB) on the metabolism of dairy cows was examined. Eleven rumen fistulated, non-pregnant and non-lactating dairy cows received equal amounts of one AS (CaCl2 or CaSO4) and one RB (NaHCO3 or KHCO3) via rumen cannula during feeding time over a period of eight days. Before the first application of AS and RB and on day eight of the treatment period, blood, urine and rumen fluid samples were taken. The following parameters were measured: whole blood: pH, base excess, bicarbonate; serum: sodium, potassium, chloride, calcium; urine: pH, net acid base excretion, sodium, potassium, chloride, calcium; rumen fluid: pH. The changes of each parameter were compared via ANOVA.The changes in acid-base balance on day eight were very small, although significant. But p-values showed that the statistical evidence was low.The most changes occurred when NaHCO3 was fed in combination with one of the AS used. In this case a small acidogenic load was seen in blood (p < 0.05), and calcium concentrations increased slightly (p < 0.05). No alkalotic reaction could be detected when any combination of AS and RB were given to the cows. Simultaneous application of AS and RB results in a loss of effectivity of AS. Neither an adequate acidification of blood nor an activation of calcium metabolism occurred. In feed ration for cows in the last weeks of pregnancy, rumen buffer must not be fed, if anionic salts are given for prevention of parturient paresis.