Epidemiology and genetic basis of ketosis in Finnish Ayrshire cattle

The epidemiology and genetic variability of ketosis in Finnish Ayrshire cattle were examined. In the spring of 1982, a new health recording system was started on all dairy farms in Finland. Ketosis data collected during the first year were analyzed. Seven percent of 8201 Finnish Ayrshire cows which were daughters of 80 randomly selected bulls were treated for ketosis. Eighty-nine percent of cases occurred within 8 weeks after parturition, with the highest occurrence 3–5 weeks after calving. When cases were categorized by month of calving the risk of ketosis was higher during indoor feeding (September-May) than during outdoor feeding (June-August). Ketosis occurrence increased with parity, but was not associated with milk yield. Problems in estimating the correlation between ketosis and milk yield were discussed. The incidence rate among bull-daughter groups varied from 0 to 26 percent. The heritability estimate of 2.3% for ketosis on the binomial scale was not significant, even though it corresponded 81% on the normal scale. Research is needed on new statistical methods for threshold characters in order that breeding programs can be designed to accoint for possible inherited susceptibility to metabolic diseases.     

An epidemiological and genetic study on registered diseases in Finnish Ayrshire cattle. II. Reproductive disorders

The epidemiology and genetic variability of the most common reproductive diseases were examined. The data set consisted of the lactation records of 70,775 Finnish Ayrshire dairy cows. Each cow was under observation for 2 days before for 305 days after calving. Lactation incidence rates (%) were: dystocia (DYST) 0.9, retained placenta (RTPL) 4.5, metritis (METR) 2.3, anoestrus and suboe&trus (ESTR) 5.2, and ovulatory dysfunction (CYST) 7.0. These diseases formed 33 % of all first treatmetns by veterinarians during farm visits. The occurrence of DYST, RTPL and METR was lowest in parity 2. ESTR decreased and CYST increased with parity. Cows calving during the dark season (September-February) had a higher risk of ESTR, METR and CYST (odds ratios (OR) 2.2–1.1) and a lower risk of RTPL (OR 0.9) than those calving during the light season (March-August). The increase in herd milk yield was positively associated with the occurrence of reproductive disorders. The cows with a history of parturient paresis had a higher risk of contracting CYST, RTPL and METR (OR 6.6–1.8), the cows with retained placenta of contracting metritis (OR 5.1), the cows with metritis of contracting ESTR and CYST (OR 1.5–1.7), the cows with mastitis of contracting METR and ESTR (OR 2.0–1.3) and the cows with ketosis of contracting METR, ESTR and CYST (OR 2.7–1.6). Heretabilities were determined for 5 diseases and for infertility in general. Heritability estimates for parity 2 were: DYST 2 %, RTPL 3 %, METR 7 %, ESTR 12 %, CYST 12 %, and infertility in general 5 %. Heritability for calving interval was 5 % in parity 1 and 6 % in parity 2.     

An epidemiological and genetic study on registered diseases in Finnish Ayrshire cattle. IV. Clinical mastitis

The epidemiology and genetic variability of clinical mastitis were examined. The data consisted of 70,775 Finnish Ayrshire cows. All cows were from milk recorded herds and calved during 1983. Each cow was under observation from the date of calving for 305 days. Only clinical mastitis diagnosed and treated by a veterinarian during the farm visits were taken into account. The lactation incidence rate of clinical mastitis (LIR) was 5.4 %. The cows calving in April-May had the highest LIR, but the seasonal variation was relatively small. The LIR increased with parity from the first to sixth parity. The cows treated for parturient paresis, infertility or ketosis had a higher risk of clinical mastitis than cows not treated for these diseases. The LIR was higher in herds with a high milk production level. The highest odds ratio estimated from parameters of the logit model was 14.8. The heritability estimates for clinical mastitis on the binomial scale were 3.2 % in parity 1, 1.6 % in parity 2, 0.6 % in parity 3 and 4, and 0.8 % in all parities (corresponding to 19.7 %, 8.3 %, 2.6 % and 3.8 % on the normal scale). These estimates indicate sufficient assurance for progeny testing of bulls and some possibilities of genetic selection against clinical mastitis. Genetic correlations between clinical mastitis and 305-days milk yield were 0.39 in parity 1, 0.51 in parity 2, 0.18 in parity 3–4 and 0.58 in all parities. This means that the best sires for milk yield had daughters with a higher LIR for clinical mastitis than the other sires.     

An epidemiological and genetic study on registered diseases in Finnish Ayrshire cattle. I. The data, disease occurrence and culling

The epidemiology and genetic variability of the most common dairy cow diseases were examined. This paper describes the data set, lactation incidence rates and culling during lactation. The data set consisted of the lactation records of 73,368 Finnish Ayrshire dairy cows. Each cow was under observation for 2 days before and 305 days after calving. Lactational incidence rates (%) for the most common diseases were: ovulatory dysfunction 7.0, ketosis 6.0, acute mastitis 5.4, an oestrus and suboestrus 5.2, retained placenta 4.5, parturient paresis 3.8 and teat injury 2.6. Multiple logistic regression was utilized to investigate the possible effects of certain factors on culling. The model predicted the log odds for culling as an additive function of the explanatory factors. Using the estimated odds and forming the odds ratios it was possible to investigate, relative risks between any combination of groups of the explanatory factors. The risk of culling increased with parity after the second parturition, and with increasing herd milk yield. Mastitis and parturient paresis had positive associations with culling, while ketosis and infertility had negative associations. Heritability estimates for culling in various parity groups were from 2 % to 9 % on the binomial scale corresponding from 5 % to 14 % on the normal scale. There was a neagtive genetic correlation between culling and previous milk production.     

Culling of dairy cows. Part I. Effects of diseases on culling in Finnish Ayrshire cows.

The effects of 15 diseases on time until culling were studied in 39,727 Finnish Ayrshire cows that calved during 1993 and were followed until the next calving or culling. The diseases studied were: dystocia, milk fever, retained placenta, displacement of the abomasum, metritis, non-parturient paresis, ketosis, rumen disorders, acute mastitis, hypomagnesemia, lameness, traumatic reticuloperitonitis, anestrus, ovarian cysts, and teat injuries. Survival analysis, using the Cox proportional hazards model, was performed and diseases were modeled as time-dependent covariates. Different stages of lactation when culling can occur were also considered. Parity, calving season and herd were included as covariates in every model. Parity had a significant effect on culling, the risk of culling being four times higher for a cow in her sixth or higher parity than for a first parity cow. The effects of diseases varied according to when the diseases occurred and when culling occurred. Mastitis, teat injuries and lameness had a significant effect on culling throughout the whole lactation. Anestrus and ovarian cysts had a protective effect against culling at the time when they were diagnosed. In general, diseases affected culling decisions mostly at the time of their occurrence. The effect seemed to decrease with time from the diagnosis of the disease. However, milk fever, dystocia and metritis also had a significant effect on culling at the end of the lactation.     

Disease frequencies in dairy cows in Sweden. IV. ketosis

An epidemiologic study of ketosis in dairy cows in Sweden covering approximately 125 000 calvings in 1268 herds is presented and various risk factors identified.The Swedish Red and White breed (SRB) had a higher incidence of ketosis than the Swedish Friesian breed (SLB). A positive report of parturient paresis, alone or in combination with a positive report of retained placenta increased the risk of ketosis in SRB cows. Simultaneous reports of parturient paresis and retained placenta increased the risk of ketosis in SLB cows. Tied cows of both breeds with pasture had a decreased risk during the months of pasture. The incidence of ketosis decreased with herd size, and tied zero-grazing cows had a higher incidence than loose-housed cows.Cows reported positive once for ketosis had an increased risk in subsequent calvings but no increased risk of removal during lactation.     

Disease frequencies in dairy cows in Sweden. VI. Tramped teat

An epidemiologic study of 11 653 episodes of tramped teat is presented and various risk factors identified.Swedish Red and White Breed (SRB) had a lower incidence than Swedish Friesian Breed (SLB). The incidence increased to reach a peak in the fifth (SRB) and fourth (SLB) parities. The incidence was highest in the month of calving and decreased throughout the lactation period. Dystocia and parturient paresis increased the risk of tramped teat in the month of calving in SRB cows. In SLB cows, parturient paresis increased the risk. Cows of both breeds with a positive history of tramped teat had an increased risk of recurrence in subsequent lactations. Loose-housed cows had a lower incidence than tied cows. A positive report of tramped teat increased the risk of removal, irrespective of mastitis status.     

Risk factors for abomasal displacement in dairy cows.

OBJECTIVE: To determine whether various periparturient events or 305-day milk production during the previous lactation period were associated with abomasal displacement in dairy cows. DESIGN: Retrospective, case-control study. ANIMALS: 75 pairs of case and control cows from 3 university-owned and 3 commercial dairy herds. PROCEDURE: Cows with abomasal displacement were matched with control cows on the basis of herd of origin, breed, age, and calving date. Frequency of specific periparturient events during the period from 2 weeks prior to parturition to diagnosis of abomasal displacement, as well as milk production during the preceding lactation period, were compared between case and control cows. RESULTS: Multivariate analyses indicated that case cows were significantly more likely to have had retained placenta, ketosis, a stillborn calf, metritis, twins, or parturient paresis than were control cows. Dystocia, mastitis, and milk production during the previous lactation period were not associated with abomasal displacement. CLINICAL IMPLICATIONS: Results indicated that a variety of periparturient events were associated with development of abomasal displacement among dairy cows.     

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.     

Subclinical ketosis in dairy cows

Subclinical ketosis is defined as a preclinical stage of ketosis. The peak prevalence of subclinical ketosis occurs during the fourth week of lactation. Herd-related factors, breed, parity, and season are other important determinants. Subclinical ketosis can be revealed by determining levels of plasma glucose, plasma NEFA and blood, and milk or urine ketone body concentration. There are theoretical and practical advantages of using milk ketone bodies. Most authors are agreed on approximate lower and upper borderlines for subclinical ketosis. The risk of an outbreak of clinical symptoms has been evaluated by some authors. Most authors have found significant negative relationships between energy balance and ketone body concentration. Some disagreement may be attributable to the fact that the diets used in different experiments can have different glucogenic potential, even if the energy content is the same. This affects the relationship between energy balance and ketone body concentration, as the ketone body level is influenced by both the energy balance and plasma glucose. Feeding silage with high butyric acid content increases the risk of subclinical ketosis. There are indications that cows with the highest milk yield directly after calving are at greatest risk for developing ketosis. Increased ketone body level secondarily reduces milk production, a decrease that has been quantified by some authors. Subclinical ketosis causes delayed reproductive functions return to normal after calving, increased intervals from calving to first and last service, and an increased frequency of ovarian cysts. The routine determination of milk acetone levels in control programs can be used to evaluate the status of individual cows, to indicate the energy feeding in early lactation at a herd level, and to evaluate sires for breeding. The heritability and the tendency toward a positive genetic correlation between milk acetone and milk yield have also been discussed, as have aspects of nutritional prevention. Factors such as energy- and protein-rich roughage, tasty high-energy concentrates, suitable feeding during the dry period, and division of the concentrates into at least four meals are considered to be important.     

Associations between health disorders of French dairy cows and early and late culling within the lactation

Data from an observational study, carried out during a 4.5 year period (1986–1990), were used to quantify the effects of health disorders on the risk of culling. The study population consisted of 47 commercial Holstein dairy herds from western France, comprising 4123 cows.

Logistic regression was used to assess the relationships between health disorders and early and late culling. Fourteen main health disorders with clinical signs and one subclinical disease were studied: abortion, periparturient accident, calving provided with assistance, digestive disorders, ketosis, locomotor disorders, mastitis, metritis, milk fever, cystic ovaries, respiratory disorders, retained placenta, teat injuries, non-traumatic udder disorders and status with respect to milk somatic cell count. Adjustments were made for year, month of calving, parity, breeding value for milk, best of the two first milk production records and reproductive performance. The possible effects of interactions among variables were also studied. The herd effect was taken into account using random effect models.

Non-traumatic udder disorders, teat injuries, milk fever and the occurrence of both ketosis and assistance at calving were significantly associated with an increased risk of being early culled (odds ratios (OR) ranging from 1.6 to 10.3). Early and late abortion, late metritis, poor peproductive performance, retained placenta, non-traumatic udder disorders within 45 days post-partum and mastitis occurring in the first 3 months of the lactation were positively associated with a late culling (OR ranging from 1.2 to 6.6). Cows with lower breeding value for milk and higher parities were high risk groups for culling. A lower level of milk production and occurrence of both reproductive disorders and poor reproductive performance were risk factors for late culling.     

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.     

Estrone and Progesterone Plasma Levels of Normal Cows and Cows with Parturient Paresis

Blood plasma concentrations of estrone and progesterone, calcium and inorganic phosphorus were measured in 22 cows (Swedish Red and White Breed) from 4 weeks prepartum up to 6 days post partum. Ten cows with parturient paresis had Ca levels below 6 mg/100 ml. Data from plasma analyses in individual cows were grouped in the following periods: 28–22, 21–15, 14–8, 7–6, 5–4, 3, 2, 1 day(s) before parturition and 1, 2, 3–6 days after parturition. Statistical comparisons of the levels of the hormones and the ratio progesterone/estrone did not reveal any significant differences between the paretic and normal cows at any time period. The results do not support the theories that high systemic levels of estrogens or an imbalance between estrogen and progesterone predispose towards parturient paresis.     

Packed cell volume (PCV) in connection with uterine prolapse and in parturient paresis in cows.

Packed cell volume was determined in 317 cows with uterine prolapse, the condition being in more than half of these cases associated with varying degrees of hypocalcaemia, in 133 cows with parturient paresis and in 73 clinically healthy newly calved cows. Independently of each other uterine prolapse and fall in plasma calcium were associated with a significant rise in PCV. The present investigation demonstrated a marked fall in circulating blood volume in a considerable number of cows suffering from uterine prolapse. The risk of irreversible hypovolemic shock developing in connection with uterine prolapse is not to be neglected, and may be aggravated by the simultaneous occurrence of hypocalcaemia, as several of the compensatory mechanisms are calcium dependent.     

The effect of concentrate feeding on calcium metabolism and plasma gastrin concentration in parturient cows

The effect of concentrate feeding on calcium metabolism was studied in pregnant cows. The concentrate (5 kg/day) was added to the diet about three weeks before expected calving. A control group was fed only hay during the whole dry period. It was earlier observed in sheep that concentrate feeding was followed by a disturbance in calcium homeostasis, but no such disturbances were observed in the cows. The concentrate fed cows consumed 50 % more calcium than the controls and were found to mobilize less calcium from the skeleton immediately after calving. There was no evidence for the theory that the gastro-intestinal hormone gastrin is involved in calcium homeostasis in the parturient cow.     

Relationship between overfeeding, metritis and ketosis in high yielding dairy cows

The association between overfeeding before calving, metritis and ketosis in seven dairy herds was investigated. The overall rate of ketonuria in 695 adult cows tested routinely between seven and 14 days post partum was 18 per cent and that of post parturient uterine diseases was 56.5 per cent. Eighty per cent of all cows with ketonuria concurrently suffered from post parturient uterine diseases. Ketonuria was found by a retrospective analysis to be independently associated with both overfeeding before calving and post parturient uterine diseases. In view of the additional risks of both metritis and ketonuria associated with overfeeding before calving and the fact that the risk of ketonuria in cows which had metritis was also found to be associated with overfeeding, it is argued that the term 'complicated' rather than 'secondary' ketosis should be applied to such cases, and that appropriate therapeutic measures should be taken accordingly.     

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.     

Fat infiltration in the liver of Finnish Ayrshire cows during early lactation

The incidence and severity of fat infiltration in the liver of Finnish Ayrshire cows at 1 and 8 weeks after calving were studied. All multiparous (n = 88) and some primiparous (n = 17) cows that calved in 20 commercial milk recorded herds were investigated. The cows lost weight and a condition score decreased significantly (p < 0.05) during early lactation. Blood samples were taken at 1, 4 and 8 weeks after calving. Ketone body concentrations were highest at 4 weeks after calving. Albumin and total protein concentrations and ornithine carbamyltransferase activity in the blood increased significantly (p = < 0.05) from 1 to 8 weeks after calving. The percentage of liver fat (v/v) was significantly (p < 0.05) greater at 1 (3.9 ± 0.5 %) than at 8 weeks (1.2 ± 0.3 %) after calving. Eighty-nine of 102 cows had less than or equal to 9 % of fat in the liver (mean 2.3 ± 0.2 %), and 13 cows had more than 9% (mean 14.9 ± 1.2%) at 1 week after calving. Only blood acetoacetate and plasma aspartate aminotransferase differed significantly between the groups. In the fatty liver group the incidence rate of treated cases of ketosis was 30.8 ± 13.3 % and of parturient paresis 23.1 ± 12.2 %. In the non-fatty liver group the rates were 10.1 ± 3.2 % and 7.8 ± 2.9 %, respectively. The differences were not significant.     

A cross-sectional study of paratuberculosis in 1155 Danish dairy cows

In a cross-sectional study on milk samples from 1155 cows from 22 Danish dairy herds, selected risk factors for paratuberculosis were identified. The diagnostic procedure used was an indirect enzyme-linked immuno-sorbent assay (ELISA) to detect antibodies against Mycobacterium avium subsp. paratuberculosis. A sample was considered test-positive if it had a corrected optical density >/=0. 025 (test sensitivity 71.4% and test specificity 89.7%). Of the 1155 samples, 8.8% (102/1155) were test-positive, and 19 out of the 22 dairy herds had >/=1 test-positive cows. The significant risk factors in a multiple logistic regression analysis were: Jersey versus large breeds, high parity versus low parity, the first month after calving versus other months of lactation, and a large herd size compared to a small herd size. The highest probability (37-38%) of a positive test was observed among older cows (parity >4) and tested within the first month after calving (irrespective of breed). The lowest probability (2%) of a positive test-result was observed among first parity, large-breed cows tested before calving or later than one month after.     

Studies on parturient paresis in dairy cows. V. On the composition and calcium binding capacity of two bovine serum protein fractions, with special regard to parturient paresis

In healthy cows unaffected by imminent or recent calving the protein in serum can directly bind the overwhelming proportion of the bound calcium. In recent calvers this capacity is considerably less. When adding ammonium sulphate to blood serum to 62 % of total saturation a protein fraction precipitates which is mainly albumin. This fraction has a far greater calcium binding capacity than the soluble fraction, which contains most of the serum globulin, and the lowering of this capacity after calving is entirely referable to the former fraction. No difference has been found in these respects between normal cows after calving and cows with parturient paresis.An analysis of 10 amino acids in the two protein fractions described above showed that the amino acid composition of both exhibits differences between recent calvers and cows outside the calving period, and likewise that each of the two fractions differs in composition between healthy cows after calving and cows with parturient paresis.