C. Svensson

Cryptosporidium parvum and Giardia intestinalis in Calf Diarrhoea in Sweden

The objective of this study conducted in 75 herds was to investigate the presence and significance of Cryptosporidium parvum and Giardia intestinalis in Swedish dairy calves in comparison with rotavirus, coronavirus and Escherichia coli K99+. The farmers were asked to collect faecal samples from each heifer calf that had diarrhoea between birth and 90 days of age, and also from a healthy calf of the same age. In total, 270 samples were collected and analysed. C. parvum, either alone or together with G. intestinalis and/or rotavirus, was detected in 16 (11%) and 6 (5%) of the samples from diarrhoeic and healthy calves, respectively. Even though a higher proportion of diarrhoeic calves shed C. parvum, the difference between the groups was not statistically significant (p = 0.067), possibly due to the low number of positive samples. G. intestinalis was found in 42 (29%) of the diarrhoea samples and in 29 (23%) of the samples from healthy calves. Rotavirus and coronavirus were demonstrated in 24% and 3% of the diarrhoea samples, respectively, whereas E. coli K99+ was only found in samples from 2 healthy calves. C. parvum and G. intestinalis were found in samples from calves 7 to 84 days of age and during all seasons. The results confirm that C. parvum is present in Swedish dairy herds and might have clinical significance. G. intestinalis was the most common agent found but the importance of this parasite remains unclear. Both parasites have suggested zoonotic potential and thus warrant further attention. In addition, rotavirus is a major pathogen in neonatal enteritis in Sweden, whereas coronavirus and E. coli K99+ seem to be of less importance.SammandragCryptosporidium parvum och Giardia intestinalis vid kalvdiarré i svenska mjölkkobesättningar.Avsikten med denna studie var att undersöka förekomst och betydelse av Cryptosporidium parvum och Giardia intestinalis hos svenska kalvar, jämfört med rotavirus, coronavirus och Escherichia coli K99+. Djurägarna i 75 mjölkkobesättningar tog träckprover från upp till 90 dagar gamla kalvar som hade diarré, samt från friska kalvar i samma ålder. Totalt insamlades och analyserades 270 prover. C. parvum, enbart eller tillsammans med G. intestinalis och/eller rotavirus, påvisades i 16 (11%) av proverna från kalvar med diarré och 6 (5%) av de friska kalvarna. Skillnaden mellan grupperna var inte statistiskt signifikant (p=0,067), möjligen beroende på det låga antalet positiva prover. G. intestinalis påvisades hos 42 (29%) prover från kalvar med diarré och hos 29 (23%) friska kalvar. Rotavirus påvisades i 24% och coronavirus i 3% av proverna från diarrékalvarna medan E. coli K99+ bara återfanns i prover från 2 friska kalvar. C. parvum och G. intestinalis påvisades i prover från kalvar mellan 7 och 84 dagars ålder och under hela året. Resultaten bekräftar att C. parvum förekommer i svenska mjölkkobesättningar och kan ha klinisk betydelse. G. intestinalis var det agens som påvisades hos flest kalvar, men parasitens betydelse för kalvhälsan är oklar. Fynden är intressanta då båda parasiterna anses ha zoonotisk potential. Resultaten styrker även tidigare iakttagelser att rotavirus är den vanligaste infektiösa orsaken till kalvdiarré i Sverige.

A field survey on the status of internal parasites in calves on organic dairy farms in southwestern Sweden

Infections with internal parasites are one of the most important causes of reduced productivity in first-grazing season cattle (FGSC). In conventional herds, nematode infections can be controlled by prophylactic anthelmintic treatments, but this is prohibited in organic production. The purpose of this investigation was to monitor the status of internal parasitism on 15 organic cattle enterprises in southwestern Sweden during the 1997 and 1998 grazing seasons, and to estimate the benefits of some management practices in parasite control. On each farm, the numbers of Eimeria alabamensis oocysts per gram of (opg) faeces were counted in seven fresh dung pats collected from the paddock 8-10 days after the turnout of FGSC. Faecal samples from 5 to 15 FGSC were also analysed for nematode eggs per gram (epg) faeces at four occasions during each grazing season. In addition, the FGSC and one group of second-grazing season cattle (SGSC) were weighed at turnout and housing and at the same time blood samples were collected, and analysed for serum pepsinogen concentration and antibodies against the lungworm, Dictyocaulus viviparus. On seven farms, 1-6 samples with more than 100000 opg were found, indicating considerable pasture contamination by E. alabamensis. However, clinical signs of coccidiosis were not observed. The highest outputs of nematode eggs were observed 45-55 days after turnout. More than 500 epg were only observed in 12 (2.2%) of the calves in 1997 and in three (0.6%) animals in 1998. Only 1% of the serum samples had pepsinogen values exceeding 3.6 U tyrosine, indicative of subclinical Ostertagia ostertagi infection. Lungworm infection was detected in five and nine herds in 1997 and 1998, respectively. The number of seropositive animals on these farms ranged between one (10%) and seven (70%). Clinical signs of dictyocaulosis were observed on two farms. The results indicate that dictyocaulosis is a problem in organic dairy herds in Sweden. On the other hand, the study shows that good management such as usage of parasite safe pastures and supplementary feeding may help control gastrointestinal parasites.

Parasite control methods in organic and conventional dairy herds in Sweden

Abstract The objectives of this study were to compare methods of parasite control and to get an indication of the magnitude of parasite infections in organic and conventional dairy herds in Sweden. In February 1997, a questionnaire with mainly multiple choice alternatives was distributed to 162 organic and 162 conventional dairy farms in central Sweden. The response rates were 84% and 72%, respectively. A majority (58%) of the conventional farmers reported that their animals were treated prophylactically, mainly with controlled-release intraruminal devices. In organic production, parasite control methods involving grazing management combined with nutritional supplementation with concentrates and/or forage was the most frequently reported anti-parasite strategy. The most common procedure was to turn calves out on pastures not grazed by any cattle in the current or previous grazing seasons. This was employed by significantly more organic than conventional farms (40% vs. 3%), as was alternating grazing with other livestock species (27% vs. 3%). Sixty percent of the organic and 52% of the conventional farmers reported that they used nutritional supplementation in the autumn, and 48% and 29% of the producers, respectively, that they used nutritional supplementation in the spring, as methods to restrict parasite problems in their calves. Outbreaks of diarrhoea in first grazing season cattle and a lower weight gain during the grazing season than in the previous winter season, problems that may be due to parasite infections, were reported more frequently from organic herds. Despite an apparently increased awareness of various worm control strategies, organic farmers thus seemed to have greater problems with parasite infections than did conventional farmers.

Eimeria alabamensis infection as a cause of diarrhoea in calves at pasture

Large numbers of oocysts of Eimeria alabamensis have been found in the faeces of calves suffering from diarrhoea shortly after being turned out to pasture. To investigate the source and clinical significance of this coccidial infection, the numbers of oocysts excreted, the consistency of the faeces and the growth rates of four groups of 12 calves were compared. Group I calves were kept indoors and their diet was unchanged, Group II calves were turned out onto a previously ungrazed pasture, Group III calves were turned out onto a permanent pasture and Group IV calves were kept indoors and fed cut grass from a previously ungrazed field. Eight days after the animals were turned out there was an almost 1000-fold increase in the numbers of oocysts in the faeces of Group III calves, the dominant species being E. alabamensis, but there were only minor fluctuations in the numbers of oocysts excreted by the other groups. It was therefore concluded that the source of the infection was oocysts that had overwintered on the permanent pasture. Most of the calves in Group III developed watery diarrhoea 5 days after turnout, but there was only a slight softening of the faeces of the calves in Groups II and IV at about the same time. The faeces of the calves in Group I was of firm consistency throughout the trial. The calves in Group III lost 18 kg during the 24 day period following turnout, whereas the calves in the other groups gained between 6 and 18 kg.

Housing, Feeding and Management of Calves and Replacement Heifers in Swedish Dairy Herds

A questionnaire was sent to 1500 randomly selected dairy herds in Sweden, asking for general information about the herds, including routines from birth to first calving and also routines at breeding, calving and during the grazing period. Fifty-eight percent of the questionnaires were returned. The preweaned calves were kept in individual calf pens in 68% and in group housing systems in 28% of the herds. Pens with slatted floors were the main housing system for replacement heifers from weaning to breeding, and tie stalls from breeding to first calving. Whole milk was used in 44% and milk replacements in 42% of the herds. The calves received, as a median, 2.5 litres of milk per meal and 2 meals per day. The median age at weaning was 8 weeks. Age was the single most common criteria used for deciding both weaning and breeding time. The median age when the heifers were first turned out to pasture was 6 months. Prophylactic anthelmintic treatment was used by 65% of the herds. The most common diet for replacement heifers before calving was a combination of grain, hay and silage.SammanfattningInhysning, utfodring och skötsel av rekryteringsdjur inom mjölkproduktionen i Sverige.En enkät skickades ut till 1500 slumpvis utvalda mjölkkobesättningar. Enkäten innehöll frågor om rutiner mellan födelse och inkalvning, rutiner vid inseminering/ betäckning, rutiner under betessäsongen samt generella frågor om besättningarna. Svarsfrekvensen var 58%. I 68% av besättningarna hölls kalvarna i ensambox under mjölkperioden, 15% använde traditionella gruppboxar med hinkutfodring och 13% inhyste sina kalvar i gruppboxar med sk kalvamma. Trettionio procent av besättningarna sparade mjölk från första urmjölkningen efter kalvningen även till kalvens andra mål. Helmjölk användes i 44% och mjölkersättning i 42% av besättningarna. Medianåldern vid avvänjning var 8 veckor. I över hälften av besättningarna (53%) gick kvigorna under någon del av perioden avvänjning till inseminering/ betäckning på spaltgolv medan 51% av besättningarna hade sina kvigor uppbundna någon del av perioden, inseminering/ betäckning till inkalvning. Den vanligaste foderstaten under uppfödningsperioden innan inkalvning var spannmål, hö och ensilage. Drygt två tredjedelar av besättningarna avmaskade sina kvigor i förebyggande syfte före eller under första betessommaren.

Risk factors for calf mortality in large Swedish dairy herds.

Abstract The aim of this study was to identify possible risk factors for 1–90 day calf mortality in large Swedish dairy herds. Sixty herds with a herd size of ≥160 cows were visited once between December 2005 and March 2006. Thirty herds were known to have low mortality (LM) and 30 were known high mortality herds (HM). Upon the visit, data about housing and management was collected from interviews with personnel responsible for the calves. The herd status regarding the calves’ passive transfer (total protein), levels of α-tocopherol, β-carotene and retinol, and excretion of faecal pathogens (Cryptosporidium spp., Escherichia coli F5, rota and corona virus) was evaluated based on targeted sampling of high risk calf groups; in each herd, blood and faecal samples were collected from calves 1–7 and 1–14 days old, respectively. Similarly, the herd status regarding clinical respiratory disease in calves and history of respiratory virus exposure was evaluated based on lung auscultations and blood samplings of calves 60–90 days old. The median calf mortality risk (in calves 1–90 days of age) among HM herds was 9% (Range: 6–24%) and among LM herds 1% (Range: 0–2%). LM and HM herds were compared using five logistic regression models, covering potential risk factors within different areas: “Disease susceptibility”, “Factors affecting the gastrointestinal tract”, “Factors related to transmission of infectious disease”, “Hygiene” and “Labour management”. The percentage of calves, 1–7 days old, with inadequate serum concentrations of α-tocopherol and β-carotene were significantly higher in HM herds compared to LM herds and also associated with higher odds of being a HM herd (OR=1.02; p =0.023 and OR=1.05; p =0.0028, respectively). The variable “Average number of faecal pathogens in the sampled target group” was significantly associated with higher odds of being a HM herd (OR=4.65; p =0.015), with a higher average in HM herds. The percentage of calves with diarrhoea treated with antibiotics was significantly higher in HM herds and was associated with higher odds of being a HM herd (OR=1.08; p =0.021). The median age at death of calves in the age interval 1–90 days that died during a one-year period was significantly lower among HM herds (13 days) than in LM herds (24 days) (p =0.0013) The results indicate that gastrointestinal disorders may be an important cause of calf mortality in large Swedish dairy herds. Furthermore, our study provides additional indications that fat soluble vitamins might play an important role for calf health.

Associations Between Housing, Management, and Morbidity During Rearing and Subsequent First-Lactation Milk Production of Dairy Cows in Southwest Sweden

Information regarding health, management, and housing from birth to first calving was collected for 1,029 Swedish Reds, 991 Swedish Holsteins, and 40 heifers of crossbreed or other breeds on bimonthly farm visits made by 3 project veterinarians to 107 dairy herds in southwest Sweden. Additional data were obtained from the official milk- and health-recording program. Milk production at first test day after calving [energy-corrected milk (ECM)1] and during the first 305 d of lactation (ECM305), respectively, were analyzed by 2-level (animal; herd) linear regression, after initial screening by univariable analyses of 67 potentially important predictors. The ECM1 ranged from 7.9 to 48.0 (median = 27.1) kg, and ECM305 ranged from 3,764 to 12,136 (median = 8,006) kg. In the final models, factors associated with ECM1 or ECM305 or both were age at first calving, body condition score at first service, breed, calfhood diarrhea, calving season, composite somatic cell count at first test day, daily weight gain from weaning to first service, housing system after calving, and increase in concentrate fed around calving. Higher age at calving was associated with higher production. Production also increased with higher daily weight gains from weaning to first service. Swedish Holsteins produced more than Swedish Reds, cows calving in May to September produced more than those calving during other months, and cows housed in short stalls after calving produced more than those in cubicles. Body condition scores > or =3.2 at first service were associated with lower ECM305 than scores < or =2.9. Animals that contracted mild diarrhea during their first 3 mo of life had lower ECM305 than animals without diarrhea, whereas animals receiving a high increase in concentrate pre- and postcalving had higher ECM305 than those subjected to a more moderate increase. Cows with a composite somatic cell count >1 million cells/milliliter at first test day produced less milk on the same day than cows with lower counts. It was concluded that rearing factors and calfhood health status can influence first lactation milk production.

Supplemental feeding with glycerol or propylene glycol of dairy cows in early lactation—Effects on metabolic status, body condition, and milk yield

The objective of this field study was to evaluate the effect of supplemental feeding with glycerol or propylene glycol to dairy cows in early lactation on metabolic status, body condition and milk yield. In total, 673 newly calved cows from 12 commercial Swedish dairy herds were randomized to daily supplementation with 450 g of glycerol (GLY), 300 g of propylene glycol (PG), or nothing (control, CON). Supplements were fed twice daily from 0 to 21 d in milk (DIM) as a top dress on concentrates. For each cow, data on parity, breed, calving date, monthly test-day milk yield, and cases of diseases were collected. Blood samples were taken at approximately 2, 5, and 8 wk postpartum (pp) and analyzed for glucose, β-hydroxybutyrate (BHBA), nonesterified fatty acids (NEFA), and insulin. Samples taken within 3 wk pp were also analyzed for insulin-like growth factor 1 (IGF-1). Measurements of body condition score (BCS) and heart girth (HG) were obtained at approximately 2 and 5 wk pp and at time of first insemination. The effects of supplemental feeding with GLY or PG on the plasma concentrations of glucose, NEFA, BHBA, insulin, and IGF-1, and BCS, HG, and occurrence of disease were analyzed. No differences in BCS or HG or in plasma concentrations of glucose, BHBA, NEFA, or IGF-1 were found between the control group and any of the treatment groups. Cows in the GLY group had lower plasma insulin concentrations during DIM 0 to 63 compared with group CON, but no difference in insulin was found between the PG group and the CON group. Cows supplemented with GLY had a higher milk yield (kg of milk and kg of energy-corrected milk) during the first 90 DIM. Cows in the PG group tended to yield more milk during the same period. No differences in the occurrence of diseases were seen between the groups. In conclusion, supplementation with GLY in early lactation did increase milk yield without a subsequent decrease of metabolic status, and supplementation with PG tended to do the same.

Heifer rearing conditions affect length of productive life in Swedish dairy cows

Associations between rearing conditions and the risk of culling in dairy cows were studied by survival analysis. Data were collected from 1039 Swedish Red cows, 1029 Swedish Holsteins, and 56 cows of other milk or cross-breeds, representing all female animals born in 109 Swedish herds during 1998. Length of productive life was defined as the number of days from 1st calving to culling. The applied Weibull proportional hazards model included time-independent effects of breed, housing from 3 to 7 months of age, number of housing changes before calving, grazing before 1st calving, herd median age at 1st calving, age at 1st calving, cow housing, herd lactational incidence risk of veterinary-reported clinical mastitis, and the random effect of herd. Time-dependent effects were year, month, the interaction year by month, parity, number of breedings, pregnancy status, the interaction parity by pregnancy status, herd mean milk-production level, relative milk yield within breed-parity, and veterinary-reported clinical mastitis. The lactation was divided into six stages in which pregnancy status was assumed to be known by the farmer and culling could occur. Median productive life time in culled cows was 780 d and 14% of the records were censored due to terminated data collection. An individual calving age of 28.2-30.9 months was associated with the highest culling risk, 1.2-fold higher than calving at < or = 25.3 months, whereas the risk decreased almost linearly with a higher herd median age at 1st calving. Housing in slatted pens with >7 calves from 3 to 7 months was associated with a 1.7-fold increase in risk, relative to litter pens. If a cow had changed housing system 4 times before 1st calving it increased the risk of culling 1.4 times, relative to two housing changes. These results show that rearing factors affect the productive life time of dairy cows in Swedish family operations.

Experimental Eimeria alabamensis infection in calves

Four groups of three conventionally reared 2-month-old bull calves were inoculated with 10 million to 400 million sporulated oocysts of Eimeria alabamensis isolated from Swedish calves which had diarrhoea while at pasture. Their appetite, clinical condition, growth rate and the dry matter content of their faeces were compared with those of three similar but uninoculated calves. The prepatent period was 6-8 days, and the period during which large numbers of oocysts were excreted was 2-7 days. In two of the inoculated calves only a slight softening of the faeces was observed. The other ten calves developed watery diarrhoea, had a poor appetite and appeared depressed. The clinical signs were most severe in the calves which received the highest doses and included signs of abdominal pain and a reluctance to rise. The growth rates of the infected calves were significantly reduced for 18 days after inoculation, and 71 days after inoculation they had not compensated for this period of reduced growth rate.