Plasma enzyme activities and acid-base equilibrium in sows in relation to the progress of labor

Temperature, heart rate and respiratory rate as well as enzymatic activities (CK, CK-MB, AST, LDH), and characteristics of base-acid-balance (pH, BE, pCO2, Lactate) were taken from 52 pigs during the period shortly before and after they gave birth. 16 of them dropped normally, 21 with conservative obstetrics and 15 with obstetrical laparotomy. In pigs with obstetrical laparotomy temperature fell significantly (p less than or equal to 0.01). Concerning heart rate and breathing rate there were no differences between the tested animals. CK-data rose significantly during and after birth. Maximum test data occurred in test-groups with dystocia. At the same time the increase of CK-MB-activities was above average (p less than or equal to 0.001). The other enzymes (AST, LDH) also showed a significant increase of activity in all sows, especially in case of difficult birth (p less than or equal to 0.01 to 0.0001). Lactate-concentration and the test data of base-acid-balance underwent serious changes. During anaesthesia in case of obstetrical laparotomy and during the first hours after the operation pH and BE fell and pCO2 rose. The increase of Lactate-data was above average. While we find metabolic acidosis during normal but difficult births, a respiratory acidosis caused by anaesthesia is found additionally in case of laparotomy.     

Efficacy and safety of ivermectin applied topically to cattle under field conditions in Australia

Fifteen controlled field trials were conducted to evaluate the efficacy against gastrointestinal nematodes and safety of ivermectin when applied topically to cattle in Australia. Three hundred and fifty-one cattle received ivermectin, and 88 were untreated controls. The trials were conducted in 3 States and included a variety of cattle breeds and environmental conditions. Faecal samples were collected before treatment and 11 to 14 days after treatment for nematode egg counts. Data from these trials show that under Australian conditions, ivermectin applied along the mid line of the back from the withers to the sacral region at a dose rate of 500 mcg/kg body weight, effectively controlled gastrointestinal nematode infections, and did not produce unacceptable adverse reactions in the animals.     

Health status of cattle in relation to the time of year

The periodicity of morbidity rate in heifers and dairy cows kept on pasture (278 animals) and in stables (187 animals) was studied in relation to macroclimatic conditions under the assumption of two peaks per annum. The following conditions were used as the parameters of morbidity: purulent inflammations of uterus, sterility, lesions of the female tract and sepsis, dystocia, retention of placenta, mastitis, foot diseases and lying down after parturition. No significant differences were found between the studied groups of animals. A statistically significant up to highly significant dependence was found between the health of the heifers and cows and macroclimatic conditions both in stables and on pasture; an increase in morbidity rate was recorded in spring and autumn.     

The grazing behaviour of cattle in relation to the sampling of infective nematode larvae on pasture

A method of sampling pasture to estimate the numbers of infective nematode larvae to which grazing cattle were exposed was based on the grazing patterns and behavioural activities of two groups of cattle and was compared with other sampling techniques. Each group of cattle consisted of six permanent members, two members fistulated at the oesophagus and one worm-free tracer calf. Grazing time and the area where grazing occurred was not significantly different for tracer calves, fistulated cattle and permanent group members, and there was no relationship between grazing time and the live weight of cattle. Grazing time, the percentage of paddock area grazed intensively and the percentage of the paddock not grazed varied with season. The most intensively grazed areas were always visited between first light and the first rest period during mid-morning, and the plant parts and pasture species eaten could easily be identified by visual examination of these areas of the paddock. Larval recoveries per 100 g pasture ingested were estimated for comparison with the grazing area method using two other manual pasture sampling methods, a sampling method using tracer calves and one using fistulated calves. Correlations between these methods were not consistent but indicated that, given the small number of data sets, all methods were sensitive enough to estimate larval availability on pasture with the exception of the tracer calf method in the overstocked 3.4-ha paddock.     

Changes in gas composition and acid-base values of venous blood samples stored under different conditions in 4 domestic species

BACKGROUND: The effect of storage temperature and time on blood gas and acid-base values has been investigated intensively in cattle and dogs; however, data are lacking in other species. OBJECTIVE: The aim of our study was to evaluate changes in gas composition and acid-base values in venous blood stored at different temperatures and for different times in 4 domestic species in Italy. METHODS: Blood samples from Comisana sheep (n = 10), Maltese goats (n = 10), Ragusana donkeys (n = 10), and Thoroughbred horses (n = 10) were analyzed after storage at 23 degrees C (room temperature) for 15 minutes (group I), 23 degrees C for 1 hour (group II), 37 degrees C for 8 hours (group III), and 4 degrees C for 24 hours (group IV). Results were analyzed using a 1-way repeated measures ANOVA. RESULTS: In all species no statistically significant differences in pH values were present in samples stored at 4 degrees C for 24 hours. This also was true for PCO2 in all species except the horse. Except for HCO3- concentration in the horse, significant changes in PO2, HCO3- concentration, base excess, and the standard bicarbonate concentration were observed for all species in samples stored at 4 degrees C. In samples stored for only 1 hour at room temperature, significant changes in most analytes were detected. CONCLUSIONS: The results of this study underline the need for rapid assessment of acid-base samples, because any delay, even for 1 hour, may affect the results.     

Subacute butyric acid exposure in cattle. 5. Effect on the acid-base equilibrium and protein metabolism in cows

Acid-base balanced in cows were but slightly affected by butyric acid exposure experiment over three weeks. Applications of sodium butyrate over the same period of time, on the other hand, was associated with buildup of alkalosis in the second half of the experimental period, with alternation of loading, compensation, and reloading being recordable. Nitrogen metabolism in cows was but slightly affected under the given experimental conditions. However, clearly noticeable impairment of nitrogen metabolism was exhibited by one cow that had fallen ill, in the course of experimentation.     

Changes in colostral and serum IgG content in swine in relation to time

Changes in the IgG concentration in the colostrum from separate teats of 6 sows and those in the sera of their 38 piglets were investigated. Colostrum was frequently sampled from parturition to 120 hours and blood was taken from the piglets from birth to 10 weeks of age. The IgG content of the colostrum decreased to 3.2% of the original concentration at the 5th day of lactation. The meaningful variation of the IgG concentration of the colostra obtained from different teats increased rapidly from 12 hours postpartum. Between-sow variation was high and no correlation of the IgG concentration of the colostrum with the average serum level of the corresponding litter could be confirmed. Of the newborn pigs, 33% possessed IgG before ingesting colostrum, the observed concentration was 0.09±0.02 mg/ml (mean±SEM). At 0.5 and 1.5 hours after access to colostrum, this value was 2.30±1.38 and 1.89±0.60 mg/ml respectively. The highest IgG concentration (39.45±1.46) was observed at 24 hours after birth. Following that, a stepwise drop occurred in the IgG level and the lowest value was observed in the 4th week of age (8.92±0.59 mg/ml). Subsequently, there was a continuous rise until 10 weeks of age when the concentration reached the value characteristic of adults. The calculated half-life of the IgG in the sera showed a significant between-litter variation. The average half-life of the serum IgG of pigs was 9.73 days.     

Therapeutic efficacy of zeta-cypermethrin pour-on for the treatment of biting and sucking lice in cattle under field conditions

OBJECTIVE: To assess the efficacy of zeta-cypermethrin pour-on to control cattle lice. DESIGN: Five field trials in south-eastern Australia. PROCEDURE: Zeta-cypermethrin pour-on, deltamethrin pour-on and pour-on vehicle were applied to groups of 10 cattle. Lice were counted before treatment and 14, 28, 42 and 56 days after treatment. RESULTS: Zeta-cypermethrin pour-on given at 2.5 mg/kg was equivalent to, or marginally more effective than a deltamethrin pour-on at 0.75 mg/kg. It eliminated B bovis and H eurysternus and gave good control of L vituli and S capillatus. Zeta-cypermethrin at 1 mg/kg gave good control of B bovis and H eurysternus but was not satisfactory against L vituli and S capillatus. CONCLUSION: Zeta-cypermethrin pour-on, given at 2.5 mg/kg, is an effective treatment for cattle lice control. Zeta-cypermethrin, and other synthetic pyrethroid pour-ons, are the treatment of choice to control B bovis.     

Efficacy of flumethrin 1% pour-on against ticks on cattle under field conditions in Ethiopia

The efficacy of a flumethrin 1% pour-on (Bayticol, Bayer AH) was evaluated against natural infestations of ticks on cattle on a dairy farm in Ethiopia during 1997/98. The cattle, (n = 92), which were Friesian/ Zebu crosses, were heavily infested with Boophilus decoloratus. Dry cows (n = 8) were randomly selected and allocated either into a treatment or a control group. Flumethrin 1 % pour-on was applied to the treatment group according to the manufacturer's recommendation, i.e. along the dorsal mid-line from the head to the base of the tail. Ticks were counted and identified in situ on treated and control animals. When the total tick counts of the treated group were similar to those on the control, the trial was discontinued. Excellent results were achieved with flumethrin against heavy tick infestations. There was a rapid kill after 24 h post-treatment, and from day 4 onwards 100% control was achieved and maintained for a further 29 days. The results obtained indicate that there was a significant difference between the mean tick counts of the control group compared with those of the treatment group (P < 0,05). The evidence presented here suggests that the flumethrin 1 % pour-on may be applied at 45 day intervals and should provide effective protection against the economically important ticks if it is used at the recommended dosage rate and applied correctly.     

Evaluation of an antigen capture ELISA for the early diagnosis of Hypoderma lineatum in cattle under field conditions

An antigen capture or sandwich ELISA (sELISA) was evaluated for the diagnosis of Hypoderma lineatum in cattle under field conditions in northwestern Spain. The kinetics of circulating hypodermin C (HyC) and specific antibodies during the course of natural infestation were determined in a group of 10 Frisian calves. In addition, oesophagi and blood samples were taken from 105 cows at a slaughterhouse in order to compare three methods for the diagnosis of H. lineatum: sandwich ELISA for the detection of the antigen HyC (sELISA), indirect ELISA for the detection of antibodies anti-HyC (iELISA) and the detection of first instars (L1) in the oesophagus. In naturally infested cattle, HyC was present in circulation at low levels during the early and late phases of the infestation. However, in the middle phase, coinciding with the presence of L1 in the oesophagus, two peaks of increased HyC concentration were observed. Specific antibodies increased progressively until the first appearance of larvae in warbles on the back. There was no correlation between antigen or antibody levels and the number of grubs in the back. Prevalence of first instars in the oesophagi of slaughtered cows was 21.9% (23/105). The percentage of cattle that were positive for circulating antigen was slightly higher (24.8%), suggesting the recent destruction of migrating larvae in some animals. However, there was no correlation between the number of L1 and HyC levels. With the iELISA, 79% of the animals were positive to Hypoderma, which means that a high percentage of those animals have been exposed to the parasite but they had no apparent current infestation. The sELISA is a good tool to follow larval development within the host; however, the episodic elevation of HyC levels limits the usefulness of this test for the early diagnosis of Hypoderma under field conditions.     

Persistent efficacy and production benefits following use of extended-release injectable eprinomectin in grazing beef cattle under field conditions

Seven studies were conducted in commercial grazing operations to confirm anthelmintic efficacy, assess acceptability, and measure the productivity response of cattle to treatment with eprinomectin in an extended-release injectable formulation (ERI) when exposed to nematode infected pastures for 120 days. The studies were conducted under one protocol in the USA in seven locations (Arkansas, Idaho, Louisiana, Minnesota, Missouri, Oregon, and Wisconsin). Each study had 67–68 naturally infected animals for a total of 475 (226 female, 249 male castrate) Angus or beef-cross cattle. The animals weighed 133–335 kg prior to treatment and were approximately 3–12 months of age. The studies were conducted under a randomized block design based on pre-treatment body weights to sequentially form 17 replicates of four animals each within sex in each study. Animals within a replicate were randomly assigned to treatments, one to Eprinomectin ERI vehicle (control) and three to Eprinomectin ERI (5%, w/v eprinomectin). Treatments were administered at 1 mL/50 kg body weight once subcutaneously anterior to the shoulder. All animals in each study grazed one pasture throughout the observation period of 120 days. Cattle were weighed and fecal samples collected pre-treatment and on 28, 56, 84, and 120 days after treatment for fecal egg and lungworm larval counts. Positive fecal samples generally were cultured en masse to determine the nematode genera attributable to the gastrointestinal helminth infection. Bunostomum, Cooperia, Haemonchus, Nematodirus, Oesophagostomum, Ostertagia, and Trichostrongylus, when present, were referred to as strongylids. At all post-treatment sampling intervals, Eprinomectin ERI-treated cattle had significantly (P < 0.05) lower strongylid egg counts than vehicle-treated controls, with ≥95% reduction after 120 days of grazing. Over this same period, Eprinomectin ERI-treated cattle gained more weight (43.9 lb/head) than vehicle-treated controls in all studies. This weight gain advantage was significant (P < 0.05) in six of the studies with the Eprinomectin ERI-treated cattle gaining an average of 42.8% and the control cattle gaining 33.1% of their initial weight. No adverse reactions were observed in the treated animals.     

Acid-base equilibrium in the blood in cattle in relation to the incidence of DFD (dark, firm, dry) meat

We studied changes in the parameters of the acid-base balance of the blood in cattle before animal transport to the slaughterhouses, after transport, after stunning and before bleeding. At the same time we studied the occurrence of DFD meat by measuring the pH value of the muscle and by determining the meat color. We found out that the disorder of acid-base balance was less manifest, with respect to the large capacity of the buffer systems of the blood, than the changes caused by glycogenolysis in the muscle.     

Routine surgical procedures in dairy cattle under field conditions: abomasal surgery, dehorning, and tail docking.

This article discusses the different methods used for the correction of left displaced abomasum. The advantages, disadvantages, and success rates of each technique are reviewed. The most common complications are described, and the economics of repeat surgery after a failed left displaced abomasum repair are examined. This article also addresses the need for anesthesia when dehorning and tail docking dairy cattle. The justifications for routine use of these two procedures are discussed, mainly from an animal welfare standpoint.     

The transfer of Boophilus microplus (Acarina: Ixodidae) from infested to uninfested cattle under field conditions

The transfer of larvae and adult males of the cattle tick, Boophilus microplus, from infested to uninfested cattle, has been demonstrated under field conditions. The role of host to host transfers in the transmission and epidemiology of anaplasmosis and babesiosis is discussed.