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Biomedical subjects

H Ciordia

Publications and source records attributed to H Ciordia.

16 recordsLinked to original sources
PubMed1990

Anthelmintic efficacy of febantel paste in naturally infected calves.

The purpose of the present study was to verify results of the lowest dose (5 mg kg-1) of febantel evaluated in an earlier trial in which there were no differences in efficacies of three dose rates (5, 7.5 and 10 mg kg-1 body weight) against natural gastrointestinal nematode infections of cattle. Fourteen Angus calves (mean weight and age of 155 kg and 525 days, respectively), from the same farm, with relatively heavy (mean of 448 eggs g-1 feces (epg] parasite burdens were selected. After an adjustment period of 8 days in drylot, beginning on 25 July, seven calves were treated with a 45.5% paste formulation of febantel. On Day 7 post-treatment, calves were necropsied for determination of residual worms. Rectal fecal samples were obtained prior to adjustment, at treatment, 5 days post-treatment and at necropsy. On both Day 5 post-treatment and at necropsy a mean of less than 1 epg was recovered from treated calves compared with 765 and 1566 epg, respectively, in control calves. Worms counts at necropsy revealed an efficacy of 98.5% against all adult abomasal worms (Haemonchus placei, 100%, P less than 0.02; Trichostrongylus axei, 99.4%, P less than 0.0001; Ostertagia ostertagi, 90.5%, P less than 0.0002). Treatment was 100% efficacious against adult small and large intestinal worms. However, numbers of Bunostomum phlebotomum, O. radiatum and Trichuris spp. recovered in the control calves were too low to enable a reliable test of drug efficacy. Treatment was not effective against either mucosal or luminal fourth stage larvae of abomasal O. ostertagi.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Effect of a single strategically timed dose of fenbendazole on cow and calf performance.

A 168-day study was conducted to evaluate the effect of a strategically timed treatment with fenbendazole on anthelmintic efficacy and performance of beef cows and calves. Eight groups of 10 Angus cow/calf pairs were allotted on 7 May 1987 to eight similarly managed 4.86-ha pastures (bermudagrass/tall fescue) on the basis of cow age, and calf sex and weight. At that time, four groups of cows received a dose of fenbendazole (5 mg kg-1) with their calves receiving fenbendazole at the same dosage 28 days later. Treated calf average daily gain (ADG) was 0.04 kg greater (P less than 0.05) than control calves (0.82 vs. 0.78 kg) during the 168-day study. Treated cow ADG was 0.09 kg greater (P less than 0.05) than control cows (0.40 vs. 0.31 kg). Although there was a reduction (P less than 0.05) in fecal egg counts following treatment of the cows, the numbers of eggs generally were low compared with egg counts of calves. From Day 28 through Day 112 post-treatment, fecal egg counts of treated calves were lower (P less than 0.05) than those of control calves. However, fecal egg counts from treated calves increased post-treatment until there were no differences (P greater than 0.05) between treated and control calves at the end of the study. The pregnancy rate tended to be higher (P = 0.12) for treated cows (98%) than for untreated control cows (75%). The actual calving rate was higher (P = 0.03), for treated cows (90%) than for untreated control cows (68%). Results indicated that a strategic anthelmintic treatment can improve cow and calf performance, but that calves born in late winter or early spring may need more than one therapeutic dose during the nursing period on pasture.

Animals↗
PubMed1988

Efficacy of morantel sustained-release bolus in control of gastrointestinal nematodes of weaned calves during the autumn-winter grazing season.

A 168-day study was conducted to evaluate the efficacy of morantel tartrate sustained-release bolus (MSRB) in controlling gastrointestinal parasitism in weaned calves during autumn-winter grazing in the temperature climate of southern United States. Sixty-two weanling Angus heifers were used to assess treatment differences. Six sentinel heifers were necropsied to assess pretrial gastrointestinal worm counts. The remaining 56 heifers were assigned to 4 groups of 14 heifers each and were placed on four 4.86-hectare dormant Bermuda grass pastures (1 group/pasture) that had been no-till interseeded with cereal rye in early October. Heifers in 2 groups were given 1 MSRB in early November; the other 2 groups served as nonmedicated controls. Three heifers (principals) from each of the 4 groups were necropsied on posttreatment days 57, 112, and 168 (end of study) for total worm recovery. Eight 5-month-old tracer steers, raised worm-free from birth, grazed the 4 pastures (2/pastures) for the first 21 days of the study and then were kept in drylot for 21 days before being necropsied. Level of larval contamination of pastures grazed by control and MSRB-treated heifers were comparable, because the mean number of nematodes recovered from tracer steers grazing the control and MSRB pastures were 47,449 and 53,835, respectively. At 28 days after treatment, MSRB-treated heifers had lower (P less than 0.05) mean egg counts/g of feces than did control heifers (280 vs 13).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Evaluation of the parasitological and production responses of a cow/calf operation to an anthelmintic program with ivermectin.

The efficacy of a treatment schedule using ivermectin, given subcutaneously at the rate of 200 micrograms kg-1, to control gastrointestinal parasitism and its effect on liveweight gains was assessed. Two herds with a total of 466 Hereford X Brangus cow/calf pairs were used. Each herd was on six pasture plots of comparable size, stocking rate, and quality and quantity of forage. Pasture groups were paired across the two herds. Pasture groups from one herd were randomly assigned to nonmedicated control and the other three to ivermectin treatment. Treatment assignments per pasture group were reversed in the other herd. The control group contained 118 cows and 112 calves and the medicated group 121 cows and 115 calves. Cows were treated in early July and the calves in late July or early August. Cattle from one herd were weighed on Days -28, 0 (day of cow treatment), 30 (day of calf treatment), 58, and 86, while the other herd was weighed on Days -29, 0 (day of cow treatment), 27 (day of calf treatment), 61, and 89. Day 0 was not the same calendar day for the two herds. Fecal samples for parasite egg counts were obtained from the rectum on weight days from five cows and six calves from each pasture; in most cases the same cattle were sampled each time. Calves treated with ivermectin gained (P less than 0.05) more weight than control calves between day of treatment for cows and the end of the trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Evaluation of the morantel sustained release bolus in cows and calves.

The efficacy of the morantel sustained release bolus (MSRB) in controlling gastrointestinal parasitism in beef cattle was assessed during the 1982 spring-autumn grazing season. Forty-eight cows and their calves were allotted to three equal groups. One group (T-1) served as a nonmedicated control group. One MSRB was administered to each calf of the T-2 group, and to each cow and calf of the T-3 group at the beginning of the study. The efficacy of the bolus was assessed by comparison of weight gain performance and parasitological data (fecal worm egg counts, herbage larval counts, worm counts from tracer and principal trial calves, and plasma pepsinogen level determinations). Though not statistically significant, treated calves from Group T-2 had a numerical mean weight gain advantage of 2.6 kg, and those from Group T-3 of 4.7 kg, over control calves. Average daily gains (ADG) for the three groups of calves were 0.69, 0.72, and 0.73 kg, respectively. Untreated cows from Group T-2 and treated cows from Group T-3 outperformed the control cows by 12.3 and 7.5 kg, respectively. Fecal worm egg counts from both groups of treated calves were significantly (P less than 0.01) lower than counts from control calves during the entire 169-day trial; notably, egg counts were reduced by 99% 28 days after MSRB administration to both groups of calves. There were no significant differences in the number of eggs counted from the three groups of cows, probably because of the very low numbers of eggs encountered. Mean total worm burdens of principal calves (six per group) necropsied at trial termination indicated a 91% (P less than 0.01) reduction in Group T-2 and an 87% reduction (P less than 0.01) in Group T-3. Worm-free tracer calves were introduced onto pastures every 28 days to monitor availability of infective larvae. The mean number of worms recovered at necropsy from tracer calves that grazed with control cattle increased as the season progressed. However, the numbers of parasites recovered each month from mid-August through mid-October from tracers that grazed pastures with treated cattle were lower (P less than 0.05) than those levels displayed at trial initiation. In addition, the mean numbers of worms from treated group tracers were lower than from the controls for each necropsy period.(ABSTRACT TRUNCATED AT 400 WORDS)

Analysis of Variance↗
PubMed1986

Ostertagia ostertagi: excretory secretory chemotactic substance from infective larvae as cause of eosinophil locomotion.

The infective (third stage) larva of Ostertagia ostertagi produced an excretory secretory substance that is chemotactic for bovine eosinophils. The eosinophil chemotactic substance was present in supernatants of larval cultures within 6 hr of incubation in Eagle's Minimum Essential Medium containing 25 mM N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid. The substance responsible for eosinophil chemotaxis has activity in small amounts, a molecular weight (MW) greater than 2000, and is heat labile at 100 C. Bovine eosinophils appeared to have a receptor for the chemotactic excretory secretory substance which is either identical or structurally similar to the previously described eosinophil chemotactic substance present in soluble third stage larval extracts. The larval substance may cause eosinophil accumulation in the abomasal tissue of cattle with ostertagiasis.

Animals↗
PubMed1985

Effect of a once-daily suckling program on gastrointestinal parasitism in Angus cows and calves.

Over a 2-year period involving a total of 168 Angus cows and their calves, 2 studies were conducted to evaluate the effect of once-daily suckling on cow reproduction, calf growth, and gastrointestinal parasitism. Experiment I compared 2 restricted suckling (RS) groups with 1 normal suckling (NS) group. Each group consisted of 24 cows with their calves (24 cows-calves/group = 24 cows and 24 calves/group). In the RS groups, suckling by the calves was restricted to once a day for 45 days, and then the calves were allowed to suckle normally throughout the remainder of the experiment. In the NS group, the calves suckled normally throughout the experiment. Experiment II compared 2 groups of RS cow-calves (24 cow-calves/group) with 2 groups of 24 NS cow-calves/group. In experiment I, there were no differences (P less than 0.05) in pregnancy rate or in the average number of nematode eggs/g of feces (epg) between the cows from the 2 treatment groups. The RS calves consistently had higher epg counts than did the NS calves during the 45 days of RS (169 vs 62 epg, P less than 0.05) and from the time of their return to pasture until weaning (266 vs 186 EPG, P = 0.27). The RS calves also had a higher average coccidia oocyst count during the RS period only. In experiment II, RS cows had a higher pregnancy rate (87.6% vs 66.0%, P less than 0.05) and a shorter postpartum interval (83 vs 101 days, P less than 0.05) than did NS cows.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Population Groups↗
PubMed1978

Cestocidal activity of albendazole in calves.

Sixty commercial-grade calves naturally infected with tapeworms (Moniezia benedeni and M expansa) were used in a controlled experiment to evaluate the anthelmintic efficacy of 4 dose levels of albendazole. Calves were randomly divided into 5 groups of 12 each. One group served as non-medicated controls. Other groups were drenched with albendazole (methyl [5-(propyltion)-1H-benzimidazol-2-yl] carbamate) at dose rates of 20, 10, 5 and 2.5 mg/kg of body weight. Calves were necropsied 14 days after treatment. Doses of 20 and 10 mg/kg were 100% efficacious in reducing the number of tapeworm scolices, and doses of 5 and 2.5 mg/kg were 97.8%. Medicated cattle did not show signs of intoxication.

Animals↗
PubMed1975

Anthelmintic treatment of subclinical parasitism of feedlot cattle in Georgia.

Forty heifer calves, 27 yearling heifers, and 64 yearling steers with naturally occurring infections of nematode parasites were treated with levamisole HCl or morantel tartrate or were not treated. Although heifer calves had much larger worm egg counts before treatment than yearling heifers, necropsies showed a smaller average number of nematodes in the calves. Both anthelmintics significantly reduced the egg counts. At the end of the experiments, 98 to 240 days after treatments, there was no significant difference among groups of cattle in respect to necropsy worm counts. An advantage of 5% in rate of gain in body weight was shown in each experiment or phase of an experiment in favor of the treated groups of cattle. Overall, an advantage of 6% in feed efficiency was calculated for the treated groups of cattle.

Animal Feed↗
PubMed1975

Occurrence of gastrointestinal parasites in Georgia cattle.

A survey of gastrointestinal nematodes in Georgia cattle was conducted from 1968 through 1973 from actual worm counts from viscera of 145 slaughtered beef cattle or from egg counts made from fecal samples from 3,273 beef and 100 dairy cattle. Beef cattle were grouped as calves, yearlings, and cows. Dairy cattle were grouped as calves, replacement heifers, and cows. Results of fecal examinations positive; 99.5, 99.3, 99.6, and 41.2% of the calves, yearlings, drylot calves, and cows, respectively, were infected with nematodes. Seventy-four percent of the eggs counted were of the Cooperia-Ostertagia - Trichostrongylus complex (C-O-T) and 21% were of the Haemonchus-Oesophagostomum complex (H-O). Sixty-nine percent of the infective larvae recovered from coprocultures made from composite samples were of Ostertagia ostertagi. Moniezia (tapeworm) eggs were seen in 16% of all the samples, more predominantly in the calves (24%) and less in the cows (smaller than 1%). Oocysts of Eimeria spp were detected in 61% of the cattle, more predominantly in younger cattle. All cattle necropsied were infected with O ostertagi. Other nematodes present, in order of decreasing frequency, were Trichostrongylus axei (97%), Haemonchus placei (66%), Cooperia punctata (63%), Cooperia oncophora (61%), Oesophagostomum radiatum (61%), Bunostomum phlebotomum (55%), Trichostrongylus colubriformis (36%), Cooperia pectinata (28%), Trichuris spp (17%), Nematodirus spathiger (9%), and Capillaria bovis (4%). Tapeworms were also recovered from 19% of the cattle at necropsy. Seventy-eight percent of the dairy cattle were positive; 98% of the calves, 80% of the heifers, and 58% of the cows. Cooperia-Ostertagia-Trichostrongylus eggs were detected in 78% and H-O eggs in 38% of the cattle. Eimeria oocysts were detected in 71% of all the dairy cattle, and Moniezia eggs were in 10% of the calves and 7% of the heifers.

Animals↗