Efficacy in broilers

Mycoplasma can increase the susceptibility of broilers to virus infections (IB, ILT, ND, and IBD) and even live vaccines. They also allow the entry of bacterial infections. This will lead to infections with Escherichia coli (Coli septicaemia) and possibly Pasteurella multocida (Fowl Cholera).

(a) Tiamutin
Treatment with 25-50 mg/kg bw is applied during the first 3 days of life. In case monovalent ionophores are not used within 7 days after the last treatment, or if compatible alternatives for coccidiosis prevention are used. This procedure “cleans” the flock of vertically transmitted Mycoplasma infections and has beneficial effects on the performance throughout the grow out period.
 

 
 

Broiler Mycoplasma treatment with Tiamutin prior to monovalent ionophores

 
 

Comparative trials have been carried out with Tiamutin and untreated control flocks, affected by combined infections of MS and E. coli. The flocks were treated with Tiamutin in drinking water during the first 3 days of life, at a therapeutic dose of 0.025%. Although treatment only took place during the early period of life, the mortality was 45% lower than in the control flock (Burch & Pickles, 1984).
 
 

Efficacy of Tiamutin in the reduction of mortality due to MS and E. coli infections

 

Various trials have been performed to test the efficacy of Tiamutin versus MG, MS and combined infections with E. coli. In these cases, doses of 25-50 mg/kg bw have been applied for 2-5 days at the start and/or at the end of the fattening period. The objective of these treatments was to ‘clean out’ the flock respectively to treat clinical disease
 

 
 

Broiler Mycoplasma treatment with Tiamutin in combination with compatible coccidiostats

 
 

In one trial, flocks of MG and MS infected birds were treated with either Tiamutin 0.0125% or with 0.05% Tylan. Treatment took place in the first 3 days of life and during days 28 and 29 of the growing period. Abdominal sac lesions were reduced 46% in the Tiamutin group and 38% in the Tylan group in comparison to the untreated controls.
 

This indicated a better efficacy of Tiamutin in reduction of damage to the respiratory system caused by Mycoplasma infections. (Shane, 1974)
 

 
 

Comparison of the efficacy of Tiamutin® (Tiamulin) and Tylosin in the reduction of airsac lesions due to MG and MS infections

 
 

In a second trial, flocks of MG and MS infected birds were treated with either Tiamutin 0.0125% or with 0.05% Tylan and airsac lesions and mortality were compared with an untreated control flock. In the control flock, mortality was 4.6% and the airsac lesion score was 13. Treatment took place during 5 days in the 7th week of life. Abdominal sac lesions were reduced 28% in the Tiamutin group and 6% in the Tylan group in comparison to the untreated controls. Mortality was reduced 64% in the Tiamutin group and 39% in the Tylan group. This confirmed the better efficacy of Tiamutin in reduction of damage to the respiratory system caused by Mycoplasma infections. (Laber, 1975)
 

Many other trials have been carried out, indicating performance of Tiamutin, being as good or better than controls or tylosin.

(a) Tiamutin
Prevention at a dose level of 30 ppm or 3.25 mg/kg is carried out during end of the fattening period e.g. between 21 and 35 days.
 

 
 

Broiler Mycoplasma prevention with Tiamutin in combination with incompatible coccidiostats

 
 

To evaluate the efficacy of different dose levels of tiamutin in combination with monovalent ionophores in Mycoplasma infected chicks, three trials were carried out. In the trials Monensin at 100ppm, Salinomycin at 60 ppm and Narasin at 60 ppm were applied in feed and Tiamulin at zero, 10, 20, 30, 40 and 50 ppm. In trial 1 with Monensin, Tiamutin was included up to 40 ppm only. Two subgroups of 10 one-day-old chicks were placed onto each of the treatment groups. In trial 1 at 3 weeks of age, one of the subgroups was challenged with M. gallisepticum into the airsacs. The remaining sub group was infected at 5 weeks of age. Birds were necropsied at respectively 5 and 7 weeks of age and scored for airsac lesions.
 

Mean results from the 3 trials (involving Monensin, Salinomycin and Narasin) are given in the table below.  At levels of 10 to 40 ppm tiamutin showed an increase of weight gain between 9.3 and 19.3% versus the non-Tiamulin medicated controls (average 698 grams). Tiamutin at 50 ppm showed a slight reduction in weight gain versus controls.
 

 
 

Main weight gain at various Tiamutin levels (ppm)

 
 

Airsac lesions reduced, as the level of Tiamulin increased, with a maximum of 66.9% with 50 ppm Tiamulin. There were no signs of ionophore toxicity or mortality observed in these trials.
 

 

Percentage reduction of mycoplasma lesion score with different levels of Tiamutin (ppm)

Either single Mycoplasma infections (CRD), or infections complicated with E. coli (complicated CRD or CCRD) can be treated with Tetramutin. The dosage level is 33 ppm Tiamutin combined with 100 ppm CTC/OTC and is compatible with monovalent ionophores. This practice leads to better returns due to improved feed conversion and less mortality. In the tables below, floorpen trial show the efficacy of the combination Tiamutin + CTC versus MG. Tiamutin was included in the feed in combination with 60 ppm salinomycin, during days 3-9, 17-23 and 31-37 in order to prevent clinical disease. The parameters body weight (BW), body weight improvement % (impr.%), feed conversion efficiency (FCE), air sac lesion scores (lesion), mortality (mort.), MG re-isolation percent are given comparing with untreated controls. The test clearly shows a significant improvement for all parameters with the use of Tiamutin + CTC. There were no signs of adverse reactions due to incompatibility with salinomycin.

 
 

Broiler Mycoplasma/E. coli prevention with Tetramutin in combination with incompatible coccidiostats

 
 

Tiamutin + CTC (Tetramutin) vs. Mycoplasma gallisepticum   Floorpen trials testing the efficacy of the combination Tiamutin + CTC vs. Mycoplasma gallisepticum Group Duration Body weight (BW) Impr.% BW Feed conversion efficacy (FCE) Imp.% FCE Lesion score Impr.% lesion score Mortality % MG reisolation % Untreated 6 wk. 1.33 - 2.35 - 357 - 11 29 33 ppm THF + 100 ppm CTC 18 days 1.59 16.6 2.11 10.2 95 73.5 5 3

 
 

In a second trial, the efficacy versus E. coli of a 3 day treatment with 33 ppm Tiamutin + 100 ppm CTC is compared with that of 250 ppm Tiamutin and with 50 ppm Doxycycline. The combination clearly reduces mortality % and proportion of birds, from which E. coli is isolated from the livers versus the untreated group. At these dosages, Tetramutin is at least as effective as Tiamutin and Doxycyclin.
 

 

Different treatments vs. CCRD   Artificial infection study testing efficacy of different treatments vs. CCRD Group Mortality % Number of birds in which E.coli was isolated from the liver Untreated 10 (33%) 8 THF 250 ppm 6 (20%) 5 Doxycycline 50 ppm 7 (23.3%) 6 THF 33 ppm + OTC 100 ppm 5 (16.7%) 3

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