Replacement pullets (RP’s) can be divided into replacements for commercial layers and replacements of breeder layers mainly for broilers. They have different production cycles, parameters and requirements.
Replacement pullets are not usually kept so intensively as broilers therefore the production and infection pressures are less, so preventive medication may be more widely spaced. However they are potentially exposed to infection over a much longer period and are repeatedly vaccinated to build up a strong protection against the major infections that they may encounter during the laying period.
Mycoplasma infections can be transmitted via the egg and pullets can be infected from an early age, or may be exposed to infection during their growing period, especially if they are kept near or on multi-age layer sites, which is quite common with layer producers. In some countries, active infection and sero-conversion take place much later on in life, when the birds have been transferred and undergoing the physiological and production stresses associated with point of lay and peak laying respectively.
The Tiamutin programmes, using 25mg tiamulin/kg bodyweight at strategic times, have been designed to deal with both situations, and can be adjusted to an individual flock’s requirement to take into account the health status, disease/challenge pressure/risk, density of stocking, vaccination programmes and other stressors.
Tiamutin has been shown not to interfere with the response to virus vaccination. By administering tiamulin simultaneously, it can reduce the stress of vaccination and prevent mycoplasma-associated disease complications.
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