We present U and B galaxy differential number counts from a field of \sim 900 arcmin ^ { 2 } , based on GOYA Survey imaging of the HST Groth-Westphal strip .
Source detection efficiency corrections as a function of the object size have been applied .
A variation of the half-exposure image method has been devised to identify and remove spurious detections .
Achieved 50 % detection efficiencies are 24.8 mag in U and 25.5 mag in B in the Vega system .
Number count slopes are d \log ( N ) / dm = 0.50 \pm 0.02 for B =21.0-24.5 , and d \log ( N ) / dm = 0.48 \pm 0.03 for U =21.0-24.0 .
Simple number count models are presented that simultaneously reproduce the counts over 15 mag in U and B , and over 10 mag in K _ { s } , using a \Lambda -dominated cosmology and SDSS local luminosity functions .
Only by setting a recent { z _ { f } } \sim 1.5 formation redshift for early-type , red galaxies do the models reproduce the change of slope observed at { K _ { s } } = 17.5 in NIR counts .
A moderate optical depth ( \tau _ { B } = 0.6 ) for all galaxy types ensures that the recent formation for ellipticals does not leave a signature in the U or B number counts , which are featureless at intermediate magnitudes .
No ad-hoc disappearing populations are needed to explain the counts if number evolution is introduced using an observationally-based z -evolution of the merger fraction .