where Yt is dependent variable (test-day milk yield), a is parameter connected with average test-day milk yield, bis parameter determining the slope of the increasing part of the function, c is parameter determining the slope of the decreasing part of the function and t is number of days after calvin
Modeling lactation curve standards for test-day milk yield in holstein, Brown Swiss and simmental cows (PDF Download Available). Available from: https://www.researchgate.net/publication/285936241_Modeling_lactation_curve_standards_for_test-day_milk_yield_in_holstein_Brown_Swiss_and_simmental_cows [accessed May 2, 2016].