This research wascarried out to evaluate five non-linear mathematical models to describe lactationcurves of Nelore cows and effect of the cow and calf intake on milk yield. Inthis study we compared the models of Sikka (1950), Nelder (1966), Wood (1967),Jenkins & Ferrell (1984) and Jenkins & Ferrell (1984) with a fit parameter.Data of production were collected from 12 primiparous cows with a mean liveweight of 359 kg (± 8) and its offspring. The milk production was estimatedweighing the calf before and after suckling, from birth to 180 days of age.Measurements were made twice a day in a weekly period after 6 hour fasting ofliquid and solids. The mathematical models of Sikka, Jenkins & Ferrell,Nelder and Wood failed to describe lactation curve appropriated due to overor underestimation of milk yield peak. Better adjustement was found for themodel of Jenkins & Ferrell with a fitting parameter. Cow and calf intakeevaluated separately was no correlated with milk yield. Conversely at evaluatingboth cow and calf together, it was found a positive and a negative correlationwith milk yield, respectively. Milk yield is is closely correlated wiht cowand calf intake, and the capacity of the calf to ingest non-dairy solids resultsin reduction of milk needs from dam.
