Autoria: THOLON, P.; PATERNO, F.; QUEIROZ, S.

Resumo: The use of growth functíons allows the stuclyof animal growth in adujthood, enabtíng the cOrTeJation between weíghts at different agesand attainmentof adutts with smalter size (A), a higher rate Df weight gain (KJand younger age at lhe inflectton point (K-1J. The selection criteria for gmwth in Nellore cattJe has changed ín 1hejast years. .iCCordíngto the demands of 1heconsumer marfc~ providing differenl patterns within the breed. The objective of th ís study was to determine the evolutíon of the growth pattern Df Netl.orecattte ~ístered at the 8razitían Association of Zebu Breeclers,born ín 1995, 2000 and 2005.. For this purpose it was determined the mean vatuesof A, scale para meter(8), K and 1heínftection point (M) which índicatíves 1heonset Df puberty, usíng the nonl.ínearmodel Ríchards.The averageasymptotic weíghl for animais bom in 1995, 2000 and 2005 were 844.8, 769.9 and 537.9 kg..respecrívely.The b values were 0.9927, 0.9928 and 0.9498, r~ve.ly. Values of K were 0.000533, 0.000645 and 0.00149 wi1h age and me inflecttoo point of aoout 59..6,49..2 and 213 months. M vatues were 0.7231, 0.7205 and 0.8983 for the three birth years considered.The cOrTelatíonsbetween A and K, A and M and K and M were equat to -0.99, -0.95 and 0.97 ín the three periods, showing the strong dependence between lhe parameters. It can be seen that a clear differentiation occurred in the growth pattern of lhe animaIs over time..The searchfor sexual precocíty Veftfied by k-1 was effective in reducing by half the age of onset Df puberty, besides the production of adult animais best suited to lighter proouction systemso( Nellore cattle.

Ano de publicação: 2012

Tipo de publicação: Resumo em anais e proceedings

Unidade: Embrapa Pecuária Sudeste

Palavras-chave: Growth pattern, Race Nellore