Efeitos de três estratégias de aleitamento sobre ganho de peso, desenvolvimento ruminal e perfil metabólico e hormonal de bezerros holandeses

Abstract

The effects of three milk feeding strategies were evaluated in 54 Holstein calves. Water and starterwere provided at all times. Milk feeding strategies were: 4L-60d (four liters 500 g of milkreplacer/day during 60 days); 6L-29d/4L-60d (six liters 750 g of milk replacer/day on the first 30days and four liters 500 g of milk replacer/day from 30 to 60 days old) and 6L-60d (six liters 750g of milk replacer/day during 60 days). Weaning was abrup at 60 days old.Six calves in each groupwere euthanized at 30, 60 and 90 days old. A completely randomized design was used for statisticalanalysis. Starter intake, weight, weight gain, stomachs and organs weight were analyzed in a factorialmodel and hormones/metabolites with random and repeated methods of a mixed procedure;meanstested with SNK (P=0.05).Initial weights and passive immunity werent different (P>0.05). During thefirst month, milk replacer consumption was less than the quantity offered. Starter intake was notdifferent between groups (P>0.05) and increased with age (P<0.05). Weight gain was higher in group6L-60d (P<0.05). Weight gain increased each week, except on week two because of diarrhea, andweek five only in group 6L-29d/4L-60d because of the reduction in milk replacer allowance. Glucose,NEFA and IGF-1 werent influenced by milk feeding strategy (P>0.05). Insulin concentration washigher in group 6L-60d (P<0.05). Glucose and insulin got higher and NEFA lower with age (P<0.05).Ruminal development was similar between groups. Strategy 6L-60d resulted in higher weight gain andfeed efficiency, without reduction of starter intake and ruminal development.