Sistemas de aleitamento convencional e fracionado na criação debezerros leiteiros

Abstract

Experiments were performed to evaluate the effect of feeding systems and conventional fractionated in creating Holstein calves. Initially aimed to evaluate intake, performance and incidence of days of diarrhea, in addition to performing technical-economic analysis of the two systems. 22 animals were used, with an average initial body weight of 37.26 kg (±3.42), with 12 males and 10 females were housed in individual pens until 59 days of age were distributed in a randomized block design. Breastfeeding conventional consisted of four liters of milk daily for 59 days and fractionated, six liters of 6° to 25°, four liters of 26º to 45º and two liters of 46º to 59º days old, and concentrated, hay Cynodon sp., water and mineral supplement provided ad libitum. The food intake and the incidence of days with diarrhea were monitored daily and animals weighed and measured weekly. Consumption data, daily weight gain, measures of growth, feed conversion and days with diarrhea incidence were analyzed in split plot. The total gain and the initial and final body weight were analyzed in a randomized block design. The initial body weight was used as a covariate. The nursing system did not affect (p>0.05) in consumption, hay, in mean weight gain, total gain and final body weight. Breastfeeding fractionated total consumption resulted in higher dry matter (p0.05) in the third period and lower cost per kilogram of total weight gain, indicating it as a strategy in dairy cattle. Subsequently, to evaluate the effect of feeding systems on rumen development and weight of internal organs, the 12 male calves, with average initial body weight of 37.0 kg (±4.21) were slaughtered at 60 days of age. Were weighed digestive tract and internal organs, and histologic measurements of papillae and rumen epithelium. The nursing system fractional provided higher (p0.05) intakes in the third period of evaluation, hay and total dry matter, and higher absolute weights of the digestive tract, intestines and omasum omasum and relative weights, large intestine, and the mitotic index of ruminas papillae. The final body weight, final body weight and proportions of empty compartments of the digestive tract as well as the weights of the rumen-reticulum, abomasum and internal organs of the animal, except for the heart, were not affected (p>0.05) by the systems. The nursing system can be fractionated alternative to improve rumen development of calves, and does not change the evaluations of internal organs, except the heart.