Efeito da estratégia de desmame sobre a resposta hematológica, anti-helmintica e o desenvolvimento de bezerras da raça nelore (Bos indicus)

Abstract

Weaning is characterized by cessation of breastfeeding to stimulate rumen development of calves. In the system of traditional weaning, calves are subjected to vaccination, worming, branding, transportation and change of ownership, and become non infants causing high levels of physical and mental stress to immunosuppression and increased susceptibility to diseases and decreased performance animal. This work aimed to develop techniques and strategies to reduce stress after weaning and improve hematologic response, anthelmintic and weight development of Nelore created under extensive in Maranhão. We used 76 calves were divided into two experimental groups (Pre-stress and stress) of 38 animals were subjected to blood collection, feces, weighing, vaccination, worming and transportation to change farm. The parameters studied were complete blood cell count of eggs per gram of feces (EPG), blood biochemistry and weight development. Statistical analysis was performed using the software Statistical Analysis System for Windows (SAS ®, 2001). In weight development, both in average daily gain (ADG) and the total weight, the treatments applied in the two groups and the five weight measurements carried no effect on weight gain in calves. In the EPG no significant difference between groups and between treatments, with the exception of the second collection (Weaning) where there was an increase in the number of stress EPG group (406.75 ± 116.4) and a smaller variation in the group pre-stress (258.11 ± 69.1). Regarding the complete blood count, there was no significant difference between treatments (P> 0.05) in the five periods studied in both groups. However, the total leukocyte count of the two experimental groups showed leukocytosis in all periods. In sanguineous biochemist, while also no significant differences between the treatments (P> 0.05), both total protein values as albumin are lower than the reference values and calcium and phosphorus in higher levels. The results revealed that weaning strategy proved to be inefficient, because the two groups responded similarly to treatment they have undergone.