Avaliações do comportamento e de estratégia alimentar de vacas leiteiras em sistema compost barn

Abstract

Good health of dairy cows is essential for successful production. Due to this, the use of technologies and food strategies in dairy farms has been growing, in order to make the system more efficient, improving management, reducing losses and increasing profitability. With this, the objective of the study was to evaluate the behavior and a feeding strategy of dairy cows in a compost barn system, through behavioral monitoring systems. In study 1, the objective was to evaluate the behavior and predict the dry matter intake (DMI) of Holstein cows in each lactation period up to 150 days in lactation (DIL), in compost barn. For this, a database of 139 cows was divided into 3 groups according to DEL: Group 1 (0 to 21 DEL), Group 2 (22 to 90 DEL) and Group 3 (91 to 150 DEL). Animal behavior data from automated collars, consumption and feeding behavior through automatic feeders and milk performance were evaluated, which were used to evaluate how each variable of the study behaves according to the lactation period and to predict DMI from of a multivariate linear regression model. DMI (P<0.01) and rumination time (P=0.04) increased up to 150 days in lactation, idle time (P=0.01) decreased. Group 2 had a shorter consumption time and meal frequency, and a higher consumption rate. As well as increased milk production and feed efficiency. In each group, a DMI prediction model was built, however, in all periods, time and consumption rate were variables used in the equations as DMI predictors. It is concluded that for Holstein cows in compost barn, feeding behavior variables are strong predictors of DMI and within each period there was a model that best adjusted to predict DMI, among the studied variables.In study 2, 20 lactating Holstein cows were randomly assigned to one of two groups (n = 10 each): a standard concentrate with milled corn as energy source (Control) or an experimental concentrate with sweet potato flour (SPF) replacing the ground corn. In order to evaluate the effect of replacing ground corn with SPF in the diet of lactating cows on milk performance, metabolism and feeding behavior. Measures of milk production and quality, DMI, feeding behavior and blood metabolites were evaluated. Milk production and composition were not affected by dietary treatments. There was no difference between treatments in the DMI, but the total time in the troughs (P<0.01), feeding time (P<0.01) and meal duration (P<0.01) were lower for the SPF group, different from the feeding rate (P<0.01), which was higher. Activity time (P<0.01) and rumination time (P<0.01) were higher and lower for the SPF group, respectively. Serum urea concentration (P<0.01) was higher for SPF compared to control. In conclusion, ground corn can be replaced by SPF without impairing the performance, feeding behavior and metabolism of dairy cows.