Indicadores produtivos, fisiológicos e comportamentais de vacas mestiças criadas a pasto no brejo paraibano.

Abstract

The milk production chain is one of the most important of the Brazilian agro-industrial complex and grows at an annual rate of 5% and is superior to all countries that occupy the first places. The objective of the research was to evaluate and quantify the effects of rainy and dry periods on the production, behavior, physiological status, and milk quality of Dutch-Zebu crossbred cows under semi-intensive system in the Brejo region, Paraiba State. The experiment was performed at the Setor de Bovinocultura of the DZ/CCA/UFPB-ARE1A-PB, during four months. Ten cows were used with average live weight of 500 kg and mean age of five years. Treatments were conducted in two distinct periods, characterizing two experimental phases, one rainy season: July/August and a dry period: October/November. Environmental indicators were evaluated: air temperature (AT), relative humidity (RH). wet globe temperature index (WGT). and physiological rectal temperature (RT), surface temperature (ST), heart rate (HR) respiratory rate (RR), ingestive behavior (feeding time, rumination and leisure), production, and milk quality. The experimental design was completely randomized with two treatments and 10 repetitions. SAS software (2011) was used, with the Tukey test (P<0.05) for means comparison. The variables CFU mL"1 , %GOR, and %LAC were not influenced by evaluated periods. The variables %PRO and %SOL were higher during the dry period, influenced by the use pasture with Brachiaria decumbens. Cows did not show difference among the behavioral parameters and periods of the year, reflecting good adaptability of animals to the Brejo region of Paraiba. The WGT index, considered stressful by literary sources, did not associate to the stress condition by the animals.