Cinética de degradação in vitro de diferentes cultivares de trevo vesiculoso

Abstract

In the southern region of Brazil, where the typical climate is lower temperatures, temperate grasses and legumes adapt better. The latter, in turn, have high protein value and are essential food alternatives to increase the nutritional value of pastures. Thus, evaluating the in vitro degradation kinetics, as well as the volume of gas produced, pH and ruminal ammonia levels, are important for the nutritional knowledge of legumes. The present study aimed to evaluate the volume of gas produced at different times of in vitro incubation, evaluate dry matter degradation and evaluate the pH and ammonia of different cultivars of bladder clover. The cultivars evaluated were: BRS Piquete, Zulu, and genotypes 1100, 1109, 1110, provided by Embrapa Clima Temperado. Three tests were conducted in the laboratory, using 100 mL bottles with 0.5 grams of sample incubated with ruminal fluid and artificial saliva for 120 hours. Two replicates per cultivar were used in each trial. Additionally, another trial was conducted, where at 48 h of incubation, the incubation was interrupted and aliquots were collected for determination of pH and ruminal ammonia. For ammonia and pH, the average value obtained was 13.72 mg/dl and 6.87, respectively. The volume of gas obtained varied between 92.05 mL/mg DM and 96.34 mL/mg DM, with an average degradation rate of 3.93%/hour. The volume of gas produced and the degradation rate found demonstrate the quality of the feed tested in the experiment, concluding that the degradation of bladder clover provides sufficient ammonia for bacterial synthesis to occur, in addition to providing conditions for microbial growth.