Comparison of digestibility technical in vitro with in situ of ten fodder in cattle “rumino-fistulados” in the “Piedemonte Llanero of Meta”

Abstract

Consumption and digestibility are topics of great interest to nutritionists, as in animal foods requires high acceptance and excellent use, with low nutrient losses by excreta. Based on the foregoing, this research was conducted, at the Llanos University, Villavicencio, the main objective was to evaluate two digestibility techniques (in situ in rumen and in vitro) of six legumes, two grasses and two non-legumes shrub to which were determined digestibility of dry matter (DM), neutral detergent fiber (NDF) and total nitrogen (TN). Legumes were: Bauhinia variegata, Piptadenia (Anadenanthera) peregrina, Cratylia argentea, Brownea ariza, Gliricidia sepium and Delonix regia, the grasses: Brachiaria decumbens and Pennisetum purpureum, and non-leguminous shrub: Tithonia diversifolia and Hibiscus rosa-sinensis. The Samples were collected from of fodder of the University, the fodders were utilized 60 days after of regrowth. The dry fodders underwent a preliminary nutritional analysis, which were determined DM, NDF and TN. In the in situ tests rumen technique was used with nylon bags, each incubated 8 grams of DM feed every three replicates at each hour (6, 12, 24, 48 y 72), in two creole heifers cross fistulated at the rumen, which were in continuous grazing Brachiaria decumbens, mineralized salt and water ad libitum. In vitro tests were conducted at the Laboratory of Animal Nutrition, for this 1 g of the sample was incubated in rumen fluid for 72 hours at 38°C, and in the residue obtained were determined DM, NDF and TN. With the information was established the curve and rate of degradation of DM, NDF and NT at 6, 12, 24, 48 and 72 hours in ten forages. In the in situ test was evaluated the pH and the ammonia nitrogen (N-NH3) at 0, 6 and 12 hours in the rumen fluid. The design was an analysis of variance to determine the range of deviation between the two techniques. The variables evaluated were the average in situ and in vitro digestibility in ruminal fluid (6, 12, 24, 48 and 72) of DM, NDF and TN of the 10 forages. The results were analyzed using T-Student test for comparison between two techniques. The statistical difference (p<0.05) from the average in situ and in vitro digestibility of DM was 100% in: B. variegata, C. argentea, B. ariza, H. rosa-sinensis and G. sepium, 60% in B. decumbens, P. purpureum, Piptadenia peregrina, T. diversifolia; and in D. regia was 80%. The NDF was 100% in: B. decumbens, T. diversifolia, C. argentea, Piptadenia peregrina, B. ariza, H. rosa-sinensis and G. sepium; 80% in P. purpureum and B. variegata; and D. regia was 60%. In the TN was 100% in: C argentea, B. ariza and G. sepium; 80% in B. decumbens, P. purpureum, B. variegata, Piptadenia peregrina and D. regia; and in T. diversifolia and H. rosa-sinensis was 60%. It was also found in the 63.333% of cases a better rate of degradation by the technique of in situ digestibility. In conclusion there are statistical differences (p<0.05) between the techniques of digestibility in situ and in vitro to estimate the dry matter digestibility, neutral detergent fiber and total nitrogen in forages studied.