Avaliação do líquido da casca da castanha de caju e quitosana como aditivo para ruminantes

Abstract

The objective of this study was to evaluate the isolated effect or the association of cashew nut liquid (CNSL) and chitosan as natural additives modulators of bovine ruminal fermentation. Ruminal fluid was collected from two lactating dairy cows, adults, castrated males, with a mean weight of 350 kg ±, distributed in a completely randomized design. The formulated diet was composed of Tifton 85 hay (Cynodon spp), representing the forage fraction and maize (49.72%), soybean meal (40.05%) and mineral supplement (10.23%) as concentrate. Supplied in the following relation forage: concentrated (V: C): 20:80; 35:65; 50:50; 65:35 and 100: 00. The additives were added in the proportions: 500 mg/kg CNSL DM; 500 mg/kg of chitosan DM; 200 mg monensin kg/DM (positive control) and association between chitosan and CNSL (500 + 500 mg/kg DM, respectively), randomly distributed in a completely randomized design. The in vitro digestibility of the OM, DM, CP, NDF, ADF and DHCEL were evaluated. The linear effect of the relations forage:Concentrated hips on IVDMD and IVDMD and quadratic effect on IVDF was observed. The effect of the additive and the F: C was verified for IVDMD; IVDOM and IVDCP. Interaction between V: C and the additive on IVDNDF, IVDADF and DHCEL was observed. In vitro samples were collected at intervals of 2 hours at 0, 2, 4, 6, 8 and 10 h after incubation ("hour 0") for analysis of pH and ammoniacal nitrogen and at 0.2 times , 4.8 of AGCCC. The inclusion of the natural additives maintained the pH above 6.0 and the minimum ammonium concentration of 10.67 mg/dL, respectively. The interaction between the V: C ratio and the additive on the concentration of the production of acetic acid, propionic acid and butyric acid was verified. The C2: C3 ratio was higher with the inclusion of the monensin antibiotic. The gas production akinetics were evaluated for parameters A (fast gas / g / g gas production), parameter B (rate of production of the fraction A / h-1), parameter C (lag time / hours), (D / h-¹ fraction) and cumulative gas production (A + D), parameter D (gas production of the slow fraction / mL gas / g). Significant effect of the additives was verified in parameter C; Of the relation V: C for the parameters A, C, D and A + D; And significant interaction of the main factors V: C and additive in the parameter A + D. The inclusion of cashew nut liquid and chitosan as additive modulators of ruminal liquid fermentation showed positive results allowing its use as an alternative to the use of ionophore antibiotics in ruminant feed. However, the inclusion of cashew nut liquid associated with chitosan did not provide satisfactory effects on nutrient digestibility. The reduction in digestibility may be related to the amount of the dose and / or the inhibitory activity of these compounds. Therefore, it is necessary that furtherstudies be performed to identify the optimum dose of the association of these two additives in bovine feed.