Palma forrageira como aditivo para silagem utilizadas na alimentação de ruminantes

Abstract

This study involved three experiments. In the first, the objective was to identify the optimal level of ideal forage cactus in the mixture that provides a good microbiological profile, as well as reducing losses during the ensiling process, optimizing dry matter recovery and aerobic stability of mixed silages. The experimental design consisted of a completely randomized design, consisting of five treatments and four replications. The treatments were represented by the inclusion of spineless cactus in the forage sorghum silage: 0; 25; 50; 75 and 100% of forage cactos in the natural matter of the mixture. There was an increasing quadratic effect (P < 0.05) on lactic acid bacteria counts (LAB) and dry matter recovery (DMR), estimating maximum values at levels of 51.8 and 33.5% of forage cactus in the silage. However, there was a decreasing quadratic effect (P < 0.05) for gas losses (GL), with the lowest value being estimated at the level of 37.9% of forage cactus in silage. There was an increasing linear effect (P < 0.05) for effluent losses (EL), time in which the silages reached the maximum temperature (TMT), aerobic stability (AS) of the silages and in the levels of ether extract (EE) and non-fibrous carbohydrate (NFC). However, there was a decreasing linear effect (P < 0.05) on mold count, maximum silage temperature (MT), dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) contents of the silages mixed. When using the forage cactus in the confection of mixed silages with sorghum, it is recommended the 50% level of forage cactus, optimizing the recovery of dry matter and aerobic stability, without affecting the nutritive value of the silage. The second experiment aimed to evaluate the effects of forage cactus as humidifier additive on fermentative, microbiological, aerobic stability, chemical composition and In situ ruminal degradability of corn grain silage at different opening times. The experimental design consisted of a completely randomized design in a 4 × 3 factorial scheme was used, consisting of four levels of dry matter (DM) (50; 60; 70 and 80% DM) and three opening periods (30; 60 and 120 days after ensiling). There was an interaction effect (P < 0.05) between DM levels of maize grain silage rehydrated with forage cactus and the opening periods on the silage yeast population, effluent losses (EL), gas losses (GL), dry matter recovery (DMR), aerobic stability (AS) and forage cactus levels on lactic acid bacteria (LAB) populations, molds and yeasts, after the AS test. The DM In situ degradability of the ensiled mass increased after the ensiling process at all levels and opening periods evaluated. When using forage cactus as a humidifying additive for corn grain, the 60% DM level is recommended when the permanence time of the ensiled mass in the silo is equal to or less than 120 days and 70% DM when it is 120 days after the silage. In the third experiment, the objective was to evaluate the fermentative characteristics of silage total mixed ration based on forage cactus and cotton cake and its effect on the productive performance and ingestive behavior of sheep in confinement. The study was divided into two experimental trials, both distributed in a completely randomized experimental design. The first experimental trial evaluated the fermentative quality of silages total mixed ration (TMR), with five repetitions per treatment, and the second evaluated the productive performance and ingestive behavior of the sheep, with eight repetitions per treatment, with the treatments represented by the pie proportions of cotton cake in the TMR (0; 20; 25 and 30% cotton cake, based on dry matter). There was a significant difference (P < 0.05) between the TMR for yeast population, pH, gas losses (GL), efluente losses (EL), dry matter recovery (DMR), ether extract intake (EEI), dry matter digestibility (DMD), organic matter (OMD), crude protein (CPD), ether extract (EED), neutral detergent fiber (NDFD), non-fibrous carbohydrate (NFCD), total digestible nutrients (TDN) and for all ingestive behavior variables, except for feeding. Thus, forage cactus ensures the fermentative and hygienic quality of the silages in the form of feed, regardless of the proportions of cotton cake. Therefore, based on the productive performance and ingestive behavior of Dorper sheep feedlot, it is recommended silage as feed with 30% cotton cake.