Utilização de fenos de euforbiáceas na ensilagem de palma forrageira miúda

Abstract

This study aimed to evaluate the losses and fermentation profile, nutritional value, aerobic stability and microbial population counts of mixed silages of small cactus forage in association with different levels of pornunça hay. Thus, this study used a completely randomized experimental design, with five treatments and five replicates, totalling 25 experimental mini- silos. The treatments consisted of inclusion levels of pornunça hay in small cactus forage silage at levels of 0, 7.5, 15.0, 22.5, and 30.0% based on natural matter. The mini-silos were made of polyvinyl chloride (PVC) material (10 cm in diameter and 30 cm in length) provided with a Bunsen valve, in order to reach a density of 700 kg/m³ and stored for 120 days until further evaluations. The data obtained were evaluated by linear and quadratic orthogonal contrasts at the 5% significance level for type-I error. There was an increasing linear effect on DM (P<0.001) and quadratic effects on MM (P<0.001), CP (P<0.001), EE (P = 0.003), NDF (P<0.001), FDA (P<0.001), hemicellulose (P<0.001) and NFC (P = 0.006) contents as the hay from the upper third of the pornunça was included in the small cactus forage silages. Despite this, the TC contents were not influenced by the inclusion of hay from the upper third of the pornunça in the small cactus forage silages (P>0.05). The pH values (P<0.001) decreased linearly, while the N-NH3 concentrations (P<0.001), as well as the acetic acid (P = 0.045) and lactic acid (P = 0.002) contents were quadratically influenced by the inclusion of hay from the upper third of the pornunça in the small forage cactus silages. There was no effect of the inclusion of hay from the upper third of the pornunça on the lactic acid bacteria counts, maximum and minimum temperatures in the silages, as well as on the breakdown of aerobic stability in the small cactus forage silages (P>0.05). On the other hand, the thermal amplitude (P = 0.040) and forage losses (P<0.001) were quadratically influenced by the inclusion of hay from the upper third in the small cactus forage silages. The efluente losses (P<0.001) and dry matter recovery (P<0.001) were influenced linearly, while gases (P<0.001) and total (P<0.001) losses were influenced quadratically by the inclusion of hay from the upper third of the pornunça in small cactus forage silage. From the data found in the present experiment, considering the values for the fermentation profile, fermentation losses, aerobic stability and nutritional quality of the silage, it can be generally concluded that it is possible to include up to 30% of pornunça hay in the small variety forage cactus silage. However, when considering the density of the ensiled material and the forage losses, it is recommended to include up to 21.2% of pornunça hay to reduce the forage losses in the small variety forage cactus silage. It is concluded that treatment three with the inclusion of 15% hay in the small forage cactus silage presented significant values of crude protein in the dry matter equivalent to 15.72%. It is considered the most appropriate from an economic point of view for the formulation of a balanced diet for small ruminants. Therefore, This level of inclusion meets the nutritional needs of the category and allows for weight gain of between 150 and 200 g per day.