Levedura Spray dry (álcool e cervejaria) na alimentação de suínos

Abstract

Six experiments were carried out to determine the nutritional values, the effects of spray dry yeast inclusion in starting, growing and finishing pigs on the performance and economic viability. The Experiment I, digestibility assays was carried out with fifteen barrow pigs, whit initial weight of 20.98 ± 7.46 kg allotted in a completely randomized design. The evaluated feeds were two spray dry yeast (sugar cane yeast- SCYSD and brewers + sugar cane yeast- BYSD). The values, as fed basis, of digestible energy (DE kcal/kg) obtained for SCYSD and BYSD, were 2.788 and 3.455 kcal/kg and metabolizable energy (ME kcal/kg) were 2.761 and 3.289, respectively. The Experiment II was carried out using 50 piglets, initial weight of 14.60 ± 1.28 kg allotted in a completely randomized design, with five treatments, five replicates and two pigs per experimental unit. The treatments consisted of five diets with increasing levels (0%, 5%, 10%, 15% and 20%) of BYSD. The inclusion of BYSD propitiated worsening the feed: gain (F:G). The Experiment III were used using 80 piglets, with initial weight of 15.16 ± 1.36 kg allotted in a completely randomized design in 5 x 2 factorial scheme, with five inclusion levels (0%, 5%, 10%, 15% and 20%) of BYSD and two physical forms of diets (meal and pellet) with, four replicates and two pigs per experimental unit. There were no interaction among the inclusion levels of BYSD and physical form. Also, no effects of inclusion levels of BYSD were observed on performance. The Experiment IV, a digestibility assays were carried out with fifteen barrow pigs, with initial weight of 55.83 ± 6.36 kg allotted in a completely randomized design. The evaluated feeds were the sames of experiment I the values, as fed xiii basis, of DE obtained for SCYSD and BYSD, were 3.496 and 3.901 kcal/kg and ME (kcal/kg) were 3.475 and 3.862, respectively. In the experiment V an ileal digestibility assays was carried out to determine the coefficient apparent and true ileal digestibility and digestible amino acids were out using three pigs with initial weight of 46.3± 2.12 kg, previously submitted to the surgery for simple T canula implantation. The treatments consisted of one diet without protein and two diets of SCYSD and BYSD, being the only protein source. The values of digestible amino acids of SCYSD and BYSD (lysine: 2.66 and 2,64; methionine+cistine: 1.11and 1,03 and threonine: 1.95 and 1,92, respectively) were used in the diet of experiment six. The values of digestible essential amino acids for SCYSD were used for amino acid composition of meals. In the Experiment VI were used 40 pigs (barrow and gilts), with initial weighing of 34.39 ± 7.57 kg in growing phase and 77.47± 6.28 kg in finishing phase, respectively allotted in a completely randomized design, with five treatments, four replicates and two pigs per experimental unit. The five inclusion levels (0%, 5%, 10%, 15% and 20%) of SCYSD were evaluated. In the growing phase, the inclusion of SCYSD propitiated worsening the daily weight gain (DWG) and fed:gain ratio (F:G). The DWG and the F:G presented difference among 20% levels of inclusion when compared with 0%. The finishing phase, presented a quadratic effect being 3.32% the better inclusion level. The DFI presented difference among levels 15% and 20% of inclusion when compared with 0%. There was a linear reduction of DWG, F:G, slaughter weight, hot carcass weight (HCW), cold carcass yield and ham weight according to SCYSD inclusion. The DWG, F:G and HCW presented differences between level 20% when compared to level 0%. The results suggest the inclusion level of 20% of BYSD in nursery piglets in form meal our pellet, without impairing performance, however, in growing and finishing phase the inclusion level of sugar cane yeast harm performance. However the economic feasibility of spray dry yeast utilization will depend on feedstuffs prices.