RESUMO Foram conduzidos dois experimentos com o objetivo de determinar o valor nutricional e avaliar o desempenho e características da carcaça de suínos alimentados com farelo de canola (Brassica napus). No Experimento I, foi conduzido um ensaio de digestibilidade total com 14 suínos mestiços de linhagem comercial, machos castrados, com 60,69 ± 4,26 kg de PV inicial. O alimento teste farelo de canola (FC), substituiu em 25% a ração referência à base de milho e farelo de soja. Cada suíno constituiu uma unidade experimental, totalizando sete unidades experimentais por ração. Os valores de energia digestível (ED) e energia metabolizável (EM) na matéria natural para o FC foram de 2995 kcal/kg e 2796 kcal/kg, respectivamente. No Experimento II, foram utilizados 50 suínos mestiços, com peso vivo inicial de 29,90 ± 1,16 kg e final de 60,33 ± 3,38 kg, na fase de crescimento, e peso vivo inicial de 60,37 ± 1,6 kg e final de 90,37 ± 3,19 kg na fase de terminação. Foi utilizado o delineamento de blocos inteiramente casualizados, com quatro tratamentos, (6, 12, 18 e 24% de FC), com 10 repetições e um suíno por unidade experimental. Adicionalmente, foi formulada uma ração testemunha, contendo 0% de FC. Os dados foram submetidos à análise de variância e adicionalmente foi aplicado o Teste de Dunnett, e análise de regressão, a 5% de probabilidade. Os resultados sugerem que é possível incluir até 24% de FC nas dietas de suínos, em crescimento e terminação, sem prejudicar o desempenho e as características da carcaça.

ABSTRACT Two experiments were performed for the purpose of determining the nutritional value and assess the performance and carcass traits in pigs fed on canola meal (Brassica napus). Experiment I consisted of a total digestibility trial conducted with 14 castrated commercial crossbred male pigs with 60.69 ± 4.26 kg initial live weight. The treatments consisted of a control diet based on maize and soybean meal and another diet containing canola meal (control + 25% canola meal). Each pig was an experimental unit, totalling seven experimental units per diet. The digestible energy and the metabolizable energy of canola meal used was 2,999 and 2,730 kcal.kg-1, respectively. These values were used to formulate the diets of the performance experiment. Experiment II included 50 crossbred pigs with an average initial live weight of 29.90 ± 1.16 kg and an average final live weight of 60.33 ± 3.38 kg during the growing phase, and an average initial live weight of 60.37 ± 1.6 kg and an average final live weight of 90.37 ± 3.19 kg during the finishing phase. The experimental design consisted of randomized blocks, with four treatments (6, 12, 18, and 24% canola meal), 10 repetitions, and one pig per experimental unit. The control diet was formulated with 0% canola meal. The data were assessed using ANOVA test and the averages of the treatments were compared using Dunnett's test and regression analysis at a 5% probability level. The results suggest that it is possible to use up to 24% canola meal in the diets for pigs during the growing and finishing phases without affecting the performance and carcass traits.

Two experiments were carried out to evaluate the reduction of crude protein (CP) in diets supplemented with synthetic amino acids for piglets of 15 to 30 kg. In the performance assay (Exp I), 60 piglets with initial weight of 15.34±0.87 kg and final weight of 30.08±1.59 kg were distributed in a randomized block design with six replicates, five treatments and two animals per experimental unit. The treatments consisted of five diets in which the CP was reduced by 1.5 percentage points, resulting in low-protein diets (19.24, 17.74, 16.24, 14.74 and 13.24%), meeting the requirements of amino acids with inclusion of L-lysine, DL-methionine, L-threonine, L-tryptophan, L-valine and L-isoleucine. The average daily gain and feed conversion according to the Linear Response Plateau model (LRP) were estimated at 14.23 and 14.79% of CP, respectively. As the CP levels were reduced, there was an increase in the essential:non-essential amino acids ratio. The plasma urea concentration decreased linearly, indicating that there was a better use for amino acids with the CP reduction. In the nitrogen balance (Exp II), 30 crossbred barrow piglets with average weight of 21.69±4.46 kg were housed in metabolic cages, distributed in a completely randomized design with five treatments and six replicates, and the experimental unit consisted of a piglet. The biological protein value in the diets remained above the ideal (70%), in which the level of 13.24% CP corresponded to the highest value. There was no difference in levels of urea in blood and urine. Reduction of protein levels is efficient in decreasing the pollution effect in the excreta, with lower nitrogen excretion in feces and urine.