The objective was to evaluate the impact of producing piglets fed diets with different crude protein (CP) levels through life cycle assessment and experimental data. In Trial I (performance), 28 crossbred barrow piglets, with an initial average weight of 15.3 ± 1.15 kg were divided into a randomized block design with four treatments, seven replications and one animal per experimental unit. In Trial II (nitrogen and phosphorus balance), 20 crossbred barrow piglets with an average weight of 21.4 ± 1.62 kg were divided in a randomized block design with four treatments, five replications and one animal per experimental unit. Four experimental feeds were evaluated: HighCP, CP18, CP17 and LowCP, with 19, 18, 17 and 16 % of CP, meeting the requirements of digestible amino acids through industrial amino acid (IAA) addition. From Trial I and II data, the environmental impact was calculated for global warming potential, acidification potential, eutrophication potential, cumulative energy demand, terrestrial ecotoxicity and land occupation (LO). Total nitrogen excretion decreased by 0.226 g d -1 for each 1 g of reduction on daily nitrogen intake. However, there was no statistical difference (p > 0.05) among experimental treatments for all impact categories. For LO, there was a reduction (p = 0.078) of impact with CP reduction, which was 8 % lower with the LowCP diet, in comparison with HighCP. Dietary CP reduction for piglets from 15 to 30 kg, through IAA supplementation, reduced the environmental impact under LO, considering soybean meal from southern Brazil and observed individual data of performance and excretion.

The digestible amino acid (AA) determination of ingredients, or experimental diets, are essential in obtaining the real levels of AA that are being studied, as well as of other indispensable AA, because the lack of a single indispensable AA may limit pig growth performance. Two experiments were conducted to determine the optimum levels and the ideal ratio of standardized ileal digestible (SID) Trp and Lys for barrows from 15 to 30 kg of live weight. The first experiment (Exp. 1) was conducted to determine the SID AA content of the basal diet used in the growth performance study (Exp. 2). Ten crossbred barrows (21.57 1.6 kg live weight) were used in Exp. 1. Pigs were fed a basal diet and a protein free diet to determine the SID of Trp, Lys, and all other indispensable AA of the basal diet. In Exp. 2, 64 barrows (15.0 71.6 kg) were allotted to 16 diets in a 4 Â 4 factorial arrangement of treatments (1.55, 1.85, 2.15, and 2.45 g SID Trp and 9.72, 11.12, 12.52, and 13.92 g SID Lys/kg) with 4 replications per treatment. In both Exp. 1 and 2, each pig was considered as an experimental unit. Growth performance, Longissimus muscle (LM), backfat thickness, and plasma urea nitrogen (PUN) were evaluated. Average daily feed intake and average daily gain increased linearly (Po 0.05) with increasing levels of SID Trp. There was a quadratic effect (P¼ 0.04) of dietary SID Trp and Lys levels on the gain:feed, and the optimal levels were estimated to be 2.1 (0.65 g/Mcal ME) and 11.98 g/kg (3.71 g/Mcal ME), respectively, resulting in a SID Trp:Lys of 17.5:100. A quadratic effect of SID Trp (P¼ 0.021) and Lys (P ¼0.026) levels on LM was observed, and the optimum levels were 2.08 and 11.36 g/kg diet, respectively, with a Trp:Lys of 18.3:100. The amount of PUN decreased linearly (P¼ 0.004) as SID Lys increased. For pigs used in our study (between 15 and 30 kg live weight), the SID Trp and SID Lys requirements are 2.10 and 11.98 g/kg, respectively. The corresponding Trp:Lys are 17.5:100.

The metabolizable energy (ME) determination for foods used in quail diets, through metabolism assays, takes time, infrastructure and financial resources, which makes the development of prediction equations based on proximal composition of foods to estimate the ME values of particular interest. The objective of this study was to adjust the prediction equations of metabolizable energy (ME) of corn for quail. The chemical compositions of 12 maize varieties were determined and a metabolism assay was carried out in order to determine the apparent metabolizable energy (AME) and nitrogen-corrected apparent metabolizable energy (AMEn) of these corn varieties. The values of chemical composition, AME and AMEn, converted to dry matter, were used to adjust the prediction equations. The initial adjustment of simple and multiple linear regression of the AME and AMEn was performed using the values of crude protein (CP), ether extract (EE), neutral (NDF) and acid (ADF) detergent fiber, mineral matter (MM), calcium (Ca) and phosphorus (P) as regressors (full model). To adjust the prediction equations the statistical procedure of simple and multiple linear regression was used, with the technique of indirect elimination (Backward). There was adjustment of 10 prediction equations, in which 5 were for AME and another 5 for AMEn and the R² values ranged from 0.20 to 0.75 and from 0.21 to 0.78, respectively. For all adjusted equations, negative correlations for MM were observed, which may be related to its dilutive effect of the gross energy contained in corn. In conclusion, the equations that showed better adjustment were AME= 5605. 46 -385 alimentos. Objetivou-se com este trabalho ajustar equações de predição dos valores de EM do milho para codornas de corte. Foi determinada a composição química de 12 diferentes cultivares de milho e realizado um ensaio de metabolismo, com estas cultivares, para determinação da EM aparente (EMA) e EMA corrigida para balanço de nitrogênio (EMAn).De posse da composição química, e dos valores de EMA e EMAn, convertidos para a matéria seca, procedeu-se com o ajuste das equações de predição. O ajuste inicial dos modelos de regressão linear simples e múltipla, dos dados de EMA e EMAn, foi realizado utilizando-se os valores de proteína bruta (PB), extrato etéreo (EE), fibras em detergentes neutro (FDN) e ácido (FDA), matéria mineral (MM), cálcio (Ca) e fósforo (P) como regressoras (modelo completo). Para o ajustamento das equações de predição, dos valores de EMA e EMAn, foi utilizado o procedimento de regressão linear simples e múltipla, por meio da técnica de eliminação indireta (Backward). Houve ajustamento de 10 equações de predição da EM do milho, sendo 5 para EMA e 5 para EMAn, cujos valores de R² variaram de 0,20 a 0,75 e de 0,21 a 0,78, respectivamente. Em todas as equações ajustadas observouse correlação negativa para a matéria mineral, o que pode estar associado ao seu efeito diluente da energia bruta contida nos milhos. Conclui-se que as equações que apresentaram melhor ajustamento foram...

Two experiments were carried out to determine the nutritional value of neutralized semi-purified glycerin (NSPG) and to evaluate the performance of pre-starting piglets (6-15 kg) fed on diets containing increasing levels of NSPG. In Experiment I, a digestibility trial with 30 barrows (11.80 ± 5.12 kg live weight) was conducted, in which they were allotted in a randomized block design. Replacement levels of the basal diet by NSPG were 3, 6, 9, and 12%. The values (as-fed-base) of digestible energy (DE) and metabolizable energy (ME) of NSPG were 3535 and 3279 kcal/kg, respectively. In Experiment II, 135 piglets, weaned at 21 days of age (6.85 ± 1.28 to 15.04 ± 2.06 kg), were allotted in a randomized-block design. Treatments consisted of five diets (3, 6, 9, and 12% NSPG as well as a control diet with 0% of NSPG), with nine replications, and three piglets per experimental unit. The results show that, in the pre-starting I (6-10 kg) phase, adding NSPG promoted a linear improvement in the average daily gain (ADG) and the feed-to-gain ratio (F:G). For the total period (6-15 kg), only linear improvements (P ≤ 0.05) to ADG were observed. The plasma variables were not influenced (P ≥ 0.05) by the inclusion of NSPG, as it remained within the biological range of the species. The results suggest that up to 12% NSPG can be included in the diets of piglets (6-15 kg) without impairing the plasmatic variables, performance, and economic feasibility. Key words: Biodiesel, co-product, piglet, performance ResumoForam conduzidos dois experimentos com o objetivo de determinar o valor nutricional da glicerina semipurificada neutralizada (GSPN) e avaliar o desempenho de suínos na fase pré-inicial (6 a 15 kg), alimentados com rações contendo níveis crescentes de GSPN. No Experimento I, foi conduzido um ensaio de digestibilidade com 30 leitões machos castrados (11,80 ± 5,12 kg), distribuídos em um delineamento em blocos casualizado. Os níveis de substituição da ração referência pela GSPN foram 3, 6, 9 e 12%. Os valores (na matéria natural) de Energia Digestível (ED) e Energia Metabolizável (EM) (3, 6, 9, 12% de GSPN e uma ração testemunha com 0% de GSPN), com nove repetições e três leitões por unidade experimental. Os resultados demonstram que na fase pré-inicial I (6 a 10 kg) a adição de GSPN promoveu melhora linear no ganho diário de peso (GDP) e conversão alimentar (CA). Para o período total (6 a 15 kg), foi observado apenas melhora linear (P ≤ 0,05) para GDP. As variáveis plasmáticas não foram influenciadas pela inclusão da GSPN. Os resultados sugerem que a GSPN pode ser incluída em até 12% em rações para leitões (6 a 15 kg) sem influenciar as variáveis plasmáticas, de desempenho e as variáveis econômicas.

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