ABSTRACT: 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.

ABSTRACT The objective of this paper was to investigate the availability of betaine present in fine wheat bran (FWB) in diets for growing pigs. We used thirty crossbred intact males, housed individually in metabolic cages and distributed in a randomized block design, with five treatments and six replicates. Blocks consisted of two periods of 15 days. Average initial body weights were 32.00±1.30 and 44.90±1.32 kg, in the first and second periods, respectively. Treatments were modified only at the level of methionine plus cysteine (Met+Cys) required and the Met+Cys sources, consisting of a negative control (NC), formulated with 80% of Met+Cys requirements, and four positive controls (PC): PCMet - NC supplemented with 1.2 g kg−1 of DL-methionine; PCBet - NC supplemented with 0.9 g kg−1 of anhydrous betaine; PCFWB - diet formulated with FWB; and PCFWB+Met - PCFWB supplemented with 1.0 g kg−1 of DL-methionine. No differences were observed on performance-related variables or on the digestibility coefficient of dry matter. Conversely, the digestibility coefficient of crude energy was lower when pigs were fed FWB and could be associated to the higher fiber content of FWB feeds. Digestible energy of feeds was higher for FWB diets, while the metabolizable energy of FWB diets did not differ from PCMet and PCBet. Nitrogen intake and apparent absorption were lower when pigs were fed FWB, but nitrogen retention, protein utilization, and biological value of the feed protein were the same among PC treatments, indicating that nitrogen from diets was used by pigs with the same efficiency, and is supported by no differences in performance-related variables. The FWB composition showed 12 g of betaine kg−1, which is available to maintain nitrogen retention and performance.

ABSTRACT The objective of this study was to evaluate the standardized ileal digestible (SID) valine and SID leucine levels on performance, backfat thickness, longissimus dorsi depth, and biochemical blood parameters of starting gilts. A total of 72 gilts, with initial weight of 15.16±1.15 kg, were distributed in a randomized block design in a 2 × 4 factorial scheme, comprised of two SID leucine levels (1.20 and 1.77%) and four SID valine levels (0.58, 0.73, 0.88, and 1.03%), with nine replicates and one animal per experimental unit. No interactions were observed for growth performance parameters. Final weight and average daily gain presented linear and quadratic effects. Setting data to the quadratic model associated with the Linear Response Plateau model, the optimal level of SID valine for average daily gain was achieved at 0.703%. A quadratic effect was also observed for average daily feed intake (ADFI), estimating the highest ADFI at 0.822% of SID valine. No branched chain amino acid (BCAA) effects were observed for backfat thickness, longissimus dorsi depth, and lean meat percentage. The interaction between levels of BCAA showed that the highest SID leucine levels (1.77%) provided a high plasma urea concentration only at low SID valine levels (0.58 and 0.73%). The SID valine requirement of starting gilts for a maximum average daily gain is achieved at 0.703%, corresponding to 9.72 g day−1, and is not affected by SID leucine levels currently used in conventional diets.

ABSTRACT This study was carried out to evaluate the effect of different levels of standardized ileal digestible (SID) methionine + cystine (Met+Cys) and vitamin B6 supplementation on the performance, blood variables, and gene expression of enzymes involved in methionine metabolism in female pigs between 75 and 100 kg. Fifty six female pigs were used (Talent × Topigs 20), averaging 75.06±1.68 kg in initial weight, allotted in a completely randomized block design arranged in a 2 × 4 factorial scheme, composed of two vitamin B6 supplementation levels (1.58 and 3.58 mg/kg) and four levels of SID Met+Cys (0.370, 0.470, 0.570, and 0.670%), with seven replicates and one animal per experimental unit. No interactions between vitamin B6 supplementation and SID Met+Cys levels were observed. The levels of SID Met+Cys and vitamin B6 supplementation did not affect animal performance. Triacylglycerols showed a quadratic response to the SID Met+Cys levels, in which the lowest plasma concentration was estimated as 0.575%. Treatments did not affect the expression of the methionine synthase and cystathionine-γ-lyase enzymes or serum homocysteine levels. The SID Met+Cys requirement for female pigs from 75 to 100 kg is equal to or lower than 10.60 g/day, which corresponds to the level of 0.370% Met+Cys in the diet and a relationship 0.48% with the SID lysine.

RESUMO: O impacto ambiental da produção animal, especialmente da suinocultura, vêm sendo objeto de crescente debate nos últimos anos. O desafio é atender a crescente demanda por alimentos a um custo acessível, mas sem comprometer a integridade ambiental. Estudos vêm demonstrando que a produçao de rações é responsável pela maior parte das emissões de CO2-eq. do sistema de produção de suínos. Isso parece indicar que estratégias de alimentação podem ser ferramentas eficientes para alcançar a sustentabilidade da cadeia suinícola. Dessa forma, a redução do conteúdo de proteína bruta da dieta através da inclusão de aminoácidos industriais, leva à diminuição da excreção de nitrogênio em suínos e, consequentemente, pode mitigar o impacto ambiental do sistema de produção de suínos. Neste sentido, para avaliação efetiva do impacto ambiental do sistema produtivo, a análise do ciclo de vida vem sendo amplamente utilizada na agricultura, mas os efeitos da alimentação ainda são pouco estudados nas condições brasileiras. Devido a importância e a grande preocupação nesta área de pesquisa, este artigo trás uma revisão atualizada com foco nas técnicas de nutrição e principalmente no seu potencial em reduzir o potencial de aquecimento global da produção de suínos, considerando ambos os efeitos diretos, relacionados à escolha dos ingredientes da ração, e os efeitos indiretos, relacionados às mudanças na eficiência de uso de nutrientes pelos animais.

ABSTRACT: Environmental impacts of livestock systems, especially pig production, have come under increasing debate in recent years. The challenge is in meeting the growing demand for food at an affordable cost, without compromising environmental integrity. Previous studies have shown that feed production is responsible for the majority of CO2-eq. emission resulting from pig farming systems. This seems to indicate that feed strategies could be an effective tool to achieve the sustainability of the pork chain. Therefore, dietary crude protein reduction, through the addition of industrial amino acids, lessens the nitrogen excretion by pigs and, consequently, could mitigate the effects on the environment of pig production. In this sense, to effectively evaluate the environmental impacts of pig production systems, life cycle assessment has been widely used in agriculture, but the effects of feed are still understudied in Brazilian conditions. Owing to the importance and the great concern in this research area, we presented in this paper an updated review focusing on the nutritional techniques and their potential to reduce the global warming potential of pig production, considering both the direct effects, related to the choice of feed ingredients and the indirect effects, related to changes in the efficiency of use of nutrient by the animals.

RESUMO: Otimizar a eficiência nutricional é essencial para aumentar a sustentabilidade do sistema de produção de suínos, especialmente em um momento onde a crescente demanda por alimentos deve ser atendida a um custo acessível, mas sem comprometer os recursos ambientais. Para tornar isso possível, é necessário o desenvolvimento de métodos eficientes e acurados para estimar as exigências nutricionais dos animais, bem como o desenvolvimento de equipamentos e sistemas que permitam aplicar esses métodos no sistema produtivo. Estimar as exigências nutricionais de suínos através de modelos matemáticos, considerando os vários fatores que impactam as exigências, pode ser um fator chave para reduzir a carga ambiental da suinocultura. Da mesma forma, formulações de rações e programas de alimentação podem auxiliar a alcançar isso. Neste contexto, o aumento do número de fases de alimentação na produção de suínos, bem como as técnicas de alimentação de precisão, podem ser ferramentas para a adequação das exigências nutricionais, uma vez que proporcionam benefícios econômicos e ambientais.

ABSTRACT: Optimizing nutrient efficiency is essential in order to increase sustainability of pig production systems, especially where the growing demand for food must be met at an affordable cost, without compromising environmental resources. To make this happen, it is necessary to develop efficient methods to accurately estimate the nutritional requirements of animals, as well as develop equipment and systems that allow for applying such expertise in the production system. Estimating the nutritional requirement of pigs through mathematical models, considering several factors that can impact the requirement, is a key factor to reduce the environmental load from pig production. Likewise, feed formulation and feeding programs, can help to achieve this. In this context, increasing the number of feeding phases in pig production, as well as precision feeding techniques, may be a tool to the esure adequacy of nutritional requirements, since its use can bring economic and environmental benefits.

O objetivo deste trabalho foi avaliar o valor nutricional e energético de subprodutos do trigo, em dietas para suínos em crescimento, e obter equações de predição da energia metabolizável. Foram utilizados 36 suínos machos, castrados, alojados em gaiolas metabólicas individuais. Realizou-se a coleta total de fezes e urina em dois períodos de dez dias: cinco para adaptação e cinco para coleta. Utilizou-se o delineamento de blocos ao acaso, tendo-se considerado o período de coleta como bloco, com seis tratamentos e seis repetições. A dieta referência foi substituída em 30% por um dos subprodutos testados: farinheta, farelo fino, farelo de trigo, farelo grosso e farelo grosso moído; este último usado para avaliar a influência da granulometria na digestibilidade. A fibra bruta foi a variável que proporcionou a melhor estimativa da energia metabolizável. O farelo fino foi superior em energia digestível e metabolizável, em comparação ao farelo grosso moído. O farelo grosso moído apresentou os menores coeficientes de digestibilidade, e a diminuição de seu diâmetro geométrico médio não aumentou a digestibilidade dos nutrientes e da energia. Entre os subprodutos avaliados, a farinheta apresenta maior energia digestível, energia metabolizável e proteína digestível, o que mostra elevado potencial para utilização em dietas para suínos em crescimento.

The objective of this work was to evaluate nutritional and energy values of wheat by‑products in diets for growing pigs, and to obtain prediction equations for metabolizable energy. Thirty‑six male pigs were housed in individual metabolic cages. Total collection of feces and urine was carried out in two periods of ten days: five days for adaptation and five days for collection. A randomized complete block design was used, considering the sampling period as a block, with six treatments and six replicates. The reference diet was replaced by 30% of one of the tested by‑products: wheat middlings, fine wheat bran, common wheat bran, coarse wheat bran, and ground coarse wheat bran; the latter was used to evaluate the influence of particle size on digestibility. Crude fiber was the variable that provided the best estimate of metabolizable energy. Fine wheat bran was superior in terms of digestible and metabolizable energy, when compared to coarse wheat bran. Ground coarse wheat bran showed lower digestibility coefficients, and the reduction in its average geometric diameter did not increase nutrient availability. Among the evaluated by‑products, wheat middlings have higher digestible energy, metabolizable energy, and digestible protein, showing high potential use in diets for growing pigs.