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This study aimed to evaluate different proportions of cactus pear in silage with BRS Capiaçu grass, along with a 10% inclusion of ground corn grain, focusing on aerobic stability, fermentative profile, chemical composition, and digestibility. The treatments included cactus pear (Opuntia spp.) at increasing levels of 0, 15, 30, 45, and 60% of the natural matter in the silage with BRS Capiaçu grass, plus 10% ground corn grain. Additionally, a control silage composed of BRS Capiaçu grass without ground corn was used. A completely randomized design was employed with six treatments and eight replications. The BRS Capiaçu grass was harvested after 100 days of regrowth. For ensiling, experimental PVC silos of known weights and of 50 cm long and 10 cm in diameter were used. The breakdown of aerobic stability of the silage without cactus pear (BRS Capiaçu grass with 10% ground corn) occurred 144 h after opening the silo. The inclusion of cactus pear in the silage with BRS Capiaçu grass and 10% ground corn grain resulted in a linear increase in pH value. Among the silages with cactus pear inclusion, there was no significant difference in gas losses (P = 0.46) and dry matter (DM) recovery (P = 0.43). There was no significant difference between the silages in terms of acetic acid content (P = 0.91). The content of DM and total digestible nutrients was lower in the control silage compared with the other silages. For each percentage unit of cactus pear inclusion, there was a reduction of 0.1195% in DM content. Additionally, for every 1% inclusion of cactus pear in silage with BRS Capiaçu grass, there was an increase of 0.2007 percentage units in DM digestibility. The optimal proportion of cactus pear in silage with BRS Capiaçu grass and 10% ground corn is up to 60% of the natural matter.(AU)

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This study aimed to assess an alkaline protease supplemented in diets with and without crude protein (CP) reduction on performance, apparent total tract digestibility (ATTD), blood parameters, and carcass and meat traits in growing-finishing pigs. Forty male pigs (26.2±1.2 kg) were randomly allocated into one of five treatments: negative control (NC, 2% and 1% reduction of CP in grower and finisher phases, respectively, no protease); NC150: NC + 150 mg protease kg−1 diet; NC300: NC + 300 mg protease kg−1 diet; PC: positive control (no CP reduction and protease); and PC300: PC + 300 mg protease kg−1 diet, with eight replicates of one pig/pen. Pigs fed NC showed greater average daily feed intake (ADFI) than pigs fed NC300 or PC and lower ADFI compared to pigs fed NC150. Pigs fed PC had lower ADFI than those fed PC300. Greater average daily gain and gain to feed ratio (G:F) were observed in pigs on NC compared with those on NC300 or NC150 and NC300, respectively. Pigs fed PC showed better G:F than pigs fed PC300. Lower coefficients of ATTD (CTTAD) of dry and organic matter (OM), digestible dry matter (DDM), digestible organic matter (DOM), and digestible protein were observed in growing II pigs fed NC compared with pigs fed NC150 or NC300. Pigs fed NC showed a lower DP compared with PC or NC150. Positive control group showed increased digestible protein compared with NC. Finishing II pigs fed NC showed lower DDM, DOM, CTTAD of OM, and gross energy than pigs fed NC150 or NC300. Pigs fed PC showed greater albumin concentration compared with pigs fed PC300 in finishing II. Pigs fed NC and PC300 showed greater luminosity in the l. thoracis muscle than pigs fed PC. A greater color score was evidenced in the l. thoracis in pigs fed PC compared with pigs fed PC300. The dietary supplementation of isolated alkaline protease and CP-reduced diets improves ATTD without supporting pig performance.(AU)

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This study aimed to evaluate the productive and reproductive performance and the nutritional metabolic condition of ewes supplemented at different stages of gestation in a synchronized reproduction system. Fourty Santa Inês × Dorper crossbreed ewes, pregnant with an average age of ten months and two previous births, were distributed in a completely randomized design, with four treatments: mineral salt, supplementation started 20 days before the estrus synchronization (ES) protocol, supplementation from confirmation of pregnancy (60 days after ES), and supplementation in the final third of gestation (90 days after ES). The adoption of supplementation strategies during the beginning, middle, or end of pregnancy changed the intake and digestibility of dry matter (g/day), with a reduction of 10.53 and 9.14%, respectively, for the mineral salt treatment, in addition to organic matter, crude protein, neutral detergent fiber, acid detergent fiber, non-fibrous carbohydrates, ether extract, and total digestible nutrients, as well as protein, energy, and mineral profiles. There was no difference in the number of ovulations and reproductive and productive performance using supplementation alternatives. Supplementation strategies during the gestation stages influence the intake and digestibility of nutrients, as well as the animal metabolic profiles. However, it does not change reproductive and productive performance.(AU)

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This study aimed to evaluate the intake, digestibility, and ingestive behavior of sheep fed with different species of forage cacti. Fifteen sheep (17.27kg ± 1 kg) were distributed in a completely randomized experimental design with three treatments and five replicates. The treatments were diets on a dry matter basis composed of 430.9 g kg-1of thornless Mandacaru cactus (Cereus hildmannianus), 525.7 g kg-1of cactus pear cv. Orelha de Elefante Mexicana (Opuntia stricta) and 492.1 g kg-1of cactus pear cv. Miúda (Nopalea cochenillifera) in addition to Sabiá hay (Mimosa caesalpiniaefolia) (194.7 to 233.8 g kg-1), plus concentrate feed. The intake of the dry matter,organic matter, ether extract, neutral detergent fiber, total carbohydrates, non-fiber carbohydrates, total digestible nutrientsand voluntary water intake in g day-1was not differ (p > 0.05) by experimental diets. There were no differences (p > 0.05) in digestibility coefficients of the dry matter,organic matter, neutral detergent fiber, total carbohydrates, non-fiber carbohydrates, and total digestible nutrientsbetween the experimental diets. The feeding times differed (p < 0.05) between diets, with a higher value for the Opuntiadiet, while the rumination times, feeding efficiency, and rumination efficiency did not differ (p > 0.05). The cactus Cereusand Opuntiaand Nopaleahave similar nutritional value in sheep's diet.(AU)

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This study evaluated forage-free diets supplemented with sodium bicarbonate (SB) based on ground flint corn on intake, apparent nutrient digestibility, ruminal parameters, and N balance. Four rumen-cannulatedDorper × Santa Inês lambs, with a body weight of 43.4 ± 0.85 kg (mean ± standard deviation) were used. The experimental design was a 4×4 Latin square. Each experimental period lasted 21 days. Experimental diets were: positive control, a diet without SB containing 400 g/kg DM of soybean hulls (CONT), and three diets based on ground flint corn, containing 10 (10SB), 20 (20SB) or 30 (30SB) g/kg DM of SB. Intake of neutral and acid detergent fiber was greater for CONT (P < 0.01) when compared to SB. Intake and apparent nutrient digestibility of dry and organic matter, ether extract, and crude protein did not differ. Intake (P = 0.01) and digestibility (P < 0.01) of non-fiber carbohydrates were greater for SB diets and neutral detergent fiber digestibility was greater (P = 0.03) for CONT. The total digestible nutrients and metabolizable energy were greater for SB (P = 0.04). Rumen concentrations of acetate (P < 0.01), isobutyrate (P < 0.01), butyrate (P < 0.01), isovalerate (P < 0.01), and total short-chain fatty acids (P < 0.01) were greater for CONT. Ruminal pH showed a quadratic (P = 0.05) response to SB levels, with greater values for 20SB. Sodium bicarbonate was efficient in increasing ruminal pH at the level of 20 g/kg DM without interfering with the intake and apparent nutrient digestibility characteristics.

O presente estudo avaliou a suplementação de bicarbonato de sódio (BS) em dietas sem forragem à base de milho moído sobre o consumo e a digestibilidade aparente dos nutrientes, os parâmetros ruminais e o balanço de N. Foram utilizados quatro cordeiros Dorper × Santa Inês, com um peso corporal inicial de 43,4 ± 0,85 kg (média ± desvio padrão). O delineamento experimental foi quadrado latino 4×4. Cada período experimental durou 21 dias. As dietas experimentais foram: controle positivo, sem BS, contendo 400 g/kg de MS de casca de soja (CONT) e três dietas à base de milho moído, sem casca de soja, contendo 10 (10BS), 20 (20BS) ou 30 (30BS) g/kg de MS de BS. O consumo de fibra em detergente neutro e ácido foi maior (P < 0,01)para o CONT quando comparado com BS. O consumo e a digestibilidade aparente da matéria seca, matéria orgânica, extrato etéreo e proteína bruta não diferiram entre os tratamentos. O consumo (P = 0,01) e digestibilidade (P < 0,01) dos carboidratos não fibrosos foram superiores para as dietas contendo BS e a digestibilidade da fibra em detergente neutro foi maior para o CONT. Os teores de nutrientes digestivos totais e energia metabolizável foram superiores para as dietas contendo BS (P = 0,04). A concentração ruminal de acetato (P < 0,01), isobutirato (P < 0,01), butirato (P < 0,01), isovalerato (P < 0,01) e ácidos graxos totais de cadeia curta (P < 0,01) foram mais elevadas para o CONT. O pHruminal apresentou resposta quadrática (P = 0,05) em relação aos níveis de BS, sendo observado maior pH para os animais alimentados com a dieta 20BS. O BS foi eficiente em aumentar o pHruminal no teor de 20 g/kg MS sem interferir no consumo e na digestibilidade aparente dos nutrientes. Portanto, 20 g/kg de MS é a dose indicada de BS em dietas sem forragem para terminação de cordeiros em confinamento.

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The aim was to evaluate if the inclusion of exogenous amylolytic enzyme affect the nutrient intake and digestibility in ewes fed high-concentrate diets containing flint corn. Five Santa Inês × Dorper crossbred ewes (54.04 ± 4.5 kg and aged 8 months) were used in a 5 x 5 Latin square design. All animals were housed in individual metabolic cages for 60 days. The treatments consisted of a control diet (without amylolytic enzyme) and four inclusion levels of an amylolytic enzyme (3,000, 6,000, 9,000, and 12,000 α-amylase dextrinizing units [DU] kg-1 dry matter [DM]). The enzyme was mixed into the feed at the time of supply to the animals. Data were analyzed by ANOVA, and orthogonal polynomial contrasts were used. Nutrient intake was not influenced by amylolytic enzyme inclusion. The digestibility of DM, organic matter, neutral detergent fiber, total carbohydrates, non-fibrous carbohydrates, and gross energy showed a quadratic increase with enzyme inclusion (P<0.05), with maximum values at levels of 7,600, 7,500, 6,300, 7,500, 7,400, and 7,800 DU kg-1 DM, respectively. Total digestible nutrients of diets also showed a quadratic increase, with a maximum value of 894 g kg-1 at a level of α-amylase activity of 7,786 DU kg-1 DM. The inclusion of the exogenous amylolytic enzyme from 6,300 to 7,800 DU kg-1 DM doesn't alter nutrient intake and improves the digestibility in ewes fed high-concentrate diets.(AU)

Objetivou-se avaliar se a inclusão de enzima amilolítica exógena afeta a ingestão e a digestibilidade dos nutrientes em ovelhas alimentadas com dietas de alto teor de concentrado contendo milho flint. Foram usadas cinco ovelhas mestiças Santa Inês × Dorper (54,04 ± 4,5 kg e 8 meses de idade) em um quadrado latino 5x5. Todos os animais foram alojados em gaiolas metabólicas individuais por 60 dias. Os tratamentos consistiram em uma dieta controle (sem enzima amilolítica) e quatro níveis de enzima amilolítica (3.000; 6.000; 9.000 e 12.000 unidades de dextrinização [UD] de α-amilase kg-1 de matéria seca [MS]). A enzima foi misturada com o alimento no momento do fornecimento aos animais. Os dados foram analisados por ANOVA e contrates ortogonais polinomiais. O consumo de nutrientes não foi influenciado pela inclusão da enzima amilolítica. A digestibilidade da MS, matéria orgânica, fibra em detergente neutro, carboidratos totais, carboidratos não fibrosos e energia bruta apresentaram efeito quadrático com a inclusão de enzima (P<0,05), com valores máximos nos níveis de inclusão da enzima 7.600; 7.500; 6.300; 7.500; 7.400 e 7.800 UD kg-1 MS, respectivamente. Os nutrientes digestíveis totais também apresentaram efeito quadrático, com máximo valor de 894 g kg-1 no nível de atividade de α-amilase de 7.786 UD kg-1 MS. A inclusão da enzima amilolítica exógena entre 6.300 e 7.800 UD kg-1 MS não modifica o consumo de nutrientes e melhora a digestibilidade de ovelhas alimentadas com dietas de alto teor de concentrado.(AU)

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The study aimed to nutritionally evaluate the silage of pineapple crop waste in sheep feeding in different planes of nutrition (L). We used eight growing sheep and four male castrated adults, in individual metabolic cages distributed in a switchback design with two treatments and three periods. The treatments were the different planes of nutrition: L = MEI/Mm, MEI/1.5Mm, and MEI/2.5Mm, in which L = MEI/Mm, MEI is the energy amount of the feed intake and Mm is the maintenance. We performed a digestibility trial of the diet composed of silage of pineapple crop waste, ground corn, and soybean meal. Data were analyzed using regression analysis. Nutrient intake behaved linearly according to the increase in the L, except for organic matter, which presented a quadratic behavior. Planes of nutrition did not affect protein and fiber digestible fractions. However, digestible fractions of fat and non-fibrous carbohydrates (NFC) increased with L. The indigestible fractions displayed a quadratic behavior with an increase in the L. Regarding the microbial synthesis efficiency, we observed a linear decrease with the increase in L. Thus, the silage of pineapple crop waste is a feed very rich in NFC. Besides, silage of pineapple crop waste presented a good alternative roughage during forage shortages. Diet inclusion of 2.5x the maintenance does not compromise the sheep performance.(AU)

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The objective of this study was to evaluate the influence of energy supplementation on associative effects between forage and concentrate supplements and on the performance of beef cattle on a tropical pasture during the rainy season. Twenty-eight Nellore bulls averaging 19 months of age and 325.2 ± 4.1 kg were allotted to a completely randomized design and distributed into four paddocks of two hectares each with a tropical pasture for 84 d. The treatments consisted of bulls on Urochloa brizantha cv. Xaraés pasture without concentrate supplementation or bulls on Urochloa brizantha cv. Xaraés pasture receiving concentrate supplementation at 15 (S15), 30 (S30) or 45% (S45) of the total digestible nutrients (TDN) requirement. All bulls had ad libitum access to mineral supplementation. The amount and chemical composition of the supplement were adjusted every 28 d. Forage and supplement intakes were evaluated in all animals using fecal markers. Crude protein: digestible organic matter ratio decreased with supplementation; consequently, the imbalance between dietary protein and energy increased. Forage intake decreased with increasing supplementation. The substitution rates of pasture for supplementary feed were 0.14, 0.33, and 0.46 for bulls from S15, S30, and S45 treatments, respectively. However, the apparent DM digestibility increased linearly with supplementation level. Supplementation improved the assimilation of ammonia-N in the rumen. Energy supplementation for Nellore bulls on tropical pastures during the rainy season provides excess energy relative to protein, resulting in a substitution effect of supplement intake on forage intake. Moreover, energy supplementation does not improve body weight gain. Protein sources should be added to supplements for balancing protein and energy levels, thereby reducing a likely substitution effect.(AU)

O objetivo deste trabalho foi avaliar a influência da suplementação energética nos efeitos associativos entre a forragem e suplemento concentrado e no desempenho de bovinos de corte em pasto tropical durante o período chuvoso. Vinte e oito touros da raça Nelore com idade média de 19 meses e 325,2 ± 4,1 kg foram alocados em delineamento inteiramente casualizado e distribuídos em quatro piquetes de dois hectares cada, com pasto tropical por 84 dias. Os tratamentos consistiram de touros em pastagem com Urochloa brizantha cv. Xaraés sem suplementação concentrada e touros em pastagem de Urochloa brizantha cv. Xaraés recebendo suplementação concentrada com 15 (S15), 30 (S30) ou 45% (S45) da necessidade de nutrientes digestíveis totais (NDT). Todos os touros tiveram acesso ad libitum à suplementação mineral. A quantidade e a composição química do suplemento foram ajustadas a cada 28 dias. A ingestão de forragem e suplemento foi avaliada em todos os animais por meio de marcadores fecais. A relação proteína bruta: matéria orgânica digestível diminuiu com a suplementação, consequentemente, o desequilíbrio entre proteína e energia da dieta aumentou. O consumo de forragem diminuiu, com efeito substitutivo do consumo de pasto pelo suplemento de 0,14, 0,33 e 0,46 para touros dos tratamentos S15, S30 e S45, respectivamente. No entanto, a digestibilidade aparente da MS aumentou linearmente com o nível de suplementação. A suplementação melhorou a assimilação do nitrogênio amoniacal no rúmen. A suplementação energética para touros Nelore em pastagens com pasto tropical durante a estação chuvosa fornece excesso de energia em relação à proteína, resultando em um efeito de substituição do consumo de forragem por suplemento. Além disso, a suplementação energética não melhora o ganho de peso corporal. Fontes de proteína devem ser adicionadas aos suplementos para equilibrar os níveis de proteína e energia, diminuindo um provável efeito de substituição.(AU)

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The objective with this study was to evaluate the effect of including dried distillers grains with solubles (DDGS) as a replacement for soybean meal on feed intake, digestibility, and total digestible nutrients (TDN), as well as plasmatic glucose and serum urea concentrations. Fifteen Saanen goats were distributed in a completely randomized design with three treatments and five replicates. Treatments were soybean meal (SBM), SBM+DDGS (12.28% of dry matter [DM]), and DDGS (23.16% of DM), as protein source in diets, common to all corn ground and mineral-vitamin supplement, and corn silage (60% of DM). Response variables were evaluated every 30 d, from 1 to 120 d after parturition. Measurements included body weight, DM intake, DM and nutrient digestibility, and blood samples. Indigestible neutral detergent fiber was used to estimate fecal excretion. There was a difference in neutral detergent fiber intake from 1 to 30 d after parturition. In the four phases of lactation evaluated, there were treatment effects on DM, organic matter, ether extract, and total carbohydrate digestibility, as well as on TDN concentration. Neutral detergent fiber digestibility was affected by treatments, except from d 61 to 90. There was no treatment effect on non-fibrous carbohydrate digestibility, regardless of period. Therefore, SBM+DDGS (12.28% of DM), as protein source on diets may be used in Saanen goat diets from 1 to 120 d of lactation without negative effects on feed intake, digestibility, and plasma glucose and urea concentrations.(AU)

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Balancing diets for protein affects both protein and energy use efficiency in cattle. This study aimed to evaluate the effects of dietary protein level on intake, digestibility and energy expenditure in Holstein heifers. Four Holstein heifers with a mean BW of 266.5 ± 10.7 kg were distributed in a 4 x 4 balanced Latin square design. Each period was comprised of 14 d for adaptation and 6 d for samplings. The heifers were fed diets with 9, 12, 15 and 18% of crude protein (CP). Total feces and urine were collected. Rumen fluid was collected at 2, 4, 6 and 8 h after feeding. The energy expenditure was evaluated at 6 a.m., 12 a.m., 6 p.m. and 12 p.m. by a closed-circuit mask technique. The intake of dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF) were similar between treatments (P > 0.05). Although the NDF digestibility was not changed (P > 0.05), the digestibilities of DM, OM, CP, non fibrous carbohydrates, and total digestible nutrients increased linearly (P < 0.05) with increasing CP levels in the diet. Urinary urea nitrogen excretion and nitrogen retained increased linearly (P < 0.01) with increasing CP levels. Dietary CP levels did not affect (P =0.53) energy expenditure in heifers. Ruminal ammonia-nitrogen concentration peaked at 2-4 h after feeding. Increasing dietary CP levels from 9 to 18% does not affect feed intake and energy expenditure in heifers. However, it improves the digestibility of OM and nitrogen retention.

O balanceamento das dietas proteicas afeta tanto a eficiência no uso de proteínas quanto a eficiência no uso de energia em bovinos. Este estudo teve como objetivo avaliar os efeitos dos níveis de proteína na dieta sobre consumo, digestibilidade e gasto de energia em novilhas Holandesas. Quatro novilhas Holandesas com um peso corporal (PC) médio de 266,5 ± 10,7 kg foram distribuídas em delineamento quadrado latino 4 x 4. Cada período era composto de 14 d para adaptação e 6 d para amostragens. As novilhas foram alimentadas com 9,12,15 e 18% de proteína bruta (PB). Fezes e urina totais foram coletadas. O líquido ruminal foi coletado às 2, 4, 6 e 8 h após a alimentação. O gasto de energia foi avaliado às 6h, 12h, 18h e 12h por uma técnica de máscara de circuito fechado. O consumo de matéria seca(MS), matéria orgânica (MO) e fibra em detergente neutro (FDN) foram similares entre os tratamentos(P > 0,05). Embora a digestibilidade do FDN não tenha sido alterada (P > 0,05), a digestibilidade de MS, MO, PB, carboidratos não-fibrosos e nutrientes digestíveis totais aumentou linearmente (P < 0,05)com o aumento dos níveis de PB na dieta. A excreção de uréia urinária e o nitrogênio retido aumentaram linearmente (P < 0,01). Os níveis de PB na dieta não afetaram (P = 0,53) o gasto de energia em novilhas. A concentração de nitrogênio amoniacal atingiu o pico em 2-4 h após a alimentação. O aumento dos níveis dietéticos de PB de 9 para 18% não afeta o consumo de ração e o gasto de energia em novilhas. Entretanto, melhora a digestibilidade da MO e a retenção de nitrogênio.

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Two experiments were conducted to investigate the effects of slow-release urea (SRU) on in vitro rumen fermentation parameters, growth performances, nutrient digestibility, and serum metabolites of beef cattle. The single factor design was applied in both experiments. Three diets with different nitrogen sources including soybean meal (Control group), slow-release urea (SRU group), and common urea (Urea group) was designed (concentrate to forage ratio was 4:6). The diets were formulated to be isoenergetic and isonitrogenous, 75% of the soybean meal in the control diet was replaced by 1.41% SRU and 1.15% urea in SRU group and Urea group, respectively. In experiment 1, five healthy Jinjiang cattle (average body weight (BW) was 380 ± 17.1 kg) with permanent rumen fistulas were used in in vitro ruminal fermentation experiment. The results showed that supplementing SRU increased the dry matter degradation rate (DMD), digestible organic matter (DOM) and propionic acid concentration in cultivated fluid, and SRU supplementation decreased pH, NH3 -N, total volatile fatty acid (TVFA), acetic acid, butyric acid concentration and microbial growth efficiency (MOEFF) in cultivated fluid. In experiment 2, eighteen Simmental crossbred cattle BW= 315 ± 5.2 kg) were stratified by BW and then assigned to the three groups to have equal BW among groups. The results showed that supplementing SRU reduced the average dry matter intake (ADMI), apparent digestibility of ether extract (EE), the activity of glutathione peroxidase (GSH-Px), the levels of IgG and IgA, and the production of thiiodothronine (T3) in serum, SRU supplementation increased the apparent digestibility of dry matter and organic matter (OM) and alanine aminotransferase (ALT) concentration in serum. These results indicated that some soybean meal could be replaced by SRU and urea in the production of beef cattle. In addition, compared with urea, SRU had a good sustained-release effect. The replacement of some soybean meal by SRU in the diet had no adverse impact on rumen fermentation, growth performance, and serum metabolites of beef cattle.(AU)

Os dois experimentos foram conduzidos para investigar os efeitos da uréia de liberação lenta nos parâmetros de fermentaçãono do rúmen em vitro, desempenho de crescimento, digestibilidade dos nutrientes e metabolitos séricos de gado de corte. O design de fator único foi aplicado em ambos os experimentos. As três dietas com diferentes fontes de nitrogênio, incluindo farelo de soja (Grupo de controle), uréia de liberação lenta (Grupo de uréia de liberação lenta) e uréia comum (Grupo de uréia) foi designado (concentre-se em relação forrageira foi de 4: 6). As dietas foram formuladas para serem isoenergéticas e isonitrógenas, 75% da farinha de soja na dieta controle foi substituída por 1,41% de uréia de liberação lenta e 1,15% de uréia no Grupo uréia de liberação lenta e Grupo uréia, respectivamente. No experimento 1, cinco gados Jinjiang saudáveis (peso corporal médio (PC) de 380 ± 17,1 kg) com fístulas ruminais permanentes foram utilizadas no experimento de fermentação do rúmen em vitro. Os resultados mostraram que a suplementação de uréia de liberação lenta aumentou a taxa de degradação da substância seca, substância orgânica digestível e concentração de ácido propiônico no líquido cultivado, e a suplementação de SRU diminuiu o pH, NH3-N, ácido graxo volátil total, ácido acético, concentração de ácido butírico e eficiência de crescimento microbiano no fluido cultivado. No experimento 2, dezoito gados mestiços Simmental (PC = 315 ± 5,2 kg) foram estratificados por PC e, em seguida, atribuído aos três grupos para ter PC igual entre os grupos. Os resultados mostraram que a suplementação de uréia de liberação lenta reduziu a ingestão média da substância seca, digestibilidade aparente do extrato etéreo, a atividade da glutationa peroxidase, os níveis de IgG e IgA, e a produção de tiiodotronina (T3) no soro, a suplementação de uréia de liberação lenta aumentou a digestibilidade aparente da concentração de substância seca e substância orgânica e concentração de alanina aminotransferase no soro. Esses resultados indicaram que algum farelo de soja pode ser substituída por uréia de liberação lenta e uréia na produção de gado de corte. Além disso, comparado com a uréia, uréia de liberação lenta teve um bom efeito de liberação sustentada. A substituição de algum farelo de soja por uréia de liberação lenta na dieta não teve impacto adverso na fermentação ruminal, desempenho de crescimento e metabolitos séricos de gados de corte.(AU)

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ABSTRACT: The inner bark or less tender sheath generated from industrial manufacture of canned babassu palm (Attalea speciosa) heart is inadequate for human consumption, often being discarded inappropriately and giving rise to environmental pollution. Accordingly, the aim of this study was to assess the intake and digestibility in sheep fed on silage of the agro-industrial co-product of babassu palm (ICBP)enriched with different additives, or on sugarcane silage. Fifteen Santa Inês sheep were distributed in a completely randomized design, consisting of five treatments and three replicates. The treatments comprised babassu palm silage enriched with broken maize (BM), broken rice (BR), cassava scrapings (CS), coffee husk combined with maize kernel (CC), and sugarcane silage (SC), all supplemented with concentrate, at a voluminous:concentrate ratio of 65:35. Silages based on ICBP and SC had similar intake of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), and non-fibrous carbohydrate (NFC). Increasing the additive fraction in ICBP silages favored the digestibility of DM, OM, CP, NFC, neutral detergent fiber (NDF), and total digestible nutrients (TDN). Our results indicated that silage based on additive-enriched ICBP can be used in the diet of ruminants, especially those based on broken maize and cassava scrapings that provide superior nutritional quality compared to the other silages assessed.

RESUMO: No processo industrial de fabricação de palmito babaçu (Attalea speciosa) em conserva, a entrecasca ou bainha menos tenra, apresenta características impróprias à alimentação humana, sendo muitas vezes descartada de forma inadequada, oferecendo riscos de poluição ambiental. De tal forma, objetivou-se avaliar o consumo e a digestibilidade em ovinos recebendo silagens de coproduto da industrialização de palmito babaçu (CIPB) com diferentes aditivos ou silagem de cana-de-açúcar. Utilizou-se 15 ovelhas da raça Santa Inês, distribuídas em delineamento inteiramente casualizado, constituindo de cinco tratamentos e três repetições. Os tratamentos compreendiam dietas de silagem de babaçu enriquecidas com quirera de milho (QM), quirera de arroz (QA), raspa de mandioca (RM), casca de café combinada com quirera de milho (CC), e silagem de cana-de-açúcar (CA), todos complementadas com concentrado, na relação volumoso:concentrado, 65:35. Silagens a base de CIPB e CA tiveram consumos de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE) e carboidrato não-fibroso (CNF) semelhantes. O incremento de aditivos às silagens de CIPB favoreceram a digestibilidade da MS, MO, PB, CNF, fibra em detergente neutro (FDN) e de nutrientes digestíveis totais (NDT). Silagem a base de CIPB pode ser utilizada na dieta de ruminantes com a inclusão de aditivos, especialmente quirera de milho e raspa de mandioca, que conferem qualidade nutricional superior às demais silagens avaliadas.

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The objective was to quantify the flow of intestinal nutrients and nitrogen excretion and retention in sheep receiving isoproteic diets. Eight Texel x Lacaune wethers (average body weight = 25±2.5 kg) were fitted with duodenal cannula and housed in metabolic cages. Wethers were assigned to the treatments in a crossover design with two periods of 20 days each, and all feces and urine produced by the wethers were collected. The treatments consisted of two isoproteic (160 g kg−1 of crude protein on dry matter basis) diets composed of red clover (RC) or lucerne (LU; Medicago sativa) silages plus corn silage and concentrate feed. The digestible organic matter and metabolizable energy intake did not differ between treatments. The intestinal non-ammonia N (NAN) flow was 5.9 g day−1 (37%) higher in RC wethers than in those of the LU treatment. This result was a consequence of both an increase in the efficiency of microbial protein synthesis (12.7% higher) and a decrease in ruminal degradable protein (RDP) content (20% lower) of the diet. However, the increase in the intestinal NAN flow was accompanied by a reduction in intestinal digestibility of N, resulting in similar daily N retention between treatments. The reduction of RDP content was probably the main reason for reductions in N urinary excretion in RC wethers compared with those in the LU treatment, showing that RC silage may be a tool for mitigating the impact of N excretion in ovine production systems, without changes in N retention.(AU)

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Foram avaliados o consumo e a digestibilidade dos nutrientes, a produção e a composição do leite de vacas Holandês x Gir alimentadas com dietas baseadas em silagem de milho suplementada com concentrado contendo ou não glicerina obtida da produção de biodiesel. Os tratamentos basearam-se na substituição parcial do amido do milho moído pelo glicerol da glicerina. O experimento foi realizado durante 96 dias utilizando delineamento em blocos casualizados, nove vacas por tratamento e três medidas repetidas no tempo. Não houve diferença (P>0,05) entre tratamentos para consumos de matéria seca, matéria orgânica, proteína bruta, fibra em detergente neutro e nutrientes digestíveis totais. Foram observados menores consumos de amido e extrato etéreo para as vacas que receberam concentrado com glicerina que, por sua vez, consumiram maior (P<0,05) quantidade de glicerol. Não houve efeito (P>0,05) da inclusão de glicerina sobre a digestibilidade dos nutrientes, produção e composição do leite, mas foi observada maior (P<0,05) produção de leite corrigida para 4% de gordura e menor teor de nitrogênio ureico no leite das vacas que receberam concentrado sem glicerina. Em dietas de vacas Holandês x Gir a suplementação da silagem de milho com concentrado contendo níveis médios de 8,12% de glicerina em substituição ao milho moído, apresenta potencial para produção de 20 kg/dia de leite com elevado teor de sólidos.

Intake, digestibility of nutrients, production and milk composition of Holstein x Gyr fed diets based on corn silage supplemented with concentrates containing glycerin or no coproduct of biodiesel production were evaluated. The treatments were based on the partial replacement of ground corn starch by the glycerol of glycerine. The experiment was conducted during 96 days using a randomized block design, nine cows per treatment and three repeated measurements over time. There was no difference (P>0.05) between treatments regarding the dry matter, organic matter, crude protein, neutral detergent fiber and total digestible nutrients. Smaller consumption of starch and lipids were observed by cows receiving concentrated with glycerin,that, in turn, consumed higher (P<0.05) amount of glycerol. There was no difference (P>0.05) among treatments for nutrient digestibility, milk production and composition, but there was a higher yield of milk corrected to 4% fat and lower levels of urea nitrogen in the milk of cows fed concentrate without glycerol (P<0.05). For Holstein x Gyr cows receiving diets based on corn silage, the supplementation with concentrate containing the average level of 8,12% of glycerine as ground corn replacer shows potential milk production of 20 kg/day with a high solid content.

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The present study evaluated the effect of variation in the amount of total dietary fiber (TDF) in sow diets, provided from 74 to 114 days of gestation, on the digestibility of nutrients and energy during gestation, as well as productivity and metabolism during gestation and lactation. Thirty-three sows were used in a randomized experimental design. The amounts of TDF in three treatment diets were 156, 223, and 282 g kg−1. The daily intake of nutrients and energy was similar for all diets the entire period of gestation, differing only in the volume of ration consumed, which was 2.1, 2.2, and 2.4 kg day−1 (days 74 to 90) and 2.5, 2.6, and 2.8 kg day−1 (days 91 to 111) for the 156, 223, and 282 g kg−1 TDF diets, respectively. During gestation, the increase in TDF resulted in a significant linear decrease in the digestible energy and apparent total tract digestibility of dry matter, gross energy, crude protein, non-fibrous carbohydrates, and organic matter. During gestation, blood concentrations of protein and globulins exhibited a quadratic response to the amount of TDF in the diet, whereas cholesterol exhibited a significant linear increase. The productivity and reproductive performance of the sows during gestation and lactation or the birth weight of the piglets were not affected by the amount of TDF, but the average daily weight gain of the litter during nursing increased linearly with increasing levels of dietary fiber. Increasing the amount of TDF reduces the digestibility of nutrients and energy, without affecting the performance of the sows during gestation and lactation or that of the piglets at birth and increasing TDF during gestation improves the weight gain of piglets during lactation.(AU)

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Sistemas de produção cada vez mais intensivos buscam fornecer para os animais toda exigência nutricional de forma exógena, porém, afim de sermos cada vez mais preciso no uso dos ingredientes buscando o equilíbrio entre produção e lucro, é necessário dados concisos com a realidade do estado de Mato Grosso, por isso, Objetivou-se avaliar o consumo e a digestibilidade de animais na fase de recria em regime de pastejo, durante o período seco do ano, consumindo diferentes níveis de proteína bruta (9;18;27;36;45%) em suplementação intensiva de 1,4 % do peso corporal. Foram utilizados 5 animais Nelores, machos, não castrados, com idade e peso médio inicial de 13 meses e 299,18 ± 42,6 kg, respectivamente. A área experimental constituiu-se de cinco piquetes de 0,33 ha de brachiaria brizantha cv. Marandu com bebedouros e comedouros individuais, a fonte de proteína bruta ofertada para os animais era o farelo de soja. O experimento foi conduzido segundo delineamento quadrado latino 5x5. Foram testados 5 níveis de proteína (9,18,27,36,45%) durante 5 períodos experimentais, os suplementos concentrados foram fornecidos na quantidade de 3,5 kg/animal/dia (base da matéria natural), uma vez ao dia. Os diferentes níveis de proteína não afetou os consumos de MS total (P = 0,52) de forragem (P = 0,53), matéria orgânica (P = 0,42) e FDN (P= 0,20), o consumo de PB apresentou efeito linear (P <0,001), as digestibilidades da MS (P= 0,50) MO (P=0,36) e FDN (P=0,44) não apresentou efeito com a inclusão da proteína bruta e consequentemente não afetou o consumo de matéria orgânica digestível (MOD) (P=0,42).

Increasingly intensive production systems seek to provide animals with all nutritional requirements exogenously, however, in order to be increasingly precise in the use of ingredients, seeking a balance between production and profit, it is necessary to provide concise data with the reality of the state of production. Mato Grosso, therefore, the objective was to evaluate the intake and digestibility of animals in the rearing phase under grazing, during the dry period of the year, consuming different levels of crude protein (9;18;27;36;45% ) in intensive supplementation of 1.4% of body weight. Five Nelore animals, male, not castrated, with initial average age and weight of 13 months and 299.18 ± 42.6 kg, respectively, were used. The experimental area consisted of five paddocks of 0.33 ha of Brachiaria brizantha cv. Marandu with individual drinkers and feeders, the source of crude protein offered to the animals was soybean meal. The experiment was conducted in a 5x5 Latin square design. 5 levels of protein (9,18,27,36,45%) were tested during 5 experimental periods, the concentrated supplements were provided in the amount of 3.5 kg/animal/day (natural matter basis), once a day . The different levels of protein did not affect the intake of total DM (P = 0.52), forage (P = 0.53), organic matter (P = 0.42) and NDF (P = 0.20), consumption of CP showed a linear effect (P <0.001), the digestibilities of DM (P= 0.50) MO (P=0.36) and NDF (P=0.44) showed no effect with the inclusion of crude protein and consequently did not affect intake of digestible organic matter (MOD) (P=0.42).

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Avaliou-se o uso de aditivos em suplemento proteico-energético sobre o consumo, digestibilidade e parâmetros ruminais de bovinos de corte na fase de recria. Foram utilizados cinco bovinos machos distribuídos em delineamento quadrado latino 5x5. Os animais foram mantidos sob pastejo contínuo em piquetes individuais de Urochloa brizantha cv. Marandu. Os tratamentos consistiam em mistura mineral (0,080 kg/animal.dia), Suplemento proteico-energético (PE) (4,0 kg/animal.dia), PE com monensina sódica (120 mg/animal.dia), PE com óleo funcional (2.500 mg/animal.dia) e PE com levedura ativa (4.000 mg/animal.dia). A suplementação PE aumentou o consumo de matéria seca total (MST), proteína bruta (PB), matéria orgânica (MO), fibra em detergente neutro corrigido para cinzas e proteínas (FDNcp) e matéria orgânica digestível (MOD) em relação a mistura mineral. Não houve efeito do uso dos aditivos sobre o consumo e digestibilidade dos nutrientes. No entanto, a suplementação PE aumentou a digestibilidade da MS, MO, PB, FDNcp e da MOD comparado a mistura mineral. A suplementação PE aumentou as concentrações de nitrogênio amoniacal ruminal e nitrogênio ureico sérico comparado a suplementação mineral. E não houve efeito do uso de aditivos sobre o metabolismo e utilização do nitrogênio. Conclui-se que o uso dos aditivos monensina, óleo funcional e levedura ativa em suplemento proteico energético não melhora os parâmetros nutricionais de bovinos de corte na fase de recria nas condições deste estudo.

The use of additives in protein-energy supplement on consumption, digestibility, and ruminal parameters of beef cattle in the growing phase was evaluated. Five male cattle were distributed in a 5x5 Latin square design. The animals were maintained under continuous grazing in individual paddocks of Urochloa brizantha cv. Marandu. The treatments consisted of mineral mixture (0.080 kg/animal.day), protein-energy supplement (PE) (4.0 kg/animal.day), PE with sodium monensin (120 mg/animal.day), PE with functional oil (2,500 mg/animal.day) and PE with active yeast (4,000 mg/animal.day). PE supplementation increased the intake of total dry matter (TDM), crude protein (CP), organic matter (OM), neutral detergent fiber corrected for ash and protein (NDFap) and digestible organic matter (DOM) in relation to the mineral mixture. There was no effect of the use of additives on nutrient intake and digestibility. However, PE supplementation increased the digestibility of DM, OM, CP, NDFap and DOM compared to the mineral mixture. PE supplementation increased ruminal ammonia nitrogen and serum urea nitrogen concentrations compared to mineral supplementation. And there was no effect of the use of additives on nitrogen metabolism and utilization. It is concluded that the use of monensin, functional oil and active yeast in a protein-energy supplement does not improve the nutritional parameters of beef cattle in the growing phase under the conditions of this study.

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Objetivou-se avaliar diferentes níveis de substituição do farelo de soja pelo farelo de mamona detoxificado, na terminação de novilhos mestiços em pastagem de Brachiaria brizantha cultivar Marandu, no período de transição águas-secas. Foram utilizados 40 novilhos mestiços Holandês-zebu, com peso inicial médio de 395,93 ± 10 kg, foram alocados de forma aleatória, em quatro tratamentos e suplementados com diferentes níveis de farelo de mamona em substituição ao farelo de soja no concentrado: 0%; 30%; 60%; 90% de substituição, adotando-se o nível de suplementação de 0,4% do peso corporal. O período experimental compreendeu 112 dias. Foi utilizado um delineamento inteiramente casualizado, com análise de regressão utilizando o Sistema de Análises Estatísticas e Genéticas. Foram avaliados o consumo e digestibilidade da matéria seca e nutrientes e desempenho animal. O consumo de matéria seca (kg), matéria orgânica (kg), fibra em detergente neutro (kg), fibra em detergente neutro do peso corporal, carboidratos não fibrosos (kg), e nutrientes digestíveis totais não foram influenciados pela substituição do farelo de soja pelo farelo de mamona. No entanto, o consumo proteína bruta (kg) e extrato etéreo (kg), mostraram-se decrescentes a medida foram aumentados os níveis de substituição do farelo de soja pelo farelo de mamona nos tratamentos. A digestibilidade da matéria seca, matéria orgânica, fibra em detergente neutro (FDNcp) e extrato etéreo, não foram afetadas pelos níveis de substituição, no entanto, para a digestibilidade da proteína bruta houve efeito linear decrescente e efeito linear crescente na digestibilidade dos carboidratos não fibrosos. O peso corporal final, ganho médio diário, conversão alimentar e rendimento da carcaça não foram afetados pelos níveis de substituição. A substituição do farelo de soja pelo farelo de mamona detoxificado pode ser efetuada em até 90% na composição do suplemento, sem comprometer o desempenho produtivo de novilhos em pastagem de Brachiaria brizantha cv. Marandu, no período de transição águas-seca.

The objective was to evaluate different levels of replacement of soybean meal by detoxified castor bean meal in the finishing of crossbred steers in Brachiaria brizantha cv. Marandu pasture in the water/dry transition period. Forty Holstein-Zebu crossbred steers with an average initial weight of 395.93 ± 10 kg were randomly allocated into four treatments and supplemented with different levels of castor bean meal to replace soybean meal in the concentrate: 0%; 30%; 60%; 90% replacement, adopting the supplementation level of 0.4% of body weight. The experimental period comprised 112 days. A completely randomized design was used, with regression analysis using the Statistical and Genetic Analysis System. The intake and digestibility of dry matter and nutrients and animal performance were evaluated. The intake of dry matter (kg), organic matter (kg), neutral detergent fiber (kg), neutral detergent fiber from body weight, nonfibrous carbohydrates (kg), and total digestible nutrients were not influenced by replacing soybean meal with castor meal. However, the intake of crude protein (kg) and ether extract (kg) showed to be decreasing as the levels of replacement of soybean meal by castor meal were increased in the treatments. The digestibility of dry matter, organic matter, neutral detergent fiber (NDFcp) and ether extract were not affected by the replacement levels, however, for crude protein digestibility there was a decreasing linear effect and an increasing linear effect on the digestibility of non-fibrous carbohydrates. Final body weight, average daily gain, feed conversion and carcass yield were not affected by replacement levels. The replacement of soybean meal by detoxified castor meal can be carried out in up to 90% of the supplement composition, without compromising the productive performance of crossbreds steers on Brachiaria brizantha cv. Marandu, in the water-dry transition period.

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A dependência de ingredientes como o farelo de soja na alimentação de suínos influencia diretamente no custo de produção, intensificando estudos envolvendo o uso de aditivos alimentares como a enzima protease. O objetivo deste estudo foi avaliar a adição de protease alcalina em dietas, com e sem redução de proteína bruta (PB), para suínos em crescimento-terminação, sobre o desempenho zootécnico, digestibilidade aparente dos nutrientes, parâmetros sanguíneos e atributos de carcaça e carne. Um total de 40 suínos machos inteiros com peso corporal inicial de 26,28 ± 1,24 kg foram alocados em um delineamento experimental inteiramente casualizados, composto de cinco tratamentos: (1) CP: controle positivo, sem redução de PB e sem enzima, e (2) CP + 0,30: CP com adição de 0,30 kg de enzima/t de ração (3) CN: controle negativo, com redução de 2 e 1% do conteúdo de PB nas fases de crescimento e terminação, respectivamente, sem enzima, (4) CN + 0,15: CN com adição de 0,15 kg de enzima/t de ração, (5) CN + 0,30: CN com adição de 0,30 kg de enzima/t de ração, com oito repetições, sendo o animal a unidade experimental. Os resultados indicaram que foram verificados efeito de tratamento sobre o consumo médio de ração diário (CRDM), ganho de peso corporal diário (GPCD) e eficiência alimentar (EA) para suínos na fase de crescimento II (P<0,0001, P=0,0398 e P=0,0007). Por meio da análise de contrastes ortogonais, foi observado que os animais do CN tiveram (P0,05) maior EA em comparação aos que consumiram CN+0,15 e CN+0,30, embora o pior GPCD e menor CRDM foi verificado para os animais que receberam CN+0,30. Não foi verificado efeito (P>0,05) de tratamento sobre as variáveis de desempenho zootécnico na fase de terminação, embora uma tendência (P=0,0729) foi observada sobre o GPCD. Houve efeito (P0,05) sobre coeficiente de digestibilidade aparente da matéria seca (CDAMS), matéria seca digestível (MSD), coeficiente de digestibilidade aparente da matéria orgânica (CDAMO), matéria orgânica digestível (MOD) e proteína disponível (PD) na fase de crescimento II. As comparações entre médias de tratamentos testadas por contrastes ortogonais indicaram que animais do tratamento CN apresentaram redução nos CDA quando comparados aos CN+0,15 e CN+0,30. Na fase de terminação II, houve diferença (P0,05) sobre MSD, CDAMO, MOD, PD e coeficiente de digestibilidade aparente da energia bruta (CDAEB). Os resultados indicaram que animais do CN tiveram menores CDA quando comparados aos que receberam CN+0,15 e CN+0,30, exceto sobre a PD. Não houve efeito (P>0,05) de tratamentos sobre os parâmetros sanguíneos na fase de crescimento II. Entretanto, na fase de terminação II, os suínos do grupo CP apresentaram (P0,05) um acréscimo de 27,65% na concentração de albumina em comparação aos com CP+0,30. Também, os animais do grupo CP tiveram (P0,05) aumento nas concentrações de PT e globulina em relação àqueles do grupo CN. Os suínos que consumiram o tratamento à base de CN e CP+0,30 apresentaram (P0,05) um aumento na luminosidade do músculo longissimus thoracis comparados aos CP, bem como foi verificada (P=0,015) maior luminosidade no músculo de suínos do grupo CN em comparação ao grupo CP. Como conclusão, a redução de PB na dieta em 2% e 1%, crescimento e terminação respectivamente, mantendo-se a suplementação de aminoácidos até a valina, não altera desempenho, características sanguíneas e características de carcaça e carne. A adição da enzima protease melhora a digestibilidade.

The dependence on ingredients such as soybean meal in swine feed influences directly the cost of production, intensifying studies involving the use of feed additives as the protease enzyme. The objective of this study was to evaluate the addition of alkaline protease in diets, with and without reduction of crude protein (PB), for growing-finishing pigs, on zootechnical performance, apparent digestibility of nutrients, blood parameters and carcass and meat attributes. A total of 40 male pigs with initial body weight of 26.28 ± 1.24 kg were allocated in a completely randomized experimental design, consisting of five treatments: (1) CP: positive control, without PB reduction and without enzyme, and (2) CP + 0.30: CP with the addition of 0.30 kg of enzyme/t of feed (3) CN: negative control, with a reduction of 2 and 1% of the PB content in the growth and finishing phases, respectively, without enzyme, (4) CN + 0.15: CN with addition of 0.15 kg of enzyme/t of feed, (5) CN + 0.30: CN with addition of 0.30 kg of enzyme/t of feed, with eight repetitions, with the animal as the experimental unit. The results indicated that there was a treatment effect on average daily feed intake (CRDM), daily body weight gain (GPCD) and feed efficiency (EA) for pigs in growth phase II (P<0.0001, P= 0.0398 and P=0.0007). Through the analysis of orthogonal contrasts, it was observed that the CN animals had (P0.05) greater EA compared to those that consumed CN+0.15 and CN+0.30, although the worst GPCD and lowest CRDM was verified for the animals that received CN+0.30. There was no effect (P>0.05) of treatment on the zootechnical performance variables in the finishing phase, although an inclination (P=0.0729) was observed on the GPCD. There was an effect (P0.05) on apparent digestibility coefficient of dry matter (CDAMS), digestible dry matter (MSD), apparent digestibility coefficient of organic matter (CDAMO), digestible organic matter (MOD) and available protein (PD) in growing phase II. Comparisons among the average of treatments tested by orthogonal contrasts indicated that animals from the CN treatment showed a reduction in CDA when compared to CN+0.15 and CN+0.30. In finishing phase II, there was a difference (P0.05) on MSD, CDAMO, MOD, PD and digestibility coefficient apparent of gross energy (CDAEB). The results indicated that CN animals had lower CDA when compared to those that received CN+0.15 and CN+0.30, except for PD. There was no effect (P>0.05) of treatments on blood parameters in growth phase II. However, in the finishing phase II, the pigs in the CP group showed (P0.05) an increase of 27.65% in albumin concentration compared to those with CP+0.30. Also, animals in the CP group had (P0.05) an increase in PT and globulin concentrations compared to those in the CN group. The pigs that consumed the treatment based on CN and CP+0.30 showed (P0.05) an increase in the luminosity of the longissimus thoracis muscle compared to the CP, as well as it was verified (P=0.015) greater luminosity in the piglet muscle from the CN group compared to the CP group. In conclusion, the reduction of PB in the diet by 2% and 1%, growth and finishing respectively, maintaining the amino acid supplementation up to valine, does not modify performance, blood characteristics, carcass and meat characteristics. The addition of the protease enzyme improves digestibility.

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Foram conduzidos dois experimentos com o objetivo de determinar os níveis ótimos à exigência em gramas por dia, bem como a relação Trp:Lys digestíveis ileais estandardizados (DIE) para suínos machos imunizados, dos 75 aos 100 kg e machos imunocastrados dos 110 aos 135 kg de peso corporal, sobre o comportamento, desempenho zootécnico,e digestibilidade aparente do trato total dos nutrientes, parâmetros sanguíneos e características de carcaça e qualidade da carne. Experimento I. Foram utilizados 64 suínos, mestiços (Landrace x Large White) com peso inicial médio de 75,55 ± 4,11 kg, distribuídos em delineamento experimental de blocos casualizados, com 16 tratamentos e quatrorepetições, em esquema fatorial 4x4, com quatro níveis de Trp DIE (1,1; 1,5; 1,9 e 2,3gde Trp/kg de dieta) e quatro níveis de Lys DIE (6,50; 8,00; 9,50 e 11,00gde Lys/kg de dieta) e um animal por unidade experimental, dos 75 aos 100 kg. Experimento II. Foram utilizados 64 suínos, mestiços (Landrace x Large White) com peso inicial médio, 135,63±8,21kg, em esquema fatorial 4x4, com quatro níveis de Trp DIE (0,75; 1,05; 1,35 e 1,65g de Trp/kg de dieta) e quatro níveis de Lys DIE (4,0; 5,5; 7,0 e 8,5g de Lys/kg de dieta) até atingirem o peso de 135 kg. Foram avaliadas as seguintes variáveis para determinação do desempenho zootécnico: peso corporal final (PCF) consumo de ração diário médio (CRDM), ganho de peso corporal diário (GPCD) e eficiência alimentar (EA). Para avaliar os parâmetros bioquímicos sanguíneos, foramdeterminados: albumina (ALB), alanina aminotransferase (ALT), aspartato aminotransferase (AST), fosfatase alcalina (FA), glicose (GLI), globulina (GLOB) proteínas totais (PT) e nitrogênio ureico plasmático (NUP) por kits comerciais. Como procedimento estatístico, adotou-se uma metodologia de superfície e resposta, utilizando modelos de regressão polinomial. No experimento I houve efeito quadrático de Trp DIE para o PCF (P=0,002), GPCD (P=0,0002) e CRDM (P=0,006), que foram estimados 1,90, 1,99 e 2,00 g/kg de Trp DIE, respectivamente. Houve efeito linear de Trp DIE (P=0,022) sobre a variável NUP.Os níveis de Trp DIE apresentaram efeito quadrático sobre os comportamentos de sentar (SEN) (P=0,0009), dormir (DORM) (P=0,011) e Ócio (P=0,030), em que foram estimados 0,16, 1,75 e 1,80 g/kg de Trp DIE, respectivamente. Ainda, para Lys DIE sentar (SEN), (P=0,013) e dormir (DORM) (P=0,001) foram estimados em 0,33 e 1,56 g/kg de Lys DIE, respectivamente. Houve efeito de interação Trp: Lys DIE sobre os coeficientes de digestibilidade aparente da matéria seca (CDAMS)(P=0,0002), proteína bruta (CDAPB) (P=0,0002), matéria orgânica (CDAMO)(P=0,0003) energia bruta (CDAEB) (P=0,00014), matéria seca digestível (MSD) (P<,0001), proteína digestível (PD)(P=0,0001), matéria orgânica digestível (MOD) (P=0,0002) e energia digestível (ED) (P=0,0014). Houveefeito quadrático dos níveis de Trp DIE sobre (MOD) (P=0,544) e energia digestível (ED) (P=0,0004), que foram estimados em 1,82 e 1,81 g/kg de Trp DIE, respectivamente. Também foi observado efeito quadrático dos níveis de Lys DIE sobre (MOD) (P=0,011) estimado em 10,16.O nível ótimo de triptofano DIE para suínos dos 75 aos 100 kg que promoveumelhorias no desempenho zootécnico: PCF,GPCD e CRDM foi de 1,90, 1,99 e 2,00 g/kg de Trp DIE, respectivamente, proporcionando redução linear do NUP, aumentando o aproveitamento da proteína bruta das dietas. Além disso, a relação 0,231 de Trp:Lys DIE (1,55 g/kg de Trp DIE e 6,5 g,/kg de Lys DIE) foi considerada como indicador de avaliação para as variáveis comportamentais. O experimento II, apresentou efeito quadrático (P<0,05) dos níveis de Trp sobre o PCF, GPCD, CRDM e EA, em que foram estimados 1,36, 1,36, 1,30 e 1,77 g/kg de Trp DIE, respectivamente, com efeito quadrático dos níveis de Lys sobre a EA, que foram estimados em nível ótimo de 7,19 g de Lys DIE/kg de ração. Para os parâmetros sanguíneos, as variáveis PT e NUP apresentaram efeito quadrático de Trp e Lys DIE, com pontos críticos estimados de 1,35 e 6,72 g/kg, respectivamente. Para as avaliações comportamentais: dormir (DORM), sentar (SEN) e beber (BEBE), apresentaram efeito quadrático dos níveis de Trp DIE estimados em 1,44, 0,76 e 1,68 g/kg, respectivamente. Para o ensaio de metabolismo, foi encontrado efeito de interação Trp: Lys DIE, sobre os coeficientes de digestibilidade aparente da matéria seca (CDAMS) (P=0,0002), proteína bruta (CDAPB) (P=0,0002), matéria orgânica (CDAMO)(P=0,0003), energia bruta (CDAEB) (P=0,00014),matéria seca digestível (MSD)(P<0,0001), proteína digestível (PD)(P=0,0001), matéria orgânica digestível (MOD) (P=0,0002) e energia digestível (ED) (P=0,0014). Ainda, oefeito quadrático dos níveis de Trp DIE sobre (MOD) (P=0,544) e energia digestível (ED) (P=0,0004), que foram estimados em 1,82 e 1,81 g/kg de Trp DIE, respectivamente. Houve também efeito quadrático dos níveis de Lys DIE sobre (MOD) (P=0,011) estimado em 10,16. Para as características quantitativas e qualitativas de carcaça, houveefeito quadrático de Trp sobre a percentagem de músculo (MUS) e carne magra (CMAG), pH, força de cisalhamento e matéria mineral (MM) estimados em 1,19; 1,23; 1,02; 0,77 e 0,99 g/kg de Trp DIE, respectivamente. Ainda, efeito quadrático de Lys DIE sobre a perda líquida por gotejamento (PLG), descongelamento (PLD), área de olho de lombo (AOL) com níveis ótimos de 6,38, 6,37e 6,20 g/kg de Lys DIE, respectivamente. Observou-se efeito linear decrescente (P<0,05) sobre a (MM) da carne, em que o aumento no nível de Lys promoveu redução na MM. A relação 0,193 de Trp:Lys DIE (1,35 g/kg de Trp DIE e 7,0 g/kg de Lys DIE) foi considerada ideal para suínos machos imunocastrados em fase de terminação, com base nas variáveis de desempenho, parâmetros sanguíneos, comportamento e características qualitativas e quantitativas de carcaça.

The objective of this study was to determine the optimal levels required in grams per dayas well as the standardized ileal digestible (SID) Trp:Lys ratio, for 75- to 100-kg immunized and 110- to 135-kg immunocastrated male pigs, and its effects on behavior, growth performance, apparent total tract digestibility, blood parameters, carcass traits and meat quality. In Experiment I, 64 crossbred male pigs (Landrace x Large White) with average initial body weight of 75.55 ± 4.11kg were assigned to a 4x4 factorial arrangement,using a randomized complete block design, based on four levels of SID Trp (1.1; 1.5; 1.9 and 2.3g of Trp/kg of diet) and four levels of SID Lys (6.50, 8.00, 9.50 and 11.00g of Lys/kg of diet), composing 16 treatments with four replicates of one animal per experimental unit (from 75 to 100 kg). In Experiment II, 64 crossbred male pigs (Landrace x Large White) with average initial body weight of 135.63±8.21kg were distributed in a 4x4 factorial arrangement, with four levels of SIDTrp (0.75, 1.05, 1.35 and 1.65g of Trp/kg of feed) and four levels of SID Lys (4.0, 5.5, 7.0 and 8.5g of Lys/kg of diet), until they reached a body weight of 135 kg. To determine growth performance the final body weight (FBW), average daily feed intake (ADFI), daily body weight gain (DBWG) and feed efficiency (FE) variables were assessed. To evaluate the blood biochemical parameters, albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AP), glucose (GLU), globulin (GLOB), total proteins (TP) and plasma urea nitrogen (PUN) were assayed using commercial kits. Theresponse surface methodology was adopted as a statistical procedure, using polynomial regression models. In experiment I, there was a quadratic effect of SID Trp for FBW (P=0.002), DBWG (P=0.0002) and ADFI (P=0.006), which were estimated at 1.90, 1.99 and 2.00 g/kg of SID Trp, respectively. There was a linear effect of SID Trp (P=0.022) on PUN. The levels of SID Trp presented a quadratic effect on the behaviors of sitting (SIT) (P=0.0009), sleeping (SLP) (P=0.011) and idle (P=0.030), which were estimated at 0.16, 1.75 and 1.80 g/kg, respectively. Also, for SID Lys,SIT (P=0.013) and SLP (P=0.001) were estimated at 0.33 and 1.56 g/kg, respectively. There was an interaction effect of SID Trp:Lys on the apparent digestibility coefficients of dry matter (ADCDM)(P=0.0002), crude protein (ADCCP) (P=0.0002), organic matter (ADCOM)(P=0.0003) and gross energy (ADCGE)(P=0.00014), digestible dry matter (DDM)(P<.0001), digestible protein (DP)(P=0.0001), digestible organic matter (DOM)(P =0.0002), and digestible energy (DE) (P=0.0014). There was aquadratic effect forSID Trp levels on DOM (P=0.544) and DE (P=0.0004), which were estimated at 1.82 and 1.81 g/kg of SID Trp, respectively. A quadratic effectwas also observed forSID Lys levels on DOM (P=0.011), estimated at 10.16. The optimal SIDTrp levels, for pigs from 75to 100kg, that improvedthe growth performance variables FBW, DBWG and ADFI were 1.90, 1.99 and 2.00 g/kg of SID, respectively, favoring linear reduction of PUN and increasing the use of dietary crude protein. Furthermore, the 0.231 SIDTrp:Lys ratio (1.55 g/kg of SID Trp and 6.5 g/kg of SID Lys) was considered as an assessment indicator for the behavioral variables. Experiment II showed a quadratic effect (P<0.05) of Trp levels on FBW, DBWG, ADFI and FE, in which 1.36, 1.36, 1.30 and 1.77 g/kg SID Trp were estimated, respectively. In addition, there was a quadratic effect of Lys on FE, estimated at an optimal level of 7.19 g of SID Lys/kg of feed. For blood parameters, the TP and PUN variables showed a quadratic effect of SID Trp and Lys, with estimated critical points at 1.35 and 6.72 g/kg, respectively. For behavioral assessments, SLP, SIT and drinking (DRK) had a quadratic effect of SID Trp levels, estimated at 1.44, 0.76 and 1.68 g/kg, respectively. For the metabolism assay, there was an interaction effect of SID Trp:Lyson ADCDM (P=0.0002), ADCCP (P=0.0002), ADCOM (P=0.0003), ADCGE (P=0.00014), DDM (P<0.0001), DP (P=0.0001), DOM and DE (P=0.0014). A quadratic effect was observed for SID Trp levels on DOM (P=0.544) and DE (P=0.0004), which were estimated at 1.82 and 1.81 g/kg of SID Trp, respectively. The optimal SIDTrp levels, for pigs from 75to 100kg, that improved the growth performance variables FBW, DBWG and ADFI were 1.90, 1.99 and 2.00 g/kg of SID, respectively, favoring linear reduction of PUN and increasing the use of dietary crude protein. Fur thermore, the 0.231 SID Trp:Lys ratio (1.55 g/kg of SID Trp and 6.5 g/kg of SID Lys) was considered as an assessment indicator for the behavioral variables. Experiment II showed a quadratic effect (P<0.05) of Trp levels on FBW, DBWG, ADFI and FE, in which 1.36, 1.36, 1.30 and 1.77 g/kg SID Trp were estimated, respectively. In addition, there was a quadratic effect of Lys on FE, estimated at an optimal level of 7.19 g of SID Lys/kg of diet. For blood parameters, the TP and PUN variables showed a quadratic effect of SID Trp and Lys, with estimated critical points at 1.35 and 6.72 g/kg, respectively. Forbehavioral assessments, SLP, SIT and drinking (DRK) had a quadratic effect of SID Trp levels, estimated at 1.44, 0.76 and 1.68 g/kg, respectively. For the metabolism assay, there was an interaction effect of SID Trp:Lyson ADCDM (P=0.0002), ADCCP (P=0.0002), ADCOM (P=0.0003), ADCGE (P=0.00014), DDM (P<0.0001), DP (P=0.0001), DOM and DE (P=0.0014).