RESUMO: A cadeia produtiva de suínos tem concentrado esforços para reduzir a quantidade e melhorar a qualidade da gordura depositada na carcaça. Devido a associação do perfil lipídico com doenças cardiovasculares, pesquisas têm sido desenvolvidas para entender como ocorre a deposição e para melhorar o perfil de ácidos graxos na carcaça. Dentre os fatores que afetam a composição dessa gordura estão a raça, o sexo e a dieta dos suínos, sendo que este último é o de maior impacto. A inclusão de ingredientes lipídicos parece uma promissora forma de modular o perfil lipídico da gordura na carcaça dos suínos, sendo observado efeito nos ácidos graxos saturados, monoinsaturados e poli-insaturados. O efeito é maior naquele ácido graxo de maior concentração na fonte utilizada. O óleo de soja pode dobrar o valor do ácido linoleico. Um subproduto do óleo de oliva incrementa em 4% o ácido oleico. E o óleo de linhaça tem a capacidade de aumentar o α-linolênico de menos de 1% para mais de 18% no total de ácidos graxos. Além da fonte, o período e a concentração influenciam na modulação do perfil de ácidos graxos.

ABSTRACT: Swine production has focused its efforts to reduce the amount and improve the quality of fat deposited on carcass. Due to the association of the lipid profile with cardiovascular diseases, researches have been developed to understand how the deposition occurs and to improve the fatty acid profile of swine fat. Among the factors that affect the fat composition, race, sex, and diet, the third one has the greatest impact. Lipid inclusion seems to be a promising way to modulate the lipid profile of fat in pig carcass, with an effect on saturated, monounsaturated and polyunsaturated fatty acids. The effect is greater in that fatty acid with the highest concentration in the source used. Soybean oil can double the value of linoleic acid, a by-product of olive oil increases oleic acid by 4%, and flaxseed oil has the ability to increase α-linolenic acid from less than 1% to over 18% in total fatty acids. In addition to the source, the duration and concentration influence the modulation of the fatty acid profile.

RESUMO: Realizou-se este estudo com o objetivo de avaliar os efeitos de níveis de cromo levedura e lisina digestível, desempenho e características de carcaça de suínos em terminação. Foram utilizados 64 machos castrados com peso inicial de 72,77 ± 7,20 kg e final de 119,44 ± 9,47 kg, distribuídos em esquema fatorial 2 x 2, sendo dois níveis (Cr0: 0 ppb e Cr800: 800 ppb) e dois níveis de lisina digestível (L0: nível recomendado e L+10%: 10%). A temperatura do ar registrada de 30,9 ± 3,7 ºC durante o período experimental foi considerada como de estresse por calor. As variáveis de desempenho não foram influenciadas (P>0,05), contudo L+10% aumentou (P<0,05) o consumo de lisina digestível diário. As características de carcaça dos animais não foram influenciadas (P>0,05) pelos níveis de cromo levedura e lisina digestível. A suplementação de 800 ppb de cromo levedura, e o aumento em 10% do nível de lisina digestível, isolados ou associados, não melhoram o desempenho e as características de carcaça de suínos em terminação submetidos a temperaturas ambientais elevadas.

ABSTRACT: This study evaluated the effects of chromium yeast and digestible lysine levels on the performance and carcass characteristics of finishing pigs. Sixty-four barrows with an initial weight of 72.77 ± 7.20 kg and final weight of 119.44 ± 9.47 kg were used, distributed in a 2 x 2 factorial scheme, with two levels of chromium yeast (Cr0: 0 ppb and Cr800: 800 ppb) and two levels of digestible lysine (L0: recommended level and L+10%: 10%). The recorded air temperature of 30.9 ± 3.7 ºC during the experimental period was considered as heat stress. Performance variables were not influenced (P>0.05); however, L+10% showed an increase (P<0.05) in daily digestible lysine intake. Carcass characteristics of the animals were not influenced (P>0.05) by the chromium or digestible lysine levels. Supplementation with 800 ppb of yeast chromium and a 10% increase in the level of digestible lysine, isolated or associated, did not improve the performance and carcass characteristics of finishing pigs, subjected to high ambient temperatures.

RESUMO: Realizou-se este estudo com o objetivo de avaliar as suplementações de cromo e a restrição energética em substituição a ractopamina para leitoas em terminação tardia. Foram utilizadas 60 leitoas, com pesos inicial de 98,87±0,25 kg e final de 122,69 ± 10,97 kg, distribuídas em delineamento de blocos ao acaso com cinco dietas: controle; cromo levedura (0,8 ppm); picolinato de cromo (0,48 ppm); ractopamina (20 ppm) e restrição energética (redução de 150 kcal de EMkg-1 de ração), com seis repetições e dois animais por unidade experimental. A dieta contendo ractopamina proporcionou melhor (P<0,05) conversão alimentar e maior peso de carcaça quente das leitoas. A dieta contendo ractopamina apresentou menor (P<0,05) custo de ração por quilograma de ganho e maior índice de eficiência econômica em relação as dietas contendo cromo e restrição energética que, por sua vez, foram superiores em comparação a dieta controle. Dietas suplementadas com cromo e ractopamina apresentaram maior (P<0,05) percentual e quantidade de carne magra e maior índice de bonificação de carcaça em relação a dieta controle e restrição energética. Concluiu-se que a redução energética não prejudica as respostas das leitoas em relação a dieta controle. A suplementação de ractopamina possibilita melhor conversão alimentar, menor custo de ração por quilograma de ganho e maior índice de eficiência econômica. As suplementações de cromo e ractopamina expressam aumento do percentual e quantidade de carne magra e do índice de bonificação das carcaças. O picolinato de cromo e o cromo levedura são potenciais substitutos a ractopamina para otimizar as características de carcaça das leitoas.

ABSTRACT: This study evaluated chromium supplements and energy restriction as substitutes for ractopamine in the diets of late finishing gilts. Sixty gilts were used, with initial weights of 98.87 ± 0.25 kg and final weights of 122.69 ± 10.97 kg, distributed in a randomized block design with five diets: control; yeast chromium (0.8 ppm); chromium picolinate (0.48 ppm); ractopamine (20 ppm) and energy restriction (reduction of 150 kcal of EM kg-1 of feed), with six replicates and two animals per experimental unit. Feeding diet containing ractopamine enabled better (P<0.05) feed conversion and greater weights of the hot carcass of the gilts. The diet containing ractopamine exhibited a lower (P<0.05) cost of feed per kilogram of gain and higher economic efficiency, when compared to diets containing chromium and energy restriction; these exhibited better outcomes, compared to the control diet. Diets supplemented with chromium and ractopamine resulted in a higher (P<0.05) percentage and quantity of lean meat and a higher rate of carcass bonus, when compared to the control diet and energy restriction. The energy reduction did not harm the gilts’ responses, compared to the control diet. Ractopamine supplementation allowed for a better feed conversion, lower feed cost per kilogram of gain, and a higher economic efficiency index. Supplements of chromium and ractopamine increased the percentage and quantity of lean meat and the bonus index of the carcasses. Therefore, chromium picolinate and chromium yeast are potential substitutes for ractopamine for optimizing the gilts carcass characteristics.

RESUMO: Este estudo foi conduzido com o objetivo de identificar os efeitos da suplementação com ractopamina, cromo picolinato, cromo levedura, ou da restrição alimentar energética, sobre o desempenho e o perfil de ácidos graxos da gordura subcutânea de fêmeas suínas em fase final de terminação. Foram utilizadas 20 fêmeas suínas, geneticamente similares, com peso inicial de 105,35 ± 4,77 kg e peso final de 131,37 ± 5,58 kg, distribuídas em delineamento experimental de blocos ao acaso em cinco tratamentos (controle; ractopamina: 20 ppm; picolinato de cromo: 0,48 ppm; cromo levedura: 0,80 ppm; e restrição energética: -150 kcal kg-1 de energia metabolizável) com quatro repetições de um animal cada. As dietas experimentais foram isonutritivas, exceto para o nível de energia metabolizável da dieta fornecida ao grupo submetido à restrição energética. Não houve efeito dos tratamentos sobre o desempenho e as características de carcaça. As suplementações com ractopamina e cromo orgânico (picolinato ou levedura) aumentaram a concentração de ácidos graxos poli-insaturados. A proporção do ácido α-linolênico foi maior com a inclusão da ractopamina ou do cromo levedura na dieta. A restrição energética aumentou a proporção n-6:n-3 e reduziu a concentração do ácido α-linolênico. As suplementações com ractopamina, picolinato de cromo, cromo levedura, ou restrição alimentar energética, não influenciaram o desempenho e as características de carcaça, mas alteraram o perfil lipídico da gordura subcutânea de fêmeas suínas. As suplementações com ractopamina e cromo orgânico aumentaram a proporção de AGPI.

ABSTRACT: This study identified the effects of dietary supplementation with ractopamine, chromium picolinate, chromium yeast, or an energetic feed restriction on the growth performance and lipid profile of subcutaneous fat, in late finishing gilts. Twenty genetically similar gilts with initial body weight of 105.35 ± 4.77 kg and a final body weight of 131.37 ± 5.58 kg were distributed in a completely randomized block design with five treatments (control; ractopamine: 20 ppm; chromium picolinate: 0.48 ppm; chromium yeast: 0.80 ppm; and energetic feed restriction: -150 kcal kg-1 of metabolizable energy), with four replicates of one animal each. The experimental diets were isonutritives, except for the metabolizable energy level of the diet fed to the group subjected to energy restriction. There were no effects on the growth performance and carcass characteristics. Ractopamine and organic chromium (picolinate and yeast) supplementation increased the concentration of total polyunsaturated fatty acid. The proportion of α-linolenic fatty acids were higher when the diets were supplemented with ractopamine or chromium yeast. The energy restriction increased the n-6:n-3 ratio and reduced α-linolenic acid concentration. Therefore, ractopamine, chromium picolinate, chromium yeast supplementation, and energetic feed restriction did not affect the growth performance or carcass characteristics but altered the lipid profile of subcutaneous fat in finishing gilts. Ractopamine and organic chromium supplementation increased PUFA in the fat of finishing female pigs.

ABSTRACT The objective of the present study was to evaluate the effects of cooling systems by negative pressure versus directed ducts on the performance of lactating sows and their litter. The experiment was conducted in a tropical climatic region in Brazil. Ninety-four lactating sows during 26.2±1.7 days of lactation were included with their 1,236 piglets. Sows were distributed using a completely randomized block design into two treatments: a negative pressure cooling (NPC) system and a directed duct cooling (DDC) system. We adopted sow parity as blocking criterion. During the experimental period, environmental temperatures inside the farrowing rooms were 22.9±1.5 and 25.4±2.5 °C, respectively, using the NPC and DDC systems. Sow daily feed intake, litter weight at weaning, piglet weight at weaning, litter daily weight gain, piglet daily gain, and daily milk production per sow were greater in the NPC system than in the DDC system. The type of cooling system did not affect piglet weight after standardization, mortality, number of piglets weaned per sow, and estrus return. The use of an NPC system can reduce the effects of higher environmental temperatures better than the DDC system. The NPC system allowed for greater feed intake, piglet and litter weight gain, weight of piglets and litter at weaning, and milk production compared with the DDC system.

RESUMO: Realizou-se este estudo com o objetivo de avaliar níveis de energia líquida (EL), mantendo a relação caloria: nutriente, no desempenho e características de carcaça de suínos dos 30 aos 70 kg. Foram utilizados 60 suínos machos castrados, com pesos iniciais de 31,94 ± 3,54 kg e finais de 71,98 ± 5,99 kg. Os animais foram distribuídos em delineamento experimental de blocos casualizados, em cinco níveis de EL (2,40; 2,45; 2,50; 2,55; 2,60 Mcal de EL kg-1 de dieta), com seis repetições e dois animais por unidade experimental. O período experimental foi dividido em fase I: 30 aos 50 kg e fase II: 50 aos 70 kg. As variáveis analisadas foram os consumos de ração diária (CRD), energia líquida (CEL) e lisina digestível (CLdig), ganho de peso diário (GPD), conversão alimentar (CA), peso final (PF), conversão de lisina digestível: ganho (CLdig:G), custo: ganho (C:G), área de olho de lombo (AOL), profundidade de músculo (PM), espessura de toucinho da primeira camada (ET1), espessura de toucinho da segunda camada (ET2), espessura de toucinho total (ETt), percentual de carne magra (CM) e o índice de bonificação de carcaça (IB). Dos 30 aos 50 kg, verificou-se aumento linear (P < 0,05) do PF, GPD e dos CEL e CLdig com o aumento dos níveis de EL na dieta. Dos 50 aos 70 kg, o aumento dos níveis de EL na dieta promoveu melhora linear (P < 0,05) do PF, GPD, CEL, CLdig e da CA dos suínos. No período total, verificou-se aumento linear (P < 0,05) do GPD, CEL, CLdig e melhora linear (P < 0,05) da CA de acordo com o aumento do nível de EL na dieta. As demais variáveis de desempenho não foram afetadas (P > 0,05) pelos níveis de EL. Verificou-se aumento (P < 0,05) da ET2 de acordo com o aumento do nível de EL, porém sem alterar (P > 0,05) as demais características de carcaça. Recomenda-se o nível 2,60 Mcal de EL kg-1 de dieta para suínos machos castrados dos 30 aos 70 kg.

ABSTRACT: This study evaluated the effect of dietary net energy (NE) levels on growth performance and carcass characteristics of barrows from 30 to 70 kg of body weight (BW). Sixty barrows with initial body weight (IBW) of 31.94 ± 3.54 kg and final body weight (FBW) of 71.98 ± 5.99 kg were allotted to one of five dietary NE levels (2.40, 2.45, 2.50, 2.55, and 2.60 Mcal kg-1), using a completely randomized block design with six replicates and two barrows per replicate. The experimental period was divided into phase I: 30 to 50 kg and phase II: 50 to 70 kg. The variables analyzed were average daily feed intake (ADFI), net energy intake (NEI), digestible lysine intake (LysI), average daily gain (ADG), feed conversion (FC), FBW, digestible lysine conversion:gain (LysI:G), Cost:Gain (C:G), loin eye area (LEA), muscle depth (MD), first backfat layer (BF1), second backfat layer (BF2), total backfat (BFt), lean meat percentage, and carcass bonus index (BI). In phase I, there was a linear increase (P < 0.05) in FBW, ADG, NEI, and LysI with increasing NE levels in the diet. In phase II, increasing dietary NE levels also increased (P < 0.05) FBW, ADG, NEI, LysI, and FC linearly. Overall, there was a linear increase (P < 0.05) in ADG, NEI, LysI, and FC with increasing NE levels in the diet. The other performance variables were not affected (P > 0.05) by the NE levels. There was an increase (P < 0.05) in BF2 with increasing NE levels, but the other carcass characteristics were not altered (P > 0.05). We recommended 2.60 Mcal of NE kg-1 in the diet for growing barrows from 30 to 70 kg.

RESUMO Este estudo objetivou avaliar os efeitos da enzima fitase e dos grãos secos de destilaria com solúveis (distillers dried grains with solubles - DDGS) sobre digestibilidade, desempenho e viabilidade econômica de suínos em crescimento. Foram realizados dois experimentos, com uma dieta de referência (RD) à base de milho e farelo de soja; RD + 200 g kg -1 DDGS (DDGS); RD + 1.000 unidades de fitase (PHY); e RD + 200 g kg -1 DDGS + 1.000 unidades de fitase (D + P). No experimento 1, oito suínos machos castrados com peso de 29,35 ± 5,74 kg foram usados através do método de coleta total, com repetição no tempo para avaliação da digestibilidade. No experimento 2, 40 suínos machos castrados 47,65 ± 3,99 kg, com cinco repetições de dois animais por unidade experimental foram usados para avaliação de desempenho e viabilidade econômica. DDGS aumentou a excreção de nitrogênio e energia nas fezes e na urina, prejudicando os coeficientes de digestibilidade e a metabolizabilidade da energia. Os animais que consumiram dietas com DDGS apresentaram pior desempenho enquanto a fitase não afetou os resultados. As dietas com a inclusão de 200 g kg -1 DDGS e 1.000 unidades de fitase não diferem no custo por quilograma em relação à dieta de controle.

ABSTRACT This study aimed to evaluate the effects of phytase enzyme and distillers dried grains with solubles (DDGS) on the digestibility, performance and economic viability of growing pigs. Two experiments were conducted with a reference diet (RD) based on corn and soybean meal: RD with 200 g kg -1 DDGS (DDGS); RD + 1,000 units of phytase (PHY); and RD + 200 g kg-1 DDGS + 1,000 units of phytase (D+P). In experiment 1, eight castrated male pigs weighing 29.35 ± 5.74 kg were used through the total collection method and replicates in time for digestibility evaluation. In experiment 2, 40 castrated male pigs 47.65 ± 3.99 kg, with five replicates of two animals per experimental unit, were used for performance and economic evaluation. DDGS increased the excretion of nitrogen and energy in feces and urine, impairing the digestibility coefficients and metabolizability of dietary energy. The animals that consumed diets with DDGS presented the worst performance, while phytase did not influence the results. Diets with the inclusion of 200 g kg -1 DDGS and 1,000 units of phytase did not differ in cost per kilogram compared to the control diet.

Abstract The objective of this unprecedented research was to evaluate performance traits, carcass yield, meat quality, and hematological parameters of pintado amazônico fish (Pseudoplatystoma reticulatum × Leiarius marmoratus) fed diets containing ractopamine (20 mg kg-1) for different periods, during the final growth phase. The following treatments were evaluated: 45 days without ractopamine supplementation (control diet); 30 days of control diet, followed by 15 days of ractopamine supplementation; 15 days of control diet, followed by 30 days of ractopamine supplementation; and 45 days of ractopamine supplementation. Performance traits, carcass yield and hematological parameters were not significantly influenced by the ractopamine supplementation periods. The pH, L* color and a* color parameters of the filet post-slaughter and the L* color of the filet post-thawing were significantly influenced by the period of supplementation with the additive in the diet. Cooking loss was significantly lower in the fillet of fish that received ractopamine. Ractopamine supplementation at the level of 20 mg kg-1 in the diet of pintado amazônico for 15, 30, or 45 days does not alter their production performance, carcass yield, or hematological parameters, but changes the qualitative traits of their filet.

ABSTRACT We examined the effect of dried distillers grains with solubles (DDGS) in diets for late gestating sows on sow and litter performance, colostrum chemical composition, and sow behavior. Sixty gestating sows of 3.77±1.65 parity were divided into three groups of 20 animals, in a randomized block design with 0 (corn-soybean meal diet), 150, or 300 g kg−1 DDGS from 84 days of gestation until farrowing. Sows fed 300 g kg−1 DDGS presented a lower frequency of standing position and eating activity. The lying lateral position was more frequent in the first 40 min post-feeding for sows fed the highest DDGS level. There was no effect of diets on sow and litter performance; however, DDGS inclusion tended to increase lactation feed intake. Inclusion of DDGS was inclined to produce more lactose and less protein in colostrum, but did not affect colostrum fat, total solids, and ash contents. Inclusion of up to 300 g kg−1 DDGS in the diet of late gestation sows does not change sow and litter performance and colostrum composition compared with corn-soybean meal diets, but it favored animal welfare.

Abstract An experiment was conducted to evaluate the fatty acid profile of subcutaneous fat from barrowS of same genetic lineage supplemented with organic chromium and selenium initiated in different weight ranges in the finishing phase using 24 carcasses. Three different diets were used that represent the time when supplementation starts: control - without the inclusion of organic Cr and Se; CrSe70 - control with 500 g ton-1 of organic Cr and Se of 70 to 130 kg in body weight; and CrSe100 - control with inclusion of 500 g ton-1 of organic Cr and Se from 100 kg to 130 kg body weight. Performance, carcass characteristics, and lipid profile were evaluated. The data were submitted to analysis of variance, and with significant differences (p<0.05), the means were compared using the Tukey test. From 70 to 100 kg, control and CrSe70 animals consumed less feed than CrSe100. From 100 kg body weight, it reduced the C20:5n3 and C24:1n9 acids and increased the activity of the Δ-6 desaturase, elongase, Δ-5 desaturase enzymes in the supplemented animals. The moment when supplementation starts of organic chromium and selenium does not improve the performance and carcass characteristics, does not change the fatty acid profile, and does not improve the quality of the fat.

ABSTRACT This study was conducted to evaluate different nutritional plans of net energy (NE) with a constant calorie:nutrient ratio on the performance of piglets from 7 to 30 kg. Sixty barrows with an initial weight of 7.11±0.89 kg were distributed among five nutritional plans: two NE-decreasing plans (A and B, starting from NE concentrations of 2.47 and 2.52 Mcal kg−1, respectively, and ending both at 2.37 Mcal kg−1) and three NE-constant plans (C, 2.37 Mcal kg−1; D, 2.42 Mcal kg−1; and E, 2.47 Mcal kg−1). The nutritional plans were composed of two decreasing plans: A, 2.47-2.42-2.37-2.37-2.37 Mcal of NE kg−1 of feed; B, 2.52-2.47-2.42-2.37-2.37 Mcal of NE kg−1 of feed; and three constant plans: C, 2.37 Mcal of NE kg−1 of feed; D, 2.42 Mcal of NE kg−1 of feed; E, 2.47 Mcal of NE kg−1 of feed, from 7 to 10, 10 to 15, 15 to 20, 20 to 25, and 25 to 30 kg, respectively, with six replicates per treatment and two animals per experimental unit. Animal performance was evaluated through the following measurements: average daily feed intake (ADFI), NE intake, standardized ileal digestible lysine intake (SID Lys intake), average daily gain (ADG), feed:gain ratio (F:G), final weight (FW), feed cost per kg of weight gain (CWG), economic efficiency index (EEI), and fecal score. Piglets’ final weight was 32.95±3.30 kg. Considering the total experimental period, there was no effect of the nutritional plan on ADG, F:G, CWG, and EEI. The final weight of piglets under plan D was higher than that recorded for those allocated to plan C, not differing from the other nutritional plans. Piglets fed under nutritional plans A and D presented higher ADFI compared with those subjected to other plans. Net energy and SID Lys intakes were significantly higher in piglets subjected to plans A, D, and E compared with those under plans B and C. Net energy nutritional plans did not influence the fecal score and the occurrence of diarrhea of the piglets. Based on our analysis, a nutritional plan containing a constant NE level of 2.42 Mcal kg−1 of feed may be recommended for piglets from 7 to 30 kg.

Abstract This study was conducted to evaluate the period of chromium yeast supplementation on lipid profile of backfat and Longissimus lumborum muscle of barrows. It was evaluated carcass samples from forty barrows, genetically similar. Pigs diets were supplemented with 0.4 mg kg-1 of chromium yeast in four periods (0, 38, 62 and 94 days before slaughter). The experimental design was completely randomized with four treatments, ten replicates, and each experimental unit consisting of one animal. Lipid profiles of backfat and Longissimus lumborum muscle were analyzed by gas chromatography. The increase in the period of chromium yeast use had a quadratic effect (P<0.05) for stearic and oleic fatty acids, and total saturated, monounsaturated and unsaturated fatty acids in backfat. DH-γ-linolenic and arachidonic fatty acids reduced when the period of chromium yeast use increased. In the meat, there was a quadratic effect (P<0.05) only in the γ-linoleic fatty acid. The use of chromium yeast for different periods influences the lipid profile of the backfat and the Longissimus lumborum muscle, with less effect in the meat.

ABSTRACT This study aimed to evaluate different periods of chromium yeast (CrY) supplementation on growth performance and quantitative carcass characteristics of growing-finishing pigs. We used eighty barrows (Duroc/Pietran × Large White/Landrace) with an initial body weight of 24.5±2.4 kg. A completely randomized block design was used within four periods of dietary CrY supplementation (control diet: CrY-free, from 25 to 110 kg; Cr25-110 kg: diet with 0.4 mg kg−1 of CrY, from 25 to 110 kg; Cr50-110 kg: diet with 0.4 mg kg−1 of CrY, from 50 to 110 kg; and Cr70-110 kg: diet with 0.4 mg kg−1 of CrY, from 70 to 110 kg), with ten replicates and two animals each. The CrY supplementation did not affect (P>0.05) either the grow performance or the carcass characteristics evaluated. The dietary supplementation of 0.4 mg kg−1 of CrY for growing-finishing pigs (25 to 110 kg) does not alter the performance neither the quantitative carcass characteristics.

Abstract To examine the association between phytase and xylanase in diets with nutritional adjustments on intestinal morphometry, serum biochemistry and microbiology of broilers, 250 broilers were evaluated in a completely randomized design with five treatments and five replicates. The following treatments were tested: positive control diet - without phytase or xylanase; negative control diet - with an energy reduction of 100 kcal/kg, without phytase or xylanase; and three diets containing xylanase and phytase and energy reductions of 50, 100 and 150 Kcal/kg. For all energy-reduced diets, the nutritional matrix of phytase with phosphorus (0.15%), calcium (0.165%) and sodium (0.035%) was considered. An effect of the association between enzyme inclusion and metabolizable energy reduction in the diets was observed only by contrast analysis, for villus height. Intestinal health was not changed. Only the serum phosphorus concentration was altered by the treatments at the different evaluated ages. The association of phytase (500 FTU/kg) with xylanase (16000 BXU/kg) in diets with reductions of up to 150 Kcal/kg metabolizable energy, 0.15% digestible P, 0.165% Ca and 0.035% Na does not alter the intestinal morphometry, serum biochemistry or microbiology of broilers.

RESUMO: Realizou-se a meta-análise com o objetivo de determinar o nível recomendado de lisina digestível e sua influência sobre o desempenho produtivo de porcas primíparas lactantes. A base de dados composta por 26 publicações, 138 dietas e 3.820 fêmeas foi desenvolvida a partir de artigos sobre a associação entre, lisina, proteína bruta e porcas primíparas lactantes. Os níveis de lisina digestível dos estudos variaram de 0,22 a 1,43% com valores médios de 0,85% de lisina digestível nas dietas, com consumo de 41,25 g dia-1. O consumo de lisina digestível das porcas apresentou correlação positiva (P<0,05) com o consumo de ração, aminoácidos essenciais, proteína bruta, energia metabolizável, perda de peso corporal da porca, produção de leite, número e peso de leitões ao desmame. O consumo de lisina indicou correlação negativa (P<0,05) para espessura de toucinho ao desmame e intervalo desmame-cio. Observou-se efeito quadrático (P<0,01) da perda de peso corporal da porca e ganho de peso diário dos leitões e efeito quadrático (P<0,01) do peso dos leitões ao desmame em função do aumento do nível de lisina da dieta. O nível de 1,04% de lisina digestível indica a menor perda de peso da porca. O maior peso dos leitões ao desmame e maior ganho de peso diário dos leitões é verificado com a inclusão de 1,30 e 1,07% de lisina digestível na dieta, respectivamente.

ABSTRACT: A meta-analysis was carried out to evaluate the recommended levels of digestible lysine and its influence on the productive performance of primiparous lactating sows. The database consisted of 26 publications, 138 diets and 3,820 sows was developed from articles on the association between, lysine, crude protein and lactating primiparous sows. The digestible lysine levels of the studies ranged from 0.22 to 1.43% with average values of 0.85% digestible lysine in the diet, with consumption of 41.25 g day-1. The digestible lysine intake of sows was positively correlated (P<0.05) with feed intake, essential amino acids, crude protein, metabolizable energy, body weight loss sows, milk production, number and weight of piglets at weaning. Digestible lysine intake showed negative correlation (P<0.05) with backfat thickness at weaning and weaning to oestrus interval. It was observed a quadratic effect (P<0.01) of body weight loss sow and daily weight gain of piglets and a quadratic effect (P<0.01) in the weight of piglets at weaning due to increased dietary lysine level. The level of 1.04% of digestible lysine indicates less weight loss sows. The greater weight of piglets at weaning and increased daily weight gain of piglets was verified with the addition of 1.30 and 1.07% digestible lysine in the diet, respectively.